Re: V4l2 :: Debugging an issue with cx8800 card.

"B. Bogart" <ben@xxxxxxxxx> · Thu, 04 Sep 2008 16:16:10 -0700

Hello Andy,

Thanks for your help.

I've not yet tried running your program, but did have some luck with:
http://moinejf.free.fr/svv.c

I managed to compile it and run it, I had to change the pixelformat to
YUVY. The resolution is correct, but the image looks like PAL.

How/where do I set the video format in V4l2?

I tried adding #define V4L2_STD_NTSC_M but that did not make any difference.

Attached is an image of the svv current output.

Oh and I'm currently looking at
http://v4l2spec.bytesex.org/spec-single/v4l2.html for reference, but
much of it is over my head.

I've only written a couple things in C.

Thanks for the pointers.
B. Bogart

Andy Walls wrote:
> On Thu, 2008-09-04 at 15:14 -0700, B. Bogart wrote:
>> Hello all,
>>
>> This issue has been lagging for years and I wanted to get some expert
>> advice on debugging it. It seems I'm the only one with a cx8800 card
>> that is having problems so I hope to take the challenge up and propose a
>> solution to the maintainer.
>>
>> So the software I'm using is GEM. It has v4l2 support, and works fine
>> with my bt848 card. Problem is I can't get things working properly with
>> my cx8800 cards.
>>
>> First HW info:
>>
>> lspci reports my tuner as:
>>
>> 00:0d.0 Multimedia video controller: Conexant CX23880/1/2/3 PCI Video
>> and Audio Decoder (rev 05)
>>
>> The card is branded as a Leadtek Winfast 2000XP Expert.
>>
>> I'm sure the problem is with the v4l2 implementation in Gem as running
>> the following command gives me perfect video on this card at 640x480:
>>
>> mplayer tv:// -tv driver=v4l2:device=/dev/video0:input=1:norm=NTSC-M
>>
>> (the output follows this message).
>>
>> So the card is capable of 640x480.
>>
>> If I run Gem on this card as 320x240 all works fine. (pictured in
>> attachment 320x240.png)
>>
>> As soon as I change the resolution to 640x480 I get the following errors
>> repeated:
>>
>> VIDIOCMCAPTURE1: Invalid argument
>> VIDIOCMCAPTURE2: Invalid argument
>>
>> And the image appears as in attachment 640x480.png
>>
>> What should my steps for debugging be?
>>
>> Is there dead-simple v4l2 example source (including output so I can
>> confirm its working) I can test with and compare with Gem sources?
> 
> I am not a V4L2 app programmer.
> 
> However, I have attached a program I wrote a while ago to exercise the
> cx18 driver and HVR-1600 as MythTV would opening an ivtv/cx18 based
> card.  The cx88 probably won't support the MPEG ioctls but I think the
> program is a pretty simple example of how to set up a v4l2 device and
> capture data.
> 
> You might want to look at the set_picture_size() call.
> 
> The V4L2 API document can be found at linuxtv.org, if you need further
> documentation on the ioctl()s.
> 
> Regards,
> Andy
> 
>> Any advice appreciated.
>>
>> B. Bogart
>>
>>
>> --
>> Here is the mplayer output:
>>
>> MPlayer dev-SVN-r26940
>> CPU: AMD Athlon(tm) 64 Processor 3200+ (Family: 15, Model: 47, Stepping: 0)
>> CPUflags:  MMX: 1 MMX2: 1 3DNow: 1 3DNow2: 1 SSE: 1 SSE2: 1
>> Compiled with runtime CPU detection.
>> Can't open joystick device /dev/input/js0: No such file or directory
>> Can't init input joystick
>> mplayer: could not connect to socket
>> mplayer: No such file or directory
>> Failed to open LIRC support. You will not be able to use your remote
>> control.
>>
>> Playing tv://.
>> TV file format detected.
>> Selected driver: v4l2
>>  name: Video 4 Linux 2 input
>>  author: Martin Olschewski <olschewski@xxxxxxxxxxxxxxxx>
>>  comment: first try, more to come ;-)
>> Selected device: Leadtek Winfast 2000XP Expert
>>  Tuner cap:
>>  Tuner rxs:
>>  Capabilites:  video capture  VBI capture device  tuner  read/write
>> streaming
>>  supported norms: 0 = PAL-BG; 1 = PAL-DK; 2 = PAL-I; 3 = PAL-M; 4 =
>> PAL-N; 5 = PAL-Nc; 6 = PAL-60; 7 = NTSC-M; 8 = NTSC-M-JP; 9 = NTSC-443;
>> 10 = SECAM-DK; 11 = SECAM-L;
>>  inputs: 0 = Television; 1 = Composite1; 2 = S-Video;
>>  Current input: 1
>>  Current format: BGR24
>> v4l2: current audio mode is : MONO
>> v4l2: ioctl set format failed: Invalid argument
>> v4l2: ioctl set format failed: Invalid argument
>> open: No such file or directory
>> [MGA] Couldn't open: /dev/mga_vid
>> open: No such file or directory
>> [MGA] Couldn't open: /dev/mga_vid
>> [VO_TDFXFB] Can't open /dev/fb0: No such file or directory.
>> s3fb: can't open /dev/fb0: No such file or directory
>> ==========================================================================
>> Opening video decoder: [raw] RAW Uncompressed Video
>> VDec: vo config request - 640 x 480 (preferred colorspace: Packed UYVY)
>> VDec: using Packed UYVY as output csp (no 0)
>> Movie-Aspect is undefined - no prescaling applied.
>> VO: [xv] 640x480 => 640x480 Packed UYVY
>> Selected video codec: [rawuyvy] vfm: raw (RAW UYVY)
>> ==========================================================================
>> Audio: no sound
>> Starting playback...
>> v4l2: 40 frames successfully processed, -39 frames dropped.
>>
>> Exiting... (Quit)
>>
>> --
>> video4linux-list mailing list
>> Unsubscribe mailto:video4linux-list-request@xxxxxxxxxx?subject=unsubscribe
>> https://www.redhat.com/mailman/listinfo/video4linux-list