MpDecoderBase Class Reference

Base class for all media processing decoders. More...

#include <MpDecoderBase.h>

Collaboration diagram for MpDecoderBase:

Public Member Functions
Creators
	MpDecoderBase (int payloadType, const MpCodecCallInfoV1 &callInfo, const MppCodecInfoV1_1 &codecInfo, const char *defaultFmtp)
	Constructor. More...
	~MpDecoderBase ()
	Destructor. More...
OsStatus	initDecode (const char *codecFmtString)
	Initializes a codec data structure for use as a decoder. More...
OsStatus	initDecode ()
	Initializes a codec data structure for use as a decoder using default fmtp. More...
OsStatus	freeDecode ()
	Frees all memory allocated to the decoder by initDecode() More...
Manipulators
int	decode (const MpRtpBufPtr &pPacket, unsigned decodedBufferLength, MpAudioSample *samplesBuffer)
	Decode incoming RTP packet. More...
Accessors
const MpCodecInfo *	getInfo () const
	Get information about the decoder. More...
int	getPayloadType ()
	Returns the RTP payload type associated with this decoder. More...
OsStatus	getSignalingData (uint8_t &event, UtlBoolean &isStarted, UtlBoolean &isStopped, uint16_t &duration)
	Get signaling data from last decoded packet. More...

Private Member Functions
bool	isInitialized () const
	Is codec initialized? More...
	MpDecoderBase (const MpDecoderBase &rMpDecoderBase)
	Copy constructor. More...
MpDecoderBase &	operator= (const MpDecoderBase &rhs)
	Assignment operator. More...

Private Attributes
int	mPayloadType
	RTP payload type associated with this decoder. More...
MpCodecInfo	mCodecInfo
	Info structure for this codec. More...
const MpCodecCallInfoV1 &	mCallInfo
	this codec. More...
void *	plgHandle
	Codec internal handle. More...
const char *	mDefaultFmtp
	Fmtp to use if not passed to initDecode(). More...

Detailed Description

Base class for all media processing decoders.

Constructor & Destructor Documentation

MpDecoderBase	(	int	payloadType,
		const MpCodecCallInfoV1 &	callInfo,
		const MppCodecInfoV1_1 &	codecInfo,
		const char *	defaultFmtp
	)

Constructor.

Parameters

[in]

payloadType

- RTP payload type associated with this decoder

~MpDecoderBase

(

)

Destructor.

MpDecoderBase ( const MpDecoderBase &  rMpDecoderBase )

private

Copy constructor.

Member Function Documentation

OsStatus initDecode

(

const char *

codecFmtString

)

Initializes a codec data structure for use as a decoder.

Return values

OS_SUCCESS	- Success
OS_NO_MEMORY	- Memory allocation failure

OsStatus initDecode

(

)

Initializes a codec data structure for use as a decoder using default fmtp.

Return values

OS_SUCCESS	- Success
OS_NO_MEMORY	- Memory allocation failure

OsStatus freeDecode

(

)

Frees all memory allocated to the decoder by initDecode()

Return values

OS_SUCCESS	- Success.
OS_INVALID_STATE	- Object has already been freed.

int decode	(	const MpRtpBufPtr &	pPacket,
		unsigned	decodedBufferLength,
		MpAudioSample *	samplesBuffer
	)

Decode incoming RTP packet.

This method is called by MprDecode for every incoming RTP packet. If codec have internal PLC, then this method is also called for every lost packet with pPacket=NULL to leverage codec's internal PLC. For signaling codecs (namely RFC2833/4733) right after decode() MprDecode calls getSignalingData() to retrieve decoded signaling data. That is decoder should cache this data internally between decode() and getSignalingData() calls.

See also

getSignalingData()

Parameters

[in]	pPacket	- Pointer to a RTP packet. May be NULL if packet was lost.
[in]	decodedBufferLength	- Length of the samplesBuffer (in samples).
[out]	samplesBuffer	- Buffer for decoded samples.

Returns

Number of decoded samples.

const MpCodecInfo * getInfo

(

)

const

Get information about the decoder.

Returns

A pointer to a MpCodecInfo object that provides information about the decoder. For codecs with only one mode supported (like G.711 and GSM) it may return pointer to static class member. More complex codecs (like Speex) may return pointer to usual class member.

int getPayloadType

(

void

)

Returns the RTP payload type associated with this decoder.

OsStatus getSignalingData	(	uint8_t &	event,
		UtlBoolean &	isStarted,
		UtlBoolean &	isStopped,
		uint16_t &	duration
	)

Get signaling data from last decoded packet.

If codec is signaling, that is it is able to carry signaling data, this function is called right after decode() to get signaling data from last decoded RTP packet.

Note

Only DTMF digits are supported. Other signaling data is not yet supported.

Default implementation just return OS_NOT_SUPPORTED.

See also

decode()

Return values

OS_SUCCESS	- Last decoded packet had signaling data, key, pressState and duration were filled with decoded values.
OS_NO_MORE_DATA	- Last packet had no meaningful signaling data.
OS_NOT_SUPPORTED	- This codec is pure audio codec and could not carry any signaling data.

bool isInitialized ( ) const

inlineprivate

Is codec initialized?

MpDecoderBase& operator= ( const MpDecoderBase &  rhs )

private

Assignment operator.

Member Data Documentation

int mPayloadType

private

RTP payload type associated with this decoder.

MpCodecInfo mCodecInfo

private

Info structure for this codec.

const MpCodecCallInfoV1& mCallInfo

private

this codec.

Pointers to actual methods of

void* plgHandle

private

Codec internal handle.

const char* mDefaultFmtp

private

Fmtp to use if not passed to initDecode().