[FFmpeg-user] fps in March 13 git: -r 29.97 = 2997 tbn ???
mjs973 at optonline.net
Sat Apr 2 13:50:58 CEST 2011
sean darcy wrote:
> Converting to an android playable file, I can't seem to set the fps.
> The input is 29.97. I tried setting -r to 29.97:
> Output #0, ipod, to 'OUTPUT1.m4v':
> encoder : Lavf52.102.0
> Stream #0.0: Video: libx264, yuv420p, 720x480 [PAR 8:9 DAR 4:3],
> q=0-69, pass 1, 10000 kb/s, 30k tbn, 29.97 tbc
> tbn is the framerate for the AVStream of the container, as I gather
> from google. It seems that -r affects tbn of the output. But really
> How do I set fps of the output?
You misunderstand the meaning of tbn. tbn is not the "framerate" of the
container, it is the timebase.
A timebase is like a clock, and indicates ticks per second. Generally,
higher values are better.
Both values of tbn you saw should work fine for your file. You got
different values because 29.97 is not *exactly* equal to 30000/1001.
Also, be careful believing the tbn / tbc "Output #0" stats - they have
been broken for months. Use 'ffmpeg -i infile' to get accurate values.
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