{############################################################################
#                   FFmpeg support for UltraStar deluxe                     #
#                                                                           #
#   Created by b1indy                                                       #
#   based on 'An ffmpeg and SDL Tutorial' (http://www.dranger.com/ffmpeg/)  #
#############################################################################}

//{$define DebugDisplay}  // uncomment if u want to see the debug stuff
//{$define DebugFrames}
//{$define Info}


unit UVideo;

interface

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}


uses SDL,
     UGraphicClasses,
     textgl,
     avcodec,
     avformat,
     avutil,
     math,
     OpenGL12,
     SysUtils,
     {$ifdef DebugDisplay}
     {$ifdef win32}
     dialogs,
     {$endif}
     {$ENDIF}
     UIni;

procedure Init;
procedure FFmpegOpenFile(FileName: pAnsiChar);
procedure FFmpegClose;
procedure FFmpegGetFrame(Time: Extended);
procedure FFmpegDrawGL(Screen: integer);
procedure FFmpegTogglePause;
procedure FFmpegSkip(Gap: Single; Start: Single);

var
  VideoOpened, VideoPaused: Boolean;
  VideoFormatContext: PAVFormatContext;
  VideoStreamIndex: Integer;
  VideoCodecContext: PAVCodecContext;
  VideoCodec: PAVCodec;
  AVFrame: PAVFrame;
  AVFrameRGB: PAVFrame;
  myBuffer: pByte;
  VideoTex: glUint;
  TexX, TexY, dataX, dataY: Cardinal;
  TexData: array of Byte;
  ScaledVideoWidth, ScaledVideoHeight: Real;
  VideoAspect: Real;
  VideoTextureU, VideoTextureV: Real;
  VideoTimeBase, VideoTime, LastFrameTime, TimeDifference, NegativeSkipTime: Extended;
  VideoSkipTime: Single;

implementation

{$ifdef DebugDisplay}
{$ifNdef win32}

procedure showmessage( aMessage : String );
begin
  writeln( aMessage );
end;

{$endif}
{$ENDIF}

procedure Init;
begin
  av_register_all;
  {$ifdef DebugDisplay}
  showmessage( 'AV_Register_ALL' );
  {$endif}
  
  VideoOpened:=False;
  VideoPaused:=False;
  
  glGenTextures(1, PglUint(@VideoTex));
  SetLength(TexData,0);
end;

procedure FFmpegOpenFile(FileName: pAnsiChar);
var errnum, i, x,y: Integer;
  lStreamsCount : Integer;
  rTimeBase: Extended;
begin
  VideoOpened    := False;
  VideoPaused    := False;
  VideoTimeBase  := 0;
  rTimeBase:=0;
  VideoTime      := 0;
  LastFrameTime  := 0;
  TimeDifference := 0;

  errnum         := av_open_input_file(VideoFormatContext, FileName, Nil, 0, Nil);
  
  if(errnum <> 0) then
  begin
{$ifdef DebugDisplay}
    case errnum of
      AVERROR_UNKNOWN: showmessage('failed to open file '+Filename+#13#10+'AVERROR_UNKNOWN');
      AVERROR_IO: showmessage('failed to open file '+Filename+#13#10+'AVERROR_IO');
      AVERROR_NUMEXPECTED: showmessage('failed to open file '+Filename+#13#10+'AVERROR_NUMEXPECTED');
      AVERROR_INVALIDDATA: showmessage('failed to open file '+Filename+#13#10+'AVERROR_INVALIDDATA');
      AVERROR_NOMEM: showmessage('failed to open file '+Filename+#13#10+'AVERROR_NOMEM');
      AVERROR_NOFMT: showmessage('failed to open file '+Filename+#13#10+'AVERROR_NOFMT');
      AVERROR_NOTSUPP: showmessage('failed to open file '+Filename+#13#10+'AVERROR_NOTSUPP');
    else showmessage('failed to open file '+Filename+#13#10+'Error number: '+inttostr(Errnum));
    end;
{$ENDIF}
    Exit;
  end
  else
  begin
    VideoStreamIndex:=-1;

    // Find which stream contains the video
    if(av_find_stream_info(VideoFormatContext) >= 0) then
    begin
      {$ifdef DebugDisplay}
       writeln( 'FFMPEG debug...  VideoFormatContext^.nb_streams : '+ inttostr( VideoFormatContext^.nb_streams ) );
      {$endif}
      for i:= 0 to MAX_STREAMS-1 do
      begin
        {$ifdef DebugDisplay}
        writeln( 'FFMPEG debug...  found stream '+ inttostr(i) + ' stream val ' + inttostr( integer(VideoFormatContext^.streams[i] ) ) );
        {$endif}
        try
          if assigned( VideoFormatContext                    ) AND
             assigned( VideoFormatContext^.streams[i]        ) AND
             assigned( VideoFormatContext^.streams[i]^.codec ) THEN
          begin
              {$ifdef DebugDisplay}
            writeln( 'FFMPEG debug...  found stream '+ inttostr(i) + ' code val ' + inttostr( integer(VideoFormatContext^.streams[i].codec ) ) );
            writeln( 'FFMPEG debug...  found stream '+ inttostr(i) + ' code Type ' + inttostr( integer(VideoFormatContext^.streams[i].codec^.codec_type ) ) );
              {$endif}
            if(VideoFormatContext^.streams[i]^.codec^.codec_type=CODEC_TYPE_VIDEO) then
            begin
              {$ifdef DebugDisplay}
              writeln( 'FFMPEG debug, found CODEC_TYPE_VIDEO stream' );
              {$endif}
              VideoStreamIndex:=i;
            end
            else
          end;
        except
          // TODO : JB_Linux ... this is excepting at line 108...  ( Was 111 previously.. so its prob todo with streams[i]^.codec ..
    {$ifdef DebugDisplay}
          writeln( 'FFMPEG error, finding video stream' );
    {$endif}
        end;

      end;
    end;
    
    if(VideoStreamIndex >= 0) then
    begin
      VideoCodecContext:=VideoFormatContext^.streams[VideoStreamIndex]^.codec;
      VideoCodec:=avcodec_find_decoder(VideoCodecContext^.codec_id);
    end
    else
    begin
{$ifdef DebugDisplay}
      showmessage('found no video stream');
{$ENDIF}
      av_close_input_file(VideoFormatContext);
      Exit;
    end;

    if(VideoCodec<>Nil) then
    begin
      errnum:=avcodec_open(VideoCodecContext, VideoCodec);
    end else begin
{$ifdef DebugDisplay}
      showmessage('no matching codec found');
{$ENDIF}
      avcodec_close(VideoCodecContext);
      av_close_input_file(VideoFormatContext);
      Exit;
    end;
    if(errnum >=0) then
    begin
{$ifdef DebugDisplay}
       showmessage('Found a matching Codec:'+#13#10#13#10+
        'Width='+inttostr(VideoCodecContext^.width)+
        ', Height='+inttostr(VideoCodecContext^.height)+#13#10+
        'Aspect: '+inttostr(VideoCodecContext^.sample_aspect_ratio.num)+'/'+inttostr(VideoCodecContext^.sample_aspect_ratio.den)+#13#10+
        'Framerate: '+inttostr(VideoCodecContext^.time_base.num)+'/'+inttostr(VideoCodecContext^.time_base.den)+#13#10+
        'rFrameRate: '+inttostr(VideoFormatContext^.streams[VideoStreamIndex]^.r_frame_rate.num)+'/'+inttostr(VideoFormatContext^.streams[VideoStreamIndex]^.r_frame_rate.den)
       );
{$endif}
      // allocate space for decoded frame and rgb frame
      AVFrame:=avcodec_alloc_frame;
      AVFrameRGB:=avcodec_alloc_frame;
    end;
    myBuffer:=Nil;
    if(AVFrame <> Nil) and (AVFrameRGB <> Nil) then
    begin
      TexX := VideoCodecContext^.width;
      TexY := VideoCodecContext^.height;
      dataX := Round(Power(2, Ceil(Log2(TexX))));
      dataY := Round(Power(2, Ceil(Log2(TexY))));
      if (dataX >1024) or (dataY>1024) then
      begin
{$ifdef DebugDisplay}
        showmessage('video too large');
{$endif}
        av_free(AVFrameRGB);
        av_free(AVFrame);
        avcodec_close(VideoCodecContext);
        av_close_input_file(VideoFormatContext);
        Exit;
      end;
      myBuffer:=av_malloc(avpicture_get_size(PIX_FMT_RGB24, dataX, dataY));
    end;
    if myBuffer <> Nil then errnum:=avpicture_fill(PAVPicture(AVFrameRGB), myBuffer, PIX_FMT_RGB24,
                dataX, dataY)
    else begin
{$ifdef DebugDisplay}
      showmessage('failed to allocate video buffer');
{$endif}
      av_free(AVFrameRGB);
      av_free(AVFrame);
      avcodec_close(VideoCodecContext);
      av_close_input_file(VideoFormatContext);
      Exit;
    end;
    if errnum >=0 then
    begin
      VideoOpened:=True;

      TexX := VideoCodecContext^.width;
      TexY := VideoCodecContext^.height;
      dataX := Round(Power(2, Ceil(Log2(TexX))));
      dataY := Round(Power(2, Ceil(Log2(TexY))));
      SetLength(TexData,dataX*dataY*3);
      // calculate some information for video display
      VideoAspect:=VideoCodecContext^.sample_aspect_ratio.num/VideoCodecContext^.sample_aspect_ratio.den;
      if (VideoAspect = 0) then
        VideoAspect:=VideoCodecContext^.width/VideoCodecContext^.height
      else
        VideoAspect:=VideoAspect*VideoCodecContext^.width/VideoCodecContext^.height;
//    if VideoAspect >= 4/3 then  // video-full-width-hack
      begin
        ScaledVideoWidth:=800.0;
        ScaledVideoHeight:=800.0/VideoAspect;
      end;
{    else                         // video-full-width-hack
      begin                       // video-full-width-hack
        ScaledVideoHeight:=600.0; // video-full-width-hack
        ScaledVideoWidth:=600.0*VideoAspect;  // video-full-width-hack
      end;                        // video-full-width-hack
}                                 // video-full-width-hack
//      VideoTimeBase:=VideoCodecContext^.time_base.num/VideoCodecContext^.time_base.den;
      VideoTimeBase:=VideoFormatContext^.streams[VideoStreamIndex]^.r_frame_rate.den/VideoFormatContext^.streams[VideoStreamIndex]^.r_frame_rate.num;
{$ifdef DebugDisplay}
      showmessage('framerate: '+inttostr(floor(1/videotimebase))+'fps');
{$endif}
      // hack to get reasonable timebase (for divx and others)
      if VideoTimeBase < 0.02 then // 0.02 <-> 50 fps
      begin
//        VideoTimeBase:=VideoCodecContext^.time_base.den/VideoCodecContext^.time_base.num;
        VideoTimeBase:=VideoFormatContext^.streams[VideoStreamIndex]^.r_frame_rate.num/VideoFormatContext^.streams[VideoStreamIndex]^.r_frame_rate.den;
        while VideoTimeBase > 50 do VideoTimeBase:=VideoTimeBase/10;
        VideoTimeBase:=1/VideoTimeBase;
      end;
//      // hack for flv (i always get 1000 fps from the file...)
//      if VideoCodecContext^.codec_id=CODEC_ID_FLV1 then VideoTimeBase:=1/29.970;

{$ifdef DebugDisplay}
      showmessage('corrected framerate: '+inttostr(floor(1/videotimebase))+'fps');

      if ((VideoAspect*VideoCodecContext^.width*VideoCodecContext^.height)>200000) then
        showmessage('you are trying to play a rather large video'+#13#10+
                    'be prepared to experience some timing problems');
{$endif}
    end;
  end;
end;

procedure FFmpegClose;
begin
  if VideoOpened then begin
    av_free(myBuffer);
    av_free(AVFrameRGB);
    av_free(AVFrame);
    avcodec_close(VideoCodecContext);
    av_close_input_file(VideoFormatContext);
    SetLength(TexData,0);
    VideoOpened:=False;
  end;
end;

procedure FFmpegTogglePause;
begin
  if VideoPaused then VideoPaused:=False
  else VideoPaused:=True;
end;

procedure FFmpegSkip(Gap: Single; Start: Single);
var seek_target: uint64;
    str: string;
begin
  VideoSkiptime:=Gap;
  NegativeSkipTime:=Start+Gap;
  if Start+Gap > 0 then begin
    av_seek_frame(VideoFormatContext,VideoStreamIndex,Floor((Gap+Start)/(VideoFormatContext^.streams[VideoStreamIndex]^.time_base.num/VideoFormatContext^.streams[VideoStreamIndex]^.time_base.den)),AVSEEK_FLAG_ANY);
    VideoTime:=Gap+Start;
  end;
end;

procedure FFmpegGetFrame(Time: Extended);
var
  FrameFinished: Integer;
  AVPacket: TAVPacket;
  errnum, x, y: Integer;
  FrameDataPtr: PByteArray;
  linesize: integer;
  myTime: Extended;
  DropFrame: Boolean;
  droppedFrames: Integer;
const
  FRAMEDROPCOUNT=3;
begin
  if not VideoOpened then Exit;
  if VideoPaused then Exit;
  if (NegativeSkipTime < 0)and(Time+NegativeSkipTime>=0) then NegativeSkipTime:=0; 
  myTime:=Time+VideoSkipTime;
  TimeDifference:=myTime-VideoTime;
  DropFrame:=False;
{  showmessage('Time:      '+inttostr(floor(Time*1000))+#13#10+
    'VideoTime: '+inttostr(floor(VideoTime*1000))+#13#10+
    'TimeBase:  '+inttostr(floor(VideoTimeBase*1000))+#13#10+
    'TimeDiff:  '+inttostr(floor(TimeDifference*1000)));
}
  if (VideoTime <> 0) and (TimeDifference <= VideoTimeBase) then begin
{$ifdef DebugFrames}
    // frame delay debug display
    GoldenRec.Spawn(200,15,1,16,0,-1,ColoredStar,$00ff00);
{$endif}
{    showmessage('not getting new frame'+#13#10+
    'Time:      '+inttostr(floor(Time*1000))+#13#10+
    'VideoTime: '+inttostr(floor(VideoTime*1000))+#13#10+
    'TimeBase:  '+inttostr(floor(VideoTimeBase*1000))+#13#10+
    'TimeDiff:  '+inttostr(floor(TimeDifference*1000)));
}
    Exit;// we don't need a new frame now
  end;
  VideoTime:=VideoTime+VideoTimeBase;
  TimeDifference:=myTime-VideoTime;
  if TimeDifference >= (FRAMEDROPCOUNT-1)*VideoTimeBase then begin // skip frames
{$ifdef DebugFrames}
    //frame drop debug display
    GoldenRec.Spawn(200,55,1,16,0,-1,ColoredStar,$ff0000);
{$endif}
//    showmessage('skipping frames'+#13#10+
//    'TimeBase:  '+inttostr(floor(VideoTimeBase*1000))+#13#10+
//    'TimeDiff:  '+inttostr(floor(TimeDifference*1000))+#13#10+
//    'Time2Skip: '+inttostr(floor((Time-LastFrameTime)*1000)));
//    av_seek_frame(VideoFormatContext,VideoStreamIndex,Floor(Time*VideoTimeBase),0);
{    av_seek_frame(VideoFormatContext,-1,Floor((myTime+VideoTimeBase)*1500000),0);
    VideoTime:=floor(myTime/VideoTimeBase)*VideoTimeBase;}
    VideoTime:=VideoTime+FRAMEDROPCOUNT*VideoTimeBase;
    DropFrame:=True;
  end;

  av_init_packet(AVPacket);
  FrameFinished:=0;
  // read packets until we have a finished frame (or there are no more packets)
  while (FrameFinished=0) and (av_read_frame(VideoFormatContext, AVPacket)>=0) do
  begin
    // if we got a packet from the video stream, then decode it
    if (AVPacket.stream_index=VideoStreamIndex) then
      errnum:=avcodec_decode_video(VideoCodecContext, AVFrame, frameFinished,
                                     AVPacket.data, AVPacket.size);
    // release internal packet structure created by av_read_frame
      av_free_packet(AVPacket);
  end;
  if DropFrame then
    for droppedFrames:=1 to FRAMEDROPCOUNT do begin
      FrameFinished:=0;
      // read packets until we have a finished frame (or there are no more packets)
      while (FrameFinished=0) and (av_read_frame(VideoFormatContext, AVPacket)>=0) do
      begin
        // if we got a packet from the video stream, then decode it
        if (AVPacket.stream_index=VideoStreamIndex) then
          errnum:=avcodec_decode_video(VideoCodecContext, AVFrame, frameFinished,
                                         AVPacket.data, AVPacket.size);
        // release internal packet structure created by av_read_frame
          av_free_packet(AVPacket);
      end;
    end;

  // if we did not get an new frame, there's nothing more to do
  if Framefinished=0 then begin
//    GoldenRec.Spawn(220,15,1,16,0,-1,ColoredStar,$0000ff);
    Exit;
  end;
  // otherwise we convert the pixeldata from YUV to RGB
  errnum:=img_convert(PAVPicture(AVFrameRGB), PIX_FMT_RGB24,
            PAVPicture(AVFrame), VideoCodecContext^.pix_fmt,
			      VideoCodecContext^.width, VideoCodecContext^.height);
//errnum:=1;
  if errnum >=0 then begin
    // copy RGB pixeldata to our TextureBuffer
    // (line by line)
{    FrameDataPtr:=Pointer(AVFrameRGB^.data[0]);
    linesize:=AVFrameRGB^.linesize[0];
    for y:=0 to TexY-1 do begin
      System.Move(FrameDataPtr[y*linesize],TexData[3*y*dataX],linesize);
    end;
}
    // generate opengl texture out of whatever we got
    glBindTexture(GL_TEXTURE_2D, VideoTex);
    glTexImage2D(GL_TEXTURE_2D, 0, 3, dataX, dataY, 0, GL_RGB, GL_UNSIGNED_BYTE, AVFrameRGB^.data[0]);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
{$ifdef DebugFrames}
    //frame decode debug display
    GoldenRec.Spawn(200,35,1,16,0,-1,ColoredStar,$ffff00);
{$endif}

  end;
end;

procedure FFmpegDrawGL(Screen: integer);
begin
  // have a nice black background to draw on (even if there were errors opening the vid)
  if Screen=1 then begin
    glClearColor(0,0,0,0);
    glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT);
  end;
  // exit if there's nothing to draw
  if not VideoOpened then Exit;
  // if we're still inside negative skip, then exit
  if (NegativeSkipTime < 0) then Exit;

  glEnable(GL_TEXTURE_2D);
  glEnable(GL_BLEND);
  glColor4f(1, 1, 1, 1);
  glBindTexture(GL_TEXTURE_2D, VideoTex);
  glbegin(gl_quads);
    glTexCoord2f(         0,          0); glVertex2f(400-ScaledVideoWidth/2, 300-ScaledVideoHeight/2);
    glTexCoord2f(         0, TexY/dataY); glVertex2f(400-ScaledVideoWidth/2, 300+ScaledVideoHeight/2);
    glTexCoord2f(TexX/dataX, TexY/dataY); glVertex2f(400+ScaledVideoWidth/2, 300+ScaledVideoHeight/2);
    glTexCoord2f(TexX/dataX,          0); glVertex2f(400+ScaledVideoWidth/2, 300-ScaledVideoHeight/2);
  glEnd;
  glDisable(GL_TEXTURE_2D);
  glDisable(GL_BLEND);

//    showmessage('Ini.MovieSize = '+inttostr(Ini.MovieSize));
    if (Ini.MovieSize < 1) then  //HalfSize BG
    begin
      // draw fading bars over top and bottom of background/video
      glEnable(GL_BLEND);
      glBegin(GL_QUADS);
        (* black top *)
        glColor4f(0,0,0,1);
        glVertex2f(0, 0);
        glVertex2f(800,0);
        glVertex2f(800,110);
        glVertex2f(0,110);
        (* top gradient *)
        glVertex2f(0, 110);
        glVertex2f(800,110);
        glColor4f(0,0,0,0);
        glVertex2f(800,130);
        glVertex2f(0,130);

        (* bottom gradient *)
        glColor4f(0,0,0,0);
        glVertex2f(0, 600-130);
        glVertex2f(800,600-130);
        glColor4f(0,0,0,1);
        glVertex2f(800,600-110);
        glVertex2f(0,600-110);
        (* black bottom *)
        glVertex2f(0, 600-110);
        glVertex2f(800,600-110);
        glVertex2f(800,600);
        glVertex2f(0,600);

      glEnd;
      glDisable(GL_BLEND);
    end

// info-stuff

{$ifdef Info}
  if VideoSkipTime+VideoTime+VideoTimeBase < 0 then begin
    glColor4f(0.7, 1, 0.3, 1);
    SetFontStyle (1);
    SetFontItalic(False);
    SetFontSize(9);
    SetFontPos (300, 0);
    glPrint('Delay due to negative VideoGap');
    glColor4f(1, 1, 1, 1);
  end;
{$endif}

{$ifdef DebugFrames}
    glColor4f(0, 0, 0, 0.2);
    glbegin(gl_quads);
      glVertex2f(0, 0);
      glVertex2f(0, 70);
      glVertex2f(250, 70);
      glVertex2f(250, 0);
    glEnd;

    glColor4f(1,1,1,1);
    SetFontStyle (1);
    SetFontItalic(False);
    SetFontSize(9);
    SetFontPos (5, 0);
    glPrint('delaying frame');
    SetFontPos (5, 20);
    glPrint('fetching frame');
    SetFontPos (5, 40);
    glPrint('dropping frame');
{$endif}
end;

end.