[FFmpeg-user] [solved] Re: Option `-b' seems not to have any effect

Rodolfo Medina rodolfo.medina at gmail.com
Sun Dec 4 16:31:18 CET 2011

On 12/02/11 19:17, Rodolfo Medina wrote:

>> Whatever value I put for `-b' (e.g.: -b 64k, -b 32k, -b 0k) the output file
>> size remains always 26M.  Is that normal?  If not, how to fix that?  Below
>> is ffmpeg's output, and many thanks indeed for any help supported.
>> Rodolfo
>> $ ffmpeg -i SDV_0597.MP4 -acodec copy -vcodec copy -t 46 -b 64k test.mp4

bat guano <batguano999 at hotmail.com> writes:

> It's no good using "-vcodec copy" in this case.
> If you want to change the video bitrate you need to specify which video codec
> to use.

"dE ." <de.techno at gmail.com> writes:

> I may be wrong, but when you're copying a stream, encoding isn't involved,
> and when encoding isn't involved, you can't control the bitrate.

You were right.  That's the code that works for my purpose:

 $ ffmpeg -i SDV_0597.MP4 -vcodec mpeg1video -acodec mp2 -t 46 -b 1000k test.mpg


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