Re: PCIe capture driver

[Hans Verkuil <hverkuil@xs4all.nl>]

On 10/27/2015 22:56, Ran Shalit wrote:
> On Tue, Oct 27, 2015 at 12:21 AM, Hans Verkuil <hverkuil@xs4all.nl> wrote:
>>
>>
>> On 10/27/2015 02:04, Ran Shalit wrote:
>>> On Mon, Oct 26, 2015 at 1:46 PM, Steven Toth <stoth@kernellabs.com> wrote:
>>>>> No, use V4L2. What you do with the frame after it has been captured
>>>>> into memory has no relevance to the API you use to capture into memory.
>>>>
>>>> Ran, I've built many open and closed source Linux drivers over the
>>>> last 10 years - so I can speak with authority on this.
>>>>
>>>> Hans is absolutely correct, don't make the mistake of going
>>>> proprietary with your API. Take advantage of the massive amount of
>>>> video related frameworks the kernel has to offer. It will get you to
>>>> market faster, assuming your goal is to build a driver that is open
>>>> source. If your licensing prohibits an open source driver solution,
>>>> you'll have no choice but to build your own proprietary API.
>>>>
>>>> --
>>>> Steven Toth - Kernel Labs
>>>> http://www.kernellabs.com
>>>
>>> Hi,
>>>
>>> Thank you very much for these valuable comments.
>>> If I may ask one more on this issue:
>>> Is there an example in linux tree, for a pci device which is used both
>>> as a capture and a display device ? (I've made a search but did not
>>> find any)
>>> The PCIe device we are using will be both a capture device and output
>>> video device (for display).
>>
>> The cobalt driver (drivers/media/pci/cobalt) does exactly that: multiple HDMI inputs and an optional HDMI output (through a daughterboard).
>>
>> Please note: using V4L2 for an output only makes sense if you will be outputting video, if the goal is to output a graphical desktop then the drm/kms API is much more suitable.
>>
>> Regards,
>>
>>         Hans
> 
> Hi Hans,
> 
> Thank you very much for the reference.
> I see that the cobalt card is not for sale ?  If it was it could help
> us in our development.

No, sorry. It's a Cisco-internal card only.
 
> In our case it is more custom design which is based on FPGA:
> 
> Cpu ---PCIe---- FPGA <<<-->>>     3xHD+3xSD inputs & 1xHD(or SD) output
> 
> As I understand there is no product chip which can do the above
> (3xHD+3xSD inputs & 1xHD(or SD) output), that's why the use of FPGA in
> the board design.

The ivtv driver (drivers/media/pci/ivtv) has SD input and output, so that can be a
useful reference for that as well. The Hauppauge PVR-350 board is no longer
sold, but you might be able to pick one up on ebay.

Regards,

	Hans