Hi Chris, On Sun, 2014-10-26 at 08:10 -0400, Christopher Neufeld wrote: > Hello Hans, > > On Sun, 26 Oct 2014 06:50:36 +0100, Hans Verkuil <hverkuil@xxxxxxxxx> said: > > >> The script that I use to set up captions invokes this command: > >> v4l2-ctl -d <DEV> --set-fmt-sliced-vbi=cc --set-ctrl=stream_vbi_format=1 > >> > >> This now errors out. Part of that is a parsing bug in v4l2-ctl, it wants > >> to see more text after the 'cc'. I can change it to > >> v4l2-ctl -d <DEV> --set-fmt-sliced-vbi=cc=1 --set-ctrl=stream_vbi_format=1 > > > This is a v4l2-ctl bug. I'll fix that asap. But using cc=1 is a valid workaround. > > >> > >> with this change, it no longer complains about the command line, but it > >> errors out in the ioctls. This behaviour is seen with three versions of > >> v4l2-ctl: the old one packaged with the old kernel, the new one packaged > >> with the newer kernel, and the git-head, compiled against the headers of > >> the new kernel. Can you verify that v4l2-ctl -d <DEV> --get-fmt-sliced-vbi --get-ctrl=stream_vbi_format also fails, and that v4l2-ctl --list-devices v4l2-ctl -d /dev/vbi<N> --set-fmt-sliced-vbi=cc=1 --set-ctrl=stream_vbi_format=1 v4l2-ctl -d /dev/vbi<N> --get-fmt-sliced-vbi --get-ctrl=stream_vbi_format both succeed on the corresponding vbi node? Looking at the v3.16 kernel code that I'm compiling right now, it looks like extra checks put in the v4l2-core don't allow setting sliced VBI formats using video device nodes: http://git.linuxtv.org/cgit.cgi/v4l-utils.git/tree/utils/v4l2-ctl/v4l2-ctl-vbi.cpp#n209 http://git.linuxtv.org/cgit.cgi/media_tree.git/tree/drivers/media/v4l2-core/v4l2-ioctl.c#n959 http://git.linuxtv.org/cgit.cgi/media_tree.git/tree/drivers/media/v4l2-core/v4l2-ioctl.c#n1192 http://git.linuxtv.org/cgit.cgi/media_tree.git/tree/drivers/media/v4l2-core/v4l2-ioctl.c#n1265 I have to actually install and test, but this is my current guess. If you can use the /dev/vbiN node as a work-around, please do. Regards, Andy > > Are you calling this when MythTV is already running? If nobody else is using > > the PVR-500, does it work? > > When my script is running, MythTV is not using that unit of the PVR-500. I > use the "recording groups" feature to ensure that that unit is made > unavailable for recordings whenever high-definition recordings are being > made. The details of what I'm doing can be found here: > https://www.mythtv.org/wiki/Captions_With_HD_PVR > > I would not expect this command to succeed if the unit were in use, in fact > the script detects that as an error case and loops until the device is > free. The v4l2-ctl command that I use has historically returned an error > if somebody had the unit's video device open for reading. Now, though, it > errors even when the unit is unused. > > For my script, it is necessary that the MythTV backend be running, the > script is invoked by the backend, but when it is invoked, nobody is using > that unit of the PVR-500 (and, in practice, the other unit is almost never > used, as it's quite rare that I make standard-definition recordings). > > My script is not used when MythTV directly makes a standard-definition > recording from the PVR-500. In that case, the program presumably issues > its own ioctl equivalents of the v4l2-ctl command, and those are not > working, because the recordings produced do not have VBI data, while those > recorded before the kernel upgrade do. > > > I won't be able to test this myself until next weekend at the earliest. > > Captions are mostly for my wife's benefit, and I checked, most of her > upcoming shows are being recorded from OTA broadcasts, which provide ATSC > captions independently of the PVR-500, so I can wait for a week or two. > > > Thank you for looking into this. > -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
