[MPlayer-users] Re: Reading raw audio/video streams
olli at lurza.secnetix.de
Fri Aug 15 20:29:26 CEST 2003
Geoffrey Hausheer wrote:
> Richard Felker wrote:
> > > Does anyone have a suggestion as to how I can make this work without
> > > generating intermediate files (either using fifos or a muxed stream to
> > > stdout?). I don't want to deal with the complexity of adding a
> > > container...that is what I'm using mencoder for in the first place.
> > Uhh, why not just use -audiofile audout.fifo instead of a file?!?!
> Well, the problem is that mencoder reads from -audiofile at a different
> rate than stdin.
> So if I have a program writing to two fifos, and mencoder reading from
> two fifos, and since fifos are always blocking, eventually mencoder ends
> up blocking on a read from one stream, while the writer ends up blocking
> on writing to the other stream, and everything deadlocks.
I had a very similar problem in my dvd-to-vcd script, which
uses mplayer + mjpegtools. The audio and the video parts
are handled in two parallel pipes, using FIFOs. During my
first attemps, I always got those dead-locks, exactly like
you did. Then I inserted huge buffering processes into
both pipes (10 Mbytes per buffer process), which decoupled
the data sources and data sinks from each other, so to speak.
No deadlocks anymore.
PS: I use "sob" for buffering, but there are other tools
for that purpose, too.
Oliver Fromme, secnetix GmbH & Co KG, Oettingenstr. 2, 80538 München
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