public List <FrameField> GetVideoFrameFields(List <int> fieldNumbers)
{
var result = new List <FrameField>();
fieldNumbers = (from f in fieldNumbers orderby f select f).ToList();
foreach (var frameNumber in fieldNumbers)
{
if ((frameNumber < 0) || (frameNumber >= TotalFields))
{
result.Add(null);
continue;
}
SeekToField(frameNumber, SeekModes.Accurate);
if (_pendingFrame != null)
{
FrameField frame = _pendingFrame.Fields[_pendingFrame.CurrentIndex];
//frame.Image.Save(@"D:\temp\image-" + frame.FrameNumber.ToString("00000") + ".png", System.Drawing.Imaging.ImageFormat.Png);
result.Add(frame);
}
else
{
result.Add(null);
}
_pendingFrame.CurrentIndex++;
if (_pendingFrame.CurrentIndex >= _pendingFrame.Fields.Length)
{
_pendingFrame = ReadVideoFrame();
}
}
return(result);
}
private void SeekToPTS(long pts, SeekModes seekMode)
{
if (seekMode == SeekModes.PreviousKeyFrame)
{
SeekToPTS(pts, true);
}
else if (seekMode == SeekModes.NextKeyFrame)
{
SeekToPTS(pts, false);
while (!_pendingFrame.IsKeyFrame)
{
var previousFrame = _pendingFrame;
_pendingFrame = ReadVideoFrame();
if (_pendingFrame == null)
{
_pendingFrame = previousFrame;
return;
}
DisposeFrame(ref previousFrame);
}
}
else
{
SeekToPTS(pts, false);
}
}
private static void DisposeFrame(ref PendingFrame frame)
{
if (frame != null)
{
frame.Dispose();
frame = null;
}
}
public FrameField GetVideoFrameField(int fieldNumber, SeekModes seekMode = SeekModes.Accurate)
{
FrameField frame = null;
SeekToField(fieldNumber, seekMode);
if (_pendingFrame != null)
{
frame = _pendingFrame.Fields[_pendingFrame.CurrentIndex];
//frame.Image.Save(@"D:\temp\image-" + frame.FrameNumber.ToString("00000") + ".png", System.Drawing.Imaging.ImageFormat.Png);
}
_pendingFrame.CurrentIndex++;
if (_pendingFrame.CurrentIndex >= _pendingFrame.Fields.Length)
{
_pendingFrame = ReadVideoFrame();
}
return(frame);
}
private PendingFrame ProcessFrame()
{
_frameOrig = (FFmpeg.AVFrame)Marshal.PtrToStructure(_pFrameOrig, typeof(FFmpeg.AVFrame));
IntPtr pStream = Marshal.ReadIntPtr(_formatContext.streams, _videoStreamIndex * 4);
var stream = (FFmpeg.AVStream)Marshal.PtrToStructure(pStream, typeof(FFmpeg.AVStream));
_videoCodecContext = (FFmpeg.AVCodecContext)Marshal.PtrToStructure(stream.codec, typeof(FFmpeg.AVCodecContext));
if (_videoFrameFirstDTS == null)
{
_videoFrameFirstDTS = _frameOrig.pkt_dts;
}
if (_videoFieldDTSDuration == null)
{
_videoFieldDTSDuration = _frameOrig.pkt_duration / _videoCodecContext.ticks_per_frame;
}
var fieldList = new List <FrameField>();
//---------- Start YUV Image ----------
if (OutputYData || OutputYImage)
{
_scalerY.ProcessImage(_pFrameOrig, _frameOrig);
}
//---------- End YUV Image ----------
//---------- Start RGB Image ----------
if (OutputRGBImage && !OutputYImage)
{
_scalerRGB.ProcessImage(_pFrameOrig, _frameOrig);
}
//---------- End RGB Image ----------
for (int fieldIndex = 0; fieldIndex < _videoCodecContext.ticks_per_frame; fieldIndex++)
{
var field = new FrameField();
if (OutputYData || OutputYImage)
{
field.YData = _scalerY.GetYData(fieldIndex);
if (OutputYImage)
{
field.Image = _scalerY.GetImage(fieldIndex);
//field.Image.Save(@"D:\temp\image.png", System.Drawing.Imaging.ImageFormat.Png);
}
}
if (OutputRGBImage && !OutputYImage)
{
field.Image = _scalerRGB.GetImage(fieldIndex);
//field.Image.Save(@"D:\temp\image.png", System.Drawing.Imaging.ImageFormat.Png);
}
field.PTS = (_frameOrig.pkt_dts - _videoFrameFirstDTS.Value) + (fieldIndex * _videoFieldDTSDuration.Value);
field.Seconds = field.PTS * _videoCodecContext.pkt_timebase.num / (double)_videoCodecContext.pkt_timebase.den;
field.FieldIndex = fieldIndex;
field.FieldNumber = (int)(field.PTS / _videoFieldDTSDuration.Value);
field.FrameNumber = (int)(field.FieldNumber / _videoCodecContext.ticks_per_frame);
field.FilePosition = _frameOrig.pkt_pos;
field.AVFrame = _frameOrig;
fieldList.Add(field);
}
var frame = new PendingFrame();
frame.Fields = fieldList.ToArray();
return(frame);
}
private void SeekToPTS(long pts, bool stopAtKeyframe, bool forceSeek = false)
{
if (forceSeek == false)
{
if ((_pendingFrame != null) && (_pendingFrame.Fields != null))
{
for (int fieldIndex = 0; fieldIndex < _pendingFrame.Fields.Length; fieldIndex++)
{
var field = _pendingFrame.Fields[fieldIndex];
if ((field.PTS == pts))
{
_pendingFrame.CurrentIndex = fieldIndex;
return;
}
}
}
}
long seekPTS = pts;
if (seekPTS < long.MaxValue)
{
seekPTS = seekPTS / PTSPerField / _videoCodecContext.ticks_per_frame * _videoCodecContext.ticks_per_frame * PTSPerField;
if (long.MaxValue - seekPTS > _videoFrameFirstDTS.Value)
{
seekPTS += _videoFrameFirstDTS.Value;
}
}
var originalPendingFrame = _pendingFrame;
long lastSeekFilePosition = -1L;
while (true)
{
if (seekPTS < 0)
{
seekPTS = 0;
}
int ret = FFmpeg.avformat_seek_file(_pFormatContext, _videoStreamIndex, 0, seekPTS, seekPTS, FFmpeg.AVSEEK_FLAG.AVSEEK_FLAG_NONE);
if (ret < 0)
{
throw new Exception("Failed to seek to first frame: " + ret.ToString());
}
FFmpeg.avcodec_flush_buffers(_pVideoCodecContext);
var pb = (FFmpeg.ByteIOContext)Marshal.PtrToStructure(_formatContext.pb, typeof(FFmpeg.ByteIOContext));
if (lastSeekFilePosition != -1L)
{
if ((lastSeekFilePosition == pb.pos) && (seekPTS != 0))
{
seekPTS -= (PTSPerField * _videoCodecContext.ticks_per_frame);
continue;
}
}
lastSeekFilePosition = pb.pos;
if (_pendingFrame != originalPendingFrame)
{
DisposeFrame(ref _pendingFrame);
}
_pendingFrame = ReadVideoFrame();
if (_pendingFrame != null)
{
if (_pendingFrame.Fields.First().PTS == pts)
{
return;
}
if (_pendingFrame.Fields.First().PTS > pts)
{
if (seekPTS == 0)
{
return;
}
seekPTS -= PTSPerField * _videoCodecContext.ticks_per_frame;
continue;
}
while (true)
{
if (stopAtKeyframe && _pendingFrame.IsKeyFrame)
{
_pendingFrame.CurrentIndex = 0;
return;
}
for (int fieldIndex = 0; fieldIndex < _pendingFrame.Fields.Length; fieldIndex++)
{
var field = _pendingFrame.Fields[fieldIndex];
if (field.PTS >= pts)
{
_pendingFrame.CurrentIndex = fieldIndex;
return;
}
}
var previousFrame = _pendingFrame;
_pendingFrame = ReadVideoFrame();
if (_pendingFrame == null)
{
_pendingFrame = previousFrame;
_pendingFrame.CurrentIndex = _pendingFrame.Fields.Length - 1;
return;
}
if (previousFrame != originalPendingFrame)
{
DisposeFrame(ref previousFrame);
}
}
}
}
}
