/// <summary>
/// Reads one frame from srcStream, performs duplicate check, writes to dstStream.
/// Call it repeatedly until all frames are processed (until false is returned).
/// </summary>
bool ProcessNextFrame()
{
if (!dupFinder.Progress())
{
return(false);
}
var dups = dupFinder.duplicates;
int lastProcessedFrameIndex = dupFinder.framesProcessed - 1;
int lookbackFrameIndex = dups [lastProcessedFrameIndex];
if (!string.IsNullOrEmpty(logDuplicatesPath))
{
using (var file = File.AppendText(logDuplicatesPath)) {
file.WriteLine(lastProcessedFrameIndex + " " + lookbackFrameIndex);
}
}
byte[] buf;
if (lookbackFrameIndex < 0 || !remux.WriteLookbackVideoFrame(lookbackFrameIndex))
{
movie.demux.VideoPosition = lastProcessedFrameIndex;
int bytesRead = movie.demux.ReadVideoFrame(out buf);
remux.WriteNextVideoFrame(buf, bytesRead);
}
if (!discardAudio && movie.demux.hasAudio)
{
int wantCnt = Mathf.RoundToInt(movie.demux.audioStreamInfo.sampleRate / movie.demux.videoStreamInfo.framerate);
movie.demux.AudioPosition = lastProcessedFrameIndex * wantCnt;
int samplesRead = movie.demux.ReadAudioSamples(out buf, wantCnt);
remux.WriteNextAudioSamples(buf, samplesRead * movie.demux.audioStreamInfo.sampleSize);
}
return(true);
}
void DropHalfTheFramesRemux()
{
// In this example we're going one level deeper in the API and work directly
// with Demux class. We could use MoviePlayerUtil.Load too, but for remuxing
// we don't need Decoders to be instantiated, because we're just copying encoded
// frame bytes around.
//
// Since we're not using decoders, we're not referencing anything from Unity API.
// Therefore it's possible to run it in separate thread.
RunInBackgroundOrNot(delegate() {
// Instantiate a demux for an input stream based on stream type.
Stream instream = File.OpenRead(infile);
Demux demux = Demux.forSource(instream);
demux.Init(instream);
// Instantiate a remux for an output stream. Here we have to explicity
// instantiate the remux we want, in this case, AviRemux, and set its
// properties. Since we're not doing much here, we can use the same
// videoStreamInfo and audioStreamInfo for remux as demux. For the video
// however we clone the stream info, because we want to change it. Since
// we're going to drop every other frame, we also need to lower the
// video framerate.
Stream outstream = File.OpenWrite(outfile);
Remux remux = new AviRemux();
var remuxVideoStreamInfo = new VideoStreamInfo(demux.videoStreamInfo);
remuxVideoStreamInfo.framerate /= 2;
remux.Init(outstream, remuxVideoStreamInfo, demux.audioStreamInfo);
// Just sum buffers and variables needed later
byte[] videoBuffer, audioBuffer;
int videoBytesRead, audioBytesRead;
// Loop until we've processed all the video frames. If we wanted to run this code
// in main Unity thread without blocking, then we could wrap it all in a coroutine
// and do "yield return 1" inside the loop.
do
{
// Here we're using sequential access to video (and audio) stream. The same could
// be achieved with random access, but then only demuxes that can seek in a file
// can be used (no streaming from network or webcam).
videoBytesRead = demux.ReadVideoFrame(out videoBuffer);
if (videoBytesRead > 0)
{
// Read the exact number of audio samples that are to be played during this frame
int samplesPerVideoFrame = (int)(demux.audioStreamInfo.sampleRate / demux.videoStreamInfo.framerate);
audioBytesRead = demux.ReadAudioSamples(out audioBuffer, samplesPerVideoFrame);
// Only write every second video frame, but all the audio samples. The total stream
// lengths will still be the same, because we've set the framerate for remuxed stream
// to half of the original.
if (demux.VideoPosition % 2 == 1)
{
remux.WriteNextVideoFrame(videoBuffer, videoBytesRead);
}
remux.WriteNextAudioSamples(audioBuffer, audioBytesRead);
}
} while(videoBytesRead > 0);
// Close the remux and demux. While it's possible to leave demux just hanging there unclosed and
// possibly introducing a memory leak, we have to Close the remux for the output to be playable.
// The reason is that AviDemux needs to write all unwritten index chunks and update the avi header
// after all frames have been written.
remux.Shutdown();
demux.Shutdown();
});
}
