Re: PCIe capture driver

[Hans Verkuil <hverkuil@xs4all.nl>]

On 11/11/2015 07:04 AM, Ran Shalit wrote:
> On Wed, Oct 28, 2015 at 12:50 AM, Hans Verkuil <hverkuil@xs4all.nl> wrote:
>>
>>
>> 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.
>>
> 
> 
> Hello Hans,
> 
> Is it possible to use the PVR-350 which is a PCI device connected to
> PCI express in mothrboard ? (I think it will required an adapter )
> Does the ivtv driver function correctly if an adapter to PCIe is connected ?

Yes, that should work. You need an adapter like this one:

http://www.dx.com/p/pci-express-to-pci-adapter-card-26080#.VkLso3yrRwE

Regards,

	Hans