#include <transcoders.h>
Inheritance diagram for OpalTranscoder:
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 |
void OpalTranscoder::AddRTPPayloadMapping | ( | RTP_DataFrame::PayloadTypes | from, | |
RTP_DataFrame::PayloadTypes | to | |||
) | [inline] |
virtual BOOL 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 Opal_GSM0610_PCM, OpalVideoTranscoder, OpalFramedTranscoder, and OpalStreamedTranscoder.
virtual BOOL 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 Opal_H261_YUV420P, Opal_YUV420P_H261, and OpalUncompVideoTranscoder.
static OpalTranscoder* OpalTranscoder::Create | ( | const OpalMediaFormat & | srcFormat, | |
const OpalMediaFormat & | dstFormat | |||
) | [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 |
virtual BOOL OpalTranscoder::ExecuteCommand | ( | const OpalMediaCommand & | command | ) | [virtual] |
Execute the command specified to the transcoder. The commands are highly context sensitive, for example VideoFastUpdate would only apply to a video transcoder.
The default behaviour simply returns FALSE.
command | Command to execute. |
Reimplemented in 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.
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 VideoFastUpdate would only apply to a video transcoder.
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.
virtual PINDEX OpalTranscoder::GetOptimalDataFrameSize | ( | BOOL | 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 Opal_H261_YUV420P, Opal_YUV420P_H261, OpalUncompVideoTranscoder, OpalFramedTranscoder, and OpalStreamedTranscoder.
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 |
static OpalMediaFormatList OpalTranscoder::GetSourceFormats | ( | const OpalMediaFormat & | dstFormat | ) | [static] |
Get a list of possible source media formats for the destination.
dstFormat | Selected destination format |
static BOOL OpalTranscoder::SelectFormats | ( | unsigned | sessionID, | |
const OpalMediaFormatList & | srcFormats, | |||
const OpalMediaFormatList & | dstFormats, | |||
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.
Returns FALSE if there is no registered media transcoder that can be used between the two named formats.
sessionID | Session ID for media formats |
srcFormats | Names of possible source formats |
dstFormats | Names of possible destination formats |
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 VideoFastUpdate would only apply to a video transcoder.
notifier | Command to execute. |
void OpalTranscoder::SetMaxOutputSize | ( | PINDEX | size | ) | [inline] |
Set the maximum output size.
void OpalTranscoder::SetRTPPayloadMap | ( | const RTP_DataFrame::PayloadMapType & | v | ) | [inline] |
virtual BOOL OpalTranscoder::UpdateOutputMediaFormat | ( | const OpalMediaFormat & | mediaFormat | ) | [virtual] |
Update the output media format. 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.
The default behaviour updates the outputMediaFormat member variable and sets the outputMediaFormatUpdated flag.
mediaFormat | New media format |
Reimplemented in OpalVideoTranscoder.
PNotifier OpalTranscoder::commandNotifier [protected] |
PINDEX OpalTranscoder::maxOutputSize [protected] |
bool OpalTranscoder::outputMediaFormatUpdated [protected] |
PMutex OpalTranscoder::updateMutex [protected] |