[MPlayer-dev-eng] [PATCH] Speedup for pcm/wav audio dump

[Felix Buenemann]

On Friday, 1. February 2002 22:34, Robert Kesterson wrote:
> On my system, the 4096-byte burst size in the pcm/wav audio output causes
> audio dumping to be unbearably slow (several minutes to dump just a few
> seconds of audio on a 1.4 GHz Athlon).  Increasing the burst size solves
> the problem -- with a caveat.  You *must* be using the "-ni" option or
> you'll get "too many video packets" error and a premature exit.  However,
> with the "-ni" option in place, an entire two-hour movie audio can be
> dumed to wav in just a few minutes.
>
> Here is a patch to ao_pcm.c that increases the burst size to 1 meg.  It
> also writes the wav header (if appropriate) first before writing the file,
> then comes back and fills it in later.  (This lets you play the wav file
> while it's still dumping so you can verify it's what you want.  It also
> lets you set up a fifo on audiodump.wav so you can pump the output
> directly to a conversion / encoding tool without needing the wav file.)
>
I think we should rather solve the problem itself instead of working around 
it, the problem is that mplayer currently can't correctly handle sound 
drivers that don't have correct drift and delay calculation.
You could look at the code from vo_null (cvs) that emulates a dummy sound 
device and make it a new patch together with changes to header handling.

-- 
Best Regards,
	Atmos
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