[FFmpeg-devel] [PATCH] ALSA for libavdevice

[Michael Niedermayer]

On Thu, Dec 25, 2008 at 11:29:16AM +0100, Stefano Sabatini wrote:
> On date Sunday 2008-12-21 21:12:35 +0100, Michael Niedermayer encoded:
> > On Sun, Dec 21, 2008 at 08:10:37PM +0100, Luca wrote:
> > > Hi,
> > > 
> > > sorry for the delayed response
> > > 
> > > On Fri, 2008-12-19 at 10:59 +0100, Nicolas George wrote:
> > > > L'octidi 28 frimaire, an CCXVII, Luca Abeni a ?crit :
> > > > > So, it seems to me that the alsa library is still not stable enough for
> > > > > what concerns the snd_pcm_htimestamp() function. :(
> > > > 
> > > > All I can say is that it works at home (Debian Testing).
> > > 
> > > Well, I tested various ubuntu installations, but none of them provides
> > > snd_pcm_htimestamp(). I've been able to compile the new alsa code only
> > > on debian unstable... I tested it on various different machines with
> > > different audio cards, but snd_pcm_htimestamp() always blocks and ffmpeg
> > > hangs.
> > > 
> > > 
> > > >  Remotely testing ALSA programs is not easy.
> > > 
> > > I know... I suppose this problem depends on the ALSA library version,
> > > but also on the driver (and on the hardware). 
> > > 
> > > 
> > > > I guess that means we will have to fall back to the av_gettime-based
> > > > timestamp, probably with a call to know the delay to ensure A-V sync.
> > > 
> > > Well, I think that a configure test for snd_pcm_htimestamp() (or for the
> > > proper libasound2 version) is surely needed to avoid breaking
> > > compilation.
> > > A fallback solution based on gettime+compensation would be even
> > > better...
> > > 
> > > 
> > > > Shall I work on a filtering function and submit it as a prerequisite patch?
> > > I do not know... I hope a alsa input with proper checking for the right
> > > alsa version can be accepted first, but this is up to Michael.
> > 
> > if its possible to test if snd_pcm_htimestamp() is working in configure
> > (that would require detecting that it hanged ...)
> > alternatively if someone happens to know which version/driver/hw works ...
> > if neither of these then i dont see how we could add snd_pcm_htimestamp()
> > based input support
> 
> Maybe complaining upstream could help, if we get it fixed then we just
> have to check for some ALSA version, rather than put random magik in
> configure.

i Definitly agree that it should be reported upstream

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Frequently ignored awnser#1 FFmpeg bugs should be sent to our bugtracker. User
questions about the command line tools should be sent to the ffmpeg-user ML.
And questions about how to use libav* should be sent to the libav-user ML.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: Digital signature
URL: <http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/attachments/20081225/0a961fcb/attachment.pgp>