Re: [PATCH 0/3] NVIDIA Tegra210 NVJPG support

[Diogo Ivo]

On 6/10/25 10:52 AM, Mikko Perttunen wrote:
> On 6/10/25 6:05 PM, Thierry Reding wrote:
> > On Fri, Jun 06, 2025 at 11:45:33AM +0100, Diogo Ivo wrote:
> > > Hello,
> > >
> > > This series adds support for the NVJPG hardware accelerator found in the
> > > Tegra210 SoC.
> > >
> > > The kernel driver is essentially a copy of the NVDEC driver as both
> > > engines are Falcon-based.
> > >
> > > For the userspace part I have written a Mesa Gallium backend [1] that,
> > > while still very much experimental, works in decoding images with VA- 
> > > API.
> > >
> > > I have been using ffmpeg to call VA-API with the following command:
> > >
> > > ffmpeg -v verbose -hwaccel vaapi -hwaccel_device /dev/dri/renderD129 
> > > -i <input.jpg> -pix_fmt bgra -f fbdev /dev/fb0
> > >
> > > which decodes <input.jpg> and shows the result in the framebuffer.
> > >
> > > The firmware for the engine can be obtained from a Linux for Tegra
> > > distribution.
> >
> > By the way, have you tried running this on anything newer than Tegra210?
> > Given your progress on this, we can probably start thinking about
> > submitting the binaries to linux-firmware.
>
> FWIW, the impression I have is that NVJPG is basically unchanged all the 
> way to Tegra234. So if we add stream ID support and the firmwares, it'll 
> probably just work. Tegra234 has the quirk that it has two instances of 
> NVJPG -- these have to be distinguished by their different class IDs. 
> But we should go ahead with the T210 support first.

I have a question here, what exactly are the stream IDs? While working
on the driver this came up and I didn't manage to figure it out.

Diogo