Decoder Libraries

MPLAB Harmony Decoder Libraries
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MPLAB Harmony Integrated Software Framework v1.08
© 2013-2016 Microchip Technology Inc. All rights reserved.
Decoder Libraries Help
Decoder Libraries Help
This section provides descriptions of the Decoder libraries that are available in MPLAB Harmony.
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AAC Decoder Library
Library Interface
AAC Decoder Library
This section describes the AAC Decoder Library.
Introduction
The AAC Decoder Library is available for the PIC32MX family of microcontrollers.
Description
The AAC Decoder Library is a premium product and is not included in the standard release of MPLAB Harmony and must be purchased
separately. Refer to the Microchip Premium MPLAB Harmony Audio web page (www.microchip.com/pic32harmonypremiumaudio) for additional
information.
This AAC algorithm Non-Modifiable Binary Code is designed for 80 MHz or greater PIC32MX MCUs. Keep in mind, this code requires 62 MIPS
peak 34 MIPS average performance, 61 KB Flash and 12 KB RAM without frame buffer memory for operation on the PIC32MX MCU. This product
is the non-modifiable binary. A modifiable source-code version of this code is also available on Microchip Direct (SW320013-2). Users are
responsible for licensing for their products through Via Licensing.
Assembly Language Issue
There is an assembly language issue in the AAC Decoder Library that misaligns the stack pointer. Contrary to the MIPS programming
specification, this error is benign except when the application is built for a device with a hardware Floating Point Unit (FPU), such as the PIC32MZ
EF family of devices. In this case, the sub-routine context-saving operations will produce an exception and stop the application. A work around
exists for this issue, which involves disabling FPU context-saving for Interrupt Service Routines (ISRs).
The work around is to convert all ISRs from:
void __ISR(vector,ipl) MyInterruptHandler(void)
and change them to:
void __attribute__((vector),interrupt(ipl),nomips16,no_fpu)) MyInterruptHandler(void)
where, vector and ipl are replaced with the actual interrupt vector and interrupt priority level.
An example of this work around can be found in the universal_audio_decoders demonstration.
So as long as no FPU operations occur in ISRs and the routines are called by ISRs, this work around will prevent the misaligned stack pointer from
causing an exception. If FPU operations result from an ISR with no_fpu enabled, a general exception will result.
Using the Library
This topic describes the basic architecture of the AAC Decoder Library and provides information and examples on its use.
Description
Interface Header File: decoder_aac.h
The interface to the AAC Decoder Library is defined in the decoder_aac.h header file. Any C language source (.c) file that uses the MP3
Decoder Library should include decoder_aac.h.
Please refer to the What is MPLAB Harmony? section for how the AAC Decoder Library interacts with the framework.
Library Overview
The Library Interface routines are divided into various sub-sections, each of which addresses one of the blocks or the overall operation of the AAC
Decoder Library module.
Library Interface
a) General Functions
Name
Description
AAC_Decoder
This is function AAC_Decoder.
AAC_WriteWavHeader
Generates the .wav file header, if applicable.
AACDecoder_GetFrameSize
Used to get the AAC Decoder frame size.
AACDecoder_GetStateSize
This function allocates memory for each channel being used.
AACDecoder_Init
Views the received point and clears the structure.
AACDecoder_InterleaveSamples
This function interleaves left and right channel data.
isAACdecoder_enabled
This is function isAACdecoder_enabled.
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AAC Decoder Library
AAC_Decode
This function decodes AAC data.
AAC_Initialize
This is function AAC_Initialize.
Library Interface
AAC_RegisterDecoderEventHandlerCallback This is function AAC_RegisterDecoderEventHandlerCallback.
AAC_GetSamplingFrequency
This is function AAC_GetSamplingFrequency.
b) Data Types and Constants
Name
Description
INTPCM
AAC_DECODER_STATES
This is type AAC_DECODER_STATES.
WAVE
This is type WAVE.
AAC_PROFILE
This is macro AAC_PROFILE.
AAC_SAMPLING_FREQUENCY_INDEX This is type AAC_SAMPLING_FREQUENCY_INDEX.
AAC_ERROR_COUNT_MAX
This is macro AAC_ERROR_COUNT_MAX.
AACDECODER_STATE_SIZE
in Bytes
FRAME_SIZE
in Samples
INPUT_BUF_SIZE
in Bytes
MAX_STACK
in Bytes
STACK
This is macro STACK.
AAC_FRAME_HEADER_SIZE
in Bytes
SetReadBytesInAppData
This is type SetReadBytesInAppData.
Description
This section describes the Application Programming Interface (API) functions of the AAC Decoder Library.
Refer to each section for a detailed description.
a) General Functions
AAC_Decoder Function
File
aac.h
C
int16_t AAC_Decoder(uint8_t * input, uint16_t inSize, uint16_t * read, int16_t * output, uint16_t *
written);
Description
This is function AAC_Decoder.
AAC_WriteWavHeader Function
Generates the .wav file header, if applicable.
File
decoder_aac.h
C
void AAC_WriteWavHeader(void * haacDecoderInfo, WAVE * wav);
Returns
None.
Description
This function is called only if the output needs to be written into a .wav file. If the output is for play out or for writing into a .pcm file, this function
shall not be called. In case of wave file generation, the application shall leave 44 bytes space free at the start of the file and begin writing decoded
samples from the 45th byte location onwards. Once the entire data had been decoded, this function is called. The function generates the .wav file
header using the information available in the state memory and fills the WaveBuf array. The application copies the content of this buffer into the file
in the reserved place available at the start of the file.
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AAC Decoder Library
Library Interface
Preconditions
None.
Example
AAC_WriteWavHeader(haacDecoderInfo, wav);
Parameters
Parameters
Description
*haacDecoderInfo
The pointer for the structure that stores decoder information
*adts_ptr
pointer to WAVE header buffer
Function
void AAC_WriteWavHeader(void *haacDecoderInfo, WAVE *wav);
AACDecoder_GetFrameSize Function
Used to get the AAC Decoder frame size.
File
decoder_aac.h
C
int32_t AACDecoder_GetFrameSize(void * haacDecoderInfo, uint8_t * adts_ptr);
Returns
This function returns the size (in bytes) of the next frame to be decoded.
Description
This function is called every time before calling the AAC decode function. The frame size is extracted from the relevant field of the ADTS header
for returning and also the frame size (in bits) is updated in the channel state.
Preconditions
None.
Parameters
Parameters
Description
*haacDecoderInfo
The pointer to the ADTS Header is passed. The application extracts the next available seven
bytes from the file and passes them as ADTS header.
*adts_ptr
The pointer to the state memory is passed.
Function
int32_t AACDecoder_GetFrameSize(void *haacDecoderInfo, uint8_t *adts_ptr);
AACDecoder_GetStateSize Function
This function allocates memory for each channel being used.
File
decoder_aac.h
C
int32_t AACDecoder_GetStateSize();
Returns
This function returns the size of the AAC Decoder state structure in bytes.
Description
Based on the return value, the application allocates the required memory for the AAC Decoder state. This function is called only once for each
channel before the channel is initialized.
If dynamic memory allocation (malloc) is not to be used, this function need not be called and the AAC Decoder state buffer shall be statically
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AAC Decoder Library
Library Interface
defined at compile time with the size of the AAC Decoder state structure (constant).
Preconditions
None.
Example
int32_t aac_State_Size;
aac_State_Size = AACDecoder_GetStateSize();
Function
int32_t AACDecoder_GetStateSize(void)
AACDecoder_Init Function
Views the received point and clears the structure.
File
decoder_aac.h
C
void AACDecoder_Init(void * haacDecoderInfo, uint8_t * adts_ptr);
Returns
None.
Description
This function is called only once for each channel before starting the decoding of the first frame. This function views the received pointer as
structure pointer and clears the entire structure. Subsequently it initializes the selective variables with the default values. Also, the information on
sampling frequency and number of channels are extracted from the header and are stored in the channel state structure.
After returning from this function, the application resets the file pointer to origin as these seven bytes will be fetched again to extract the frame size
through the function mentioned next.
Preconditions
None.
Example
int32_t aac_State_Size;
AACDecoder_Init(haacDecoderInfo, appData.data);
Parameters
Parameters
Description
*haacDecoderInfo
The pointer for the structure that stores decoder information
*adts_ptr
pointer to AAC header structure
Function
void AACDecoder_Init( void *haacDecoderInfo, uint8_t *adts_ptr);
AACDecoder_InterleaveSamples Function
This function interleaves left and right channel data.
File
decoder_aac.h
C
int16_t AACDecoder_InterleaveSamples(INTPCM * pTimeCh0, void * state);
Returns
This function returns the number of samples in the I/O buffer:
•
1024 - for mono
•
2048 - for stereo
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AAC Decoder Library
Library Interface
Description
For stereo audio, the left and right channels are interleaved here and stored in the same I/O buffer. For mono channels, nothing is done.
Preconditions
None.
Example
outSize = AACDecoder_InterleaveSamples(outBuf, haacDecoderInfo);
Parameters
Parameters
Description
*pState
The pointer to the state memory is passed. The details about the number of channels, mono
or stereo, is used.
*outBuf
Pointer to the I/O buffer.
Function
int32_t AACDecoder_InterleaveSamples (void *pState, int16_t *outBuf);
isAACdecoder_enabled Function
File
aac.h
C
bool isAACdecoder_enabled();
Description
This is function isAACdecoder_enabled.
AAC_Decode Function
This function decodes AAC data.
File
decoder_aac.h
C
int16_t AAC_Decode(void * DecoderState, uint8_t * inBufferptr, INTPCM * pTimeData, int16_t * outFlag,
int32_t * restBytes);
Returns
This function returns either the value '0' or '1' to indicate the status of the decode operation.
•
0 - indicates success
•
1 - indicates failure or end of available encoded data. Upon receiving the value '1', the application aborts processing the channel.
Description
This function is called once to decode one frame. This function will be called in an infinite while loop until the end of frame is detected or the
decode function returns the value '1'.
Preconditions
None.
Example
errorStatus = AAC_Decode(haacDecoderInfo, inBuffer, outBuf, &outFlag, &restbit);
Parameters
Parameters
Description
*DecoderState
The pointer to the state memory is passed.
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AAC Decoder Library
Library Interface
*inBufferptr
Pointer to the input buffer, where the encoded bit stream is available. Based on the return
value from AACDecoder_GetFrameSize(), the application fetches the needed bytes from the
bit stream file and fills in this buffer.
*pTimeData
Pointer to the buffer where the output samples are to be stored
*outFlag
The pointer to a variable for output flag: 0 for no valid data (for initial few frames) 1 for valid
data present (for all subsequent frames) After decoding the frame, the function indicates
whether valid data is present in the output buffer.
•
restBytes - Pointer to the variable that indicates how many bytes have not decoded.
•
Normally the number is 0.
Function
int32_t AAC_Decode(void *DecoderState,uint8_t *inBufferptr,short *pTimeData, int16_t *outFlag)
AAC_Initialize Function
File
aac.h
C
bool AAC_Initialize(void * heap, uint16_t size, uint8_t * ptr, SYS_FS_HANDLE aacFilehandle);
Description
This is function AAC_Initialize.
AAC_RegisterDecoderEventHandlerCallback Function
File
aac.h
C
void AAC_RegisterDecoderEventHandlerCallback(SetReadBytesInAppData fptr);
Description
This is function AAC_RegisterDecoderEventHandlerCallback.
AAC_GetSamplingFrequency Function
File
aac.h
C
int32_t AAC_GetSamplingFrequency(uint8_t * ptr);
Description
This is function AAC_GetSamplingFrequency.
b) Data Types and Constants
INTPCM Type
File
decoder_aac.h
C
typedef short INTPCM;
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AAC Decoder Library
Library Interface
Section
Middleware & Other Library Configuration
AAC_DECODER_STATES Enumeration
File
aac.h
C
typedef enum {
AAC_GET_FRAME_SIZE,
AAC_DECODE_FRAME
} AAC_DECODER_STATES;
Description
This is type AAC_DECODER_STATES.
WAVE Structure
File
decoder_aac.h
C
typedef struct {
int32_t riff;
int32_t len;
int32_t wave;
int32_t fmt;
int32_t sublen;
int16_t mode;
int16_t num_chnls;
int32_t samp_freq;
int32_t bytes_per_sec;
int16_t bytes_per_sample;
int16_t bits_per_sample;
int32_t data;
int32_t data_len;
} WAVE;
Members
Members
Description
int16_t mode;
1 for uncompressed PCM
int16_t num_chnls;
1 for mono and 2 for stereo
int32_t bytes_per_sec;
bytes_per_sample * samp_freq
int16_t bytes_per_sample;
bits_per_sample/8 * num_channels : bytes per set of sample
int16_t bits_per_sample;
bits per word (left or right - not both)
Description
This is type WAVE.
AAC_PROFILE Macro
File
decoder_aac.h
C
#define AAC_PROFILE 1
Description
This is macro AAC_PROFILE.
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AAC Decoder Library
Library Interface
AAC_SAMPLING_FREQUENCY_INDEX Enumeration
File
aac.h
C
typedef enum {
SAMPLING_FREQUENCY_IDX0 = 0,
SAMPLING_FREQUENCY_IDX1,
SAMPLING_FREQUENCY_IDX2,
SAMPLING_FREQUENCY_IDX3,
SAMPLING_FREQUENCY_IDX4,
SAMPLING_FREQUENCY_IDX5,
SAMPLING_FREQUENCY_IDX6,
SAMPLING_FREQUENCY_IDX7,
SAMPLING_FREQUENCY_IDX8,
SAMPLING_FREQUENCY_IDX9,
SAMPLING_FREQUENCY_IDX10,
SAMPLING_FREQUENCY_IDX11,
SAMPLING_FREQUENCY_IDX12,
SAMPLING_FREQUENCY_IDX13,
SAMPLING_FREQUENCY_IDX14,
SAMPLING_FREQUENCY_IDX15
} AAC_SAMPLING_FREQUENCY_INDEX;
Description
This is type AAC_SAMPLING_FREQUENCY_INDEX.
AAC_ERROR_COUNT_MAX Macro
File
aac.h
C
#define AAC_ERROR_COUNT_MAX 1
Description
This is macro AAC_ERROR_COUNT_MAX.
AACDECODER_STATE_SIZE Macro
File
decoder_aac.h
C
#define AACDECODER_STATE_SIZE 11032
// in Bytes
Description
in Bytes
FRAME_SIZE Macro
File
decoder_aac.h
C
#define FRAME_SIZE 1024
// in Samples
Description
in Samples
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AAC Decoder Library
Files
INPUT_BUF_SIZE Macro
File
decoder_aac.h
C
#define INPUT_BUF_SIZE (6144*2/8)
// in Bytes
Description
in Bytes
MAX_STACK Macro
File
decoder_aac.h
C
#define MAX_STACK 0x5000
// in Bytes
Description
in Bytes
STACK Macro
File
decoder_aac.h
C
#define STACK 1
Description
This is macro STACK.
AAC_FRAME_HEADER_SIZE Macro
File
decoder_aac.h
C
#define AAC_FRAME_HEADER_SIZE 7
// in Bytes
Description
in Bytes
SetReadBytesInAppData Type
File
aac.h
C
typedef void (* SetReadBytesInAppData)(int32_t val);
Description
This is type SetReadBytesInAppData.
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AAC Decoder Library
Files
Files
Files
Name
Description
aac.h
Frame enumerators.
decoder_aac.h
This file consists of the abstract function and input output buffer size declaration for decoding
purposes.
Description
This section lists the source and header files used by the MP3 Decoder Library.
aac.h
Frame enumerators.
Enumerations
Name
Description
AAC_DECODER_STATES
This is type AAC_DECODER_STATES.
AAC_SAMPLING_FREQUENCY_INDEX This is type AAC_SAMPLING_FREQUENCY_INDEX.
Functions
Name
Description
AAC_Decoder
This is function AAC_Decoder.
AAC_GetSamplingFrequency
This is function AAC_GetSamplingFrequency.
AAC_Initialize
This is function AAC_Initialize.
AAC_RegisterDecoderEventHandlerCallback This is function AAC_RegisterDecoderEventHandlerCallback.
isAACdecoder_enabled
This is function isAACdecoder_enabled.
Macros
Name
Description
AAC_ERROR_COUNT_MAX
This is macro AAC_ERROR_COUNT_MAX.
Name
Description
SetReadBytesInAppData
This is type SetReadBytesInAppData.
Types
Description
AAC Decoder Library Support File
This header file consists of frame enumerators.
File Name
aac.h
Company
Microchip Technology Inc.
decoder_aac.h
This file consists of the abstract function and input output buffer size declaration for decoding purposes.
Functions
Name
Description
AAC_Decode
This function decodes AAC data.
AAC_WriteWavHeader
Generates the .wav file header, if applicable.
AACDecoder_GetFrameSize
Used to get the AAC Decoder frame size.
AACDecoder_GetStateSize
This function allocates memory for each channel being used.
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AAC Decoder Library
AACDecoder_Init
Views the received point and clears the structure.
AACDecoder_InterleaveSamples
This function interleaves left and right channel data.
Name
Description
AAC_FRAME_HEADER_SIZE
in Bytes
AAC_PROFILE
This is macro AAC_PROFILE.
AACDECODER_STATE_SIZE
in Bytes
FRAME_SIZE
in Samples
INPUT_BUF_SIZE
in Bytes
MAX_STACK
in Bytes
STACK
This is macro STACK.
Name
Description
WAVE
This is type WAVE.
Name
Description
Files
Macros
Structures
Types
INTPCM
Description
AAC Decoder Library Interface File
The header file consists of function declaration for the abstract functions to invoke decoding . The header file also defines the size of input samples
and i/p and o/p buffer. This configuration header must not define any prototypes or data definitions (or include any files that do). It only provides
macro definitions for build-time configuration options that are not instantiated until used by another MPLAB Harmony module or application.
File Name
decoder_aac.h
Company
Microchip Technology Inc.
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MP3 Decoder Library
Library Interface
MP3 Decoder Library
This section describes the MP3 Decoder Library.
Introduction
The MP3 Decoder Library is available for the PIC32 family of microcontrollers.
Description
The MP3 Decoder Library is a premium product and is not included in the standard release of MPLAB Harmony and must be purchased
separately. Refer to the Microchip Premium MPLAB Harmony Audio web page (www.microchip.com/pic32harmonypremiumaudio) for additional
information.
The Compact MP3 algorithm is designed to fit in small memory footprint PIC32MX Microcontrollers. This code requires only 28 MIPS of
performance (CD Quality audio), 42 KB Flash and 11 KB RAM memory for operation on the PIC32MX. This part number is for Non-modifiable
binary code. Source code is also available (refer to the previous web link). Users are responsible for patent-only licensing through Technicolor.
Assembly Language Issue
There is an assembly language issue in the MP3 Decoder Library that misaligns the stack pointer. Contrary to the MIPS programming
specification, this error is benign except when the application is built for a device with a hardware Floating Point Unit (FPU), such as the PIC32MZ
EF family of devices. In this case, the sub-routine context-saving operations will produce an exception and stop the application. A work around
exists for this issue, which involves disabling FPU context-saving for Interrupt Service Routines (ISRs).
The work around is to convert all ISRs from:
void __ISR(vector,ipl) MyInterruptHandler(void)
and change them to:
void __attribute__((vector),interrupt(ipl),nomips16,no_fpu)) MyInterruptHandler(void)
where, vector and ipl are replaced with the actual interrupt vector and interrupt priority level.
An example of this work around can be found in the universal_audio_decoders demonstration.
So as long as no FPU operations occur in ISRs and the routines are called by ISRs, this work around will prevent the misaligned stack pointer from
causing an exception. If FPU operations result from an ISR with no_fpu enabled, a general exception will result.
Using the Library
This topic describes the basic architecture of the MP3 Decoder Library and provides information and examples on its use.
Description
Interface Header File: decoder_mp3.h
The interface to the MP3 Decoder Library is defined in the decoder_mp3.h header file. Any C language source (.c) file that uses the MP3
Decoder Library should include decoder_mp3.h.
Please refer to the What is MPLAB Harmony? section for how the MP3 Decoder Library interacts with the framework.
Library Overview
The Library Interface routines are divided into various sub-sections, each of which addresses one of the blocks or the overall operation of the MP3
Decoder Library module.
Library Interface
a) General Functions
Name
Description
MP3_Decode
This is function MP3_Decode.
MP3Initialize
The function views the received pointer as a structure pointer and clears the entire
structure.
MP3_EventHandler
This is function MP3_EventHandler.
MP3Decode
This function is called once to decode one frame.
MP3DecoderGetStateSize
This function allocates memory used for decoding.
MP3_ParseVBR
This is function MP3_ParseVBR.
MP3DecoderInit
The function views the received pointer as a structure pointer and clears the entire
structure.
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MP3 Decoder Library
isMP3decoder_enabled
This is function isMP3decoder_enabled.
ID3_Initialize
void ID3_Initialize ( void );
ID3_EventHandler
This is function ID3_EventHandler.
ID3_Parse
This is function ID3_Parse.
ID3_ParseFrameV22
This is function ID3_ParseFrameV22.
ID3_ParseFrameV23
This is function ID3_ParseFrameV23.
ID3_Parse_Frame
This is function ID3_Parse_Frame.
MP3Decode
This function is called once to decode one frame.
MP3_GetAudioSize
This is function MP3_GetAudioSize.
MP3_UpdatePlaytime
This is function MP3_UpdatePlaytime.
MP3_Initialize
This is function MP3_Initialize.
Library Interface
MP3_RegisterDecoderEventHandlerCallback This is function MP3_RegisterDecoderEventHandlerCallback.
MP3_GetChannels
This is function MP3_GetChannels.
b) Data Types and Constants
Name
Description
MP3_FORMAT
MP3_STATE_SIZE
11024
MP3_EVENT
This is type MP3_EVENT.
MP3_FRAME_HEADER
This is type MP3_FRAME_HEADER.
MP3_STATE
This is type MP3_STATE.
MP3_XING_HEADER
This is type MP3_XING_HEADER.
MP3_ERROR_COUNT_MAX
This is macro MP3_ERROR_COUNT_MAX.
MP3_HEADER_CHANNELS_DUAL
This is macro MP3_HEADER_CHANNELS_DUAL.
MP3_HEADER_CHANNELS_JOINT
This is macro MP3_HEADER_CHANNELS_JOINT.
MP3_HEADER_CHANNELS_MONO
This is macro MP3_HEADER_CHANNELS_MONO.
MP3_HEADER_CHANNELS_STEREO
This is macro MP3_HEADER_CHANNELS_STEREO.
MP3_HEADER_SAMPLERATE_32000
This is macro MP3_HEADER_SAMPLERATE_32000.
MP3_HEADER_SAMPLERATE_44100
This is macro MP3_HEADER_SAMPLERATE_44100.
MP3_HEADER_SAMPLERATE_48000
This is macro MP3_HEADER_SAMPLERATE_48000.
MP3_HEADER_SAMPLERATE_RESV
This is macro MP3_HEADER_SAMPLERATE_RESV.
MP3_PLAYTIME_H
This is macro MP3_PLAYTIME_H.
MP3_XING_HEADER_START_MONO
This is macro MP3_XING_HEADER_START_MONO.
MP3_XING_HEADER_START_STEREO This is macro MP3_XING_HEADER_START_STEREO.
ID3_EVENT
This is type ID3_EVENT.
ID3_STATE
This is type ID3_STATE.
ID3V1_EXTENDED_TAG
This is type ID3V1_EXTENDED_TAG.
ID3V1_TAG
This is type ID3V1_TAG.
ID3V2_TAG_HEADER
This is type ID3V2_TAG_HEADER.
ID3V22_FRAME
This is type ID3V22_FRAME.
ID3V22_FRAME_HEADER
This is type ID3V22_FRAME_HEADER.
ID3V23_FRAME
This is type ID3V23_FRAME.
ID3V23_FRAME_HEADER
This is type ID3V23_FRAME_HEADER.
ID3_H
This is macro ID3_H.
ID3_STRING_SIZE
This is macro ID3_STRING_SIZE.
ID3V22_ALBUM
This is macro ID3V22_ALBUM.
ID3V22_ARTIST
This is macro ID3V22_ARTIST.
ID3V22_TITLE
This is macro ID3V22_TITLE.
ID3V22_ZERO
This is macro ID3V22_ZERO.
ID3V23_ALBUM
This is macro ID3V23_ALBUM.
ID3V23_ARTIST
This is macro ID3V23_ARTIST.
ID3V23_TITLE
This is macro ID3V23_TITLE.
ID3V23_ZERO
This is macro ID3V23_ZERO.
MP3_CHANNEL_INFO
MP3MPEG1L3_SAMPLES_PER_FRAME MPEG1 LayerIII, samples per frame
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MP3 Decoder Library
Library Interface
MP3MPEG2L3_SAMPLES_PER_FRAME MPEG2/2.5 LayerIII, samples per frame
MP3_DEC
This is type MP3_DEC.
DecoderEventHandlerCB
This is type DecoderEventHandlerCB.
Description
This section describes the Application Programming Interface (API) functions of the MP3 Decoder Library.
Refer to each section for a detailed description.
a) General Functions
MP3_Decode Function
File
mp3.h
C
bool MP3_Decode(uint8_t * input, uint16_t inSize, uint16_t * read, uint8_t * output, uint16_t * written);
Description
This is function MP3_Decode.
MP3Initialize Function
The function views the received pointer as a structure pointer and clears the entire structure.
File
decoder_mp3_microaptiv.h
C
bool MP3Initialize(void * state);
Returns
This function returns a boolean value.
•
0 - indicates unsuccessful initialization
•
1 - indicates successful initialization
Description
The function views the received pointer as a structure pointer and clears the entire structure. Subsequently, it initializes the selective variable with
the default values. The function is called only once before initiating the decoding process.
Preconditions
None.
Example
MP3Initialize ( mp3.decoderVars );
Parameters
Parameters
Description
*state
The pointer to the allocated state memory is passed.
Function
bool MP3Initialize(void *state);
MP3_EventHandler Function
File
mp3.h
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MP3 Decoder Library
Library Interface
C
bool MP3_EventHandler(MP3_EVENT event, uint32_t data);
Description
This is function MP3_EventHandler.
MP3Decode Function
This function is called once to decode one frame.
File
decoder_mp3_microaptiv.h
C
uint16_t MP3Decode(void * state, uint8_t * in, uint16_t inSize, uint16_t * used, MP3_FORMAT * format, void
* outBuffer, uint16_t * outSize);
Returns
This function returns either the value '0' or '1' to indicate the status of the decode operation.
•
1 - indicates success
•
0 - indicates failure or end of available encoded data. Upon receiving the value '0' the application aborts processing the channel.
Description
This function is called once to decode one frame. This function will be called in an infinite while loop until the end of the frame is detected or the
decode function returns the value '0'. Unlike most speech applications where the encoded data for each frame is deterministic, this is not the case
for audio applications. Therefore, the application provides a portion of input data (usually more than what is necessary for a single frame). The
decoder parses the input and decodes it with a portion of the data. The decode function passes the information of how many bytes of data were
used to the application so that the application saves the remaining data and presents to the decoder for the subsequent frame.
Preconditions
None.
Example
MP3Decode ( mp3.decoderVars, input, inSize, read, &mp3.format, output, written )
Parameters
Parameters
Description
*state
The pointer to the state memory is passed.
*in
The pointer to the input buffer , where the encoded bit stream is available.
inSize
A variable of data type uint16_t indicating the number of valid bytes available in the input
buffer.
*used
The pointer to a variable is passed to the function. After decoding the frame the function
writes the number of bytes consumed from the current frame decoder operation.
*format
The pointer to a channel info structure is passed to the function the decider updates this
structure after every call
*outBuffer
The pointer to the output sample buffer where the decided pcm samples are to be written,
*outSize
The pointer to a variable is passed to the function. After decoding the frame the function
writes the number of valid bytes available in the output buffer.
Function
uint16_t MP3Decode ( void *state, uint8_t *in, uint16_t inSize, uint16_t *used,
MP3_FORMAT *format, void *outBuffer, uint16_t *outSize);
MP3DecoderGetStateSize Function
This function allocates memory used for decoding.
File
decoder_mp3_microaptiv.h
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MP3 Decoder Library
Library Interface
C
uint32_t MP3DecoderGetStateSize();
Returns
This function returns the size of the MP3 Decoder state structure in bytes.
Description
Based on the return value, the application allocates the required memory for the MP3 Decoder state. This function is called only once before
initializing the decoder state. If dynamic memory allocation (malloc) is not needed, it is not necessary to call this function and the MP3 Decoder
state buffer will be statically defined at the compile time with the size of the MP3 decoder state structure.
Preconditions
None.
Example
Word mp3StateSize;
mp3StateSize = MP3DecoderGetStateSize();
Function
uint32_t MP3DecoderGetStateSize(void);
MP3_ParseVBR Function
File
mp3.h
C
bool MP3_ParseVBR(uint8_t* data);
Description
This is function MP3_ParseVBR.
MP3DecoderInit Function
The function views the received pointer as a structure pointer and clears the entire structure.
File
decoder_mp3_advanced.h
C
void MP3DecoderInit(void * State);
Returns
None.
Description
The function views the received pointer as a structure pointer and clears the entire structure. Subsequently, it initializes the selective variable with
the default values. The function is called only once before initiating the decoding process.
Preconditions
None.
Example
MP3Initialize ( mp3.decoderVars );
Parameters
Parameters
Description
*state
The pointer to the allocated state memory is passed.
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MP3 Decoder Library
Library Interface
Function
void MP3DecoderInit(void *state);
isMP3decoder_enabled Function
File
mp3.h
C
bool isMP3decoder_enabled();
Description
This is function isMP3decoder_enabled.
ID3_Initialize Function
File
id3.h
C
int32_t ID3_Initialize(uint8_t * buffer);
Description
void ID3_Initialize ( void );
ID3_EventHandler Function
File
id3.h
C
bool ID3_EventHandler(ID3_EVENT event, uint32_t data);
Description
This is function ID3_EventHandler.
ID3_Parse Function
File
id3.h
C
uint32_t ID3_Parse(uint8_t * buff, uint16_t size);
Description
This is function ID3_Parse.
ID3_ParseFrameV22 Function
File
id3.h
C
void ID3_ParseFrameV22(ID3V22_FRAME * frame, uint32_t frameSize, char * id, uint16_t event);
Description
This is function ID3_ParseFrameV22.
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MP3 Decoder Library
Library Interface
ID3_ParseFrameV23 Function
File
id3.h
C
void ID3_ParseFrameV23(ID3V23_FRAME * frame, uint32_t frameSize, char * id, uint16_t event);
Description
This is function ID3_ParseFrameV23.
ID3_Parse_Frame Function
File
id3.h
C
uint32_t ID3_Parse_Frame(uint8_t * buffer, size_t left, int8_t * ret);
Description
This is function ID3_Parse_Frame.
MP3Decode Function
This function is called once to decode one frame.
File
decoder_mp3_advanced.h
C
int16_t MP3Decode(void * state, uint8_t * In, uint16_t inSize, uint16_t * used, MP3_CHANNEL_INFO * format,
void * outBuffer, uint16_t * outSize);
Returns
This function returns either the value '0' or '1' or '2' to indicate the status of the decode operation.
•
0 - indicates success
•
1 - indicates that no data is available (thus marking end of file)
•
2 - indicates failure or invalid or corrupted data
Description
This function is called once to decode one frame. This function will be called in an infinite while loop until the end of the frame is detected or the
decode function returns the value '0'. Unlike most speech applications where the encoded data for each frame is deterministic, this is not the case
for audio applications. Therefore, the application provides a portion of input data (usually more than what is necessary for a single frame). The
decoder parses the input and decodes it with a portion of the data. The decode function passes the information of how many bytes of data were
used to the application so that the application saves the remaining data and presents to the decoder for the subsequent frame.
Preconditions
None.
Example
MP3Decode ( mp3.decoderVars, input, inSize, read, &mp3.format, output, written )
Parameters
Parameters
Description
*state
The pointer to the state memory is passed.
*in
The pointer to the input buffer , where the encoded bit stream is available.
inSize
A variable of data type uint16_t indicating the number of valid bytes available in the input
buffer.
*used
The pointer to a variable is passed to the function. After decoding the frame the function
writes the number of bytes consumed from the current frame decoder operation.
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MP3 Decoder Library
Library Interface
*format
The pointer to a channel info structure is passed to the function. The decoder updates this
structure after every call. Additional member 'MPEG_Type' to indicate the MPEG version is
added in this structure.
*outBuffer
The pointer to the output sample buffer where the decided pcm samples are to be written,
*outSize
The pointer to a variable is passed to the function. After decoding the frame the function
writes the number of valid bytes available in the output buffer.
Function
int16_t MP3Decode ( void *state, uint8_t *In, uint16_t inSize, uint16_t *used,
MP3_CHANNEL_INFO *format, void *outBuffer, uint16_t *outSize);
MP3_GetAudioSize Function
File
mp3.h
C
uint32_t MP3_GetAudioSize();
Description
This is function MP3_GetAudioSize.
MP3_UpdatePlaytime Function
File
mp3.h
C
uint32_t MP3_UpdatePlaytime();
Description
This is function MP3_UpdatePlaytime.
MP3_Initialize Function
File
mp3.h
C
bool MP3_Initialize(void * heap, uint16_t size, SYS_FS_HANDLE mp3Filehandle);
Description
This is function MP3_Initialize.
MP3_RegisterDecoderEventHandlerCallback Function
File
mp3.h
C
void MP3_RegisterDecoderEventHandlerCallback(DecoderEventHandlerCB fptr);
Description
This is function MP3_RegisterDecoderEventHandlerCallback.
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MP3 Decoder Library
Library Interface
MP3_GetChannels Function
File
mp3.h
C
uint8_t MP3_GetChannels();
Description
This is function MP3_GetChannels.
b) Data Types and Constants
MP3_FORMAT Structure
File
decoder_mp3_microaptiv.h
C
typedef struct {
uint16_t Kbps;
uint16_t sampleRate;
uint8_t bitsPerSample;
uint8_t channels;
} MP3_FORMAT;
Section
Middleware & Other Library Configuration
MP3_STATE_SIZE Macro
File
mp3.h
C
#define MP3_STATE_SIZE 16876//11024
Description
11024
MP3_EVENT Enumeration
File
mp3.h
C
typedef enum {
MP3_EVENT_STREAM_START,
MP3_EVENT_SAMPLERATE,
MP3_EVENT_BITRATE,
MP3_EVENT_TRACK_TIME
} MP3_EVENT;
Description
This is type MP3_EVENT.
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MP3 Decoder Library
Library Interface
MP3_FRAME_HEADER Union
File
mp3.h
C
typedef union {
uint32_t data;
struct {
uint8_t sync0 : 8;
uint8_t CRC : 1;
uint8_t layer : 2;
uint8_t mpeg : 2;
uint8_t sync1 : 3;
uint8_t padding : 1;
uint8_t samprate : 2;
uint8_t bitrate : 4;
uint8_t nc : 4;
uint8_t extend : 2;
uint8_t stereo : 2;
}
} MP3_FRAME_HEADER;
Description
This is type MP3_FRAME_HEADER.
MP3_STATE Enumeration
File
mp3.h
C
typedef enum {
MP3_STATE_STREAM
} MP3_STATE;
Description
This is type MP3_STATE.
MP3_XING_HEADER Structure
File
mp3.h
C
typedef struct {
int8_t tag[4];
union {
uint32_t flags;
struct {
uint32_t frameInfo : 1;
uint32_t sizeInfo : 1;
uint32_t tocInfo : 1;
uint32_t qualityInfo : 1;
}
}
uint8_t frames[4];
uint8_t size[4];
uint8_t toc[100];
uint8_t quality;
} MP3_XING_HEADER;
Description
This is type MP3_XING_HEADER.
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MP3 Decoder Library
Library Interface
MP3_ERROR_COUNT_MAX Macro
File
mp3.h
C
#define MP3_ERROR_COUNT_MAX 1
Description
This is macro MP3_ERROR_COUNT_MAX.
MP3_HEADER_CHANNELS_DUAL Macro
File
mp3.h
C
#define MP3_HEADER_CHANNELS_DUAL 0b10
Description
This is macro MP3_HEADER_CHANNELS_DUAL.
MP3_HEADER_CHANNELS_JOINT Macro
File
mp3.h
C
#define MP3_HEADER_CHANNELS_JOINT 0b01
Description
This is macro MP3_HEADER_CHANNELS_JOINT.
MP3_HEADER_CHANNELS_MONO Macro
File
mp3.h
C
#define MP3_HEADER_CHANNELS_MONO 0b11
Description
This is macro MP3_HEADER_CHANNELS_MONO.
MP3_HEADER_CHANNELS_STEREO Macro
File
mp3.h
C
#define MP3_HEADER_CHANNELS_STEREO 0b00
Description
This is macro MP3_HEADER_CHANNELS_STEREO.
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MP3 Decoder Library
Library Interface
MP3_HEADER_SAMPLERATE_32000 Macro
File
mp3.h
C
#define MP3_HEADER_SAMPLERATE_32000 0b10
Description
This is macro MP3_HEADER_SAMPLERATE_32000.
MP3_HEADER_SAMPLERATE_44100 Macro
File
mp3.h
C
#define MP3_HEADER_SAMPLERATE_44100 0b00
Description
This is macro MP3_HEADER_SAMPLERATE_44100.
MP3_HEADER_SAMPLERATE_48000 Macro
File
mp3.h
C
#define MP3_HEADER_SAMPLERATE_48000 0b01
Description
This is macro MP3_HEADER_SAMPLERATE_48000.
MP3_HEADER_SAMPLERATE_RESV Macro
File
mp3.h
C
#define MP3_HEADER_SAMPLERATE_RESV 0b11
Description
This is macro MP3_HEADER_SAMPLERATE_RESV.
MP3_PLAYTIME_H Macro
File
mp3.h
C
#define MP3_PLAYTIME_H
Description
This is macro MP3_PLAYTIME_H.
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Library Interface
MP3_XING_HEADER_START_MONO Macro
File
mp3.h
C
#define MP3_XING_HEADER_START_MONO 17
Description
This is macro MP3_XING_HEADER_START_MONO.
MP3_XING_HEADER_START_STEREO Macro
File
mp3.h
C
#define MP3_XING_HEADER_START_STEREO 32
Description
This is macro MP3_XING_HEADER_START_STEREO.
ID3_EVENT Enumeration
File
id3.h
C
typedef enum {
ID3_EVENT_TAG_ARTIST,
ID3_EVENT_TAG_ALBUM,
ID3_EVENT_TAG_TITLE
} ID3_EVENT;
Description
This is type ID3_EVENT.
ID3_STATE Enumeration
File
id3.h
C
typedef enum {
ID3_STATE_INIT,
ID3_STATE_READ_V1,
ID3_STATE_READ_V2_HEADER,
ID3_STATE_READ_V2_FRAME,
ID3_STATE_FINISHED
} ID3_STATE;
Description
This is type ID3_STATE.
ID3V1_EXTENDED_TAG Structure
File
id3.h
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MP3 Decoder Library
Library Interface
C
typedef struct {
uint8_t tag[4];
int8_t title[60];
int8_t artist[60];
int8_t album[60];
uint8_t speed;
int8_t genre[30];
int8_t startTime[6];
int8_t endTime[6];
} ID3V1_EXTENDED_TAG;
Description
This is type ID3V1_EXTENDED_TAG.
ID3V1_TAG Structure
File
id3.h
C
typedef struct {
uint8_t tag[3];
int8_t title[30];
int8_t artist[30];
int8_t album[30];
int8_t year[4];
union {
int8_t comment[30];
struct {
int8_t commentShort[28];
uint8_t zero;
uint8_t track;
}
}
uint8_t genre;
} ID3V1_TAG;
Description
This is type ID3V1_TAG.
ID3V2_TAG_HEADER Structure
File
id3.h
C
typedef struct {
uint8_t tag[3];
uint8_t version;
uint8_t empty;
uint8_t flag;
uint8_t size[4];
} ID3V2_TAG_HEADER;
Description
This is type ID3V2_TAG_HEADER.
ID3V22_FRAME Structure
File
id3.h
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MP3 Decoder Library
Library Interface
C
typedef struct {
uint8_t id[3];
uint8_t size[3];
uint8_t encoding;
uint8_t contents[1];
} ID3V22_FRAME;
Description
This is type ID3V22_FRAME.
ID3V22_FRAME_HEADER Structure
File
id3.h
C
typedef struct {
uint8_t id[3];
uint8_t size[3];
} ID3V22_FRAME_HEADER;
Description
This is type ID3V22_FRAME_HEADER.
ID3V23_FRAME Structure
File
id3.h
C
typedef struct {
uint8_t id[4];
uint8_t size[4];
uint8_t flags[2];
uint8_t encoding;
uint8_t contents[1];
} ID3V23_FRAME;
Description
This is type ID3V23_FRAME.
ID3V23_FRAME_HEADER Structure
File
id3.h
C
typedef struct {
uint8_t id[4];
uint8_t size[4];
uint8_t flags[2];
} ID3V23_FRAME_HEADER;
Description
This is type ID3V23_FRAME_HEADER.
ID3_H Macro
File
id3.h
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Library Interface
C
#define ID3_H
Description
This is macro ID3_H.
ID3_STRING_SIZE Macro
File
id3.h
C
#define ID3_STRING_SIZE 128
Description
This is macro ID3_STRING_SIZE.
ID3V22_ALBUM Macro
File
id3.h
C
#define ID3V22_ALBUM "TAL"
Description
This is macro ID3V22_ALBUM.
ID3V22_ARTIST Macro
File
id3.h
C
#define ID3V22_ARTIST "TP1"
Description
This is macro ID3V22_ARTIST.
ID3V22_TITLE Macro
File
id3.h
C
#define ID3V22_TITLE "TT2"
Description
This is macro ID3V22_TITLE.
ID3V22_ZERO Macro
File
id3.h
C
#define ID3V22_ZERO "\0\0\0"
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Library Interface
Description
This is macro ID3V22_ZERO.
ID3V23_ALBUM Macro
File
id3.h
C
#define ID3V23_ALBUM "TALB"
Description
This is macro ID3V23_ALBUM.
ID3V23_ARTIST Macro
File
id3.h
C
#define ID3V23_ARTIST "TPE1"
Description
This is macro ID3V23_ARTIST.
ID3V23_TITLE Macro
File
id3.h
C
#define ID3V23_TITLE "TIT2"
Description
This is macro ID3V23_TITLE.
ID3V23_ZERO Macro
File
id3.h
C
#define ID3V23_ZERO "\0\0\0\0"
Description
This is macro ID3V23_ZERO.
MP3_CHANNEL_INFO Structure
File
decoder_mp3_advanced.h
C
typedef struct {
int16_t bitsPerWord;
int16_t channels;
int32_t samplingRate;
int32_t bitRate;
int32_t MPEG_Type;
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Library Interface
} MP3_CHANNEL_INFO;
Section
Middleware & Other Library Configuration
MP3MPEG1L3_SAMPLES_PER_FRAME Macro
File
mp3.h
C
#define MP3MPEG1L3_SAMPLES_PER_FRAME 1152 // MPEG1 LayerIII, samples per frame
Description
MPEG1 LayerIII, samples per frame
MP3MPEG2L3_SAMPLES_PER_FRAME Macro
File
mp3.h
C
#define MP3MPEG2L3_SAMPLES_PER_FRAME 576
// MPEG2/2.5 LayerIII, samples per frame
Description
MPEG2/2.5 LayerIII, samples per frame
MP3_DEC Structure
File
mp3.h
C
typedef struct {
uint16_t mp3SampleRate;
uint32_t mp3BitRate;
uint32_t mp3Duration;
uint32_t firstFramePos;
bool isVBR;
uint32_t mp3ValidBytes;
uint8_t stereo;
} MP3_DEC;
Members
Members
Description
uint32_t firstFramePos;
first frame position in file
uint32_t mp3ValidBytes;
for VBR MP3, mp3ValidBytes is the number of bytes in file is given by XING header, for CBR
MP3, mp3ValidBytes is MP3 audio file size - first frame position
Description
This is type MP3_DEC.
DecoderEventHandlerCB Type
File
mp3.h
C
typedef bool (* DecoderEventHandlerCB)(uint32_t event, uint32_t data);
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Files
Description
This is type DecoderEventHandlerCB.
Files
Files
Name
Description
mp3.h
MP3 Decoder support API.
id3.h
MP3 Decoder ID3 parser header API.
decoder_mp3_advanced.h
This file consists of the abstract function and input output buffer size declaration for decoding
purpose
decoder_mp3_microaptiv.h
This file consists of the abstract function and input output buffer size declaration for decoding
purpose
Description
This section lists the source and header files used by the MP3 Decoder Library.
mp3.h
MP3 Decoder support API.
Enumerations
Name
Description
MP3_EVENT
This is type MP3_EVENT.
MP3_STATE
This is type MP3_STATE.
Functions
Name
Description
isMP3decoder_enabled
This is function isMP3decoder_enabled.
MP3_Decode
This is function MP3_Decode.
MP3_EventHandler
This is function MP3_EventHandler.
MP3_GetAudioSize
This is function MP3_GetAudioSize.
MP3_GetChannels
This is function MP3_GetChannels.
MP3_Initialize
This is function MP3_Initialize.
MP3_ParseVBR
This is function MP3_ParseVBR.
MP3_RegisterDecoderEventHandlerCallback This is function MP3_RegisterDecoderEventHandlerCallback.
MP3_UpdatePlaytime
This is function MP3_UpdatePlaytime.
Macros
Name
Description
MP3_ERROR_COUNT_MAX
This is macro MP3_ERROR_COUNT_MAX.
MP3_HEADER_CHANNELS_DUAL
This is macro MP3_HEADER_CHANNELS_DUAL.
MP3_HEADER_CHANNELS_JOINT
This is macro MP3_HEADER_CHANNELS_JOINT.
MP3_HEADER_CHANNELS_MONO
This is macro MP3_HEADER_CHANNELS_MONO.
MP3_HEADER_CHANNELS_STEREO
This is macro MP3_HEADER_CHANNELS_STEREO.
MP3_HEADER_SAMPLERATE_32000
This is macro MP3_HEADER_SAMPLERATE_32000.
MP3_HEADER_SAMPLERATE_44100
This is macro MP3_HEADER_SAMPLERATE_44100.
MP3_HEADER_SAMPLERATE_48000
This is macro MP3_HEADER_SAMPLERATE_48000.
MP3_HEADER_SAMPLERATE_RESV
This is macro MP3_HEADER_SAMPLERATE_RESV.
MP3_PLAYTIME_H
This is macro MP3_PLAYTIME_H.
MP3_STATE_SIZE
11024
MP3_XING_HEADER_START_MONO
This is macro MP3_XING_HEADER_START_MONO.
MP3_XING_HEADER_START_STEREO This is macro MP3_XING_HEADER_START_STEREO.
MP3MPEG1L3_SAMPLES_PER_FRAME MPEG1 LayerIII, samples per frame
MP3MPEG2L3_SAMPLES_PER_FRAME MPEG2/2.5 LayerIII, samples per frame
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MP3 Decoder Library
Files
Structures
Name
Description
MP3_DEC
This is type MP3_DEC.
MP3_XING_HEADER
This is type MP3_XING_HEADER.
Name
Description
DecoderEventHandlerCB
This is type DecoderEventHandlerCB.
Name
Description
MP3_FRAME_HEADER
This is type MP3_FRAME_HEADER.
Types
Unions
Description
MP3 Decoder Library Interface File
This header file consists of support function declarations.
File Name
mp3.h
Company
Microchip Technology Inc.
id3.h
MP3 Decoder ID3 parser header API.
Enumerations
Name
Description
ID3_EVENT
This is type ID3_EVENT.
ID3_STATE
This is type ID3_STATE.
Name
Description
ID3_EventHandler
This is function ID3_EventHandler.
ID3_Initialize
void ID3_Initialize ( void );
ID3_Parse
This is function ID3_Parse.
ID3_Parse_Frame
This is function ID3_Parse_Frame.
ID3_ParseFrameV22
This is function ID3_ParseFrameV22.
ID3_ParseFrameV23
This is function ID3_ParseFrameV23.
Name
Description
ID3_H
This is macro ID3_H.
ID3_STRING_SIZE
This is macro ID3_STRING_SIZE.
ID3V22_ALBUM
This is macro ID3V22_ALBUM.
ID3V22_ARTIST
This is macro ID3V22_ARTIST.
ID3V22_TITLE
This is macro ID3V22_TITLE.
ID3V22_ZERO
This is macro ID3V22_ZERO.
ID3V23_ALBUM
This is macro ID3V23_ALBUM.
ID3V23_ARTIST
This is macro ID3V23_ARTIST.
ID3V23_TITLE
This is macro ID3V23_TITLE.
ID3V23_ZERO
This is macro ID3V23_ZERO.
Functions
Macros
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Files
Structures
Name
Description
ID3V1_EXTENDED_TAG
This is type ID3V1_EXTENDED_TAG.
ID3V1_TAG
This is type ID3V1_TAG.
ID3V2_TAG_HEADER
This is type ID3V2_TAG_HEADER.
ID3V22_FRAME
This is type ID3V22_FRAME.
ID3V22_FRAME_HEADER
This is type ID3V22_FRAME_HEADER.
ID3V23_FRAME
This is type ID3V23_FRAME.
ID3V23_FRAME_HEADER
This is type ID3V23_FRAME_HEADER.
Description
MP3 Decoder Timekeeping and Delay Routines Definitions Header File
This file provides MP3 Decoder ID3 parser header APIs.
File Name
id3.h
Company
Microchip Technology Inc.
decoder_mp3_advanced.h
This file consists of the abstract function and input output buffer size declaration for decoding purpose
Functions
Name
Description
MP3Decode
This function is called once to decode one frame.
MP3DecoderInit
The function views the received pointer as a structure pointer and clears the entire structure.
Name
Description
Structures
MP3_CHANNEL_INFO
Description
MP3 Decoder Library Interface File
The header file consists of function declaration for the abstract functions to invoke decoding . The header file also defines the size of input samples
and i/p and o/p buffer.
File Name
decoder_mp3_advanced.h
Company
Microchip Technology Inc.
decoder_mp3_microaptiv.h
This file consists of the abstract function and input output buffer size declaration for decoding purpose
Functions
Name
Description
MP3Decode
This function is called once to decode one frame.
MP3DecoderGetStateSize
This function allocates memory used for decoding.
MP3Initialize
The function views the received pointer as a structure pointer and clears the entire structure.
Name
Description
Structures
MP3_FORMAT
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Files
Description
MP3 Decoder Library Interface File
The header file consists of function declaration for the abstract functions to invoke decoding . The header file also defines the size of input samples
and i/p and o/p buffer.
File Name
decoder_mp3_microaptiv.h
Company
Microchip Technology Inc.
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Opus Decoder Library
Using the Library
Opus Decoder Library
This section describes the Opus Decoder Library.
Introduction
Introduces the Opus Decoder Library.
Description
Opus is an open, royalty-free, highly versatile audio codec. Opus is unmatched for interactive speech and music transmission over the Internet, but
is also intended for storage and streaming applications. It is standardized by the Internet Engineering Task Force (IETF) as RFC 6716, which
incorporated technology from Skype's SILK codec and Xiph.Org's CELT codec.
Opus Features
Supported features are:
•
Bit rates from 6 kb/s to 510 kb/s
•
Sampling rates from 8 kHz (narrowband) to 48 kHz (fullband)
•
Frame sizes from 2.5 ms to 60 ms
•
Support for both constant bit rate (CBR) and variable bit rate (VBR)
•
Audio bandwidth from narrowband to fullband
•
Support for speech and music
•
Support for mono and stereo
•
Support for up to 255 channels (mult-istream frames)
•
Dynamically adjustable bit rate, audio bandwidth, and frame size
•
Good loss robustness and packet loss concealment (PLC)
•
Floating point and fixed-point implementation
The full specification, RFC 6716, including the reference implementation is available from http://www.opus-codec.org. An up-to-date
implementation of the Opus standard is available from the Opus Codec downloads page by visiting: https://www.opus-codec.org/downloads/
Typical Applications
•
Building and home safety systems; Intercoms
•
Smart appliances
•
Walkie-talkies
•
Toys
•
Robots
•
Any application using message playback
Resources
Feature
Option
Usage
Opus Library Flash Size
Release Build
< 143 KB
Opus Decoder RAM
Heap Size (Mono mode)
17 KB
Heap Size (Stereo mode)
25 KB
Opus Decoding Performance
PIC32MX270F512L device)
(measured
using
a 16 kbps Voice
12 kbps Voice
6.8 MCPS/13.6 MIPS
4.8 MCPS/9.6 MIPS
Using the Library
This topic describes the basic architecture of the Opus Decoder Library and provides information and examples on its use.
Description
Interface Header File: opus.h
The interface to the Opus Decoder Library is defined in the opus.h header file. Any C language source (.c) file that uses the Opus Decoder
Library should include opus.h.
Please refer to the What is MPLAB Harmony? section for how the Opus Decoder Library interacts with the framework.
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Opus Decoder Library
Using the Library
Abstraction Model
Describes the abstraction model for the Opus Decoder Library.
Description
This Opus Library is an Open Source/Free Software patent-free audio compression format designed for interactive speech and music transmission
over the Internet. The MPLAB Harmony framework provides an abstraction layer to easily interact with this library. Refer to the
universal_audio_decoders demonstration for reference.
Abstraction Model Diagram
Library Overview
The Library Interface routines are divided into various sub-sections, each of which addresses one of the blocks or the overall operation of the Opus
Decoder Library module.
How the Library Works
This section describes how to work with the MPLAB Harmony Opus abstraction layer interface, which provides simplifier APIs for using the Opus
Decoder Library.
Description
For complete documentation and how to implement Opus, visit https://www.opus-codec.org.
Code Example
The following code provides an example for initializing the Opus Decoder and decoding a packet.
void DECODER_Initialize(decoder_type){
switch(decoder_type){
case OPUS:
APP_ERROR_MSG ret = OPUS_Initialize(appDataPtr->fileHandle);
if(ret == APP_SUCCESS)
{
// setup other components,
// for example, audio CODEC, display, etc...
}
}
}
void App_Task()
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Library Interface
{
while(1){
while(audio is not end){
// Read one Opus packet
appData.nBytesRead = OPUS_DiskRead(input_ptr);
// Decode one packet
ret = OPUS_Decoder (input_ptr,inSize,read,output,written,outBufSize);
if(ret == success)
{
// continue decoding
}else{
// handle decoding errors;
}
}
// Clean up
OPUS_Cleanup();
break;
}
}
Library Interface
a) General Functions
Name
Description
OPUS_ARG_NONNULL
This is function OPUS_ARG_NONNULL.
OPUS_ARG_NONNULL
This is function OPUS_ARG_NONNULL.
opus_decoder_create
Allocates and initializes an decoder state.
opus_decoder_destroy
Frees an OpusDecoder allocated by opus_decoder_create.
opus_decoder_get_size
Gets the size of an OpusDecoder structure.
opus_encoder_create
Allocates and initializes an encoder state.
opus_encoder_destroy
Frees an OpusEncoder allocated by opus_encoder_create.
opus_encoder_get_size
Gets the size of an OpusEncoder structure.
isOPUSdecoder_enabled
Checks if Opus decoder is enabled by MHC configuration.
OPUS_Cleanup
Frees the memory allocated by the Opus Decoder.
OPUS_Decoder
Called once to decode one Opus packet.
OPUS_DiskRead
Called once to read one Opus packet.
OPUS_GetChannels
Returns the number of channels for this Opus audio.
OPUS_GetSamplingRate
Returns the sampling rate of Opus audio.
OPUS_Initialize
Initializes the Opus decoder and creates an Opus decoder state structure.
b) Data Types and Constants
Name
Description
OpusDecoder
Opus decoder state.
OpusEncoder
This contains the complete state of an Opus encoder. It is position independent and can be
freely copied. See opus_encoder_create,opus_encoder_init.
OPUS_H
Opus reference implementation API
OPUS_ERROR_MSG
Ogg Container Structures
opusDecDcpt
This is type opusDecDcpt.
sOggPageHdr
header of an Ogg page, full segment info included
sOpusHeader
This is type sOpusHeader.
sOpusPktDcpt
decoder data packet descriptor
sOpusStreamDcpt
info needed by the stream at run-time
DECODER_OPUS_SUPPORT_H
This is macro DECODER_OPUS_SUPPORT_H.
OPUS_INPUT_BUFFER_SIZE
MACROS
OPUS_MAX_FRAME_SIZE
120ms @ 48Khz
OPUS_OUTPUT_BUFFER_SIZE
This is macro OPUS_OUTPUT_BUFFER_SIZE.
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Library Interface
Description
This section describes the Application Programming Interface (API) functions of the Opus Decoder Library.
Refer to each section for a detailed description.
a) General Functions
OPUS_ARG_NONNULL Function
File
opus.h
C
OPUS_ARG_NONNULL(1);
Description
This is function OPUS_ARG_NONNULL.
OPUS_ARG_NONNULL Function
File
opus.h
C
OPUS_ARG_NONNULL(4);
Description
This is function OPUS_ARG_NONNULL.
opus_decoder_create Function
Allocates and initializes an decoder state.
File
opus.h
C
OPUS_EXPORT OPUS_WARN_UNUSED_RESULT OpusDecoder * opus_decoder_create(opus_int32 Fs, int channels, int *
error);
Returns
•
OpusEncoder - Opus encoder state structure.
Description
This function allocates and initializes an decoder state.
Remarks
Internally, Opus stores data at 48000 Hz, so that should be the default value for Fs. However, the decoder can efficiently decode to buffers at 8,
12, 16, and 24 kHz so if for some reason the caller cannot use data at the full sample rate, or knows the compressed data does not use the full
frequency range, it can request decoding at a reduced rate. Likewise, the decoder is capable of filling in either mono or interleaved stereo pcm
buffers, at the caller's request.
Preconditions
None.
Example
None.
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Library Interface
Parameters
Parameters
Description
Fs
Sampling rate of input signal (Hz). This must be one of 8000, 12000, 16000, 24000, or 48000.
channels
Number of channels (1 or 2) in input signal.
error
(out) OPUS_OK Success or opus_errorcodes.
Function
OPUS_EXPORT OPUS_WARN_UNUSED_RESULT
OpusDecoder *opus_decoder_create(opus_int32 Fs,
int channels, int *error)
opus_decoder_destroy Function
Frees an OpusDecoder allocated by opus_decoder_create.
File
opus.h
C
OPUS_EXPORT void opus_decoder_destroy(OpusDecoder * st);
Returns
None.
Description
This function frees an OpusDecoder allocated by opus_decoder_create.
Remarks
None.
Preconditions
None.
Example
None.
Parameters
Parameters
Description
st
State to be freed.
Function
OPUS_EXPORT void opus_decoder_destroy( OpusDecoder *st)
opus_decoder_get_size Function
Gets the size of an OpusDecoder structure.
File
opus.h
C
OPUS_EXPORT OPUS_WARN_UNUSED_RESULT int opus_decoder_get_size(int channels);
Returns
•
int - The size in bytes.
Description
This function gets the size of an OpusDecoder structure.
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Opus Decoder Library
Library Interface
Remarks
None.
Preconditions
None.
Example
None.
Parameters
Parameters
Description
channels
Number of channels. This value must be 1 or 2.
Function
OPUS_EXPORT OPUS_WARN_UNUSED_RESULT int opus_decoder_get_size(int channels)
opus_encoder_create Function
Allocates and initializes an encoder state.
File
opus.h
C
OPUS_EXPORT OPUS_WARN_UNUSED_RESULT OpusEncoder * opus_encoder_create(opus_int32 Fs, int channels, int
application, int * error);
Returns
•
OpusEncoder - Opus encoder state structure.
Description
This function allocates and initializes an encoder state. There are three coding modes:
OPUS_APPLICATION_VOIP provides the best quality at a given bit rate for voice signals. It enhances the input signal by high-pass filtering and
emphasizing formants and harmonics. Optionally, t includes in-band forward error correction to protect against packet loss. Use this mode for
typical VoIP applications. Because of the enhancement, even at high bit rates the output may sound different from the input.
OPUS_APPLICATION_AUDIO provides the best quality at a given bit rate for most non-voice signals like music. Use this mode for music and
mixed (music/voice) content, broadcast, and applications requiring less than 15 ms of coding delay.
OPUS_APPLICATION_RESTRICTED_LOWDELAY configures a low-delay mode that disables the speech-optimized mode in exchange for
slightly reduced delay. This mode can only be set on a newly initialized or freshly reset encoder because it changes the codec delay.
Remarks
Regardless of the sampling rate and the number channels selected, the Opus encoder can switch to a lower audio bandwidth or number of
channels if the bit rate selected is too low. This also means that it is safe to always use 48 kHz stereo input and let the encoder optimize the
encoding.
Preconditions
None.
Example
None.
Parameters
Parameters
Description
Fs
Sampling rate of input signal (Hz). This value must be one of 8000, 12000, 16000, 24000, or
48000.
channels
Number of channels (1 or 2) in input signal.
application
Coding mode ( OPUS_APPLICATION_VOIP/ OPUS_APPLICATION_AUDIO/
OPUS_APPLICATION_RESTRICTED_LOWDELAY).
error
opus_errorcodes of this function.
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Opus Decoder Library
Library Interface
Function
OPUS_EXPORT OPUS_WARN_UNUSED_RESULT
OpusEncoder *opus_encoder_create(opus_int32 Fs,
int channels, int application, int *error)
opus_encoder_destroy Function
Frees an OpusEncoder allocated by opus_encoder_create.
File
opus.h
C
OPUS_EXPORT void opus_encoder_destroy(OpusEncoder * st);
Returns
None.
Description
This function frees an OpusEncoder allocated by opus_encoder_create.
Remarks
None.
Preconditions
None.
Example
None.
Parameters
Parameters
Description
st
State to be freed.
Function
OPUS_EXPORT void opus_encoder_destroy( OpusEncoder *st)
opus_encoder_get_size Function
Gets the size of an OpusEncoder structure.
File
opus.h
C
OPUS_EXPORT OPUS_WARN_UNUSED_RESULT int opus_encoder_get_size(int channels);
Returns
•
int - The size in bytes.
Description
This function gets the size of an OpusEncoder structure.
Remarks
None.
Preconditions
None.
Example
None.
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Opus Decoder Library
Library Interface
Parameters
Parameters
Description
channels
Number of channels. This value must be 1 or 2.
Function
OPUS_EXPORT OPUS_WARN_UNUSED_RESULT int opus_encoder_get_size(int channels)
isOPUSdecoder_enabled Function
Checks if Opus decoder is enabled by MHC configuration.
File
opus_support.h
C
bool isOPUSdecoder_enabled();
Returns
None.
Description
The function checks if Opus decoder is enabled by MHC configuration.
Preconditions
None.
Example
bool opusEnabled = isOPUSdecoder_enabled ();
Function
bool isOPUSdecoder_enabled()
OPUS_Cleanup Function
Frees the memory allocated by the Opus Decoder.
File
opus_support.h
C
void OPUS_Cleanup();
Returns
None.
Description
This function frees the memory that was allocated by the Opus Decoder and is called when the Opus Decoder ends.
Preconditions
None.
Example
OPUS_Cleanup();
Function
void OPUS_Cleanup()
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Opus Decoder Library
Library Interface
OPUS_Decoder Function
Called once to decode one Opus packet.
File
opus_support.h
C
OPUS_ERROR_MSG OPUS_Decoder(const uint8_t * input, uint16_t inSize, uint16_t * read, int16_t * output,
uint16_t * written, uint16_t outSize);
Returns
The status code of this function.
Description
This function is called once to decode one packet, this function will be called in an infinite while loop until the end of the packet is detected or the
decode function returns failure value.
Preconditions
None.
Example
OPUS_ERROR_MSG ret = OPUS_Decoder(input, inSize, read, output, written, outSize);
Parameters
Parameters
Description
*input
The pointer to the input buffer, where the encoded bit stream is available
inSize
A variable of data type uint16_t indicating the number of valid bytes available in the input
buffer
*read
The pointer to a variable is passed to the function. After decoding the packet the function
writes the number of bytes consumed from the current frame decoder operation
*output
The pointer to the output sample buffer where the decided PCM samples are to be written
*written
The pointer to a variable is passed to the function. After decoding the frame the function
writes the number of valid bytes available in the output buffer
outSize
A variable that indicates the size of output buffer, used for avoiding buffer overwritten.
Function
OPUS_ERROR_MSG OPUS_Decoder(const uint8_t *input, uint16_t inSize, uint16_t *read,
int16_t *output, uint16_t *written, uint16_t outSize)
OPUS_DiskRead Function
Called once to read one Opus packet.
File
opus_support.h
C
int32_t OPUS_DiskRead(uint8_t * inBuff);
Returns
This function returns the size of this Opus packet.
Description
This function is called once to read one Opus packet.
Preconditions
None.
Example
int32_t bytesRead = OPUS_DiskRead(inputBuffer);
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Library Interface
Parameters
Parameters
Description
*inBuff
The pointer to the input buffer, where the Opus encoded data are to be written.
Function
int32_t
OPUS_DiskRead(uint8_t *inBuff)
OPUS_GetChannels Function
Returns the number of channels for this Opus audio.
File
opus_support.h
C
uint8_t OPUS_GetChannels();
Returns
•
-1 - 1 channel, mono mode
•
-2 - 2 channels, stereo mode
Description
This function returns the number of channels for this Opus audio.
Preconditions
None.
Example
uint8_t channelNumber = OPUS_GetChannels();
Function
uint8_t
OPUS_GetChannels()
OPUS_GetSamplingRate Function
Returns the sampling rate of Opus audio.
File
opus_support.h
C
int32_t OPUS_GetSamplingRate();
Returns
The sampling rate of Opus audio.
Description
This function returns the sampling rate of this Opus file, return value is always 48000, Opus playback sample rate should be 48000 as described in
the OggOpus spec.
Preconditions
None.
Example
int32_t sampleRate = OPUS_GetSamplingRate();
Function
int32_t
OPUS_GetSamplingRate()
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Opus Decoder Library
Library Interface
OPUS_Initialize Function
Initializes the Opus decoder and creates an Opus decoder state structure.
File
opus_support.h
C
OPUS_ERROR_MSG OPUS_Initialize(const SYS_FS_HANDLE opus_file_handler);
Returns
The status code of this function.
Description
This function initializes the Opus decoder and creates an Opus decoder state structure.
Preconditions
None.
Example
OPUS_ERROR_MSG ret = OPUS_Initialize(fileHandler);
Parameters
Parameters
Description
opus_file_handler
The file handler of current Opus file which will be decoded.
Function
OPUS_ERROR_MSG OPUS_Initialize(const SYS_FS_HANDLE opus_file_handler)
b) Data Types and Constants
OpusDecoder Type
Opus decoder state.
File
opus.h
C
typedef struct OpusDecoder OpusDecoder;
Description
Opus decoder state.
This structure contains the complete state of an Opus decoder. It is position independent and can be freely copied. See
opus_decoder_create,opus_decoder_init.
Remarks
None.
OpusEncoder Type
This contains the complete state of an Opus encoder. It is position independent and can be freely copied. See
opus_encoder_create,opus_encoder_init.
File
opus.h
C
typedef struct OpusEncoder OpusEncoder;
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Library Interface
Description
Opus encoder state
This contains the complete state of an Opus encoder. It is position independent and can be freely copied. See
opus_encoder_create,opus_encoder_init.
Remarks
None.
OPUS_H Macro
Opus reference implementation API
File
opus.h
C
#define OPUS_H
File Name
opus.h
OPUS_ERROR_MSG Enumeration
File
opus_support.h
C
typedef enum {
OPUS_SUCCESS = 1,
OPUS_READ_ERROR,
OPUS_STREAM_ERROR,
OPUS_BUFF_ERROR,
OPUS_STREAM_END,
OPUS_PLAYBACK_ERROR,
OPUS_OUT_OF_MEM_ERROR,
OPUS_DISK_ERROR,
OPUS_GENERAL_ERROR
} OPUS_ERROR_MSG;
Description
Ogg Container Structures
opusDecDcpt Structure
File
opus_support.h
C
typedef struct {
int processedPktNo;
int currPktNo;
int nInBytes;
} opusDecDcpt;
Members
Members
Description
int processedPktNo;
counter of processed packets
int currPktNo;
number of the currently received packet from the stream
int nInBytes;
bytes available in the input buffer
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Library Interface
Description
This is type opusDecDcpt.
sOggPageHdr Structure
File
opus_support.h
C
typedef struct {
int32_t pageCapture;
int8_t struct_ver;
int8_t headerFlags;
int64_t granulePos;
int32_t streamNo;
int32_t pageNo;
int32_t pageCrc;
uint8_t pageSegments;
uint8_t segmentTbl[255];
} sOggPageHdr;
Members
Members
Description
int32_t pageCapture;
should be OGG_ID_MAGIC
int8_t struct_ver;
version of the Ogg file format. Should be 0 (RFC3533)
int8_t headerFlags;
an eOggHeaderFlags value
int64_t granulePos;
stream dependent position info
int32_t streamNo;
logical bit stream identifier
int32_t pageNo;
page sequence number
int32_t pageCrc;
CRC32 checksum of the page
uint8_t pageSegments;
number of page segments to follow
uint8_t segmentTbl[255];
actually segmentTbl[pageSegments]; contains the lace values for all segments in the page
Description
header of an Ogg page, full segment info included
sOpusHeader Structure
File
opus_support.h
C
typedef struct {
char signature[8];
uint8_t version;
uint8_t channels;
uint16_t preskip;
uint32_t input_sample_rate;
uint16_t gain;
uint8_t channel_mapping;
int8_t nb_streams;
int8_t nb_coupled;
unsigned char stream_map[255];
} sOpusHeader;
Members
Members
Description
char signature[8];
Magic signature: "OpusHead
uint8_t version;
Version number: 0x01 for this spec
uint8_t channels;
Number of channels: 1..255
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Library Interface
uint16_t preskip;
This is the number of samples (at 48kHz) to discard from the decoder output when starting
playback
uint32_t input_sample_rate;
Original input sample rate in Hz, this is not the sample rate to use for playback of the encoded
data
uint16_t gain;
output gain in dB
uint8_t channel_mapping;
This byte indicates the order and semantic meaning of various channels encoded in each
Opus packet The rest is only used if channel_mapping != 0
int8_t nb_streams;
This field indicates the total number of streams so the decoder can correctly parse the packed
Opus packets inside the Ogg packet
int8_t nb_coupled;
Describes the number of streams whose decoders should be configured to produce two
channels
Description
This is type sOpusHeader.
sOpusPktDcpt Structure
File
opus_support.h
C
typedef struct {
int pktBytes;
int pktSeqNo;
} sOpusPktDcpt;
Members
Members
Description
int pktBytes;
how many bytes in this packet
int pktSeqNo;
packet sequence number
Description
decoder data packet descriptor
sOpusStreamDcpt Structure
File
opus_support.h
C
typedef struct {
sOggPageHdr pageHdr;
int segIx;
int pktIx;
int prevBytes;
} sOpusStreamDcpt;
Members
Members
Description
sOggPageHdr pageHdr;
current page header
int segIx;
current packet segment index in the current page
int pktIx;
current packet index, 0 -> ...
int prevBytes;
previous value of the bytes in the encoded output buffer
Description
info needed by the stream at run-time
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Files
DECODER_OPUS_SUPPORT_H Macro
File
opus_support.h
C
#define DECODER_OPUS_SUPPORT_H
Description
This is macro DECODER_OPUS_SUPPORT_H.
OPUS_INPUT_BUFFER_SIZE Macro
File
opus_support.h
C
#define OPUS_INPUT_BUFFER_SIZE (1024*2)
Description
MACROS
OPUS_MAX_FRAME_SIZE Macro
File
opus_support.h
C
#define OPUS_MAX_FRAME_SIZE (960*6) // 120ms @ 48Khz
Description
120ms @ 48Khz
OPUS_OUTPUT_BUFFER_SIZE Macro
File
opus_support.h
C
#define OPUS_OUTPUT_BUFFER_SIZE (1024*7)
Description
This is macro OPUS_OUTPUT_BUFFER_SIZE.
Files
Files
Name
Description
opus.h
Opus reference implementation API.
opus_support.h
This is file opus_support.h.
Description
This section lists the source and header files used by the Opus Decoder Library.
opus.h
Opus reference implementation API.
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Files
Functions
Name
Description
OPUS_ARG_NONNULL
This is function OPUS_ARG_NONNULL.
OPUS_ARG_NONNULL
This is function OPUS_ARG_NONNULL.
opus_decoder_create
Allocates and initializes an decoder state.
opus_decoder_destroy
Frees an OpusDecoder allocated by opus_decoder_create.
opus_decoder_get_size
Gets the size of an OpusDecoder structure.
opus_encoder_create
Allocates and initializes an encoder state.
opus_encoder_destroy
Frees an OpusEncoder allocated by opus_encoder_create.
opus_encoder_get_size
Gets the size of an OpusEncoder structure.
Name
Description
OPUS_H
Opus reference implementation API
Name
Description
OpusDecoder
Opus decoder state.
OpusEncoder
This contains the complete state of an Opus encoder. It is position independent and can be
freely copied. See opus_encoder_create,opus_encoder_init.
Macros
Types
Description
Opus codec Library
Opus reference implementation API.
File Name
opus.h
Company
Microchip Technology Inc.
opus_support.h
Enumerations
Name
Description
OPUS_ERROR_MSG
Ogg Container Structures
Name
Description
isOPUSdecoder_enabled
Checks if Opus decoder is enabled by MHC configuration.
OPUS_Cleanup
Frees the memory allocated by the Opus Decoder.
OPUS_Decoder
Called once to decode one Opus packet.
OPUS_DiskRead
Called once to read one Opus packet.
OPUS_GetChannels
Returns the number of channels for this Opus audio.
OPUS_GetSamplingRate
Returns the sampling rate of Opus audio.
OPUS_Initialize
Initializes the Opus decoder and creates an Opus decoder state structure.
Name
Description
DECODER_OPUS_SUPPORT_H
This is macro DECODER_OPUS_SUPPORT_H.
OPUS_INPUT_BUFFER_SIZE
MACROS
OPUS_MAX_FRAME_SIZE
120ms @ 48Khz
OPUS_OUTPUT_BUFFER_SIZE
This is macro OPUS_OUTPUT_BUFFER_SIZE.
Functions
Macros
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Files
Structures
Name
Description
opusDecDcpt
This is type opusDecDcpt.
sOggPageHdr
header of an Ogg page, full segment info included
sOpusHeader
This is type sOpusHeader.
sOpusPktDcpt
decoder data packet descriptor
sOpusStreamDcpt
info needed by the stream at run-time
Description
This is file opus_support.h.
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Speex Decoder Library
Using the Library
Speex Decoder Library
This section describes the Speex Decoder Library.
Introduction
Introduces the Speex Decoder Library.
Description
Speex is a Code Excited Linear Prediction (CELP) based open source patent-free audio compression format designed for speech.
Speex Features
•
Fixed-point implementation
•
Narrowband (8 kHz) and wideband (16 kHz) bit-streams
•
Wide range of bit-rates available (from 2.15 kbps to 44 kbps)
•
Perceptual enhancement (attempts to reduce the perception of the noise/distortion produced by the encoding/decoding process. In most cases,
perceptual enhancement brings the sound further from the original objectively (e.g. considering only SNR), but in the end it still sounds better
(subjective improvement)
Visit www.speex.org for further details and complete documentation
Typical Applications
•
Answering machines; Voice recorders
•
Building and home safety systems; Intercoms
•
Smart appliances
•
Walkie-talkies; Toys and robots
•
Any application using message playback
Resources
Feature
Option
Usage
Speex Library Flash Size
Release Build
< 60 KB
Debug Build
< 92 KB
Dynamic
4 KB
Stack
2 KB
Narrow Mode
280 KB/sec
Speex Decoder RAM
Speex Decoding Performance
Using the Library
This topic describes the basic architecture of the Speex Decoder Library and provides information and examples on its use.
Description
Interface Header File: speex.h
The interface to the Speex Decoder Library is defined in the speex.h header file. Any C language source (.c) file that uses the Speex Decoder
Library should include speex.h.
Please refer to the What is MPLAB Harmony? section for how the Speex Decoder Library interacts with the framework.
Abstraction Model
Describes the abstraction model for the Speex Decoder Library.
Description
This Speex Library is an Open Source/Free Software patent-free audio compression format designed for speech. The MPLAB Harmony framework
provides an abstraction layer to easily interact with this library. Refer to the universal_audio_decoders demonstration for reference.
Abstraction Model Diagram
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Speex Decoder Library
Using the Library
Library Overview
The Library Interface routines are divided into various sub-sections, each of which addresses one of the blocks or the overall operation of the
Speex Decoder Library module.
How the Library Works
This section describes how to work with the MPLAB Harmony Speex abstraction layer interface, which provides simplifier APIs for using the Speex
Decoder Library.
Description
For complete documentation and how to implement Speex, visit www.speex.org.
Code Example
The following code provides an example for initializing the Speex Decoder Library and reading and decoding one Speex packet.
void Decoder_Initialize(decoder_type){
switch (decoder_type){
case SPEEX:
ret = SPEEX_Initialize();
if(ret == success)
{
// start decoding
}
}
}
void App_Task()
{
while(1){
while(audio is not end){
// Read one Speex packet
appData.nBytesRead = SPEEX_DiskRead(input_ptr);
// Decode one packet
ret = SPEEX_Decoder (input_ptr,inSize,read,output,written);
if(ret == success)
{
// continue decoding
}else{
// handle decoding errors;
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Speex Decoder Library
Library Interface
}
}
// Clean up
SPEEX_Cleanup();
}
}
Library Interface
a) General Functions
Name
Description
isSPEEXdecoder_enabled
Indicates whether the Speex Decoder is enabled.
SPEEX_Cleanup
Frees the memory allocated by the Speex Decoder.
SPEEX_Decoder
Called once to decode one packet.
SPEEX_DiskRead
Reads one packet of Ogg-Speex audio.
SPEEX_GetBitrate
Returns the bit rate of Ogg-Speex audio.
SPEEX_GetSamplingRate
Returns the sampling rate of Ogg-Speex audio.
SPEEX_Initialize
Reads the Speex header page and initializes the Speex Decoder state.
b) Data Types and Constants
Name
Description
eSpxFlags
Speex flags
pProgressFnc
progress display function
progressDcpt
encoder/decoder progress activity descriptor
sOggPageSegHdr
header of an Ogg page, full segment info included
SPEEX_ERROR_MSG
This is type SPEEX_ERROR_MSG.
spxCdcDcpt
Speex codec descriptor common part of encoder/decoder since we don't take the trouble to
have a type to distinguish between descriptors, we need to have a common part
spxDecDcpt
This is type spxDecDcpt.
sSpeexHeader
the Speex header, the first page in the Speex stream
sSpxPktDcpt
decoder data packet descriptor
sSpxRunDcpt
run-time Speex descriptor obtained from the stream with AudioStreamGetRunInfo()
sSpxStreamDcpt
info needed by the stream at run-time
OGG_ID_SPEEX
The Speex packet ID
SPEEX_INPUT_BUFFER_SIZE
This is macro SPEEX_INPUT_BUFFER_SIZE.
SPEEX_OUTPUT_BUFFER_SIZE This is macro SPEEX_OUTPUT_BUFFER_SIZE.
SPEEX_STRING_LENGTH
The size of the Speex string
SPEEX_SUPPORT_H
This is macro SPEEX_SUPPORT_H.
SPEEX_VENDOR_STR
comment in Ogg header
SPEEX_VERSION
The Speex version string
SPEEX_VERSION_ID
Version identifier
SPEEX_VERSION_LENGTH
The size of the Speex version string
SPX_CODEC_BUFF_DIV
20% is sufficient
SPX_CODEC_BUFF_MUL
Values to adjust the average decoder buffer size
Description
This section describes the Application Programming Interface (API) functions of the Speex Decoder Library.
Refer to each section for a detailed description.
a) General Functions
isSPEEXdecoder_enabled Function
Indicates whether the Speex Decoder is enabled.
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Library Interface
File
speex.h
C
bool isSPEEXdecoder_enabled();
Returns
This function returns a Boolean value.
•
true - Indicates that the Speex Decoder is enabled
•
false - Indicates that the Speex Decoder is disabled
Description
This function indicates whether the Speex Decoder is enabled.
Preconditions
None.
Example
appData.SPEEX_decoder_enabled
= isSPEEXdecoder_enabled();
Function
bool isSPEEXdecoder_enabled()
SPEEX_Cleanup Function
Frees the memory allocated by the Speex Decoder.
File
speex.h
C
void SPEEX_Cleanup();
Returns
None.
Description
This function frees the memory that was allocated by the Speex Decoder and is called when the Speex Decoder ends.
Preconditions
None.
Example
SPEEX_Cleanup();
Function
void SPEEX_Cleanup()
SPEEX_Decoder Function
Called once to decode one packet.
File
speex.h
C
SPEEX_ERROR_MSG SPEEX_Decoder(uint8_t * input, uint16_t inSize, uint16_t * read, int16_t * output, uint16_t
* written);
Returns
This function returns an enum value.
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•
SPEEX_SUCCESS - Indicates success
•
SPEEX_READ_ERROR - Indicates read failure
•
SPEEX_STREAM_ERROR - Indicates Ogg-Speex parsing error
•
SPEEX_STREAM_END - Indicates end of the stream
Library Interface
Description
This function is called once to decode one frame. This function will be called in an infinite while loop until the end of the frame is detected or the
decode function returns failure value.
Preconditions
None.
Example
res = SPEEX_Decoder (input,inSize,read,output,written);
Parameters
Parameters
Description
*input
The pointer to the input buffer , where the encoded bit stream is available
inSize
A variable of data type uint16_t indicating the number of valid bytes available in the input
buffer
*read
The pointer to a variable is passed to the function. After decoding the frame the function
writes the number of bytes consumed from the current frame decoder operation.
*output
The pointer to the output sample buffer where the decided PCM samples are to be written,
*written
The pointer to a variable is passed to the function. After decoding the frame the function
writes the number of valid bytes available in the output buffer.
Function
SPEEX_ERROR_MSG SPEEX_Decoder(uint8_t *input, uint16_t inSize, uint16_t *read,
int16_t *output, uint16_t *written);
SPEEX_DiskRead Function
Reads one packet of Ogg-Speex audio.
File
speex.h
C
int32_t SPEEX_DiskRead(uint8_t * inBuff);
Returns
This function returns the size of reading bytes.
Description
This function is called once to read one packet.
Preconditions
None.
Example
appData.nBytesRead = SPEEX_DiskRead(ptr);
Parameters
Parameters
Description
*inBuff
The pointer to the input buffer, where one packet data is to to be written
Function
int32_t SPEEX_DiskRead(uint8_t *inBuff)
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Library Interface
SPEEX_GetBitrate Function
Returns the bit rate of Ogg-Speex audio.
File
speex.h
C
int32_t SPEEX_GetBitrate();
Returns
This function returns the bit rate.
Description
This function returns the bit rate rate of Ogg-Speex audio.
Preconditions
This function can only be called after the SPEEX_Initialize function.
Example
decoderBitrate = SPEEX_GetBitrate()/1000;
Function
int32_t SPEEX_GetBitrate()
SPEEX_GetSamplingRate Function
Returns the sampling rate of Ogg-Speex audio.
File
speex.h
C
int32_t SPEEX_GetSamplingRate();
Returns
This function returns the sampling rate.
Description
This function returns the sampling rate of Ogg-Speex audio.
Preconditions
This function can only be called after the SPEEX_Initialize function.
Example
sampling_frequency = SPEEX_GetSamplingRate();
Function
int32_t SPEEX_GetSamplingRate()
SPEEX_Initialize Function
Reads the Speex header page and initializes the Speex Decoder state.
File
speex.h
C
SPEEX_ERROR_MSG SPEEX_Initialize(uintptr_t spx_file_handle);
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Library Interface
Returns
This function returns an enum value.
•
SPEEX_SUCCESS - Indicates success
•
SPEEX_READ_ERROR - Indicates read failure
•
SPEEX_STREAM_ERROR - Indicates Ogg-Speex parsing error
•
SPEEX_STREAM_END - Indicates end of the stream
Description
The function internally calls the Speex Codec Decoder initialization function. The function is called only once before initiating the decoding process.
Preconditions
Call SPEEX_Cleanup function before this function for safety.
Example
SPEEX_Cleanup();
APP_ERROR_MSG res = SPEEX_Initialize();
Function
SPEEX_ERROR_MSG SPEEX_Initialize();
b) Data Types and Constants
eSpxFlags Enumeration
File
speex.h
C
typedef enum {
SPX_FLAG_WB = 0x1,
SPX_FLAG_VBR = 0x2,
SPX_FLAG_BRATE_OVR = 0x4,
SPX_FLAG_PRCPT_ENH = 0x8
} eSpxFlags;
Members
Members
Description
SPX_FLAG_WB = 0x1
wide/narrow band
SPX_FLAG_VBR = 0x2
VBR
SPX_FLAG_BRATE_OVR = 0x4
bit rate setting overrides the encoder quality
SPX_FLAG_PRCPT_ENH = 0x8
decoder perceptual enhancement on/off
Description
Speex flags
Remarks
at most 8 flags are supported right now!
pProgressFnc Type
File
speex.h
C
typedef void (* pProgressFnc)(int nBytes);
Description
progress display function
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Library Interface
progressDcpt Structure
File
speex.h
C
typedef struct {
int progressStep;
int progressCnt;
pProgressFnc progressFnc;
} progressDcpt;
Members
Members
Description
int progressStep;
no of bytes to process before calling the progress callback
int progressCnt;
current counter
pProgressFnc progressFnc;
progress callback
Description
encoder/decoder progress activity descriptor
sOggPageSegHdr Structure
File
speex.h
C
typedef struct {
int32_t pageCapture;
int8_t struct_ver;
int8_t headerFlags;
int64_t granulePos;
int32_t streamNo;
int32_t pageNo;
int32_t pageCrc;
int8_t pageSegments;
uint8_t segmentTbl[255];
} sOggPageSegHdr;
Members
Members
Description
int32_t pageCapture;
should be OGG_ID_MAGIC
int8_t struct_ver;
version of the Ogg file format. Should be 0 (RFC3533)
int8_t headerFlags;
an eOggHeaderFlags value
int64_t granulePos;
stream dependent position info
int32_t streamNo;
logical bit stream identifier
int32_t pageNo;
page sequence number
int32_t pageCrc;
CRC32 checksum of the page
int8_t pageSegments;
number of page segments to follow
uint8_t segmentTbl[255];
actually segmentTbl[pageSegments]; contains the lace values for all segments in the page
Description
header of an Ogg page, full segment info included
SPEEX_ERROR_MSG Enumeration
File
speex.h
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Library Interface
C
typedef enum {
SPEEX_SUCCESS = 1,
SPEEX_READ_ERROR,
SPEEX_STREAM_ERROR,
SPEEX_BUFF_ERROR,
SPEEX_STREAM_END,
SPEEX_PLAYBACK_ERROR,
SPEEX_OUT_OF_MEM_ERROR,
SPEEX_DISK_ERROR,
SPEEX_GENERAL_ERROR
} SPEEX_ERROR_MSG;
Description
This is type SPEEX_ERROR_MSG.
spxCdcDcpt Structure
File
speex.h
C
typedef struct {
SpeexBits spxBits;
void* spxState;
int inBuffSize;
int outBuffSize;
int nOutBytes;
} spxCdcDcpt;
Members
Members
Description
SpeexBits spxBits;
codec control structure
void* spxState;
codec state
int inBuffSize;
input buffer size
int nOutBytes;
bytes available in the output buffer
Description
Speex codec descriptor common part of encoder/decoder since we don't take the trouble to have a type to distinguish between descriptors, we
need to have a common part
spxDecDcpt Structure
File
speex.h
C
typedef struct {
spxCdcDcpt cdc;
int framesPerPacket;
int frameSize;
int processedPktNo;
int currPktNo;
int nInBytes;
int outFrameSize;
} spxDecDcpt;
Members
Members
Description
spxCdcDcpt cdc;
common part
int framesPerPacket;
frames per Ogg packet
int frameSize;
size of the frames
int processedPktNo;
counter of processed packets
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int currPktNo;
number of the currently received packet from the stream
int nInBytes;
bytes available in the input buffer
Library Interface
Description
This is type spxDecDcpt.
sSpeexHeader Structure
File
speex.h
C
typedef struct {
char speexString[SPEEX_STRING_LENGTH];
char speexVer[SPEEX_VERSION_LENGTH];
int32_t speexVerId;
int32_t headerSize;
int32_t sampleRate;
int32_t wBand;
int32_t modeBitsStreamVer;
int32_t nChannels;
int32_t bitRate;
int32_t frameSamples;
int32_t vbr;
int32_t framesPerPacket;
int32_t extraHeaders;
int32_t reserved1;
int32_t reserved2;
} sSpeexHeader;
Members
Members
Description
char speexString[SPEEX_STRING_LENGTH];
identify the Speex bit-stream: OGG_ID_SPEEX
char speexVer[SPEEX_VERSION_LENGTH];
Speex version that encoded the file
int32_t speexVerId;
Speex version (for checking compatibility)
int32_t headerSize;
sizeof(SpeexHeader)
int32_t sampleRate;
Sampling rate used
int32_t wBand;
0 for narrowband, 1 for wideband
int32_t modeBitsStreamVer;
Version ID of the bit-stream
int32_t nChannels;
Number of channels encoded
int32_t bitRate;
Bit-rate used
int32_t frameSamples;
Size of frames, samples
int32_t vbr;
1 for a VBR encoding, 0 otherwise
int32_t framesPerPacket;
Number of frames stored per Ogg packet
int32_t extraHeaders;
Number of additional headers after the comments
int32_t reserved1;
Reserved for future use, 0
int32_t reserved2;
Reserved for future use, 0
Description
the Speex header, the first page in the Speex stream
sSpxPktDcpt Structure
File
speex.h
C
typedef struct {
int pktBytes;
int pktSeqNo;
} sSpxPktDcpt;
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Library Interface
Members
Members
Description
int pktBytes;
how many bytes in this packet
int pktSeqNo;
packet sequence number
Description
decoder data packet descriptor
sSpxRunDcpt Structure
File
speex.h
C
typedef struct {
int streamNo;
int streamVer;
unsigned short frameSamples;
unsigned short bitRate;
unsigned char framesPerPacket;
unsigned char packetsPerPage;
unsigned char complexity;
unsigned char qualFactor;
char spxFlags;
char reserved[3];
} sSpxRunDcpt;
Members
Members
Description
int streamNo;
stream number inside the container
int streamVer;
stream version
unsigned short frameSamples;
Size of frames, in samples
unsigned short bitRate;
encoder bit rate
unsigned char framesPerPacket;
Number of frames stored per Ogg packet, <10
unsigned char packetsPerPage;
number of packets in an Ogg page <= 255
unsigned char complexity;
encoder complexity 1-10
unsigned char qualFactor;
encoder quality factor 1-10
char spxFlags;
eSpxFlags: run time flags, wideband, VBR
char reserved[3];
future expansion/padding
Description
run-time Speex descriptor obtained from the stream with AudioStreamGetRunInfo()
sSpxStreamDcpt Structure
File
speex.h
C
typedef struct {
sSpxRunDcpt runDcpt;
sOggPageSegHdr pageHdr;
int segIx;
int pktIx;
int prevBytes;
} sSpxStreamDcpt;
Members
Members
Description
sSpxRunDcpt runDcpt;
global info
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sOggPageSegHdr pageHdr;
current page header
int segIx;
current packet segment index in the current page
int pktIx;
current packet index, 0 -> ...
int prevBytes;
previous value of the bytes in the encoded output buffer
Library Interface
Description
info needed by the stream at run-time
OGG_ID_SPEEX Macro
File
speex.h
C
#define OGG_ID_SPEEX "Speex
"
// The Speex packet ID
Description
The Speex packet ID
SPEEX_INPUT_BUFFER_SIZE Macro
File
speex.h
C
#define SPEEX_INPUT_BUFFER_SIZE 1024
Description
This is macro SPEEX_INPUT_BUFFER_SIZE.
SPEEX_OUTPUT_BUFFER_SIZE Macro
File
speex.h
C
#define SPEEX_OUTPUT_BUFFER_SIZE 1024*7
Description
This is macro SPEEX_OUTPUT_BUFFER_SIZE.
SPEEX_STRING_LENGTH Macro
File
speex.h
C
#define SPEEX_STRING_LENGTH 8
// The size of the Speex string
Description
The size of the Speex string
SPEEX_SUPPORT_H Macro
File
speex.h
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Speex Decoder Library
Library Interface
C
#define SPEEX_SUPPORT_H
Description
This is macro SPEEX_SUPPORT_H.
SPEEX_VENDOR_STR Macro
File
speex.h
C
#define SPEEX_VENDOR_STR "Encoded by Microchip Audio Library ver 1.0"
// comment in Ogg header
Description
comment in Ogg header
SPEEX_VERSION Macro
File
speex.h
C
#define SPEEX_VERSION "speex-1.2beta3"
// The Speex version string
Description
The Speex version string
SPEEX_VERSION_ID Macro
File
speex.h
C
#define SPEEX_VERSION_ID 1
// Version identifier
Description
Version identifier
SPEEX_VERSION_LENGTH Macro
File
speex.h
C
#define SPEEX_VERSION_LENGTH 20
// The size of the Speex version string
Description
The size of the Speex version string
SPX_CODEC_BUFF_DIV Macro
File
speex.h
C
#define SPX_CODEC_BUFF_DIV 5
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Description
20% is sufficient
SPX_CODEC_BUFF_MUL Macro
File
speex.h
C
#define SPX_CODEC_BUFF_MUL 6
// Values to adjust the average decoder buffer size
Description
Values to adjust the average decoder buffer size
Files
Files
Name
Description
speex.h
This file is an abstraction layer of the Speex Library.
Description
This section lists the source and header files used by the Speex Decoder Library.
speex.h
This file is an abstraction layer of the Speex Library.
Enumerations
Name
Description
eSpxFlags
Speex flags
SPEEX_ERROR_MSG
This is type SPEEX_ERROR_MSG.
Name
Description
isSPEEXdecoder_enabled
Indicates whether the Speex Decoder is enabled.
SPEEX_Cleanup
Frees the memory allocated by the Speex Decoder.
SPEEX_Decoder
Called once to decode one packet.
SPEEX_DiskRead
Reads one packet of Ogg-Speex audio.
SPEEX_GetBitrate
Returns the bit rate of Ogg-Speex audio.
SPEEX_GetSamplingRate
Returns the sampling rate of Ogg-Speex audio.
SPEEX_Initialize
Reads the Speex header page and initializes the Speex Decoder state.
Name
Description
OGG_ID_SPEEX
The Speex packet ID
SPEEX_INPUT_BUFFER_SIZE
This is macro SPEEX_INPUT_BUFFER_SIZE.
Functions
Macros
SPEEX_OUTPUT_BUFFER_SIZE This is macro SPEEX_OUTPUT_BUFFER_SIZE.
SPEEX_STRING_LENGTH
The size of the Speex string
SPEEX_SUPPORT_H
This is macro SPEEX_SUPPORT_H.
SPEEX_VENDOR_STR
comment in Ogg header
SPEEX_VERSION
The Speex version string
SPEEX_VERSION_ID
Version identifier
SPEEX_VERSION_LENGTH
The size of the Speex version string
SPX_CODEC_BUFF_DIV
20% is sufficient
SPX_CODEC_BUFF_MUL
Values to adjust the average decoder buffer size
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Files
Structures
Name
Description
progressDcpt
encoder/decoder progress activity descriptor
sOggPageSegHdr
header of an Ogg page, full segment info included
spxCdcDcpt
Speex codec descriptor common part of encoder/decoder since we don't take the trouble to
have a type to distinguish between descriptors, we need to have a common part
spxDecDcpt
This is type spxDecDcpt.
sSpeexHeader
the Speex header, the first page in the Speex stream
sSpxPktDcpt
decoder data packet descriptor
sSpxRunDcpt
run-time Speex descriptor obtained from the stream with AudioStreamGetRunInfo()
sSpxStreamDcpt
info needed by the stream at run-time
Name
Description
pProgressFnc
progress display function
Types
Description
Speex Decoder Library Interface Definition
This file contains the Speex Decoder-specific definitions and function prototypes.
File Name
speex.h
Company
Microchip Technology Inc.
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WMA Decoder Library
Library Interface
WMA Decoder Library
This section describes the WMA Decoder Library.
Introduction
The WMA Decoder Library is available for the PIC32 family of microcontrollers.
Description
The WMA Decoder Library is a premium product and is not included in the standard release of MPLAB Harmony and must be purchased
separately. The library is only available in binary format, and is only available to Microsoft Windows Media Component Licensees. For licensing
information, please visit: http://windows.microsoft.com/en-us/windows/windowsmedia-components-licensing. Refer to the Microchip Premium
MPLAB Harmony Audio web page (www.microchip.com/pic32harmonypremiumaudio) for additional information.
Windows Media Audio (WMA) developed by Microsoft, is a format enabling the storage of digital audio using the Lossy compression algorithm.
The Microchip WMA Decoder can decode audio signals sampled at up to 48 kHz with up to two discrete channels. The WMA Decoder also
supports VBR and CBR encoded audio stream. In most circumstances, .wma files are contained in Advance Systems Format (ASF), which is
supported by the WMA Decoder. The WMA Decoder library is optimized (C/ASM) and is available for all PIC32MX devices.
Assembly Language Issue
There is an assembly language issue in the WMA Decoder Library that misaligns the stack pointer. Contrary to the MIPS programming
specification, this error is benign except when the application is built for a device with a hardware Floating Point Unit (FPU), such as the PIC32MZ
EF family of devices. In this case, the sub-routine context-saving operations will produce an exception and stop the application. A work around
exists for this issue, which involves disabling FPU context-saving for Interrupt Service Routines (ISRs).
The work around is to convert all ISRs from:
void __ISR(vector,ipl) MyInterruptHandler(void)
and change them to:
void __attribute__((vector),interrupt(ipl),nomips16,no_fpu)) MyInterruptHandler(void)
where, vector and ipl are replaced with the actual interrupt vector and interrupt priority level.
An example of this work around can be found in the universal_audio_decoders demonstration.
So as long as no FPU operations occur in ISRs and the routines are called by ISRs, this work around will prevent the misaligned stack pointer from
causing an exception. If FPU operations result from an ISR with no_fpu enabled, a general exception will result.
Using the Library
This topic describes the basic architecture of the WMA Decoder Library and provides information and examples on its use.
Description
Interface Header File: decoder_wma.h
The interface to the WMA Decoder Library is defined in the decoder_wma.h header file. Any C language source (.c) file that uses the MP3
Decoder Library should include decoder_wma.h.
Please refer to the What is MPLAB Harmony? section for how the WMA Decoder Library interacts with the framework.
Library Overview
The Library Interface routines are divided into various sub-sections, each of which addresses one of the blocks or the overall operation of the
WMA Decoder Library module.
Library Interface
a) General Functions
Name
Description
stpnr
This is function stpnr.
WMA_Decode
This function is called once to decode one or multiple frames.
WMA_Decoder_Init
This function reads the pointers and clears the structure.
WMA_FileGetPCM
Extracts the 16-bit samples.
WMA_GetEncodeData
Retrieves encoded data from the WAVE file header.
WMA_GetStateSize
This function requires the required memory for the WMA Decoder state.
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WMA_PacketData
Extracts the encoded bitstream from the packet's payload.
WMA_PacketDatasize
This function determines the packet size for decoding.
WMA_Parser
Parses the WMA data.
WMA_Decoder
This is function WMA_Decoder.
WMA_SamplingFrequency_Get
This is function WMA_SamplingFrequency_Get.
WMA_Header_Current_Offset
This function returns the amount of data used and updates the pointer.
WMA_WaveHdr
Generates the .wav file header and fills the WavBuf array.
WMA_FileDecodeClr
Clears all of the allocated memory.
WMA_FreeMemory
This is function WMA_FreeMemory.
isWMAdecoder_enabled
This is function isWMAdecoder_enabled.
WMA_BitRate_Get
This is function WMA_BitRate_Get.
WMA_GetHeaderPacketOffset
This is function WMA_GetHeaderPacketOffset.
WMA_Initialize
This is function WMA_Initialize.
WMA_RegisterAppCallback
This is function WMA_RegisterAppCallback.
WMA_GetChannels
This is function WMA_GetChannels.
Library Interface
b) Data Types and Constants
Name
Description
SYS_DEBUG_BUFFER_DMA_READY This should be defined in system_config.h. It is added here as a build safe-guard.
WMA_DECODER_STATES
This is type WMA_DECODER_STATES.
WMA_ERROR_COUNT_MAX
This is macro WMA_ERROR_COUNT_MAX.
WMA_H
This is macro WMA_H.
Chnl_Info
This is type Chnl_Info.
WMA_Status
This is type WMA_Status.
BYTES_PER_SAMPLE
This is macro BYTES_PER_SAMPLE.
MAX_SAMPLES
in Bytes #define WAVE_HEADER_SIZE 44 //in Bytes
WMA_MAX_INPUT_BUFFER_SIZE
in Bytes
GetReadBytesInAppData
This is type GetReadBytesInAppData.
SetReadBytesReadFlagInAppData
This is type SetReadBytesReadFlagInAppData.
Description
This section describes the Application Programming Interface (API) functions of the WMA Decoder Library.
Refer to each section for a detailed description.
a) General Functions
stpnr Function
File
decoder_wma.h
C
static __inline int stpnr(int x);
Description
This is function stpnr.
WMA_Decode Function
This function is called once to decode one or multiple frames.
File
decoder_wma.h
C
int32_t WMA_Decode(void* paudec, int* pcSamplesReady, int* paudecState);
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Library Interface
Returns
This function returns the error type.
Description
This function is called once to decode one or multiple frames. This function will be called in an infinite while loop until the end-of-frame is detected
or the decode function returns an error value. Unlike most speech applications, where the encoded data for each frame is deterministic, this is not
the case in audio applications. Therefore, the application provides a chunk of input packet data (usually more than what is necessary for a single
frame). The decoder parses them and decodes with a portion of the data. The decode function passes the information of how many bytes of data
were used to the application so that the application saves the remaining data and presents to the decoder for the subsequent frame.
Remarks
None.
Preconditions
None.
Example
Int res;
res = WMA_Decode(WMA_State, &nDecodedSamples, &chnlInfo.WMAState);
Parameters
Parameters
Description
paudec
The pointer to the WMA Decoder handler
pcSamplesReady
The pointer to the number of decoded samples
paudecState
The pointer to the state of the decoder
Function
int32_t WMA_Decode (void* paudec, int* pcSamplesReady, int* paudecState);
WMA_Decoder_Init Function
This function reads the pointers and clears the structure.
File
decoder_wma.h
C
WMA_Status WMA_Decoder_Init(void* pState, Chnl_Info * chnl, char * WMADataBuf);
Returns
This function returns the error result.
Description
This function views the received pointer as structure pointer and clears the entire structure. Subsequently, it initializes the selective variables with
the default values. This function is called only once for each file before starting the decoding of an entire packet.
Preconditions
None.
Example
void *WMA_State;
Chnl_Info chnlInfo;
WMA_Status WMA_status;
char WMA_InBuf[MAX_INPUT_BUF];
WMA_Status = WMA_Decoder_Init (WMA_State, &chnlInfo, WMA_InBuf);
Parameters
Parameters
Description
pState
The pointer to the allocated state memory.
*chnl
Holds the essential audio file information and state of the file
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WMADataBuf
WMA Decoder Library
Library Interface
The pointer to the input buffer
Function
WMA_Status WMA_Decoder_Init (void* pState, Chnl_Info *chnl, char * WMADataBuf);
WMA_FileGetPCM Function
Extracts the 16-bit samples.
File
decoder_wma.h
C
uint32_t WMA_FileGetPCM(void * pInt, short * pCh, uint32_t max_nsamples);
Returns
This function returns the number of samples.
Description
This function is used to extract the 16-bit samples.
Preconditions
None.
Example
nDecodedSamples = WMA_FileGetPCM (WMA_State, WMA_OutBuf, nDecodedSamples);
Parameters
Parameters
Description
*pInt
The pointer to the WMA handler
*pCh
The pointer to the output data
max_nsamples
Total number of samples
Function
uint32_t WMA_FileGetPCM (void *pInt, short *pCh, uint32_t max_nsamples);
WMA_GetEncodeData Function
Retrieves encoded data from the WAVE file header.
File
decoder_wma.h
C
void WMA_GetEncodeData(void * fWMA, char * pData, int pDtSz);
Returns
None.
Description
The function is used to retrieve the encoded data from the WAVE file header.
Preconditions
None.
Parameters
Parameters
Description
*fWMA
The WMA file
*pData
The pointer to the data
pDtSz
The pointer to the data size
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WMA Decoder Library
Library Interface
Function
void WMA_GetEncodeData(void *fWMA, char *pData, int pDtSz);
WMA_GetStateSize Function
This function requires the required memory for the WMA Decoder state.
File
decoder_wma.h
C
uint32_t WMA_GetStateSize();
Returns
This function returns the size of the WMA Decoder state structure in bytes.
Description
Based on the return value, the application allocates the required memory for the WMA Decoder state. This function is called only once for each
channel before the channel is initialized. If dynamic memory allocation (malloc) is not needed, it is not necessary to call this function and the WMA
Decoder state buffer will be statically defined at compile time with the size of the WMA Decoder state structure (constant).
Preconditions
None.
Example
unsigned long nDecodedSamples;
nDecodedSamples = WMA_GetStateSize();
Function
uint32_t WMA_GetStateSize(void);
WMA_PacketData Function
Extracts the encoded bitstream from the packet's payload.
File
decoder_wma.h
C
int WMA_PacketData(void * p, char * InBuf, int residue);
Returns
None.
Description
This function is used to extract the encoded bitstream from the packet’s payload. This function is repeated until there are no bytes to decode.
Preconditions
None.
Example
void *WMA_State;
Chnl_Info chnlInfo;
Int res, residue;
res = WMA_PacketData(WMA_State,WMA_InBuf,residue);
Parameters
Parameters
Description
*p
The pointer to the WMA handler
InBuf
The pointer to the input buffer
residue
The pointer to the input file
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WMA Decoder Library
Library Interface
Function
int WMA_PacketData(void *p, char * InBuf, int residue);
WMA_PacketDatasize Function
This function determines the packet size for decoding.
File
decoder_wma.h
C
int32_t WMA_PacketDatasize(void * p);
Returns
This function returns the packet data size.
Description
This function determines the packet size for decoding and sends request to the main program to read the number of bytes data for decoding. This
function is called repetitively until there are no bytes to decode.
Preconditions
None.
Example
void *WMA_State;
int packetdatasize;
packetdatasize = WMA_PacketDatasize(WMA_State);
Parameters
Parameters
Description
*p
The pointer to the WMA handler
Function
int32_t WMA_PacketDatasize(void *p);
WMA_Parser Function
Parses the WMA data.
File
decoder_wma.h
C
int WMA_Parser(void * pInt);
Returns
None.
Description
This function is used to parse the WMA data.
Preconditions
None.
Parameters
Parameters
Description
*pInt
The pointer to the WMA handler
Function
int WMA_Parser(void *pInt);
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WMA Decoder Library
Library Interface
WMA_Decoder Function
File
wma.h
C
int16_t WMA_Decoder(uint8_t * input, uint16_t inSize, uint16_t * read, int16_t * output, uint16_t *
written);
Description
This is function WMA_Decoder.
WMA_SamplingFrequency_Get Function
File
wma.h
C
int32_t WMA_SamplingFrequency_Get();
Description
This is function WMA_SamplingFrequency_Get.
WMA_Header_Current_Offset Function
This function returns the amount of data used and updates the pointer.
File
decoder_wma.h
C
uint32_t WMA_Header_Current_Offset(void * pInt);
Returns
This function returns the amount of data used.
Description
This function returns the amount of data used and updates the file pointer location to read input data from the current offset after parsing the
header information. This function is called only once for each file before starting the decoding of entire packets.
Preconditions
None.
Example
Uint32_t packet_offset;
packet_offset = WMA_Header_Current_Offset(WMA_State);
Parameters
Parameters
Description
*pInt
The pointer to the WMA Handler
Function
uint32_t WMA_Header_Current_Offset(tWMAFileStateInternal *pInt)
WMA_WaveHdr Function
Generates the .wav file header and fills the WavBuf array.
File
decoder_wma.h
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Library Interface
C
void WMA_WaveHdr(char * WavHdr, void * hWMA, uint32_t DataLen);
Returns
None.
Description
For wave file generation, the application will leave 44 bytes of free space at the beginning of the file and begins writing decoded samples from the
45th byte location onwards. Once the entire data had been decoded, this function is called. The function generates the .wav file header and fills
the WavBuf array. The application copies the contents of this buffer into the reserved place available at the beginning of the file.
Preconditions
None.
Example
WMA_WaveHdr(WavBuf, WMA_State, DataLen);
Parameters
Parameters
Description
*WavHdr
The pointer to the header buffer of a WAVE file. The buffer size is 44 bytes.
*hWMA
The pointer to the WMA Handler
DataLen
Integer variable indicating the total number of samples written into the file
Function
void WMA_WaveHdr(char *WavHdr, void *hWMA, uint32_t DataLen);
WMA_FileDecodeClr Function
Clears all of the allocated memory.
File
decoder_wma.h
C
void WMA_FileDecodeClr(void* WMA_State);
Returns
None.
Description
This function is used to clear all of the allocated WMA state memory.
Preconditions
None.
Function
void WMA_FileDecodeClr(void* WMA_State);
WMA_FreeMemory Function
File
wma.h
C
void WMA_FreeMemory();
Description
This is function WMA_FreeMemory.
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Library Interface
isWMAdecoder_enabled Function
File
wma.h
C
bool isWMAdecoder_enabled();
Description
This is function isWMAdecoder_enabled.
WMA_BitRate_Get Function
File
wma.h
C
int32_t WMA_BitRate_Get();
Description
This is function WMA_BitRate_Get.
WMA_GetHeaderPacketOffset Function
File
wma.h
C
int32_t WMA_GetHeaderPacketOffset();
Description
This is function WMA_GetHeaderPacketOffset.
WMA_Initialize Function
File
wma.h
C
void WMA_Initialize(SYS_FS_HANDLE wmaFilehandle, uint32_t inputBufferSize);
Description
This is function WMA_Initialize.
WMA_RegisterAppCallback Function
File
wma.h
C
void WMA_RegisterAppCallback(SetReadBytesReadFlagInAppData fptr0, GetReadBytesInAppData fptr1);
Description
This is function WMA_RegisterAppCallback.
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Library Interface
WMA_GetChannels Function
File
wma.h
C
uint8_t WMA_GetChannels();
Description
This is function WMA_GetChannels.
b) Data Types and Constants
SYS_DEBUG_BUFFER_DMA_READY Macro
File
sys_debug.h
C
#define SYS_DEBUG_BUFFER_DMA_READY
Description
This should be defined in system_config.h. It is added here as a build safe-guard.
WMA_DECODER_STATES Enumeration
File
wma.h
C
typedef enum {
WMA_GET_FRAME_SIZE,
WMA_DECODE_FRAME
} WMA_DECODER_STATES;
Description
This is type WMA_DECODER_STATES.
WMA_ERROR_COUNT_MAX Macro
File
wma.h
C
#define WMA_ERROR_COUNT_MAX 1
Description
This is macro WMA_ERROR_COUNT_MAX.
WMA_H Macro
File
wma.h
C
#define WMA_H
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WMA Decoder Library
Library Interface
Description
This is macro WMA_H.
Chnl_Info Structure
File
decoder_wma.h
C
typedef struct {
long SamplesPerSec;
long Channels;
long BitRate;
long Version;
long ByteUsed;
int WMAState;
long PacketSize;
} Chnl_Info;
Members
Members
Description
long SamplesPerSec;
Sampling Frequency
long Channels;
No of Channels
long BitRate;
Bit Rate
long Version;
WMA Version
long ByteUsed;
Used Input Data
int WMAState;
Input or Decode State
long PacketSize;
Size of Packet
Description
This is type Chnl_Info.
WMA_Status Enumeration
File
decoder_wma.h
C
typedef enum {
WMA_NO_ERR = 0,
WMA_NEED_DATA = 1,
WMA_ERR = 2
} WMA_Status;
Description
This is type WMA_Status.
BYTES_PER_SAMPLE Macro
File
decoder_wma.h
C
#define BYTES_PER_SAMPLE 2
Description
This is macro BYTES_PER_SAMPLE.
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Files
MAX_SAMPLES Macro
File
decoder_wma.h
C
#define MAX_SAMPLES 2048
//in Bytes
Description
in Bytes #define WAVE_HEADER_SIZE 44 //in Bytes
WMA_MAX_INPUT_BUFFER_SIZE Macro
File
decoder_wma.h
C
#define WMA_MAX_INPUT_BUFFER_SIZE 1024*20
//in Bytes
Description
in Bytes
GetReadBytesInAppData Type
File
wma.h
C
typedef int32_t (* GetReadBytesInAppData)();
Description
This is type GetReadBytesInAppData.
SetReadBytesReadFlagInAppData Type
File
wma.h
C
typedef void (* SetReadBytesReadFlagInAppData)(int32_t val, bool b);
Description
This is type SetReadBytesReadFlagInAppData.
Files
Files
Name
Description
wma.h
WMA Decoder support API.
decoder_wma.h
This file consists of the abstract function and input output buffer size declaration for decoding
purpose
Description
This section lists the source and header files used by the MP3 Decoder Library.
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WMA Decoder Library
Files
wma.h
WMA Decoder support API.
Enumerations
Name
Description
WMA_DECODER_STATES
This is type WMA_DECODER_STATES.
Name
Description
isWMAdecoder_enabled
This is function isWMAdecoder_enabled.
WMA_BitRate_Get
This is function WMA_BitRate_Get.
WMA_Decoder
This is function WMA_Decoder.
WMA_FreeMemory
This is function WMA_FreeMemory.
WMA_GetChannels
This is function WMA_GetChannels.
WMA_GetHeaderPacketOffset
This is function WMA_GetHeaderPacketOffset.
WMA_Initialize
This is function WMA_Initialize.
WMA_RegisterAppCallback
This is function WMA_RegisterAppCallback.
WMA_SamplingFrequency_Get
This is function WMA_SamplingFrequency_Get.
Name
Description
WMA_ERROR_COUNT_MAX
This is macro WMA_ERROR_COUNT_MAX.
WMA_H
This is macro WMA_H.
Name
Description
GetReadBytesInAppData
This is type GetReadBytesInAppData.
Functions
Macros
Types
SetReadBytesReadFlagInAppData This is type SetReadBytesReadFlagInAppData.
Description
MP3 Decoder Library Interface File
This header file consists of support function declarations.
File Name
wma.h
Company
Microchip Technology Inc.
decoder_wma.h
This file consists of the abstract function and input output buffer size declaration for decoding purpose
Enumerations
Name
Description
WMA_Status
This is type WMA_Status.
Name
Description
stpnr
This is function stpnr.
WMA_Decode
This function is called once to decode one or multiple frames.
WMA_Decoder_Init
This function reads the pointers and clears the structure.
WMA_FileDecodeClr
Clears all of the allocated memory.
WMA_FileGetPCM
Extracts the 16-bit samples.
WMA_GetEncodeData
Retrieves encoded data from the WAVE file header.
Functions
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WMA Decoder Library
WMA_GetStateSize
This function requires the required memory for the WMA Decoder state.
WMA_Header_Current_Offset
This function returns the amount of data used and updates the pointer.
WMA_PacketData
Extracts the encoded bitstream from the packet's payload.
WMA_PacketDatasize
This function determines the packet size for decoding.
WMA_Parser
Parses the WMA data.
WMA_WaveHdr
Generates the .wav file header and fills the WavBuf array.
Name
Description
BYTES_PER_SAMPLE
This is macro BYTES_PER_SAMPLE.
MAX_SAMPLES
in Bytes #define WAVE_HEADER_SIZE 44 //in Bytes
Files
Macros
WMA_MAX_INPUT_BUFFER_SIZE in Bytes
Structures
Name
Description
Chnl_Info
This is type Chnl_Info.
Description
WMA Decoder Library Interface File
The header file consists of function declaration for the abstract functions to invoke decoding . The header file also defines the size of input samples
and i/p and o/p buffer.
File Name
decoder_wma.h
Company
Microchip Technology Inc.
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Index
Index
ID3_H macro 28
ID3_Initialize function 19
ID3_Parse function 19
A
AAC Decoder Library 3
aac.h 12
AAC_Decode function 7
AAC_Decoder function 4
AAC_DECODER_STATES enumeration 9
AAC_ERROR_COUNT_MAX macro 10
AAC_FRAME_HEADER_SIZE macro 11
AAC_GetSamplingFrequency function 8
AAC_Initialize function 8
AAC_PROFILE macro 9
AAC_RegisterDecoderEventHandlerCallback function 8
AAC_SAMPLING_FREQUENCY_INDEX enumeration 10
AAC_WriteWavHeader function 4
AACDecoder_GetFrameSize function 5
AACDecoder_GetStateSize function 5
AACDecoder_Init function 6
AACDecoder_InterleaveSamples function 6
AACDECODER_STATE_SIZE macro 10
Abstraction Model 37, 53
ID3_Parse_Frame function 20
ID3_ParseFrameV22 function 19
ID3_ParseFrameV23 function 20
ID3_STATE enumeration 26
ID3_STRING_SIZE macro 29
ID3V1_EXTENDED_TAG structure 26
ID3V1_TAG structure 27
ID3V2_TAG_HEADER structure 27
ID3V22_ALBUM macro 29
ID3V22_ARTIST macro 29
ID3V22_FRAME structure 27
ID3V22_FRAME_HEADER structure 28
ID3V22_TITLE macro 29
ID3V22_ZERO macro 29
ID3V23_ALBUM macro 30
ID3V23_ARTIST macro 30
ID3V23_FRAME structure 28
ID3V23_FRAME_HEADER structure 28
ID3V23_TITLE macro 30
ID3V23_ZERO macro 30
B
INPUT_BUF_SIZE macro 11
BYTES_PER_SAMPLE macro 78
INTPCM type 8
Introduction 3, 14, 36, 53, 68
C
AAC Decoder Library 3
Chnl_Info structure 78
MP3 Decoder Library 14
D
Opus Decoder Library 36
Speex Decoder Library 53
Decoder Libraries Help 2
decoder_aac.h 12
decoder_mp3_advanced.h 34
decoder_mp3_microaptiv.h 34
DECODER_OPUS_SUPPORT_H macro 50
decoder_wma.h 80
WMA Decoder Library 68
isAACdecoder_enabled function 7
isMP3decoder_enabled function 19
isOPUSdecoder_enabled function 43
isSPEEXdecoder_enabled function 55
isWMAdecoder_enabled function 76
DecoderEventHandlerCB type 31
L
E
Library Interface 3, 14, 38, 55, 68
eSpxFlags enumeration 59
AAC Decoder Library 3
F
MP3 Decoder Library 14
Files 12, 32, 50, 66, 79
Opus Decoder Library 38
Speex Decoder Library 55
AAC Decoder Library 12
MP3 Decoder Library 32
WMA Decoder Library 68
Opus Decoder Library 50
Library Overview 3, 14, 37, 54, 68
Speex Decoder Library 66
AAC Decoder Library 3
WMA Decoder Library 79
MP3 Decoder Library 14
Opus Decoder Library 37
FRAME_SIZE macro 10
Speex Decoder Library 54
G
GetReadBytesInAppData type 79
WMA Decoder Library 68
M
H
MAX_SAMPLES macro 79
How the Library Works 37, 54
MAX_STACK macro 11
I
MP3 Decoder Library 14
id3.h 33
MP3_CHANNEL_INFO structure 30
ID3_EVENT enumeration 26
MP3_DEC structure 31
mp3.h 32
ID3_EventHandler function 19
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Index
MP3_Decode function 16
OpusEncoder type 46
MP3_ERROR_COUNT_MAX macro 24
P
MP3_EVENT enumeration 22
MP3_EventHandler function 16
pProgressFnc type 59
MP3_FORMAT structure 22
progressDcpt structure 60
MP3_FRAME_HEADER union 23
S
MP3_GetAudioSize function 21
MP3_GetChannels function 22
MP3_HEADER_CHANNELS_DUAL macro 24
MP3_HEADER_CHANNELS_JOINT macro 24
MP3_HEADER_CHANNELS_MONO macro 24
MP3_HEADER_CHANNELS_STEREO macro 24
MP3_HEADER_SAMPLERATE_32000 macro 25
MP3_HEADER_SAMPLERATE_44100 macro 25
MP3_HEADER_SAMPLERATE_48000 macro 25
MP3_HEADER_SAMPLERATE_RESV macro 25
MP3_Initialize function 21
MP3_ParseVBR function 18
MP3_PLAYTIME_H macro 25
MP3_RegisterDecoderEventHandlerCallback function 21
MP3_STATE enumeration 23
MP3_STATE_SIZE macro 22
MP3_UpdatePlaytime function 21
MP3_XING_HEADER structure 23
MP3_XING_HEADER_START_MONO macro 26
MP3_XING_HEADER_START_STEREO macro 26
MP3Decode function 17, 20
MP3DecoderGetStateSize function 17
MP3DecoderInit function 18
MP3Initialize function 16
MP3MPEG1L3_SAMPLES_PER_FRAME macro 31
MP3MPEG2L3_SAMPLES_PER_FRAME macro 31
SetReadBytesInAppData type 11
SetReadBytesReadFlagInAppData type 79
sOggPageHdr structure 48
sOggPageSegHdr structure 60
sOpusHeader structure 48
sOpusPktDcpt structure 49
sOpusStreamDcpt structure 49
Speex Decoder Library 53
speex.h 66
SPEEX_Cleanup function 56
SPEEX_Decoder function 56
SPEEX_DiskRead function 57
SPEEX_ERROR_MSG enumeration 60
SPEEX_GetBitrate function 58
SPEEX_GetSamplingRate function 58
SPEEX_Initialize function 58
SPEEX_INPUT_BUFFER_SIZE macro 64
SPEEX_OUTPUT_BUFFER_SIZE macro 64
SPEEX_STRING_LENGTH macro 64
SPEEX_SUPPORT_H macro 64
SPEEX_VENDOR_STR macro 65
SPEEX_VERSION macro 65
SPEEX_VERSION_ID macro 65
SPEEX_VERSION_LENGTH macro 65
SPX_CODEC_BUFF_DIV macro 65
SPX_CODEC_BUFF_MUL macro 66
O
spxCdcDcpt structure 61
OGG_ID_SPEEX macro 64
spxDecDcpt structure 61
Opus Decoder Library 36
sSpeexHeader structure 62
opus.h 50
sSpxPktDcpt structure 62
OPUS_ARG_NONNULL function 39
sSpxRunDcpt structure 63
OPUS_Cleanup function 43
sSpxStreamDcpt structure 63
OPUS_Decoder function 44
STACK macro 11
opus_decoder_create function 39
stpnr function 69
opus_decoder_destroy function 40
SYS_DEBUG_BUFFER_DMA_READY macro 77
opus_decoder_get_size function 40
U
OPUS_DiskRead function 44
Using the Library 3, 14, 36, 53, 68
opus_encoder_create function 41
AAC Decoder Library 3
opus_encoder_destroy function 42
MP3 Decoder Library 14
opus_encoder_get_size function 42
Opus Decoder Library 36
OPUS_ERROR_MSG enumeration 47
Speex Decoder Library 53
OPUS_GetChannels function 45
WMA Decoder Library 68
OPUS_GetSamplingRate function 45
OPUS_H macro 47
W
OPUS_Initialize function 46
WAVE structure 9
OPUS_INPUT_BUFFER_SIZE macro 50
WMA Decoder Library 68
OPUS_MAX_FRAME_SIZE macro 50
wma.h 80
OPUS_OUTPUT_BUFFER_SIZE macro 50
WMA_BitRate_Get function 76
opus_support.h 51
WMA_Decode function 69
opusDecDcpt structure 47
WMA_Decoder function 74
OpusDecoder type 46
WMA_Decoder_Init function 70
© 2013-2016 Microchip Technology Inc.
MPLAB Harmony v1.08
83
Index
WMA_DECODER_STATES enumeration 77
WMA_ERROR_COUNT_MAX macro 77
WMA_FileDecodeClr function 75
WMA_FileGetPCM function 71
WMA_FreeMemory function 75
WMA_GetChannels function 77
WMA_GetEncodeData function 71
WMA_GetHeaderPacketOffset function 76
WMA_GetStateSize function 72
WMA_H macro 77
WMA_Header_Current_Offset function 74
WMA_Initialize function 76
WMA_MAX_INPUT_BUFFER_SIZE macro 79
WMA_PacketData function 72
WMA_PacketDatasize function 73
WMA_Parser function 73
WMA_RegisterAppCallback function 76
WMA_SamplingFrequency_Get function 74
WMA_Status enumeration 78
WMA_WaveHdr function 74
© 2013-2016 Microchip Technology Inc.
MPLAB Harmony v1.08
84
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