[FFmpeg-user] Raw files differs

Carl Eugen Hoyos ceffmpeg at gmail.com
Sun Sep 17 14:57:52 EEST 2017

2017-09-17 13:11 GMT+02:00 m.kamalasubha m.kamalasubha
<m.kamalasubha at gmail.com>:
> Hello guys,
>   I converted a video file from MP4 format to TS format using the following
> ffmpeg command.
>    * ffmpeg -i <input.mp4> -c copy -bsf h264_mp4toannexb <output.ts>*
>     => simply copies the A/V data from .mp4 to .ts
>   I used the below command to fetch raw video data  for first 30 seconds
> from both input.mp4 and output.ts
>    * ffmpeg -ss 00:00:00 -i <input.mp4> -t 00:00:30 -vcodec rawvideo
> -pix_fmt rgb24 -f rawvideo -an <mp4_video_rawfile>*
> *    ffmpeg -ss 00:00:00 -i <output.ts> -t 00:00:30 -vcodec rawvideo
> -pix_fmt rgb24 -f rawvideo -an <ts_video_rawfile>*
>   I expect the raw video data to be same between both <input.mp4> and
> <output.ts> since <output.ts> is generated using simple stream copy from
> <input.mp4>. But I find that *<mp4_video_rawfile> and <ts_video_rawfile>
> differs* (though both file size being same) and that first few frames were
> found missing in <ts_video_rawfile> when compared with <mp4_video_rawfile>.
> Can you please explain why raw files differs?

Complete, uncut console output missing.

The differences are related to different start times, you cannot remux
everything 1:1.

Carl Eugen

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