[FFmpeg-user] ffmpeg duplicating frames

[Yogesh Tyagi]

Hi,

Can somebody help me understand why ffmpeg need to duplicate frames
while transcoding to YUV ?

I give following command

ffmpeg -i temp.ts -frames 200 temp.yuv


 ffmpeg -i temp.ts.ts -frames 200 temp.yuv
ffmpeg version 0.9.2, Copyright (c) 2000-2012 the FFmpeg developers
  built on Sep 22 2012 22:31:38 with gcc 4.4.3
  configuration: --enable-libx264 --enable-gpl
  libavutil    51. 32. 0 / 51. 32. 0
  libavcodec   53. 42. 4 / 53. 42. 4
  libavformat  53. 24. 2 / 53. 24. 2
  libavdevice  53.  4. 0 / 53.  4. 0
  libavfilter   2. 53. 0 /  2. 53. 0
  libswscale    2.  1. 0 /  2.  1. 0
  libpostproc  51.  2. 0 / 51.  2. 0
[mpegts @ 0x9aacaa0] PES packet size mismatch
Input #0, mpegts, from 'temp.ts':
  Duration: 00:00:06.87, start: 0.525389, bitrate: 20991 kb/s
  Program 1
    Stream #0:0[0x1000]: Video: mpeg2video (Main) ([2][0][0][0] /
0x0002), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 20000 kb/s, 29.97 fps,
29.97 tbr, 90k tbn, 59.94 tbc
    Stream #0:1[0x1001]: Audio: mp2 ([3][0][0][0] / 0x0003), 48000 Hz,
stereo, s16, 224 kb/s
File 'temp.yuv' already exists. Overwrite ? [y/N] y
w:1920 h:1080 pixfmt:yuv420p tb:1/1000000 sar:1/1 sws_param:
Output #0, rawvideo, to 'temp.yuv':
  Metadata:
    encoder         : Lavf53.24.2
    Stream #0:0: Video: rawvideo (I420 / 0x30323449), yuv420p,
1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 200 kb/s, 90k tbn, 29.97 tbc
Stream mapping:
  Stream #0:0 -> #0:0 (mpeg2video -> rawvideo)
Press [q] to stop, [?] for help
frame=  200 fps= 11 q=0.0 Lsize=  607500kB time=00:00:06.67
bitrate=745750.3kbits/s dup=3 drop=0
video:607500kB audio:0kB global headers:0kB muxing overhead 0.000000%

ffmpeg shows that is has duplicated 3 frames.Why ffmpeg needs to
duplicated frames even in case of decoding to YUV?


Thanks,
Yogesh