AudioCodec Class Reference

The codec class is a virtual used for transcoding audio samples between linear frames (or other known format) and an encoded "sample" buffer.process codec interface. More...

#include <bayonneaudio.h>

Inheritance diagram for AudioCodec:

List of all members.


Public Member Functions
	AudioCodec (const char *n, Encoding e)
virtual	~AudioCodec ()
virtual short	getImpulse (void *data, unsigned samples=0)
	Get the impulse energy level of a frame of X samples in the specified codec format.
virtual short	getPeak (void *data, unsigned samples=0)
	Get the peak energy level within the frame of X samples.
virtual bool	isSilent (short threashold, void *data, unsigned samples=0)
	Signal if the current audio frame is silent.
virtual unsigned	encode (Linear buffer, void *dest, unsigned lsamples)=0
	Encode a linear sample frame into the codec sample buffer.
virtual unsigned	decode (Linear buffer, void *source, unsigned lsamples)=0
	Decode the sample frame into linear samples.
Info	getInfo (void)
	Get an info description for this codec.
Static Public Member Functions
static void	endCodec (AudioCodec *codec)
	End use of a requested codec.
static AudioCodec *	getCodec (Encoding encoding, const char *format=NULL, bool loaded=false)
static AudioCodec *	getCodec (Info &info, bool loaded=false)
static bool	load (const char *name)
	Load a named codec set into process memory.
static bool	load (Encoding e)
	Find and load a codec file by it's encoding type.
Protected Member Functions
	AudioCodec ()
virtual AudioCodec *	getByFormat (const char *format)
virtual AudioCodec *	getByInfo (Info &info)
Protected Attributes
AudioCodec *	next
Encoding	encoding
const char *	name
Info	info
Static Protected Attributes
static Mutex	lock
static AudioCodec *	first

Detailed Description

The codec class is a virtual used for transcoding audio samples between linear frames (or other known format) and an encoded "sample" buffer.process codec interface.

This class is only abstract and describes the core interface for loadable codec modules. This class is normally merged with AudioSample. A derived AudioCodecXXX will typically include a AudioRegisterXXX static class to automatically initialize and register the codec with the codec registry.

Author:: David Sugar <dyfet@ostel.com>

Constructor & Destructor Documentation

AudioCodec::AudioCodec ( ) [protected]

AudioCodec::AudioCodec ( const char * n,

Encoding e

)

virtual AudioCodec::~AudioCodec ( ) [inline, virtual]

Member Function Documentation

virtual unsigned AudioCodec::decode ( Linear buffer,

void * source,

unsigned lsamples

) [pure virtual]

Decode the sample frame into linear samples.

Returns:
number of bytes scanned.

Parameters:

buffer sample buffer to save linear samples into.

source for encoded data.

number of samples to extract.

virtual unsigned AudioCodec::encode ( Linear buffer,

void * dest,

unsigned lsamples

) [pure virtual]

Encode a linear sample frame into the codec sample buffer.

Parameters:

number of bytes written.

buffer linear sample buffer to use.

dest buffer to store encoded results.

lsamples The number of linear samples.

static void AudioCodec::endCodec ( AudioCodec * codec ) [static]

End use of a requested codec.
If constructed then will be deleted.

Parameters:

pointer to getCodec returned coded pointer.

virtual AudioCodec* AudioCodec::getByFormat ( const char * format ) [inline, protected, virtual]

virtual AudioCodec* AudioCodec::getByInfo ( Info & info ) [inline, protected, virtual]

static AudioCodec* AudioCodec::getCodec ( Info & info,

bool loaded = false

) [static]

static AudioCodec* AudioCodec::getCodec ( Encoding encoding,

const char * format = NULL,

bool loaded = false

) [static]

virtual short AudioCodec::getImpulse ( void * data,

unsigned samples = 0

) [virtual]

Get the impulse energy level of a frame of X samples in the specified codec format.

Returns:
average impulse energy of frame (sumnation).

Parameters:

buffer of encoded samples.

number of encoded samples.

Info AudioCodec::getInfo ( void ) [inline]

Get an info description for this codec.

Returns:
info.

virtual short AudioCodec::getPeak ( void * data,

unsigned samples = 0

) [virtual]

Get the peak energy level within the frame of X samples.

Returns:
peak energy impulse in frame (largest).

Parameters:

buffer of encoded samples.

number of encoded samples.

virtual bool AudioCodec::isSilent ( short threashold,

void * data,

unsigned samples = 0

) [virtual]

Signal if the current audio frame is silent.
This can be deterimed either by an impulse computation, or, in some cases, some codecs may signal and flag silent packets.

Returns:
true if silent

Parameters:

threashold to use if not signaled.

buffer of encoded samples.

number of encoded samples.

static bool AudioCodec::load ( Encoding e ) [static]

Find and load a codec file by it's encoding type.
Converts the type into a codec name and invokes the other loader...

Returns:
true if successful.

Parameters:

encoding type for file.

static bool AudioCodec::load ( const char * name ) [static]

Load a named codec set into process memory.

Returns:
true if successful.

Parameters:

name of codec set to load.