Re: [dpdk-users] dpdk - for video frames too ?

[Thomas Monjalon <thomas.monjalon@6wind.com>]

Hi,

The dev mailing list is more appropriate for this discussion.

2015-12-04 18:30, Ran Shalit:
> On Thu, Nov 12, 2015 at 10:49 AM, Thomas Monjalon
> <thomas.monjalon@6wind.com> wrote:
> > 2015-11-12 09:14, Ran Shalit:
> >> I need to develop a driver/application which capture and output video
> >> frames from PCIe device , and is using Intel cpu (i7), Centand Intel's
> >> media sdk server framework for the video compression.
> >>
> >> I am not sure what will be a better choice between the following 2 options:
> >> 1. application which use dpdk for capture and output to the PCIe device
> >> 2. v4l driver for the PCIe device
> >>
> >> dpdk is supposed to be able to read/write from PCIe device too.
> >> I tried to see the prons/cons of dpdk compared to v4l.
> >>
> >> prons of dpdk, as I understand them:
> >> 1. userspace application (easier debugging compared to kernel
> >> debugging of v4l device driver)
> >> 2. supposed better performance
> >>
> >> cons of dpdk compared to v4l:
> >> 1. I could not find examples for PCIe device usage , or samples for
> >> showing how application (such as media sdk) use dpdk video frames.
> >
> > There is no API for video currently.
> > There is an API for networking drivers and a crypto API is coming.
> > If you feel a DPDK poll mode driver would be a good design, you are
> > welcome to do it. In case it brings some performance improvement,
> > it can be decided (no guarantee) to integrate it in the scope of the DPDK.
> 
> Hi Thomas,
> 
> I've reply for a message posted some time ago.
> Is dpdk capable of recieveing and sending buffers from PCIe using DMAs ?

Of course yes.

> I think that if the buffers represent video or not is less important,
> because the important thing is to be capable to stream buffers from
> (or to) the PCIe device.
> Do you think it is ready to be used for such purpose ?

You need to write a driver for your device.
Then your application needs an video API in DPDK.

> I ask becuase I try to see which alternative is better v4l2 or dpdk.
> Dpdk can be used from userspace which in my opinion is great
> advantage, but if it can't do these streaming of buffers from PCIe,
> than probably I should stick with v4l2 development.

I think your development would be welcome in DPDK.