libhelix::CommonHelix Class Reference

Common Simple Arduino API. More...

#include <CommonHelix.h>

Inheritance diagram for libhelix::CommonHelix:

Public Member Functions
void	setOutput (Print &output)
virtual bool	begin ()
	Starts the processing.
virtual void	end ()
	Releases the reserved memory.
virtual size_t	write (const void *in_ptr, size_t in_size)
	decodes the next segments from the input. The data can be provided in one short or in small incremental pieces. It is suggested to be called in the Arduino Loop. If the provided data does not fit into the buffer it is split up into small pieces that fit
	operator bool ()
	returns true if active
virtual void	setDelay (int delayMs)
	Defines the delay that is added at each segment.
uint64_t	timeOfLastWrite ()
	Provides the timestamp in ms of last write.
uint64_t	timeOfLastResult ()
	Provides the timestamp in ms of last decoded result.
void	flush ()
	Decode open packets.
virtual size_t	maxFrameSize ()=0
void	setMaxFrameSize (size_t len)
	Define your optimized maximum frame size in bytes.
virtual size_t	maxPCMSize ()=0
void	setMaxPCMSize (size_t len)
	Define your optimized maximum pcm buffer size in bytes.
void	setRaw (bool)
	Obsolete!

Protected Member Functions
bool	presync ()
	make sure that we start with a valid sync: remove ID3 data
bool	resynch (int rc)
bool	removeInvalidData (int pos)
virtual size_t	writeChunk (const void *in_ptr, size_t in_size)
virtual int	decode ()=0
	Decode w/o parsing.
virtual bool	allocateDecoder ()=0
	Allocate the decoder.
virtual int	findSynchWord (int offset=0)=0
virtual int	minFrameBufferSize ()

Protected Attributes
bool	active = false
bool	is_raw = false
Vector< uint8_t >	pcm_buffer {0}
SingleBuffer< uint8_t >	frame_buffer {0}
size_t	max_frame_size = 0
size_t	max_pcm_size = 0
size_t	frame_counter = 0
int	delay_ms = -1
uint64_t	time_last_write = 0
uint64_t	time_last_result = 0
Print *	out = nullptr

Detailed Description

Common Simple Arduino API.

Author

Phil Schatzmann

Copyright

GPLv3

Member Function Documentation

findSynchWord()

virtual int libhelix::CommonHelix::findSynchWord ( int  offset = 0 )

protectedpure virtual

Finds the synchronization word in the frame buffer (starting from the indicated offset)

Implemented in libhelix::MP3DecoderHelix, and libhelix::AACDecoderHelix.

maxFrameSize()

virtual size_t libhelix::CommonHelix::maxFrameSize ( )

pure virtual

Provides the maximum frame size in bytes - this is allocated on the heap and you can reduce the heap size my minimizing this value

Implemented in libhelix::MP3DecoderHelix, and libhelix::AACDecoderHelix.

maxPCMSize()

virtual size_t libhelix::CommonHelix::maxPCMSize ( )

pure virtual

Provides the maximum pcm buffer size in bytes - this is allocated on the heap and you can reduce the heap size my minimizing this value

Implemented in libhelix::MP3DecoderHelix, and libhelix::AACDecoderHelix.

removeInvalidData()

bool libhelix::CommonHelix::removeInvalidData ( int  pos )

inlineprotected

removes invalid data not starting with a synch word.

Returns

Returns true if we still have data to be played

resynch()

bool libhelix::CommonHelix::resynch ( int  rc )

inlineprotected

advance on invalid data, returns true if we need to continue the processing

writeChunk()

virtual size_t libhelix::CommonHelix::writeChunk ( const void *  in_ptr, size_t  in_size  )

inlineprotectedvirtual

Prevent bug in underflow detection for AAC

---

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

• src/CommonHelix.h