diff options
| -rw-r--r-- | src/media/UVideo.pas | 135 |
1 files changed, 85 insertions, 50 deletions
diff --git a/src/media/UVideo.pas b/src/media/UVideo.pas index 06577d9e..197fc572 100644 --- a/src/media/UVideo.pas +++ b/src/media/UVideo.pas @@ -126,6 +126,7 @@ type fFrameBuffer: PByte; //**< stores a FFmpeg video frame fFrameTex: GLuint; //**< OpenGL texture for FrameBuffer + fFrameTexValid: boolean; //**< if true, fFrameTex contains the current frame fTexWidth, fTexHeight: cardinal; {$IFDEF UseSWScale} @@ -137,11 +138,11 @@ type fTimeBase: extended; //**< FFmpeg time base per time unit fTime: extended; //**< video time position (absolute) - fLoopTime: extended; //**< video time position (relative to current loop) + fLoopTime: extended; //**< start time of the current loop procedure Reset(); - function DecodeFrame(var AVPacket: TAVPacket; out pts: double): boolean; - procedure SynchronizeVideo(Frame: PAVFrame; var pts: double); + function DecodeFrame(): boolean; + procedure SynchronizeTime(Frame: PAVFrame; var pts: double); procedure GetVideoRect(var ScreenRect, TexRect: TRectCoords); @@ -240,6 +241,7 @@ begin fTime := 0; fStream := nil; fStreamIndex := -1; + fFrameTexValid := false; fEOF := false; @@ -453,7 +455,7 @@ begin fOpened := False; end; -procedure TVideoPlayback_FFmpeg.SynchronizeVideo(Frame: PAVFrame; var pts: double); +procedure TVideoPlayback_FFmpeg.SynchronizeTime(Frame: PAVFrame; var pts: double); var FrameDelay: double; begin @@ -473,12 +475,21 @@ begin fTime := fTime + FrameDelay; end; -function TVideoPlayback_FFmpeg.DecodeFrame(var AVPacket: TAVPacket; out pts: double): boolean; +{** + * Decode a new frame from the video stream. + * The decoded frame is stored in fAVFrame. fTime is updated to the new frame's + * time. + * @param pts will be updated to the presentation time of the decoded frame. + * returns true if a frame could be decoded. False if an error or EOF occured. + *} +function TVideoPlayback_FFmpeg.DecodeFrame(): boolean; var FrameFinished: Integer; VideoPktPts: int64; pbIOCtx: PByteIOContext; errnum: integer; + AVPacket: TAVPacket; + pts: double; begin Result := false; FrameFinished := 0; @@ -555,9 +566,9 @@ begin end; pts := pts * av_q2d(fStream^.time_base); - // synchronize on each complete frame + // synchronize time on each complete frame if (frameFinished <> 0) then - SynchronizeVideo(fAVFrame, pts); + SynchronizeTime(fAVFrame, pts); end; // free the packet from av_read_frame @@ -569,13 +580,12 @@ end; procedure TVideoPlayback_FFmpeg.GetFrame(Time: Extended); var - AVPacket: TAVPacket; errnum: Integer; - myTime: Extended; + NewTime: Extended; TimeDifference: Extended; DropFrameCount: Integer; - pts: double; i: Integer; + Success: boolean; const FRAME_DROPCOUNT = 3; begin @@ -585,41 +595,50 @@ begin if fPaused then Exit; - // current time, relative to last fLoop (if any) - myTime := Time - fLoopTime; - // time since the last frame was returned - TimeDifference := myTime - fTime; - - {$IFDEF DebugDisplay} - DebugWriteln('Time: '+inttostr(floor(Time*1000)) + sLineBreak + - 'VideoTime: '+inttostr(floor(fTime*1000)) + sLineBreak + - 'TimeBase: '+inttostr(floor(fTimeBase*1000)) + sLineBreak + - 'TimeDiff: '+inttostr(floor(TimeDifference*1000))); - {$endif} + // requested stream position (relative to the last loop's start) + NewTime := Time - fLoopTime; - // check if a new frame is needed - if (fTime <> 0) and (TimeDifference < fTimeBase) then + // check if current texture still contains the active frame + if (fFrameTexValid) then begin - {$ifdef DebugFrames} - // frame delay debug display - GoldenRec.Spawn(200,15,1,16,0,-1,ColoredStar,$00ff00); - {$endif} + // time since the last frame was returned + TimeDifference := NewTime - fTime; {$IFDEF DebugDisplay} - DebugWriteln('not getting new frame' + sLineBreak + - 'Time: '+inttostr(floor(Time*1000)) + sLineBreak + - 'VideoTime: '+inttostr(floor(fTime*1000)) + sLineBreak + - 'TimeBase: '+inttostr(floor(fTimeBase*1000)) + sLineBreak + - 'TimeDiff: '+inttostr(floor(TimeDifference*1000))); + DebugWriteln('Time: '+inttostr(floor(Time*1000)) + sLineBreak + + 'VideoTime: '+inttostr(floor(fTime*1000)) + sLineBreak + + 'TimeBase: '+inttostr(floor(fTimeBase*1000)) + sLineBreak + + 'TimeDiff: '+inttostr(floor(TimeDifference*1000))); {$endif} - // we do not need a new frame now - Exit; + // check if last time is more than one frame in the past + if (TimeDifference < fTimeBase) then + begin + {$ifdef DebugFrames} + // frame delay debug display + GoldenRec.Spawn(200,15,1,16,0,-1,ColoredStar,$00ff00); + {$endif} + + {$IFDEF DebugDisplay} + DebugWriteln('not getting new frame' + sLineBreak + + 'Time: '+inttostr(floor(Time*1000)) + sLineBreak + + 'VideoTime: '+inttostr(floor(fTime*1000)) + sLineBreak + + 'TimeBase: '+inttostr(floor(fTimeBase*1000)) + sLineBreak + + 'TimeDiff: '+inttostr(floor(TimeDifference*1000))); + {$endif} + + // we do not need a new frame now + Exit; + end; end; - // update video-time to the next frame - fTime := fTime + fTimeBase; - TimeDifference := myTime - fTime; + {$IFDEF VideoBenchmark} + Log.BenchmarkStart(15); + {$ENDIF} + + // fetch new frame (updates fTime) + Success := DecodeFrame(); + TimeDifference := NewTime - fTime; // check if we have to skip frames if (TimeDifference >= FRAME_DROPCOUNT*fTimeBase) then @@ -640,19 +659,18 @@ begin // skip half of the frames, this is much smoother than to skip all at once for i := 1 to DropFrameCount (*div 2*) do - DecodeFrame(AVPacket, pts); + Success := DecodeFrame(); end; - {$IFDEF VideoBenchmark} - Log.BenchmarkStart(15); - {$ENDIF} - - if (not DecodeFrame(AVPacket, pts)) then + // check if we got an EOF or error + if (not Success) then begin if fLoop then begin - // Record the time we looped. This is used to keep the loops in time. otherwise they speed + // we have to loop, so rewind SetPosition(0); + // record the start-time of the current loop, so we can + // determine the position in the stream (fTime-fLoopTime) later. fLoopTime := Time; end; Exit; @@ -695,6 +713,9 @@ begin fCodecContext^.width, fCodecContext^.height, PIXEL_FMT_OPENGL, GL_UNSIGNED_BYTE, fAVFrameRGB^.data[0]); + if (not fFrameTexValid) then + fFrameTexValid := true; + {$ifdef DebugFrames} //frame decode debug display GoldenRec.Spawn(200, 35, 1, 16, 0, -1, ColoredStar, $ffff00); @@ -738,7 +759,9 @@ begin acoLetterBox: begin ScaledVideoWidth := RenderW; ScaledVideoHeight := RenderH * ScreenAspect/fAspect; - end; + end + else + raise Exception.Create('Unhandled aspect correction!'); end; // center video @@ -858,6 +881,14 @@ procedure TVideoPlayback_FFmpeg.Stop; begin end; +{** + * Sets the stream's position. + * The stream is set to the first keyframe with timestamp <= Time. + * Note that fTime is set to Time no matter if the actual position seeked to is + * at Time or the time of a preceding keyframe. fTime will be updated to the + * actual frame time when GetFrame() is called the next time. + * @param Time new position in seconds + *} procedure TVideoPlayback_FFmpeg.SetPosition(Time: real); var SeekFlags: integer; @@ -871,13 +902,18 @@ begin // TODO: handle fLoop-times //Time := Time mod VideoDuration; - // backward seeking might fail without AVSEEK_FLAG_BACKWARD - SeekFlags := AVSEEK_FLAG_ANY; - if (Time < fTime) then - SeekFlags := SeekFlags or AVSEEK_FLAG_BACKWARD; + // Do not use the AVSEEK_FLAG_ANY here. It will seek to any frame, even + // non keyframes (P-/B-frames). It will produce corrupted video frames as + // FFmpeg does not use the information of the preceding I-frame. + // The picture might be gray or green until the next keyframe occurs. + // Instead seek the first keyframe smaller than the requested time + // (AVSEEK_FLAG_BACKWARD). As this can be some seconds earlier than the + // requested time, let the sync in GetFrame() do its job. + SeekFlags := AVSEEK_FLAG_BACKWARD; fTime := Time; fEOF := false; + fFrameTexValid := false; if (av_seek_frame(fFormatContext, fStreamIndex, Floor(Time/fTimeBase), SeekFlags) < 0) then begin @@ -890,7 +926,6 @@ end; function TVideoPlayback_FFmpeg.GetPosition: real; begin - // TODO: return video-position in seconds Result := fTime; end; |