On Friday 19 October 2007 19:30:59 Duncan Webb wrote: > 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-sing > >le/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?
The PVR-350 output uses it: if you playback a file with embedded WSS signals, then those will be reproduced on the TV-out, automatically switching the TV to widescreen. > 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). The video_aspect of most 16:9 broadcasts should still be 4:3 (unless it is an anamorphic broadcast). The captured picture is 4:3 because of the black bars. > >> 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 ^^^^^^^^^^ Not supported (PVR-350 can do no raw 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. Updated v4l2-ctl to get --get-sliced-vbi-out-cap and --get-sliced-vbi-cap to work: was a v4l2-ctl bug. You can use the ivtv-1.0 branch: http://ivtvdriver.org/viewcvs/ivtv/branches/1.0/ > > >> 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 Regards, Hans _______________________________________________ ivtv-devel mailing list [email protected] http://ivtvdriver.org/mailman/listinfo/ivtv-devel
