[Interest] Video acceleration with gstreamer 1.0 omx and Qt 5.9.4 / 5.10 eglfs on RPI3 (brcm)

Petar Koretić petar.koretic at gmail.com
Fri Feb 2 16:01:16 CET 2018


Well, so couple days more of testing Yocto and Boot2Qt the issue seems to
be in the Qt somewhere.
I decided to build Qt 5.9.4 and even 5.10.1 snapshot using latest Boot2Qt
layer.
Adding gstreamer1.0-omx to the layer and building the image with that
results in a great smooth video when played with gstreamer directly,
ie gst-play-1.0 test.mp4 (this video comes from youtube-dl -f 137+140
https://www.youtube.com/watch?v=T63MCogI4sM)
but playing that same video using Video qml element there are obvious frame
drops.

In essence there is no ability to get a smooth video playback on RPI3 by
using Qt/QML and any stock method approach as of this moment using bcm or
vc4 driver with buildroot, yocto, rasbpian or archarm.
This definitely surprised me as default Boot2Qt image is obviously unusable
for the RPI QML Video playout. I ran out of free time, so I doubt I will
have time to investigate more.
Next I would try latest gstreamer in hope that there were some improvements
in the sink element that QML uses since 1.10.4 is built by Boot2Qt and
1.12.4 is the latest if I am not mistaken.

Best regards,
Petar

On Wed, Jan 31, 2018 at 6:53 PM, Paolo Angelelli <paolo.angelelli at qt.io>
wrote:

> Maybe this could be relevant:
> https://gstreamer.freedesktop.org/data/events/gstreamer-
> conference/2016/John%20Sadler%20-%20Smooth%20video%20on%
> 20Raspberry%20Pi%20with%20gst-mmal%20(Lightning%20Talk).pdf
>
> On Wed, 31 Jan 2018 18:48:47 +0100
> Petar Koretić <petar.koretic at gmail.com> wrote:
>
> > Thanks Paolo,
> > I also found something along that lines so I will be trying this next.
> >
> > Vlad, thanks, I actually took buildroot one from that page to make sure
> it
> > works :)
> > yocto was also next on my list, but for the lack of time I always end up
> > using buildroot in the end as it should work the same, and I knew I had
> > this running on raspbian so I thought this will "just work" as I would
> > somewhat expect this to be pretty standard
> >
> > Best regards,
> > Petar
> >
> >
> > On Wed, Jan 31, 2018 at 6:42 PM, Vlad Stelmahovsky <
> > vladstelmahovsky at gmail.com> wrote:
> >
> > > Hi
> > >
> > > have you  checked the link: http://www.jumpnowtek.
> > > com/rpi/Raspberry-Pi-Systems-with-Yocto.html ?
> > >
> > > On Wed, Jan 31, 2018 at 5:28 PM, Petar Koretić <
> petar.koretic at gmail.com>
> > > wrote:
> > >
> > >> Hi all.
> > >>
> > >> So I haven't played around with this for some time but around one year
> > >> ago or more I think I got this up running fairly easily. This was
> maybe
> > >> still with gstreamer 0.10.
> > >>
> > >> For the past two days I was trying to get video working with
> acceleration
> > >> on the RPI player through QtMultimedia using QML Video element.
> > >>
> > >> Using VC4 driver is a no go as there is no acceleration support in the
> > >> driver yet as far as I know but the simple fullhd video played pretty
> > >> nicely as far as it goes.
> > >>
> > >> Anyway I went back the standard omx route.
> > >> I tried to build and use Qt 5.9 creating a system using buildroot as I
> > >> always do and later checking with latest raspbian stretch.
> > >> Both methods compiled without issues using eglfs and gstreamer 1 and
> > >> using the broadcom driver.
> > >>
> > >> In the end these are the instructions that I decided to follow for
> > >> rasbian http://www.tal.org/tutorials/building-qt-510-raspberry-pi-de
> > >> bian-stretch
> > >> where I used gstreamer-omx-rpi package.
> > >>
> > >> Playing example full hd video (http://cdn3.viblast.com/strea
> > >> ms/hls/airshow/2670k/stream.m3u8) or any mp4 youtube file results in
> a
> > >> not so smooth video with obvious stutters (gpu_mem is at 256mb)
> > >> .GST_DEBUG=omx:4 shows that the omx is being used.
> > >>
> > >> I remember that I was able to play two videos at the same time (one
> full
> > >> hd, one smaller) with animations without issues but I'm not sure if
> this
> > >> was using eglfs and gstreamer 1.0 as it was more than a year ago.
> > >>
> > >> Is this expected to work in this setup with gstreamer omx on rpi and
> > >> broadcom driver using eglfs or which route should I go? Any help is
> > >> appreciated as I've tried a fair bit of different things and I'm still
> > >> trying but can't understand if this should be possible at all.
> > >>
> > >> Best regards,
> > >> Petar
> > >>
> > >>
> > >>
> > >>
> > >>
> > >>
> > >>
> > >> _______________________________________________
> > >> Interest mailing list
> > >> Interest at qt-project.org
> > >> http://lists.qt-project.org/mailman/listinfo/interest
> > >>
> > >>
> > >
> > >
> > > --
> > > Best regards,
> > > Vlad
> > >
>
> _______________________________________________
> Interest mailing list
> Interest at qt-project.org
> http://lists.qt-project.org/mailman/listinfo/interest
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.qt-project.org/pipermail/interest/attachments/20180202/4c9726a5/attachment.html>


More information about the Interest mailing list