Hi Gary, On Wednesday 31 August 2011 02:07:36 Gary Thomas wrote: > On 2011-08-30 16:50, Laurent Pinchart wrote: > > 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 ? > > It's a BT656 encoder - 8-bit UYVY 4:2:2 Then you will first have to add YUV support to the CCDC. It wouldn't be fun if it worked out of the box, would it ? :-) -- 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
