AACEncoderFAAC Class Reference

AAC Encoder (AAC-LC and HE-AAC v1) using faac: https://github.com/pschatzmann/codec-faac. More...

#include <CodecAACFAAC.h>

Inheritance diagram for AACEncoderFAAC:

Public Member Functions
	AACEncoderFAAC ()=default
	AACEncoderFAAC (Print &out_stream)
	~AACEncoderFAAC () override
AudioInfo	audioInfo () override
	provides the actual input AudioInfo
virtual AudioInfo	audioInfoOut ()
bool	begin () override
bool	begin (AudioInfo info) override
faac_encoder *	driver ()
	Provides access to the faac encoder handle.
faac_encoder_info &	encoderInfo ()
	Provides the information of the opened encoder.
void	end () override
	Encodes the remaining data and releases the encoder.
virtual uint32_t	frameDurationUs ()
	Optional rtsp function: provide the frame duration in microseconds.
virtual int	frameSize ()
bool	getAudioSpecificConfig (const uint8_t *&data, uint32_t &len)
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	setAdts (bool enabled)
	Defines if ADTS headers are generated (default true)
void	setAudioInfo (AudioInfo from) override
	Defines the sample rate, number of channels and bits per sample.
void	setBitrate (uint32_t bps)
void	setObjectType (faac_object_type type)
void	setOutput (Print &out_stream) override
	Defines the output stream.
void	setQuality (uint32_t quality)
void	setRateControl (faac_rate_control rc)
size_t	write (const uint8_t *data, size_t len) override

Protected Member Functions
bool	encode (const int16_t *samples, uint32_t sample_count, uint32_t *p_written=nullptr)
void	writeBlocking (Print *out, uint8_t *data, size_t len)

Static Protected Member Functions
static uint32_t	defaultBitrate (AudioInfo info)

Protected Attributes
uint32_t	bitrate = (uint32_t)-1
faac_encoder *	enc = nullptr
faac_encoder_info	enc_info
size_t	frame_samples = 0
AudioInfo	info
faac_object_type	object_type = FAAC_OBJ_LOW
Vector< uint8_t >	out_buffer {0}
Print *	p_print = nullptr
Vector< int16_t >	pcm_buffer {0}
size_t	pcm_pos = 0
uint32_t	quant_quality = 0
faac_rate_control	rate_control = FAAC_RC_AUTO
bool	use_adts = true

Detailed Description

AAC Encoder (AAC-LC and HE-AAC v1) using faac: https://github.com/pschatzmann/codec-faac.

The encoder consumes PCM in frames of 1024 (LC) or 2048 (HE-AAC) samples per channel, so this class buffers arbitrary write sizes and encodes full frames automatically. By default ADTS is generated: if you want raw AAC frames call setAdts(false) and use getAudioSpecificConfig() to get the ASC. Only 16 bit PCM input is supported.

Author

Phil Schatzmann

Copyright

GPLv3

Constructor & Destructor Documentation

AACEncoderFAAC() [1/2]

AACEncoderFAAC ( )

default

AACEncoderFAAC() [2/2]

AACEncoderFAAC ( Print &  out_stream )

inline

~AACEncoderFAAC()

~AACEncoderFAAC ( )

inlineoverride

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]

bool begin ( AudioInfo  info )

inlineoverridevirtual

Reimplemented from AudioWriter.

defaultBitrate()

static uint32_t defaultBitrate ( AudioInfo  info )

inlinestaticprotected

Scales FAAC_DEFAULT_BITRATE (defined for stereo @ 44100 Hz) by sample rate and channel count.

driver()

faac_encoder * driver ( )

inline

Provides access to the faac encoder handle.

encode()

bool encode ( const int16_t *  samples, uint32_t  sample_count, uint32_t *  p_written = nullptr  )

inlineprotected

encoderInfo()

faac_encoder_info & encoderInfo ( )

inline

Provides the information of the opened encoder.

end()

void end ( )

inlineoverridevirtual

Encodes the remaining data and releases the encoder.

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.

getAudioSpecificConfig()

bool getAudioSpecificConfig ( const uint8_t *&  data, uint32_t &  len  )

inline

Provides the AudioSpecificConfig (needed for raw output e.g. in a MP4 container). Returns false if not available.

mime()

const char * mime ( )

inlineoverridevirtual

Provides the mime type of the encoded result.

Implements AudioEncoder.

operator bool()

operator bool ( )

inlineoverridevirtual

Implements AudioWriter.

samplesPerFrame()

virtual uint16_t samplesPerFrame ( )

inlinevirtualinherited

Optional rtsp function: provide samples per the frame.

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

setAdts()

void setAdts ( bool  enabled )

inline

Defines if ADTS headers are generated (default true)

setAudioInfo()

void setAudioInfo ( AudioInfo  from )

inlineoverridevirtualinherited

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

Implements AudioWriter.

Reimplemented in MP3EncoderLAME, EncoderBasic, CodecChain, DSFEncoder, FLACEncoder, MP3EncoderShine, OpusAudioEncoder, OpusMultiStreamAudioEncoder, WAVEncoder, CodecNOP, G7xxEncoder, G729Encoder, BinaryContainerEncoder, OggContainerEncoder, OSCContainerEncoder, H264RtpEncoder, JPEGRtpEncoder, and MetaDataFilterEncoder.

setBitrate()

void setBitrate ( uint32_t  bps )

inline

Defines the total target bitrate in bps (for all channels). If not called, the bitrate is derived from FAAC_DEFAULT_BITRATE.

setObjectType()

void setObjectType ( faac_object_type  type )

inline

Defines the object type: FAAC_OBJ_AUTO, FAAC_OBJ_LOW (default) or FAAC_OBJ_HE_AAC_V1

setOutput()

void setOutput ( Print &  out_stream )

inlineoverridevirtual

Defines the output stream.

Reimplemented from AudioEncoder.

setQuality()

void setQuality ( uint32_t  quality )

inline

Defines the quantizer quality (1..5000) for VBR: it is only used if the bitrate is 0

setRateControl()

void setRateControl ( faac_rate_control  rc )

inline

Defines the rate control: FAAC_RC_AUTO (default), FAAC_RC_VBR, FAAC_RC_ABR or FAAC_RC_CBR

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

bitrate

uint32_t bitrate = (uint32_t)-1

protected

enc

faac_encoder* enc = nullptr

protected

enc_info

faac_encoder_info enc_info

protected

frame_samples

size_t frame_samples = 0

protected

info

AudioInfo info

protectedinherited

object_type

faac_object_type object_type = FAAC_OBJ_LOW

protected

out_buffer

Vector<uint8_t> out_buffer {0}

protected

p_print

Print* p_print = nullptr

protected

pcm_buffer

Vector<int16_t> pcm_buffer {0}

protected

pcm_pos

size_t pcm_pos = 0

protected

quant_quality

uint32_t quant_quality = 0

protected

rate_control

faac_rate_control rate_control = FAAC_RC_AUTO

protected

use_adts

bool use_adts = true

protected

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

• src/AudioTools/AudioCodecs/CodecAACFAAC.h