How To use DeviceStillPicture ?
Commit Message
On 01/06/08 14:13, Martin Dauskardt wrote:
> I have seen that plugins use this in a different way.
>
> For example in this order:
> DevicePlay
> DeviceStillPicture
> DeviceFreeze
> So the next action to display a new Stillimage would start with DevicePlay
>
> Others call neither Freeze nor Play. The dvd-Plugin calls DeviceClear and
> DevicePlay before DeviceStillPicture.
>
> I remember that Klaus once stated that DeviceStillPicture could be seen as a
> trickmode, so that always a Play has to follow to resume from trickmode. But
> is it necessary to Freeze the Stillpicture before?
>
> And I wonder: How should a device plugin handle the StillPicture function? Is
> it necessary that StillPicture also calls a Clear() to clear the internal
> decoder buffers? It looks like that vdr is not doing this in dvbdevice.c,
> although I am not sure if the av7110 ioctl VIDEO_STILLPICTURE does
> internally clear the buffers.
Incidentally I'm currently writing a simple picture viewer plugin,
and there I just call DeviceStillPicture() without anything else.
In order to make the FF-DVB cards display both frames of a still
picture (thus avoiding jagged lines) you may want to apply the
following patch to the driver:
Klaus
@@ -1125,6 +1125,8 @@
dvb_ringbuffer_flush_spinlock_wakeup(&av7110->avout);
ret = play_iframe(av7110, pic->iFrame, pic->size,
file->f_flags & O_NONBLOCK);
+ if (!ret)
+ ret = vidcom(av7110, AV_VIDEO_CMD_FREEZE, 1);
break;
}