void ClientTrickPlayState::updateStateOnScaleChange()
{
fScale = fNextScale;
// Change our source objects to reflect the change in scale:
// First, close the existing trick play source (if any):
if (fTrickPlaySource != NULL)
{
fTrickModeFilter->forgetInputSource();
// so that the underlying Transport Stream source doesn't get deleted by:
Medium::close(fTrickPlaySource);
fTrickPlaySource = NULL;
fTrickModeFilter = NULL;
}
if (fNextScale != 1.0f)
{
// Create a new trick play filter from the original Transport Stream source:
UsageEnvironment &env = fIndexFile->envir(); // alias
fTrickModeFilter = MPEG2TransportStreamTrickModeFilter
::createNew(env, fOriginalTransportStreamSource, fIndexFile, int(fNextScale));
fTrickModeFilter->seekTo(fTSRecordNum, fIxRecordNum);
// And generate a Transport Stream from this:
fTrickPlaySource = MPEG2TransportStreamFromESSource::createNew(env);
fTrickPlaySource->addNewVideoSource(fTrickModeFilter, fIndexFile->mpegVersion());
fFramer->changeInputSource(fTrickPlaySource);
}
else
{
// Switch back to the original Transport Stream source:
reseekOriginalTransportStreamSource();
fFramer->changeInputSource(fOriginalTransportStreamSource);
}
}
unsigned long ClientTrickPlayState::updateStateFromNPT(double npt, double streamDuration) {
fNPT = (float)npt;
// Map "fNPT" to the corresponding Transport Stream and Index record numbers:
unsigned long tsRecordNum, ixRecordNum;
fIndexFile->lookupTSPacketNumFromNPT(fNPT, tsRecordNum, ixRecordNum);
updateTSRecordNum();
if (tsRecordNum != fTSRecordNum) {
fTSRecordNum = tsRecordNum;
fIxRecordNum = ixRecordNum;
// Seek the source to the new record number:
reseekOriginalTransportStreamSource();
// Note: We assume that we're asked to seek only in normal
// (i.e., non trick play) mode, so we don't seek within the trick
// play source (if any).
fFramer->clearPIDStatusTable();
}
unsigned long numTSRecordsToStream = 0;
float pcrLimit = 0.0;
if (streamDuration > 0.0) {
// fNPT might have changed when we looked it up in the index file. Adjust "streamDuration" accordingly:
streamDuration += npt - (double)fNPT;
if (streamDuration > 0.0) {
// Specify that we want to stream no more data than this.
if (fNextScale == 1.0f) {
// We'll be streaming from the original file.
// Use the index file to figure out how many Transport Packets we get to stream:
unsigned long toTSRecordNum, toIxRecordNum;
float toNPT = (float)(fNPT + streamDuration);
fIndexFile->lookupTSPacketNumFromNPT(toNPT, toTSRecordNum, toIxRecordNum);
if (toTSRecordNum > tsRecordNum) { // sanity check
numTSRecordsToStream = toTSRecordNum - tsRecordNum;
}
} else {
// We'll be streaming from the trick play stream.
// It'd be difficult to figure out how many Transport Packets we need to stream, so instead set a PCR
// limit in the trick play stream. (We rely upon the fact that PCRs in the trick play stream start at 0.0)
int direction = fNextScale < 0.0 ? -1 : 1;
pcrLimit = (float)(streamDuration/(fNextScale*direction));
}
}
}
fFramer->setNumTSPacketsToStream(numTSRecordsToStream);
fFramer->setPCRLimit(pcrLimit);
return numTSRecordsToStream;
}
void ClientTrickPlayState::updateStateFromNPT(double npt) {
fNPT = (float)npt;
// Map "fNPT" to the corresponding Transport Stream and Index record numbers:
unsigned long tsRecordNum, ixRecordNum;
fIndexFile->lookupTSPacketNumFromNPT(fNPT, tsRecordNum, ixRecordNum);
updateTSRecordNum();
if (tsRecordNum != fTSRecordNum) {
fTSRecordNum = tsRecordNum;
fIxRecordNum = ixRecordNum;
// Seek the source to the new record number:
reseekOriginalTransportStreamSource();
// Note: We assume that we're asked to seek only in normal
// (i.e., non trick play) mode, so we don't seek within the trick
// play source (if any).
fFramer->clearPIDStatusTable();
}
}
unsigned long ClientTrickPlayState::updateStateFromNPT(double npt, double streamDuration) {
fNPT = (float)npt;
// Map "fNPT" to the corresponding Transport Stream and Index record numbers:
unsigned long tsRecordNum, ixRecordNum;
fIndexFile->lookupTSPacketNumFromNPT(fNPT, tsRecordNum, ixRecordNum);
updateTSRecordNum();
if (tsRecordNum != fTSRecordNum) {
fTSRecordNum = tsRecordNum;
fIxRecordNum = ixRecordNum;
// Seek the source to the new record number:
reseekOriginalTransportStreamSource();
// Note: We assume that we're asked to seek only in normal
// (i.e., non trick play) mode, so we don't seek within the trick
// play source (if any).
fFramer->clearPIDStatusTable();
}
// NPT might have changed when we looked it up in the index file. Adjust "streamDuration" accordingly:
streamDuration += npt - (double)fNPT;
unsigned long numTSRecordsToStream = 0;
if (streamDuration > 0.0) {
// Use the index file to figure out how many Transport Packets we get to stream:
unsigned long toTSRecordNum, toIxRecordNum;
float toNPT = (float)(fNPT + streamDuration);
fIndexFile->lookupTSPacketNumFromNPT(toNPT, toTSRecordNum, toIxRecordNum);
if (toTSRecordNum > tsRecordNum) { // sanity check
numTSRecordsToStream = toTSRecordNum - tsRecordNum;
}
}
fFramer->setNumTSPacketsToStream(numTSRecordsToStream);
return numTSRecordsToStream;
}
