From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from hermes.mlbassoc.com ([64.234.241.98]:34064 "EHLO mail.chez-thomas.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752594Ab1H3Wpn (ORCPT ); Tue, 30 Aug 2011 18:45:43 -0400 Message-ID: <4E5D6813.4040707@mlbassoc.com> Date: Tue, 30 Aug 2011 16:45:39 -0600 From: Gary Thomas MIME-Version: 1.0 To: Laurent Pinchart CC: linux-media@vger.kernel.org Subject: Re: Getting started with OMAP3 ISP References: <4E56734A.3080001@mlbassoc.com> <201108291249.33118.laurent.pinchart@ideasonboard.com> In-Reply-To: <201108291249.33118.laurent.pinchart@ideasonboard.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: On 2011-08-29 04:49, Laurent Pinchart wrote: > Hi Gary, > > 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? What pixel format would I use with ffmpeg? 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. Thanks again -- ------------------------------------------------------------ Gary Thomas | Consulting for the MLB Associates | Embedded world ------------------------------------------------------------