On Wed, 2018-03-14 at 13:05 +0100, Javier Martin wrote:
> Sorry everyone about my previous e-mail with all the HTML garbage. Here
> is the plain text answer instead.
>
> Hi Philipp,
>
> thanks for your answer.
>
> On 13/03/18 12:20, Philipp Zabel wrote:
> > Hi Javier,
> >
> > On Mon, 2018-03-12 at 17:54 +0100, Javier Martin wrote:
> >> Hi,
> >> we have an i.MX6 Solo based board running the latest mainline kernel
> >> (4.15.3).
> >>
> >> As part of our development we were measuring the decoding
> performance of
> >> the i.MX6 coda chip.
> >>
> >> For that purpose we are feeding the decoder with 640x368 @ 30fps H.264
> >> streams that have been generated by another i.MX6 coda encoder
> >> configured with fixed qp = 25 and gopsize = 16.
Those are the defaults. Is the encoder running on the same system, at
the same time? Or are you decoding a previously encoded stream (multiple
previously encoded streams)?
[...]
> I'm currently using 3.1.1 both for encoding and decoding. I think I got
> it from the latest BSP provided by NXP. Now that you mention it the
> driver is printing these messages at probe time which I had ignored so far:
>
> coda 2040000.vpu: Firmware code revision: 46056
> coda 2040000.vpu: Initialized CODA960.
> coda 2040000.vpu: Unsupported firmware version: 3.1.1
> coda 2040000.vpu: codec registered as /dev/video[3-4]
That is strange, commit be7f1ab26f42 ("media: coda: mark CODA960
firmware versions 2.3.10 and 3.1.1 as supported") was merged
in v4.14.
> Do you think I should use an older version instead?
Unfortunately I have no indication that this would help.
> Also, do you think it would be worth trying different parameters in the
> encoder to see how the decoder responds in those cases?
Possibly. It would be interesting to know if this happens more often for
low resolutions / low quality / static frames than high resolutions /
high quality / high movement.
I fear this may be some interaction between coda context switches and
bitstream reader unit state.
regards
Philipp
