[meta-freescale] QtMultimedia on i.MX6

[Otavio Salvador]

On Thu, Jul 4, 2013 at 12:14 PM, Thomas Senyk
<thomas.senyk at pelagicore.com> wrote:
> On Thursday, 04 July, 2013 17:03:03 Thomas Senyk wrote:
>> Hi,
>>
>> I've started to investigate to see the QtMultimedia-gstreamer integration on
>> the i.MX6 could be optimized.
>>
>> I'm writing this mail to sync with others who might already done some work
>> or investigations on this matter, to get hints where to start and what's
>> worth to investigate.
>>
>>
>>
>> State right now:
>>
>> The HW-decoders are used (according to gstreamer log).
>> That's a very good start/out of the box experience! Good job..freescale I
>> guess?
>>
>> There is still a lot of cpu load:
>>    - 720p: smooth playback but~18% complete cpu load => ~70% of one core
>>    - 1080p: playback not smooth and ~27% complete cpu load -> 100% of one
>> core + some additional cpu load
>>
>> The obvious reason for this cpu load is some sort of memcopy and/or
>> conversion.
>>   ... gstreamer doesn't render into gpu-memory directly.
>>   ... or (if you want it the other way around) the gstreamer (/cpu) memory
>> isn't mapped into gpu-memory (which is possibly on the imx6)
>>
>>
>>
>>
>> Started to do some digging:
>>
>> One of the first things I tried was to compile gst-plugin-gl (which is part
>> of the meta-fsl-arm layer via a .bbappend).
>> The current recipe is driver-version-1.1.0 based and is not building out of
>> the box (at least not for me) ... I got gst-plugins-gl-0.10.3.1.tar.gz
>> (based on 4.0.0) building.**
>>
>> So, after I got it deployed I hoped for magic to happen and everything is
>> perfect now ... no big surprise: it's not :) nothing changed, possibly the
>> gst-pipline build by qtmultimedia is the ame.
>>
>>
>>
>> The reason for this mail / some questions:
>>
>> So I though, I write this mail before I waste a lot of time.
>> What does people think is the best way forward?
>> Try to convince QtMultimedia to use glsink?
>> Try to use a fakesink/memory-based-sink and try to map the cpu memory into
>> gpu memory via vivante APIs?
>>
>> Does anyone have c/c++ code I could try?
>> Ideally for direct framebuffer/EGL use (I'm not using X11)
>> I found: https://github.com/andreluizeng/i.MX6-Video-Streaming-Texture.git
>>  .. but it's crashing rather early and I'm not sure the if the time is well
>> spend fix this code? Anyone used it before?
>> Does anyone know if gst-plugins-gl is applicable for framebuffer/EGL setups?
>>
>>
>> Greet
>> Thomas
>
> Ok ... what is it with me and sending mails 1minute to early all the time ...
> After I pressed "send", I had a very simple and obvious idea .. why not just
> simply try glimagesink instead of mfw_v4lsink:
>
> gst-launch filesrc location=sintel_trailer-1080p.mp4 typefind=true ! aiurdemux !
> vpudec !  glimagesink
>
>  ... long shot, but:
> It's actually working!
> It just opens /dev/fb0 and renders the video into it.
>
> 1080p with 0%(!!) cpu load!
>
> I think that pretty much answers all questions I had ;)
> The way forward: patch QtMultimedia to use glimagesink
>  ... I hope it's going to be trivial to just give him a active FBO or texture.
>
>
> Sorry to everybody who read my way to long mail ;)

It was very good read. By the way, Rogerio (add in Cc) started to try
to get the gst-plugin-gl code more manageble in bitbucket
(https://bitbucket.org/Freescale/gstreamer-gst-plugins-gl/commits/all)
but it was not finished. Maybe you could help on this and we could try
to merge the Vivante backend upstream? This would allow us to drop the
bbappend completely.

>> ** some more info in gst-plugin-gl:
>> It's 'detected' on the board:
>> root at nitrogen-1:~# gst-inspect |grep gl
>> opengl:  glupload: OpenGL upload
>> opengl:  gldownload: OpenGL video maker
>> opengl:  glimagesink: OpenGL video sink
>> opengl:  glfiltercube: OpenGL cube filter
>> opengl:  gleffects: Gstreamer OpenGL Effects
>>
>> ... if someone is interested on how I got it building, let me know. If I got
>> something useful out of it (read: "it's tested") I'll start a discussion on
>> how to upstream it properly into meta-fsl-arm (by the way: I find the
>> current setup of how to bbappend and it's patch looks like very weird)
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--
Otavio Salvador                             O.S. Systems
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