[MPlayer-dev-eng] [PATCH] Fix regression in v4l2 channel tuning on cx88 cards

[Jon Doe]

Can someone have a look at this? It's been bugging me for 4 years.
Used to work perfectly.

Thanks!

On Tue, May 1, 2012 at 10:16 AM, Jon Doe <ffplay99 at gmail.com> wrote:
> Hi,
>
> This patch tries to improve (not completely fix) a v4l regression from
> svn r27057 which introduced per channel resetting of v4l2 normids when
> tuning channels. The relevant bug report can be found at
> http://bugzilla.mplayerhq.hu/show_bug.cgi?id=1326. I tested on cx88
> and bt878 based cards. Only the cx88 is affected.
>
> The problem is that cx88 based cards will reset the picture size to
> 320x240 when changing norms, squashing the picture to a quarter size
> in the top left corner when changing channels in mplayer. The cx8800
> driver needs to reset the picture size due to a hardware filter
> recalculation requirement when changing norms. Others have also
> noticed this problem in the driver, but no comprehensive fix was found
> - see http://www.mail-archive.com/linux-media@vger.kernel.org/msg00157.html
>
> The fix proposed is to only change the norm if the new channel norm
> (eg. NTSC) differs from the current norm (eg. PAL-I), as specified in
> the user config file. This should at least work for most people most
> of the time and speed up channel tuning at the same time.