On Wednesday 28 November 2007 13:09:45 TheHog wrote:
> From: Hans Verkuil <[EMAIL PROTECTED]>
> Date: 21-Nov-2007 09:28
>
> > On Wednesday 21 November 2007 02:57:32 TheHog wrote:
> > > With ivtv 0.10.6, I get the error "IOError: [Errno 16] Device or
> > > resource busy" when setting the input (v4l2-ctl -i, ioctl). With
> > > ivtv 0.10.5 it did work. That is, with 0.10.6 it is not possible
> > > to change the input from tuner to e.g. composite or svideo while
> > > the device is open. Is this a know issue? Is it solved in a later
> > > version? Note that 0.10.6 is the current default in Gentoo.
> >
> > No, this is a feature: changing inputs like that could cause a
> > corrupt MPEG stream so I changed the driver to prevent people from
> > switching to another input when a capture is in progress.
>
> What exaclty causes the bad packets in the MPEG stream? Is it the PVR
> firmware or ivtv?
It's really the hardware: changing the input will mean changing the
settings of the digitizer chip (saa7115 or cx2584x). This means that
the cx23416 can receive a bad frame from the digitizer which means that
the MPEG stream also gets corrupted.
> I found some code in xine's input_pvr plugin that
> copes with corrupted streams: it does an close/open on the device to
> obtain a valid stream again. That's probably why Freevo users didn't
> encounter the issue.
>
> Do you plan to re-enable the functionality to switch inputs while a
> capture is in progress in the future?
I have no plans, unless someone can figure out how to safely change
inputs. There might be some magic incantation, but experience has shown
that it is quite tricky to get it working under all circumstances.
Regards,
Hans
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