[mythtv-users] Re: Has anyone setup v4l2 succesfully?

[Jarod C. Wilson]

On Friday, Reza Naima wrote:

>>> Then, is there something I have to do to enable v4l2 support?  I
>>> couldn't find any mention of what to turn on or off to use that 
>>> rather
>>> than the v4l code.
>>
>> Install the kernel. Install your v4l2 driver. The APIs are there. It
>> just works.
>
> I did, and it's still defaulting to the v4l1 API, no tthe v4l2 API..

Out of curiosity, what card are you using? Does it work with the v4l 
API? If your card is working as such, then what is the reason for 
wanting to switch to the v4l2 API? (The old adage: if it ain't broke, 
don't fix it).

>>> So, if you run 'v4l-conf', what output do you get?
>>
>> Dunno. Never touched it before. Is there some reason I should have had
>> to? I just installed the kernel, installed my driver, and it all 
>> works.
>
>
> I actually wanted to see the output you are getting.  It will tell you
> if you are actually using v4l2 or v4l1..

Or it will tell me nothing:
# v4l-conf
ioctl VT_GETSTATE: Invalid argument

But v4l-info gives me this (snipped for brevity):
# v4l-info

### v4l2 device info [/dev/video0] ###
general info
     VIDIOC_QUERYCAP
         driver                  : "ivtv"
         card                    : "Vanilla iTVC15 card"
         bus_info                : "0"
         version                 : 0.0.1
         capabilities            : 0x1030001 
[VIDEO_CAPTURE,TUNER,AUDIO,READWRITE]

standards
     VIDIOC_ENUMSTD(0)
         index                   : 0
         id                      : 0x3000 [NTSC_M,NTSC_M_JP]
         name                    : "NTSC"
         frameperiod.numerator   : 1001
         frameperiod.denominator : 30000
         framelines              : 525
<snip>

inputs
     VIDIOC_ENUMINPUT(0)
         index                   : 0
         name                    : "Composite 0"
         type                    : CAMERA
         audioset                : 1
         tuner                   : 0
         std                     : 0x3000 [NTSC_M,NTSC_M_JP]
         status                  : 0x0 []
<snip>

tuners
     VIDIOC_G_TUNER(0)
         index                   : 0
         name                    : "ivtv TV Tuner"
         type                    : ANALOG_TV
         capability              : 0x12 [NORM,STEREO]
         rangelow                : 0
         rangehigh               : 0
         rxsubchans              : 0x2 [STEREO]
         audmode                 : STEREO
         signal                  : 0
         afc                     : 0

video capture
     VIDIOC_G_FMT(VIDEO_CAPTURE)
         type                    : VIDEO_CAPTURE
         fmt.pix.width           : 720
         fmt.pix.height          : 480
         fmt.pix.pixelformat     : 0x00000000 [....]
         fmt.pix.field           : INTERLACED
         fmt.pix.bytesperline    : 0
         fmt.pix.sizeimage       : 131072
         fmt.pix.colorspace      : unknown
         fmt.pix.priv            : 0
<snip>

It looks to me like I'm using v4l2. Not that I care one way or another. 
I installed the kernel, installed the driver, and it works. :)

> Otherwise, how are you so sure
> that you are actually using v4l2 other that what's stated in the kernel
> manifest?

Because I trust the guy who put the kernel together, and the ivtv 
drivers say it is a v4l2 card. And because the output I just looked at 
says so. :)

> I tried that exact same kernel, but it still used v4l1...

But does the card work? Again, if it ain't broke, don't fix it.

What do v4l-conf and v4l-info give for output on your system?

-jcw