OPAL
Version 3.10.4
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#include <transcoders.h>
Public Member Functions | |
Construction | |
OpalTranscoder (const OpalMediaFormat &inputMediaFormat, const OpalMediaFormat &outputMediaFormat) | |
Protected Attributes | |
PINDEX | maxOutputSize |
PNotifier | commandNotifier |
PMutex | updateMutex |
unsigned | m_sessionID |
bool | outputIsRTP |
bool | inputIsRTP |
bool | acceptEmptyPayload |
bool | acceptOtherPayloads |
unsigned | m_inClockRate |
unsigned | m_outClockRate |
Operations | |
virtual bool | UpdateMediaFormats (const OpalMediaFormat &inputMediaFormat, const OpalMediaFormat &outputMediaFormat) |
virtual PBoolean | ExecuteCommand (const OpalMediaCommand &command) |
virtual PINDEX | GetOptimalDataFrameSize (PBoolean input) const =0 |
virtual PBoolean | ConvertFrames (const RTP_DataFrame &input, RTP_DataFrameList &output) |
virtual PBoolean | Convert (const RTP_DataFrame &input, RTP_DataFrame &output)=0 |
PINDEX | GetMaxOutputSize () const |
void | SetMaxOutputSize (PINDEX size) |
void | SetCommandNotifier (const PNotifier ¬ifier) |
const PNotifier & | GetCommandNotifier () const |
void | NotifyCommand (const OpalMediaCommand &command) const |
Notify command notifier of command. | |
unsigned | GetSessionID () const |
Get session ID for the transcoder (from OpalMediaStream) | |
void | SetSessionID (unsigned id) |
Set session ID for the transcoder (from OpalMediaStream) | |
virtual void | SetInstanceID (const BYTE *instance, unsigned instanceLen) |
RTP_DataFrame::PayloadTypes | GetPayloadType (PBoolean input) const |
virtual bool | AcceptComfortNoise () const |
virtual bool | AcceptEmptyPayload () const |
virtual bool | AcceptOtherPayloads () const |
virtual void | GetStatistics (OpalMediaStatistics &statistics) const |
void | CopyTimestamp (RTP_DataFrame &dst, const RTP_DataFrame &src, bool inToOut) const |
static OpalTranscoder * | Create (const OpalMediaFormat &srcFormat, const OpalMediaFormat &dstFormat, const BYTE *instance=NULL, unsigned instanceLen=0) |
static bool | SelectFormats (const OpalMediaType &mediaType, const OpalMediaFormatList &srcFormats, const OpalMediaFormatList &dstFormats, const OpalMediaFormatList &allFormats, OpalMediaFormat &srcFormat, OpalMediaFormat &dstFormat) |
static bool | FindIntermediateFormat (const OpalMediaFormat &srcFormat, const OpalMediaFormat &dstFormat, OpalMediaFormat &intermediateFormat) |
static OpalMediaFormatList | GetDestinationFormats (const OpalMediaFormat &srcFormat) |
static OpalMediaFormatList | GetSourceFormats (const OpalMediaFormat &dstFormat) |
static OpalMediaFormatList | GetPossibleFormats (const OpalMediaFormatList &formats) |
This class embodies the implementation of a specific transcoder instance used to convert data from one format to another.
An application may create a descendent off this class and override functions as required for implementing a transcoder.
OpalTranscoder::OpalTranscoder | ( | const OpalMediaFormat & | inputMediaFormat, |
const OpalMediaFormat & | outputMediaFormat | ||
) |
Create a new transcoder implementation.
inputMediaFormat | Input media format |
outputMediaFormat | Output media format |
virtual bool OpalTranscoder::AcceptComfortNoise | ( | ) | const [inline, virtual] |
Reimplemented in OpalPluginStreamedAudioTranscoder, and OpalPluginFramedAudioTranscoder.
virtual bool OpalTranscoder::AcceptEmptyPayload | ( | ) | const [inline, virtual] |
References acceptEmptyPayload.
virtual bool OpalTranscoder::AcceptOtherPayloads | ( | ) | const [inline, virtual] |
References acceptOtherPayloads.
virtual PBoolean OpalTranscoder::Convert | ( | const RTP_DataFrame & | input, |
RTP_DataFrame & | output | ||
) | [pure virtual] |
Convert the data from one format to another. This function takes the input data as a RTP_DataFrame and converts it to its output format, placing it into the RTP_DataFrame provided.
Returns false if the conversion fails.
input | Input data |
output | Output data |
Implemented in OpalStreamedTranscoder, OpalFramedTranscoder, OpalVideoTranscoder, and Opal_G711_PCM.
virtual PBoolean OpalTranscoder::ConvertFrames | ( | const RTP_DataFrame & | input, |
RTP_DataFrameList & | output | ||
) | [virtual] |
Convert the data from one format to another. This function takes the input data as a RTP_DataFrame and converts it to its output format, placing it (possibly) into multiple RTP_DataFrame objects.
The default behaviour makes sure the output list has only one element in it and calls the Convert() function.
Returns false if the conversion fails.
input | Input data |
output | Output data |
Reimplemented in OpalPluginVideoTranscoder, OpalRFC4175Decoder, and OpalRFC4175Encoder.
void OpalTranscoder::CopyTimestamp | ( | RTP_DataFrame & | dst, |
const RTP_DataFrame & | src, | ||
bool | inToOut | ||
) | const |
static OpalTranscoder* OpalTranscoder::Create | ( | const OpalMediaFormat & | srcFormat, |
const OpalMediaFormat & | dstFormat, | ||
const BYTE * | instance = NULL , |
||
unsigned | instanceLen = 0 |
||
) | [static] |
Create an instance of a media conversion function. Returns NULL if there is no registered media transcoder between the two named formats.
srcFormat | Name of source format |
dstFormat | Name of destination format |
instance | Unique instance identifier for transcoder |
instanceLen | Length of instance identifier |
virtual PBoolean OpalTranscoder::ExecuteCommand | ( | const OpalMediaCommand & | command | ) | [virtual] |
Execute the command specified to the transcoder. The commands are highly context sensitive, for example OpalVideoUpdatePicture would only apply to a video transcoder.
The default behaviour simply returns false.
command | Command to execute. |
Reimplemented in OpalPluginVideoTranscoder, OpalPluginStreamedAudioTranscoder, OpalPluginFramedAudioTranscoder, and OpalVideoTranscoder.
static bool OpalTranscoder::FindIntermediateFormat | ( | const OpalMediaFormat & | srcFormat, |
const OpalMediaFormat & | dstFormat, | ||
OpalMediaFormat & | intermediateFormat | ||
) | [static] |
Find media intermediate format for transcoders. This function attempts to find the intermediate media format that will allow two transcoders to be used to get data from the source format to the destination format.
If there is a transcoder that can go directly from the source format to the destination format then the function returns true but the intermediateFormat parmaeter will be an invlid format.
Returns false if there is no registered media transcoder that can be used between the two named formats.
srcFormat | Selected destination format to be used |
dstFormat | Selected destination format to be used |
intermediateFormat | Intermediate format that can be used |
const PNotifier& OpalTranscoder::GetCommandNotifier | ( | ) | const [inline] |
Get the notifier to receive commands generated by the transcoder. The commands are highly context sensitive, for example OpalVideoUpdatePicture would only apply to a video transcoder.
References commandNotifier.
static OpalMediaFormatList OpalTranscoder::GetDestinationFormats | ( | const OpalMediaFormat & | srcFormat | ) | [static] |
Get a list of possible destination media formats for the destination.
srcFormat | Selected source format |
PINDEX OpalTranscoder::GetMaxOutputSize | ( | ) | const [inline] |
Get maximum output size.
References maxOutputSize.
virtual PINDEX OpalTranscoder::GetOptimalDataFrameSize | ( | PBoolean | input | ) | const [pure virtual] |
Get the optimal size for data frames to be converted. This function returns the size of frames that will be most efficient in conversion. A RTP_DataFrame will attempt to provide or use data in multiples of this size. Note that it may not do so, so the transcoder must be able to handle any sized packets.
input | Flag for input or output data size |
Implemented in OpalStreamedTranscoder, OpalFramedTranscoder, and OpalVideoTranscoder.
RTP_DataFrame::PayloadTypes OpalTranscoder::GetPayloadType | ( | PBoolean | input | ) | const |
input | Flag for input or output data size |
static OpalMediaFormatList OpalTranscoder::GetPossibleFormats | ( | const OpalMediaFormatList & | formats | ) | [static] |
Get a list of possible media formats that can do bi-directional media.
formats | Destination format list |
unsigned OpalTranscoder::GetSessionID | ( | ) | const [inline] |
Get session ID for the transcoder (from OpalMediaStream)
References m_sessionID.
static OpalMediaFormatList OpalTranscoder::GetSourceFormats | ( | const OpalMediaFormat & | dstFormat | ) | [static] |
Get a list of possible source media formats for the destination.
dstFormat | Selected destination format |
virtual void OpalTranscoder::GetStatistics | ( | OpalMediaStatistics & | statistics | ) | const [virtual] |
Reimplemented in OpalVideoTranscoder.
void OpalTranscoder::NotifyCommand | ( | const OpalMediaCommand & | command | ) | const |
Notify command notifier of command.
static bool OpalTranscoder::SelectFormats | ( | const OpalMediaType & | mediaType, |
const OpalMediaFormatList & | srcFormats, | ||
const OpalMediaFormatList & | dstFormats, | ||
const OpalMediaFormatList & | allFormats, | ||
OpalMediaFormat & | srcFormat, | ||
OpalMediaFormat & | dstFormat | ||
) | [static] |
Find media format(s) for transcoders. This function attempts to find and intermediate media format that will allow two transcoders to be used to get data from the source format to the destination format.
There could be many possible matches between the two lists, so preference is given to the order of the destination formats.
At least one of the two selected medai formats (source or destination) must also be of the specified media type ("audio", "video" etc).
Returns false if there is no registered media transcoder that can be used to get from src to dst for the media type.
mediaType | Media type for selection. |
srcFormats | Names of possible source formats |
dstFormats | Names of possible destination formats |
allFormats | Master list of formats for merging options |
srcFormat | Selected source format to be used |
dstFormat | Selected destination format to be used |
void OpalTranscoder::SetCommandNotifier | ( | const PNotifier & | notifier | ) | [inline] |
Set a notifier to receive commands generated by the transcoder. The commands are highly context sensitive, for example OpalVideoUpdatePicture would only apply to a video transcoder.
notifier | Command to execute. |
References commandNotifier.
virtual void OpalTranscoder::SetInstanceID | ( | const BYTE * | instance, |
unsigned | instanceLen | ||
) | [virtual] |
Set the unique instance identifier for transcoder
instance | Unique instance identifier for transcoder |
instanceLen | Length of instance identifier |
void OpalTranscoder::SetMaxOutputSize | ( | PINDEX | size | ) | [inline] |
Set the maximum output size.
References maxOutputSize.
void OpalTranscoder::SetSessionID | ( | unsigned | id | ) | [inline] |
Set session ID for the transcoder (from OpalMediaStream)
References m_sessionID.
virtual bool OpalTranscoder::UpdateMediaFormats | ( | const OpalMediaFormat & | inputMediaFormat, |
const OpalMediaFormat & | outputMediaFormat | ||
) | [virtual] |
Update the input and output media formats. This can be used to adjust the parameters of a codec at run time. Note you cannot change the basic media format, eg change GSM0610 to G.711, only options for that format, eg 6k3 mode to 5k3 mode in G.723.1. If the formats are different then a OpalMediaFormat::Merge() is performed.
If a format is empty (invalid) it is ignored and does not update the internal variable. In this way only the input or output side can be updated.
The default behaviour updates the inputMediaFormat and outputMediaFormat member variables.
inputMediaFormat | Input media format |
outputMediaFormat | Output media format |
Reimplemented in OpalFramedTranscoder, OpalPluginVideoTranscoder, OpalPluginStreamedAudioTranscoder, OpalPluginFramedAudioTranscoder, and OpalVideoTranscoder.
bool OpalTranscoder::acceptEmptyPayload [protected] |
Referenced by AcceptEmptyPayload().
bool OpalTranscoder::acceptOtherPayloads [protected] |
Referenced by AcceptOtherPayloads().
PNotifier OpalTranscoder::commandNotifier [protected] |
Referenced by GetCommandNotifier(), and SetCommandNotifier().
bool OpalTranscoder::inputIsRTP [protected] |
unsigned OpalTranscoder::m_inClockRate [protected] |
unsigned OpalTranscoder::m_outClockRate [protected] |
unsigned OpalTranscoder::m_sessionID [protected] |
Referenced by GetSessionID(), and SetSessionID().
PINDEX OpalTranscoder::maxOutputSize [protected] |
Referenced by GetMaxOutputSize(), and SetMaxOutputSize().
bool OpalTranscoder::outputIsRTP [protected] |
PMutex OpalTranscoder::updateMutex [protected] |