Hans Verkuil wrote: >> Hi all, >> > >> 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)
Okay >> 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. Sliced VBI is nice and easy, and I understand the difference between the two. I think mainly I'm confused about the VBI options to v4l2-ctl. >> 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. Thanks, why do you embed the wss data, are there any players that use it? AFAIK mplayer can't process the ivtv packets, which is very annoying when I've recorded a 16:9 mpeg and mplayer shrinks it vertically. The video_aspect control does work correctly, just that I don't yet set it when the wss signal indicates 14:9 or 16:9 (working on this). >> 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 This reports if a stream is embedded or not >> --get-fmt-sliced-vbi This reports the what is being sliced into the mpeg stream >> --get-sliced-vbi-cap >> --get-sliced-vbi-out-cap >> --get-fmt-sliced-vbi-out This reports what can be embedded into an output stream >> --get-fmt-vbi This reports the raw vbi lines >> --get-fmt-vbi-out The others don't work for me, may be I need to upgrade something. >> 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. Don't seem to work, tested this with a PVR-500 on kernel 2.6.18.5 and ivtv-0.10.5 as well. >> 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. Thanks for this, something I can safely remove. Cheers Duncan _______________________________________________ ivtv-devel mailing list [email protected] http://ivtvdriver.org/mailman/listinfo/ivtv-devel
