[MPlayer-dev-eng] [PATCH] v4l2 interface

Jindrich Makovicka makovick at kmlinux.fjfi.cvut.cz
Mon Jan 13 15:12:48 CET 2003


Martin Olschewski wrote:

>Hello,
>
>I am using a TV-card with a Philips saa7134 chip.  Gerd Knorr's
>v4l2 driver is afaik the only available driver for this card.
>Since mplayer has a v4l interface only, I had to add a new
>interface.  The very first try was based on the 0.1.x version
>of the v4l2 driver but many changes have been necessary to
>make it work with the 0.2.x version.
>
>This patch brings to you what I am using for a couple of weeks
>now.  The attached tvi_v4l2.c has to be placed in libmpdemux/.
>The command lind parameters should be the same as for v4l, i.e.
>mencoder -tv on:driver=v4l2:adevice=/dev/dsp:...
>Since the v4l2 driver supports oss only, there is no support
>for alsa.
>
>If somebody is interessed in this interface I would be glad to
>hear from you, especially if you use it with an other tv-card
>than the Tevion MD 9717 that I have.  Please be award that the
>interface (like the whole mplayer project ;-) is still under
>heavy development.
>  
>
Please send this patch to mplayer-users, too, to get a wider test-base.

I'd like to commit this code if you're willing to maintain it so we 
could have a working and well tested v4l2 capture when v4l2 appears in 
the kernel.

Unfortunately, I don't use v4l2 and am unfamiliar with the new 
interface. How exactly does this tvi and v4l2 maintain the a/v sync? I 
found that you pass the samplerate to v4l2 but it's not clear to me how 
v4l2 knows which audio device is used, and thus which timebase it should 
use.

Regards,

-- 
Jindrich Makovicka




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