GetSample Method (original) (raw)
Summary
Gets a media sample delivered from a stream.
Syntax
Parameters
Stream
The zero based stream index for which to get the sample.
lTimeout
Maximum time to wait for a sample, in milliseconds. If lTimeOut is -1, the method's time-out interval never elapses.
Return Value
A MediaSample object
Example
using Leadtools;
using Leadtools.Multimedia;
using LeadtoolsMultimediaExamples.Fixtures;
public bool _result = false;
public ConvertCtrlForm _form = new ConvertCtrlForm();
public ConvertCtrl _convertctrl;
// input files and output file
string inFile1 = Path.Combine(LEAD_VARS.MediaDir, "ConvertCtrl_Source1.avi");
string inFile2 = Path.Combine(LEAD_VARS.MediaDir, "ConvertCtrl_Source2.avi");
string outFile = Path.Combine(LEAD_VARS.MediaDir, "ConvertCtrl_ConcatAVIFilesExample.avi");
public void ConcatAVIFilesExample()
{
ConvertCtrl pConvert1;
ConvertCtrl pConvert2;
MultiStreamSource pMSSource;
MultiStreamTarget pMSTarget;
Int64 lStart, lVideoMediaStart, lAudioMediaStart;
MediaType pmt;
MediaType pInsertedMediaType;
pConvert1 = new ConvertCtrl(true);
pConvert2 = new ConvertCtrl(true);
pMSSource = new MultiStreamSource();
pMSTarget = new MultiStreamTarget();
// set the start time to be 0
lStart = 0;
lVideoMediaStart = 0;
lAudioMediaStart = 0;
// set the input filename
pConvert1.SourceFile = inFile1;
// set the output sample to a target object
pMSTarget.StreamCount = 2;
// set the target media types for video and audio streams
pmt = new MediaType();
pmt.Type = Constants.MEDIATYPE_Video;
pMSTarget.SetAcceptedMediaType(0, pmt);
pmt.Type = Constants.MEDIATYPE_Audio;
pMSTarget.SetAcceptedMediaType(1, pmt);
pmt = null;
// get the inserted media type for the first stream
pInsertedMediaType = pMSTarget.GetAcceptedMediaType(0);
pInsertedMediaType = null;
// set convert 1 target object
pConvert1.TargetObject = pMSTarget;
// start the source conversion, so we can get the media sample format
pConvert1.StartConvert();
// initialize convert 2
// get the output media sample format and put it into the source object
pMSSource.StreamCount = 2;
pmt = pMSTarget.GetConnectedMediaType(0);
pMSSource.SetMediaType(0, pmt);
pmt = null;
pmt = pMSTarget.GetConnectedMediaType(1);
pMSSource.SetMediaType(1, pmt);
pmt = null;
// get the inserted media type for the first stream
pInsertedMediaType = pMSSource.GetMediaType(0);
pInsertedMediaType = null;
// set the output filename
pConvert2.TargetFile = outFile;
// set the source for convert 2
pConvert2.SourceObject = pMSSource;
// start the dest conversion
pConvert2.StartConvert();
// convert first file
ConcateFile(pConvert1, pMSTarget, pMSSource, ref lStart, ref lVideoMediaStart, ref lAudioMediaStart);
/*
Restrict the output format to the media type of the source for the first file
That is because the two files must have the same media type for both video and audio
With video, you have to make sure the files have the same frame rate! Minor changes in
the frame rate might make the connection fail!
The control will tolerate differences in frame rate if you comment the next line
*/
pmt = pMSTarget.GetConnectedMediaType(0);
pMSTarget.SetAcceptedMediaType(0, pmt);
pmt = null;
pmt = pMSTarget.GetConnectedMediaType(1);
pMSTarget.SetAcceptedMediaType(1, pmt);
pmt = null;
// change the source file to second file
pConvert1.SourceFile = inFile2;
// start converting again
pConvert1.StartConvert();
// convert second file
ConcateFile(pConvert1, pMSTarget, pMSSource, ref lStart, ref lVideoMediaStart, ref lAudioMediaStart);
// deliver end of sample to stop the conversion
pMSSource.DeliverEndOfStream(0, 1000);
pMSSource.DeliverEndOfStream(1, 1000);
if (pConvert2.State == ConvertState.Running)
pConvert2.StopConvert();
// free the source and target objects
pConvert2.ResetSource();
pConvert1.ResetTarget();
pConvert1.Dispose();
pConvert2.Dispose();
pMSSource.Dispose();
pMSTarget.Dispose();
_result = File.Exists(outFile);
}
void ConcateFile(ConvertCtrl pConvert1,
MultiStreamTarget pMSTarget,
MultiStreamSource pMSSource,
ref long lStart,
ref long lVideoMediaStart,
ref long lAudioMediaStart)
{
MediaSample pmsSrc = null;
MediaSample pmsDst = null;
long MediaTimeStart;
long MediaTimeStop;
long LastVideoMediaStop;
long LastAudioMediaStop;
long LastStart;
long LastStop;
int lSampleStream;
int lActualDataLength;
LastStop = 0;
LastVideoMediaStop = 0;
LastAudioMediaStop = 0;
do
{
// get the sample, allowing 10 s for the operation to complete
try
{
lSampleStream = pMSTarget.WaitForSample(1000);
}
catch (COMException cex)
{
if (cex.ErrorCode == (int)ErrorCode.VFW_E_TIMEOUT)
{
// end of the stream
break;
}
_result = false;
break;
}
try
{
// get the target sample
pmsSrc = pMSTarget.GetSample(lSampleStream, 0);
// get the source buffer
pmsDst = pMSSource.GetSampleBuffer(lSampleStream, 2000);
}
catch (Exception)
{
_result = false;
break;
}
try
{
// get the source media time
pmsSrc.GetMediaTime(out MediaTimeStart, out MediaTimeStop);
// check sample media type
MediaType sampleMediaType = pMSTarget.GetConnectedMediaType(lSampleStream);
if (sampleMediaType.Type == Constants.MEDIATYPE_Video) // video stream media time
{
pmsDst.SetMediaTime(MediaTimeStart + lVideoMediaStart, MediaTimeStop + lVideoMediaStart);
LastVideoMediaStop = MediaTimeStop;
}
else // audio stream media time
{
pmsDst.SetMediaTime(MediaTimeStart + lAudioMediaStart, MediaTimeStop + lAudioMediaStart);
LastAudioMediaStop = MediaTimeStop;
}
}
catch (Exception)
{
pmsDst.ResetMediaTime();
}
try
{
// get the source sample time
pmsSrc.GetTime(out LastStart, out LastStop);
// set the destination sample time
pmsDst.SetTime(lStart + LastStart, lStart + LastStop);
}
catch(Exception)
{
pmsDst.ResetTime();
}
// copy the data
lActualDataLength = pmsSrc.ActualDataLength;
// set the destination buffer
// we could Marshal the unmanaged buffer here, but no need since we are mearly
// setting the destination to the source buffer contents (unaltered data)
pmsDst.SetData(lActualDataLength, pmsSrc.GetData(lActualDataLength));
// copy the other flags
pmsDst.Discontinuity = pmsSrc.Discontinuity;
pmsDst.Preroll = pmsSrc.Preroll;
pmsDst.SyncPoint = pmsSrc.SyncPoint;
// dispose the source sample, since we don't need it anymore. This makes the buffer available for reuse
pmsSrc.Dispose();
// deliver the destination sample
pMSSource.DeliverSample(lSampleStream, 1000, pmsDst);
// dispose the destination sample, since we don't need it anymore. This makes the buffer available for reuse
pmsDst.Dispose();
}
while (true);
pConvert1.StopConvert();
lStart += LastStop;
lVideoMediaStart += LastVideoMediaStop;
lAudioMediaStart += LastAudioMediaStop;
}
static class LEAD_VARS
{
public const string MediaDir = @"C:\LEADTOOLS23\Media";
}