[MPlayer-users] Latest SVN audio sync & high cpu usage with channels=6

Jesús Guerrero i92guboj at terra.es
Thu Sep 24 23:26:44 CEST 2009

On Thu, 24 Sep 2009 21:14:11 +0000 (UTC), Carl Eugen Hoyos
<cehoyos at ag.or.at> wrote:
> Jesús Guerrero <i92guboj <at> terra.es> writes:
>> >> You could try:
>> >> -demuxer lavf -channels 6
>> It takes oss by default, only music and sound no voices (probably it
>> up 5.1, that's why).
> What about CPU usage?
> ALSA problems are often the reason for performance problems.

I didn't notice first time, but you are right, with oss the cpu is much
lower. So the problem could be in the interaction of alsa with the current
svn. I am using the in-kernel alsa modules from 2.6.30, snd_ca0106. And if
this is an alsa problem it won't be the first one, nor the last that hits
me I suppose.

>> >> -channels 6 -ac -a52,
>                        --^--
>> Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
>> Selected video codec: [ffodivx] vfm: ffmpeg (FFmpeg MPEG-4)
>> Cannot find codec for audio format 0x2000.
>> Audio: no sound
> Very hard to believe ...

Well, I just copy paste, the command lines I used are:

./mplayer -ao alsa -channels 6 -ac -a52 ../../media/conceptronic/Tropa\
de\ élite-José\ Padilha-2007.avi
./mplayer -ao alsa -channels 6 -ac -a52
../../media/conceptronic/Passengers-Rodrigo\ García-2008.avi

Same results on both.

>> >> -channels 6 -ao oss
>> Channels messed up with oss, no voices only music and effects, so I
>> know whether it syncs or not.
> You see that in MPlayer's status line ("A-V").

Thank you. With oss then it's more than ok, it's zero almost always except
for very minor (and completely imperceptible) peaks. With alsa it continues
growing at a more or less constant rate, at a reason of more than 1000 per
ten seconds or so (it's a rough approximation).

Do you think it's worth to try an older kernel which would mean an older
alsa version?

Jesús Guerrero

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