[MEncoder-users] How to determine size of audio in an avi

[Oded Shimon]

On Thu, Sep 15, 2005 at 09:35:32PM -1000, Jason Addison wrote:
> > > Is there a way to determine the size of the audio without dumping it to a
> > > file?
> 
> > >
> > > When you play the file, it should tell you both the video and audio
> > > bitrates in KBps.  Just multiply by the length of the movie.
> > 
> > But this will work only in those rare cases where audio is CBR (which is
> > uncommon these days) and average video bitrate stored in header is
> > accurate, which usually isn't true for MPEG containers.
> > 
> > So streamcopying to /dev/null is IMHO the fastest and the most accurate
> > way.
> 
> How do you streamcopy to /dev/null?
> Is it like this?
> <from section 8.1.10 "Audio">
> mplayer source_file.vob -aid 129 -dumpaudio -dumpfile /dev/null
> but, then how do you find the size of the file that would have resulted?
> 
> Is there a utility that will give all the stats of an avi like the
> encoding used for audio and video the sizes of the respective parts,
> average bitrate, height/width of the video, ...?

mencoder bla.avi -ovc copy -oac copy -o /dev/null

Video stream:   84.356 kbit/s  (10544 bps)  size: 36754799 bytes  3485.680 secs  87142 frames
Audio stream:  128.005 kbit/s  (16000 bps)  size: 55781376 bytes  3486.192 secs

- ods15