FLACDecoder Class Reference

Decoder for FLAC. Depends on https://github.com/pschatzmann/arduino-libflac. We support an efficient streaming API and an very memory intensitiv standard interface. So you should prefer the streaming interface where you call setOutput() before the begin and copy() in the loop. Validated with http://www.2l.no/hires/. More...

#include <CodecFLAC.h>

Inheritance diagram for FLACDecoder:

Public Member Functions
	FLACDecoder (bool isOgg=false)
	Default Constructor.
	~FLACDecoder ()
	Destructor - calls end();.
virtual void	addNotifyAudioChange (AudioInfoSupport &bi)
	Adds target to be notified about audio changes.
AudioInfo	audioInfo ()
	Provides the audio information for the current stream.
virtual AudioInfo	audioInfoOut ()
bool	begin ()
	Starts the processing.
virtual void	clearNotifyAudioChange ()
	Deletes all change notify subscriptions.
bool	copy ()
	Stream Interface: Process a single frame - only relevant when input stream has been defined.
bool	copyAll ()
	Process all available data.
void	end ()
	Releases the reserved memory.
void	flush ()
	Process all data in the buffer.
bool	isNotifyActive ()
	Checks if the automatic AudioInfo update is active.
bool	isOgg () const
	returns true of the stream is ogg
const char *	mime () override
	Provides "audio/flac" or "audio/ogg".
	operator bool ()
	Checks if the class is active.
virtual bool	removeNotifyAudioChange (AudioInfoSupport &bi)
	Removes a target in order not to be notified about audio changes.
void	setInput (Stream &inStream)
	Stream Interface: Decode directly by taking data from the stream.
void	setMD5 (bool flag)
	Activate/deactivate md5 checking: call this before calling begin()
void	setNotifyActive (bool flag)
	Deactivate/Reactivate automatic AudioInfo updates: (default is active)
void	setOgg (bool isOgg)
virtual void	setOutput (AudioOutput &out_stream)
	Defines the output streams and register to be notified.
virtual void	setOutput (AudioStream &out_stream)
	Defines the output streams and register to be notified.
virtual void	setOutput (Print &out_stream)
	Defines the output Stream.
void	setTimeout (uint64_t readTimeout=10000)

Protected Member Functions
bool	isEof (int bytes)
	We return eof when we were subsequently getting 0 bytes for the timeout period.
bool	isInputFromStream ()
	Check if input is directly from stream - instead of writes.
void	notifyAudioChange (AudioInfo info)
size_t	readBytes (uint8_t *data, size_t len) override
	Reads bytes from the input stream.
void	setAudioInfo (AudioInfo newInfo) override
	Defines the input AudioInfo.

Static Protected Member Functions
static void	error_callback (const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data)
	Error callback.
static FLAC__StreamDecoderReadStatus	read_callback (const FLAC__StreamDecoder *decoder, FLAC__byte result_buffer[], size_t *bytes, void *client_data)
	Callback which reads from stream.
static FLAC__StreamDecoderWriteStatus	write_callback (const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 *const buffer[], void *client_data)
	Output decoded result to final output stream.

Protected Attributes
FLAC__StreamDecoder *	decoder = nullptr
AudioInfo	info
FLAC__StreamDecoderInitStatus	init_status
bool	is_active = false
bool	is_md5_checing = false
bool	is_notify_active = true
bool	is_ogg = false
Vector< AudioInfoSupport * >	notify_vector
Stream *	p_input = nullptr
	Input stream for encoded audio data.
Print *	p_print = nullptr
	Output stream for decoded PCM data.
uint64_t	read_timeout_ms = 10000
uint64_t	time_last_read = 0

Detailed Description

Decoder for FLAC. Depends on https://github.com/pschatzmann/arduino-libflac. We support an efficient streaming API and an very memory intensitiv standard interface. So you should prefer the streaming interface where you call setOutput() before the begin and copy() in the loop. Validated with http://www.2l.no/hires/.

Author

Phil Schatzmann

Copyright

GPLv3

Member Function Documentation

addNotifyAudioChange()

virtual void addNotifyAudioChange ( AudioInfoSupport &  bi )

inlinevirtualinherited

Adds target to be notified about audio changes.

Reimplemented in CodecNOP, EncodedAudioOutput, EncodedAudioStream, AACDecoderFDK, DecoderBasic, MP3DecoderHelix, MP3DecoderMAD, OggContainerDecoder, Pipeline, and Pipeline::ModifyingStreamAdapter.

audioInfo()

AudioInfo audioInfo ( )

inlinevirtual

Provides the audio information for the current stream.

Returns audio format information such as sample rate, channels, and bits per sample that was determined from the decoded audio stream.

Returns

AudioInfo structure containing format information

Implements StreamingDecoder.

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()

bool begin ( )

inlinevirtual

Starts the processing.

Initializes the decoder and prepares it for processing audio data. Must be called before any copy() operations.

Returns

true if initialization was successful, false otherwise

Implements StreamingDecoder.

copy()

bool copy ( )

inlinevirtual

Stream Interface: Process a single frame - only relevant when input stream has been defined.

Implements StreamingDecoder.

copyAll()

bool copyAll ( )

inlineinherited

Process all available data.

Convenience method that calls copy() repeatedly until all available data has been processed.

Returns

true if any data was processed, false if no data was available

end()

void end ( )

inlinevirtual

Releases the reserved memory.

Cleans up any resources allocated by the decoder and stops processing.

Implements StreamingDecoder.

mime()

const char * mime ( )

inlineoverridevirtual

Provides "audio/flac" or "audio/ogg".

Implements StreamingDecoder.

operator bool()

operator bool ( )

inlinevirtual

Checks if the class is active.

Returns

true if the decoder is ready and active, false otherwise

Implements StreamingDecoder.

readBytes()

size_t readBytes ( uint8_t *  data, size_t  len  )

inlineoverrideprotectedvirtual

Reads bytes from the input stream.

Derived classes must implement this to read data from their input source.

Parameters

data	Buffer to store the read data
len	Maximum number of bytes to read

Returns

Number of bytes actually read

Implements StreamingDecoder.

setAudioInfo()

void setAudioInfo ( AudioInfo  info )

inlineoverrideprotectedvirtualinherited

Defines the input AudioInfo.

Implements AudioInfoSupport.

setInput()

void setInput ( Stream &  inStream )

inlineinherited

Stream Interface: Decode directly by taking data from the stream.

This is more efficient than feeding the decoder with write: just call copy() in the loop to process data from the input stream.

Parameters

inStream

The input stream containing encoded audio data

setOutput() [1/3]

virtual void setOutput ( AudioOutput &  out_stream )

inlinevirtualinherited

Defines the output streams and register to be notified.

Sets the output stream and registers for audio info change notifications.

Parameters

out_stream

The AudioOutput to write decoded audio data to

Reimplemented in MultiStreamingDecoder.

setOutput() [2/3]

virtual void setOutput ( AudioStream &  out_stream )

inlinevirtualinherited

Defines the output streams and register to be notified.

Sets the output stream and registers for audio info change notifications.

Parameters

out_stream

The AudioStream to write decoded audio data to

Reimplemented in MultiStreamingDecoder.

setOutput() [3/3]

virtual void setOutput ( Print &  out_stream )

inlinevirtualinherited

Defines the output Stream.

Sets where the decoded PCM audio data will be written to.

Parameters

out_stream

The Print stream to write decoded audio data to

Reimplemented in StreamingDecoderAdapter, and MultiStreamingDecoder.

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

• src/AudioTools/AudioCodecs/CodecFLAC.h