[FFmpeg-devel] libavformat and video4linux2 acquire problems

Limin Wang lance.lmwang
Thu May 10 03:53:52 CEST 2007

Hi luca,

> >> If you provide a patch, and it does not break dv capturing or similar 
> >> things, I'll be very happy to apply it.
> > 
> > Please review the attached patch
> Thanks. I'll have a look tonight, and I'll commit tomorrow.
> > I have check dv1394, it'll not break if standard is NULL and input is -1 case.
> Uhmm... I did not try, but I see this code in dv1394.c:
>   if (ap->standard && !strcasecmp(ap->standard, "pal"))
>          dv->format = DV1394_PAL;
>      else
>          dv->format = DV1394_NTSC;
>      if (ap->channel)
>          dv->channel = ap->channel;
>      else
>          dv->channel = DV1394_DEFAULT_CHANNEL;
> So, standard==NULL should not be a problem (unless strcasecmp() crashes 
> if the first parameter is NULL --- I'll check that), but channel == -1 
> can be a problem, because dv->channel will be set to -1 instead of 
> DV1394_DEFAULT_CHANNEL. But I do not know what this would imply...
> So, maybe the safest thing is to remove the "video_channel = -1" part 
> from your patch... I'll think about it later.

Oh, yes, maybe fix by below way, at least, it'll work as the same of the old way.

-      if (ap->channel)
+      if (ap->channel>=0)
          dv->channel = ap->channel;


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