Hi Gary, On Wednesday 31 August 2011 00:45:39 Gary Thomas wrote: > On 2011-08-29 04:49, Laurent Pinchart wrote: > > On Thursday 25 August 2011 18:07:38 Gary Thomas wrote: > >> Background: I have working video capture drivers based on the > >> TI PSP codebase from 2.6.32. In particular, I managed to get > >> a driver for the TVP5150 (analogue BT656) working with that kernel. > >> > >> Now I need to update to Linux 3.0, so I'm trying to get a driver > >> working with the rewritten ISP code. Sadly, I'm having a hard > >> time with this - probably just missing something basic. > >> > >> I've tried to clone the TVP514x driver which says that it works > >> with the OMAP3 ISP code. I've updated it to use my decoder device, > >> but I can't even seem to get into that code from user land. > >> > >> Here are the problems I've had so far: > >> * udev doesn't create any video devices although they have been > >> > >> registered. I see a full set in /sys/class/video4linux > >> > >> # ls /sys/class/video4linux/ > >> v4l-subdev0 v4l-subdev3 v4l-subdev6 video1 video4 > >> v4l-subdev1 v4l-subdev4 v4l-subdev7 video2 video5 > >> v4l-subdev2 v4l-subdev5 video0 video3 video6 > > > > It looks like a udev issue. I don't think that's related to the kernel > > drivers. > > > >> Indeed, if I create /dev/videoX by hand, I can get somewhere, but > >> I don't really understand how this is supposed to work. e.g. > >> > >> # v4l2-dbg --info /dev/video3 > >> > >> Driver info: > >> Driver name : ispvideo > >> Card type : OMAP3 ISP CCP2 input > >> Bus info : media > >> Driver version: 1 > >> Capabilities : 0x04000002 > >> > >> Video Output > >> Streaming > >> > >> * If I try to grab video, the ISP layer gets a ton of warnings, but > >> > >> I never see it call down into my driver, e.g. to check the current > >> format, etc. I have some of my own code from before which fails > >> miserably (not a big surprise given the hack level of those > >> programs). > >> > >> I tried something off-the-shelf which also fails pretty bad: > >> # ffmpeg -t 10 -f video4linux2 -s 720x480 -r 30 -i /dev/video2 > >> > >> junk.mp4 > >> > >> I've read through Documentation/video4linux/omap3isp.txt without > >> learning much about what might be wrong. > >> > >> Can someone give me some ideas/guidance, please? > > > > In a nutshell, you will first have to configure the OMAP3 ISP pipeline, > > and then capture video. > > > > Configuring the pipeline is done through the media controller API and the > > V4L2 subdev pad-level API. To experiment with those you can use the > > media-ctl command line application available at > > http://git.ideasonboard.org/?p=media- ctl.git;a=summary. You can run it > > with --print-dot and pipe the result to dot -Tps to get a postscript > > graphical view of your device. > > > > Here's a sample pipeline configuration to capture scaled-down YUV data > > from a sensor: > > > > ./media-ctl -r -l '"mt9t001 3-005d":0->"OMAP3 ISP CCDC":0[1], "OMAP3 ISP > > CCDC":2->"OMAP3 ISP preview":0[1], "OMAP3 ISP preview":1->"OMAP3 ISP > > resizer":0[1], "OMAP3 ISP resizer":1->"OMAP3 ISP resizer output":0[1]' > > ./media-ctl -f '"mt9t001 3-005d":0[SGRBG10 1024x768], "OMAP3 ISP > > CCDC":2[SGRBG10 1024x767], "OMAP3 ISP preview":1[YUYV 1006x759], "OMAP3 > > ISP resizer":1[YUYV 800x600]' > > > > After configuring your pipeline you will be able to capture video using > > the V4L2 API on the device node at the output of the pipeline. > > Getting somewhere now, thanks. When I use this full pipeline, I can get > all the way into my driver where it's trying to start the data. > > What if I want to use less of the pipeline? For example, I'd normally be > happy with just the CCDC output. How would I do that? Then connect CCDC's pad 1 to the CCDC output video node and capture on that video node. > What pixel format would I use with ffmpeg? What does your subdev deliver ? > n.b. I know most of these are pretty n00b questions - I'd look up the > answers for myself, but I've had precious little success finding any > documentation, especially on media-ctl and/or the OMAP3 ISP setups. -- Regards, Laurent Pinchart -- 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
