EncoderL8 Class Reference

EncoderL8s - 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. By default the encoded data is represented as uint8_t, so the values are from 0 to 255. More...

#include <CodecL8.h>

Inheritance diagram for EncoderL8:

Public Member Functions
	EncoderL8 (bool isSigned=false)
	EncoderL8 (Print &out)
AudioInfo	audioInfo () override
	provides the actual input AudioInfo
virtual AudioInfo	audioInfoOut ()
bool	begin () override
	starts the processing using the actual RAWAudioInfo
virtual bool	begin (AudioInfo info)
bool	begin (Print &out)
	starts the processing
int16_t	convertSample (int16_t sample)
void	end () override
	stops the processing
virtual uint32_t	frameDurationUs ()
	Optional rtsp function: provide the frame duration in microseconds.
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.
void	setSigned (bool isSigned)
	By default the encoded values are unsigned, but can change them to signed.
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
Vector< int8_t >	buffer
AudioInfo	info
bool	is_open
bool	is_signed = false
Print *	p_print = nullptr

Detailed Description

EncoderL8s - 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. By default the encoded data is represented as uint8_t, so the values are from 0 to 255.

Author

Phil Schatzmann

Copyright

GPLv3

Constructor & Destructor Documentation

EncoderL8() [1/2]

EncoderL8 ( bool  isSigned = false )

inline

EncoderL8() [2/2]

EncoderL8 ( Print &  out )

inline

Member Function Documentation

audioInfo()

AudioInfo audioInfo ( )

inlineoverridevirtualinherited

provides the actual input AudioInfo

Implements AudioInfoSupport.

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

begin() [1/3]

bool begin ( )

inlineoverridevirtual

starts the processing using the actual RAWAudioInfo

Implements AudioWriter.

begin() [2/3]

virtual bool begin ( AudioInfo  info )

inlinevirtualinherited

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

begin() [3/3]

bool begin ( Print &  out )

inline

starts the processing

convertSample()

int16_t convertSample ( int16_t  sample )

inline

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, OpusOggEncoder, MP3ParserEncoder, and MetaDataFilterEncoder.

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 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, FLACEncoder, OpusAudioEncoder, WAVEncoder, CodecNOP, G7xxEncoder, BinaryContainerEncoder, OggContainerEncoder, OSCContainerEncoder, and MetaDataFilterEncoder.

setOutput()

void setOutput ( Print &  out_stream )

inlineoverridevirtual

Defines the output Stream.

Reimplemented from AudioEncoder.

setSigned()

void setSigned ( bool  isSigned )

inline

By default the encoded values are unsigned, but can change them to signed.

write()

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

buffer

Vector<int8_t> buffer

protected

info

AudioInfo info

protectedinherited

is_open

bool is_open

protected

is_signed

bool is_signed = false

protected

p_print

Print* p_print = nullptr

protected

---

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

• src/AudioTools/AudioCodecs/CodecL8.h