> Hi all, > > I've become quite confused with the different settings for the VBI > controls and I wondering is someone can clear up what is what. > Unfortunately the README.vbi in ivtv-1.0.0 is a bit outdated by recent > changes
I'll have a look at that, it's indeed outdated. >>From what I understand is a PVR-350 has four VBI capabilities: > VBI Capture > VBI Output > Sliced VBI Capture > Sliced VBI Output No, VBI Output is not possible and sliced VBI output is limited to closed captioning (NTSC) and the widescreen signal (PAL). (VPS is also possible but never used in practice) > > and a PVR-500 has 2 > VBI Capture > Sliced VBI Capture > > Capture is what is received from the outside world and Output is what is > sent to the world. So I'm mostly interested in Capture. > > I am a bit confused by the Sliced VBI capabilities, how do they differ > from the VBI capabilities. Can you explain the differences? See sections 4.7 and 4.8 in the V4L2 specification: http://www.linuxtv.org/downloads/video4linux/API/V4L2_API/spec-single/v4l2.html Basically raw VBI just passes the vertical blank 'image' to the application and the application will have to decode the actual data from the image. With sliced VBI the hardware will do that for you which means that the application only receives the real payload data which is much shorter than the raw data. Having sliced VBI is particularly important when you want to put that data into an MPEG stream since raw VBI would increase the MPEG stream too much. > To embed a teletext VBI stream in the mpeg file, is it just a case of > calling v4l2-ctl with: > --set-fmt-sliced-vbi=teletext and > --set-ctrl=stream_vbi_format=1 > or do I need something else as well? No, that's it. For PAL you usually want to capture the wss signal as well, so I would do -set-fmt-sliced-vbi=teletext,wss. > It there any more documentation on these v4l2-ctl options, I can't find > any except for the output of v4l2-ctl and the http://www.linuxtv.org > pages and they are both a bit terse. The v4l2-ctl options reflect the actual V4L2 API. So combine v4l2-ctl with the V4L2 spec (see link above) and you should be able to figure out what each option does. > > --get-ctrl=stream_vbi_format > --get-fmt-sliced-vbi > --get-sliced-vbi-cap > --get-sliced-vbi-out-cap > --get-fmt-sliced-vbi-out > --get-fmt-vbi > --get-fmt-vbi-out > > It seems from tests that the Output controls are not working, at least > with kernel 2.6.22.5 and ivtv 1.0.0 on a PVR-350 card, see the > attachment for details. That's weird. --get-sliced-vbi-cap and --get-sliced-vbi-out-cap should work. I'll take a look tonight. > The external control "Video Pulldown" has it gone or been replaced, if > has been replaced what is the new control? It was removed because is doesn't do anything. Apparently it isn't implemented in the firmware. Regards, Hans _______________________________________________ ivtv-devel mailing list [email protected] http://ivtvdriver.org/mailman/listinfo/ivtv-devel
