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

bat guano batguano999 at hotmail.com
Fri Dec 2 16:47:37 CET 2011


> 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? 
> $ ffmpeg -i SDV_0597.MP4 -acodec copy -vcodec copy -t 46 -b 64k test.mp4
> FFmpeg version r11872+debian_0.svn20080206-17, Copyright (c) 2000-2008 Fabrice Bellard, et al.
> configuration: --enable-gpl --enable-libfaad --enable-pp --enable-swscaler --enable-x11grab --prefix=/usr --enable-libgsm --enable-libtheora --enable-libvorbis --enable-pthreads --disable-strip --enable-libdc1394 --disable-armv5te --disable-armv6 --disable-altivec --disable-vis --enable-shared --disable-static


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. 


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