Hello everyone,
I think that I am experiencing a bug in bttv video driver.
What I am trying to do is to make an application which would ( as
well as some other things ) display video from bttv card, decode the
NTSC closed-caption data and display them as subtitles. It almost
works, but I observe an annoying effect. After moving/resizing
the window for some time /dev/video device stops producing any meaningful
picture. The picture starts to look like when the tuner is tuned to
the wrong channel ( a few randomly filled lines near the very edge of
window ), with the only exception that BTTV card is connected to VCR
and the tuner is not used at all.
Here is the more detailed explanation. I call:
devv4l=open("/dev/video", O_RDWR);
devvbi=open("/dev/vbi", O_RDONLY);
(... initialize v4l device, set parameters, etc. ...)
Every time the window is moved or resized, program issues a few
calls to ioctl(devv4l, xxx ...), where xxx is VIDIOC_S_CAP,
VIDIOC_S_WIN, VIDIOC_G_PICT/VIDIOC_S_PICT. I turn off capture when
window starts moving and turn it back on after a short period of
time after it's ended. Note that I don't do _anything_ with /dev/vbi.
It was just opened, that's enough to cause the effect.
I saw a bug report very similar to this in the mailing list,
but it was quite some time ago ( in October or like that; the message
mentioned xawtv 3.23 ). My driver version is quite new, it is the one
which is included in kernel 2.4.3. I didn't see anything about vbi in
changelog, so I didn't try to upgrade to newer driver.
Does anybody know about this problem and what can be done to solve
it?
--
Best regards,
Eugene
mailto:divx@xxxxxxx or sparky@xxxxxxxxxxxxxxx
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