G729Encoder Class Reference

G.729 encoder using the bcg729 library. More...

#include <CodecG729.h>

Inheritance diagram for G729Encoder:

Public Member Functions
	G729Encoder (bool is_vad_enabled=false)
AudioInfo	audioInfo () override
	provides the actual input AudioInfo
virtual AudioInfo	audioInfoOut ()
bool	begin () override
virtual bool	begin (AudioInfo info)
void	end () override
virtual uint32_t	frameDurationUs ()
	Optional rtsp function: provide the frame duration in microseconds.
virtual int	frameSize ()
const char *	mime () override
	Provides the mime type of the encoded result.
	operator bool () override
virtual uint16_t	samplesPerFrame ()
	Optional rtsp function: provide samples per the frame.
void	setAudioInfo (AudioInfo info) override
	Defines the sample rate, number of channels and bits per sample.
void	setOutput (Print &out_stream) override
	Default output assignment (encoders may override to store Print reference)
void	setVADEnabled (bool enabled)
size_t	write (const uint8_t *data, size_t len) override

Protected Member Functions
void	processByte (uint8_t byte)
void	writeBlocking (Print *out, uint8_t *data, size_t len)

Protected Attributes
size_t	buffer_pos = 0
bcg729EncoderChannelContextStruct *	encoder_ctx = nullptr
AudioInfo	info
Vector< uint8_t >	input_buffer
bool	is_active = false
Print *	p_print = nullptr
Vector< uint8_t >	result_buffer
bool	vad_enabled = false

Detailed Description

G.729 encoder using the bcg729 library.

Accepts 16-bit PCM samples at 8 000 Hz (mono) and writes compressed G.729 frames to the configured output. Frames are produced every 80 input samples (10 ms):

• Normal speech frame : 10 bytes
• SID / comfort-noise : 2 bytes (only when VAD is enabled)

VAD (Voice Activity Detection) is enabled by default; pass false to the constructor to disable it and always produce 10-byte speech frames.

Input must be exactly 8 000 Hz / mono / 16-bit PCM. Passing any other AudioInfo via setAudioInfo() logs an error and the fixed format is enforced.

Bitrate: 8 kbps (10 bytes × 8 bits/byte ÷ 0.01 s) which gives 1 kbytes/s Compression ratio: 16:1 (w/o SID frame)

Note

Requires https://github.com/pschatzmann/codec-bcg729

Author

Phil Schatzmann

Copyright

GPLv3

Constructor & Destructor Documentation

G729Encoder()

G729Encoder ( bool  is_vad_enabled = false )

inline

Member Function Documentation

audioInfo()

AudioInfo audioInfo ( )

inlineoverridevirtualinherited

provides the actual input AudioInfo

Implements AudioInfoSupport.

Reimplemented in CodecNOP, MP3EncoderShine, BinaryContainerEncoder, and MP3ParserEncoder.

audioInfoOut()

virtual AudioInfo audioInfoOut ( )

inlinevirtualinherited

provides the actual output AudioInfo: this is usually the same as audioInfo() unless we use a transforming stream

Reimplemented in MP3EncoderShine, PureDataStream, PWMAudioOutput< PWMDriverT >, ChannelFormatConverterStreamT< T >, ChannelFormatConverterStream, NumberFormatConverterStreamT< TFrom, TTo >, NumberFormatConverterStream, FormatConverterStream, Pipeline, ResampleStream, ResampleStreamT< TInterpolator >, and SupportedRatesStream.

begin() [1/2]

bool begin ( )

inlineoverridevirtual

Implements AudioWriter.

begin() [2/2]

virtual bool begin ( AudioInfo  info )

inlinevirtualinherited

Reimplemented in OpusOggEncoder, OggContainerEncoder, DecoderBasic, AudioDecoder, AACEncoderFDK, AACEncoderVO, OggContainerDecoder, and MetaDataFilterEncoder.

end()

void end ( )

inlineoverridevirtual

Implements AudioWriter.

frameDurationUs()

virtual uint32_t frameDurationUs ( )

inlinevirtualinherited

Optional rtsp function: provide the frame duration in microseconds.

Reimplemented in ADPCMEncoder, MP3EncoderShine, OpusOggEncoder, MP3ParserEncoder, and MetaDataFilterEncoder.

frameSize()

virtual int frameSize ( )

inlinevirtualinherited

Optional rtsp function: provide the encoded size (in bytes) of one frame, once known (e.g. after the encoder has seen real data). Lets an RTSPFormat size its RTP fragments to match one frame instead of a fixed guess, so throughput actually tracks frameDurationUs() - a fragment size covering several frames' worth of bytes sent at one-frame timing overruns real-time bandwidth and, over UDP (no flow control), causes packet loss. Returns 0 if not yet known/not applicable (fixed-frame-size codecs have no need to override this).

Reimplemented in ADPCMEncoder, EncoderALAC, AMRNBEncoder, AMRWBEncoder, and MP3ParserEncoder.

mime()

const char * mime ( )

inlineoverridevirtual

Provides the mime type of the encoded result.

Implements AudioEncoder.

operator bool()

operator bool ( )

inlineoverridevirtual

Implements AudioWriter.

processByte()

void processByte ( uint8_t  byte )

inlineprotected

samplesPerFrame()

virtual uint16_t samplesPerFrame ( )

inlinevirtualinherited

Optional rtsp function: provide samples per the frame.

Reimplemented in OpusAudioEncoder, OpusMultiStreamAudioEncoder, MP3EncoderShine, MP3ParserEncoder, and MetaDataFilterEncoder.

setAudioInfo()

void setAudioInfo ( AudioInfo  from )

inlineoverridevirtual

Defines the sample rate, number of channels and bits per sample.

Reimplemented from AudioEncoder.

setOutput()

void setOutput ( Print &  out_stream )

inlineoverridevirtual

Default output assignment (encoders may override to store Print reference)

Reimplemented from AudioEncoder.

setVADEnabled()

void setVADEnabled ( bool  enabled )

inline

write()

size_t write ( const uint8_t *  data, size_t  len  )

inlineoverridevirtual

Implements AudioWriter.

writeBlocking()

void writeBlocking ( Print *  out, uint8_t *  data, size_t  len  )

inlineprotectedinherited

Member Data Documentation

buffer_pos

size_t buffer_pos = 0

protected

encoder_ctx

bcg729EncoderChannelContextStruct* encoder_ctx = nullptr

protected

info

AudioInfo info

protectedinherited

input_buffer

Vector<uint8_t> input_buffer

protected

is_active

bool is_active = false

protected

p_print

Print* p_print = nullptr

protected

result_buffer

Vector<uint8_t> result_buffer

protected

vad_enabled

bool vad_enabled = false

protected

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The documentation for this class was generated from the following file:

• src/AudioTools/AudioCodecs/CodecG729.h