EncoderL16 Class Reference

EncoderL16s - Condenses 16 bit PCM data stream to 8 bits data. Most microcontrollers can not process 8 bit audio data directly. 8 bit data however is very memory efficient and helps if you need to store audio on constrained resources. This encoder translates 16bit data into 8bit data. More...

#include <CodecL16.h>

Inheritance diagram for EncoderL16:

Public Member Functions
	EncoderL16 ()
	EncoderL16 (Print &out)
AudioInfo	audioInfo () override
	provides the actual input AudioInfo
virtual AudioInfo	audioInfoOut ()
virtual bool	begin () override
	starts the processing using the actual RAWAudioInfo
virtual bool	begin (AudioInfo info)
bool	begin (Print &out)
	starts the processing
void	end () override
	stops the processing
virtual uint32_t	frameDurationUs ()
	Optional rtsp function: provide the frame duration in microseconds.
virtual int	frameSize ()
bool	isOpen ()
const char *	mime () override
	Provides "audio/pcm".
	operator bool () override
virtual uint16_t	samplesPerFrame ()
	Optional rtsp function: provide samples per the frame.
void	setAudioInfo (AudioInfo from) override
	Defines the sample rate, number of channels and bits per sample.
void	setOutput (Print &out_stream) override
	Defines the output Stream.
virtual size_t	write (const uint8_t *data, size_t len) override
	Writes PCM data to be encoded as RAW.

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

Protected Attributes
AudioInfo	info
bool	is_open
Print *	p_print = nullptr

Detailed Description

EncoderL16s - Condenses 16 bit PCM data stream to 8 bits data. Most microcontrollers can not process 8 bit audio data directly. 8 bit data however is very memory efficient and helps if you need to store audio on constrained resources. This encoder translates 16bit data into 8bit data.

Author

Phil Schatzmann

Copyright

GPLv3

Constructor & Destructor Documentation

EncoderL16() [1/2]

EncoderL16 ( )

inline

EncoderL16() [2/2]

EncoderL16 ( Print &  out )

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() [1/3]

virtual bool begin ( )

inlineoverridevirtual

starts the processing using the actual RAWAudioInfo

Implements AudioWriter.

begin() [2/3]

virtual bool begin ( AudioInfo  info )

inlinevirtualinherited

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

begin() [3/3]

bool begin ( Print &  out )

inline

starts the processing

end()

void end ( )

inlineoverridevirtual

stops the processing

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.

isOpen()

bool isOpen ( )

inline

mime()

const char * mime ( )

inlineoverridevirtual

Provides "audio/pcm".

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.

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.

setOutput()

void setOutput ( Print &  out_stream )

inlineoverridevirtual

Defines the output Stream.

Reimplemented from AudioEncoder.

write()

virtual size_t write ( const uint8_t *  data, size_t  len  )

inlineoverridevirtual

Writes PCM data to be encoded as RAW.

Implements AudioWriter.

writeBlocking()

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

inlineprotectedinherited

Member Data Documentation

info

AudioInfo info

protectedinherited

is_open

bool is_open

protected

p_print

Print* p_print = nullptr

protected

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

• src/AudioTools/AudioCodecs/CodecL16.h