Adding Linux support for the Ion Video 2 PC analog video capture device (em28xx)

Adding Linux support for the Ion Video 2 PC analog video capture device (em28xx)

[Alexandre-Xavier Labonté-Lamoureux]

Hi,

I have an Ion Video 2 PC and a StarTech svid2usb23 (id: 0xeb1a,
0x5051). I have documented them here:
https://linuxtv.org/wiki/index.php/Ion_Video_2_PC

I can get them to be recognized by patching the em28xx driver. I use
"EM2860_BOARD_TVP5150_REFERENCE_DESIGN".
(The patch can be found here:
https://www.linuxtv.org/wiki/index.php/Ion_Video_2_PC#Making_it_work)

Yet, it almost works, there is only one bug.

When I plug something yellow composite input of the device, it
captures one frame then stops. If I disconnect the composite video so
that there is no video input, then it starts capturing frames again.
So the device doesn't want to capture video when there is input, it
only captures frames when their is nothing connected to it.

I can see that it stops capturing frames by looking at the frame
counter in qv4l2.
I have made a video about this problem: https://youtu.be/z96OfgHGDao?t=40s
You can see what I explained in the previous paragraph at 1:58 in the video.

These are the chips inside the Ion Video 2 PC:
* Empia EM2860
* Empia EMP202
* 5150AM1

What would be the next thing to do to make it work? Thanks.

Best regards,
Alexandre

Re: Adding Linux support for the Ion Video 2 PC analog video capture device (em28xx)

[Mauro Carvalho Chehab]

Em Wed, 17 Aug 2016 15:26:40 -0400
Alexandre-Xavier Labonté-Lamoureux  <axdoomer@gmail.com> escreveu:

> Hi,
> 
> I have an Ion Video 2 PC and a StarTech svid2usb23 (id: 0xeb1a,
> 0x5051). I have documented them here:
> https://linuxtv.org/wiki/index.php/Ion_Video_2_PC
> 
> I can get them to be recognized by patching the em28xx driver. I use
> "EM2860_BOARD_TVP5150_REFERENCE_DESIGN".
> (The patch can be found here:
> https://www.linuxtv.org/wiki/index.php/Ion_Video_2_PC#Making_it_work)
> 
> Yet, it almost works, there is only one bug.
> 
> When I plug something yellow composite input of the device, it
> captures one frame then stops. If I disconnect the composite video so
> that there is no video input, then it starts capturing frames again.
> So the device doesn't want to capture video when there is input, it
> only captures frames when their is nothing connected to it.
> 
> I can see that it stops capturing frames by looking at the frame
> counter in qv4l2.
> I have made a video about this problem: https://youtu.be/z96OfgHGDao?t=40s
> You can see what I explained in the previous paragraph at 1:58 in the video.
> 
> These are the chips inside the Ion Video 2 PC:
> * Empia EM2860
> * Empia EMP202
> * 5150AM1
> 
> What would be the next thing to do to make it work? Thanks.

It seems that you're using some game console to generate images.
Those usually output video in progressive mode, instead of using
interlaced mode. Maybe that's the cause of the issues you're
having.

You could try to write a quick hack by patching em28xx_v4l2_init, at 
drivers/media/usb/em28xx/em28xx-video.c.

Seek for those lines:

        if (dev->board.is_webcam)
                v4l2->progressive = true;

And comment the first one. If this works, then we may add a modprobe
parameter (like saa7134) or something else to fix it.

Thanks,
Mauro

Re: Adding Linux support for the Ion Video 2 PC analog video capture device (em28xx)

[Alexandre-Xavier Labonté-Lamoureux]

Hi Mauro!

Thank you for your help.

I made the change that you suggested. It fixed the video freeze. I
still have issues though. There is a huge green bar at the bottom of
the screen and the colors don't work correctly.

On my Atari Flashback, the screen is in black and white:
http://imgur.com/a/U6Shv

I tried on my Nintendo 64 to see if I would get the same result, what
I got is a disco effect: https://youtu.be/WLlqJ7T3y4g
As you can see, it goes through the whole range of color hues. The
frame rate is low, but that's my screen recorder's fault.

What should I do next?

Best regards,
Alexandre-Xavier

On Thu, Aug 18, 2016 at 5:29 AM, Mauro Carvalho Chehab
<mchehab@s-opensource.com> wrote:
> Em Wed, 17 Aug 2016 15:26:40 -0400
> Alexandre-Xavier Labonté-Lamoureux  <axdoomer@gmail.com> escreveu:
>
>> Hi,
>>
>> I have an Ion Video 2 PC and a StarTech svid2usb23 (id: 0xeb1a,
>> 0x5051). I have documented them here:
>> https://linuxtv.org/wiki/index.php/Ion_Video_2_PC
>>
>> I can get them to be recognized by patching the em28xx driver. I use
>> "EM2860_BOARD_TVP5150_REFERENCE_DESIGN".
>> (The patch can be found here:
>> https://www.linuxtv.org/wiki/index.php/Ion_Video_2_PC#Making_it_work)
>>
>> Yet, it almost works, there is only one bug.
>>
>> When I plug something yellow composite input of the device, it
>> captures one frame then stops. If I disconnect the composite video so
>> that there is no video input, then it starts capturing frames again.
>> So the device doesn't want to capture video when there is input, it
>> only captures frames when their is nothing connected to it.
>>
>> I can see that it stops capturing frames by looking at the frame
>> counter in qv4l2.
>> I have made a video about this problem: https://youtu.be/z96OfgHGDao?t=40s
>> You can see what I explained in the previous paragraph at 1:58 in the video.
>>
>> These are the chips inside the Ion Video 2 PC:
>> * Empia EM2860
>> * Empia EMP202
>> * 5150AM1
>>
>> What would be the next thing to do to make it work? Thanks.
>
> It seems that you're using some game console to generate images.
> Those usually output video in progressive mode, instead of using
> interlaced mode. Maybe that's the cause of the issues you're
> having.
>
> You could try to write a quick hack by patching em28xx_v4l2_init, at
> drivers/media/usb/em28xx/em28xx-video.c.
>
> Seek for those lines:
>
>         if (dev->board.is_webcam)
>                 v4l2->progressive = true;
>
> And comment the first one. If this works, then we may add a modprobe
> parameter (like saa7134) or something else to fix it.
>
> Thanks,
> Mauro