[mythtv-users] Arm Based Frontend

Mon Apr 21 23:35:32 UTC 2014

On Sat, Apr 19, 2014 at 11:53 AM, Timothy Krantz <tkrantz at stahurabrenner.com
> wrote:

> Hello all,
>
> I know, here we go again, another question about low power front ends.
>
> Well, not really.  I ran across some notes that said there was now VDPAU
> for the sunxi/mali400 chip devices.  It seems to sit on top of the “binary
> blob” drivers.
>
> So, I fired up my trusty hackberry board and installed Fedora 20, got it
> completely up to date with the latest kernel off of the sunxi site.
> 3.4.79ish.  Followed all the instructions on installing “binary blob”
> drivers and fbturbo and finally VDPAU.
>
> Then, being a masochist I downloaded the latest fixes .027 and went about
> compiling mythtv.  Yes on the hackberry itself, I have not yet fiddled with
> cross compiling.  I only compiled libs programs and yes it took forever.
> There was a syntax error in the ffmpeg portion.  I found a patch for it in
> the ffmpeg forums and then it compiled ok.  In fact everything compiled ok.
>
> So, I fired up mythfrontend.  Damned if it did not come up.  I set video
> play back to vdpau slim, audio to the hdmi device and went to play back a
> recording.  I chose a very low file for my first test.  A recording of “It
> takes a thief”.  After some crackling, it played.  Yep it played.  Not
> perfectly.  Not usably, but it played.  Oddly it played too fast as if I
> had chosen to play it back at maybe 1.5 times normal.  There was some video
> tearing but the VDPAU stuff is still very new, perhaps that will change.  I
> can’t get the OSD to appear, not sure why.  Choosing OpenGL for the painter
> gives a black screen (I fell back to qt).  Oh and playback continued with
> 30-50 percent idle processor.  Audio seems to be sketchy, I will try it
> with the non-hdmi connector to see if that makes a difference.
>
> Playing back higher quality digital programs produced similar results.
> Attempts to playback recordings from my HDPVR resulted in a ball of
> scrambled pixels in the center of the screen.
>
> Anyway, I **think** this may be the farthest anyone has gotten with one
> of these boards and I just wanted to share my experience.
>
>
>
> Small update, I got past the missing OSD by setting an environment
> variable.
>
>
>
> I believe this to be the source of being unable to play recordings from my
> HDPVR (a message coming from the VDPAU layer I guess) :
>
> [VDPAU SUNXI] We can’t decode interlaced frames yet! Sorry
>
>
>
> And this may be the root of the “too fast” playback issue:
>
> 2014-04-19 14:25:07.913903 I  VidOutVDPAU: Enabled deinterlacing.
>
> 2014-04-19 14:25:07.914129 E  VSYNC: DRMVideoSync: VBlank ioctl did not
> work, unimplemented in this driver?
>
> 2014-04-19 14:25:07.918892 I  Player(0): Video timing method: RTC
>
> 2014-04-19 14:25:07.919016 I  Player(0): Display Refresh Rate: 60.013
> Video Frame Rate: 29.970
>
> 2014-04-19 14:25:07.919092 I  Player(0): SetFrameInterval ps:1 scan:1
>
> 2014-04-19 14:25:07.924087 I  playCtx: StartPlaying(): took 0 ms to start
> player.
>
> 2014-04-19 14:25:07.924217 I  TV: Created player.
>
> 2014-04-19 14:25:07.924393 I  TV: StartPlayer(0, WatchingPreRecorded,
> main) -- end ok
>
> 2014-04-19 14:25:07.925670 I  TV: Changing from None to WatchingPreRecorded
>
> 2014-04-19 14:25:07.938901 I  VidOutVDPAU: Created VDPAU decoder (2 ref
> frames)
>
> 2014-04-19 14:25:07.942618 I  TV: DrawUnusedRects() -- begin
>
> 2014-04-19 14:25:07.942740 I  TV: DrawUnusedRects() -- end
>
> 2014-04-19 14:25:07.943057 I  TV: Main UI disabled.
>
> 2014-04-19 14:25:07.943125 I  TV: HandleStateChange(0) -- end
>
> 2014-04-19 14:25:07.943454 I  TV: tv->Playback() -- end
>
> 2014-04-19 14:25:07.943511 I  TV: Entering main playback loop.
>
> 2014-04-19 14:25:08.005643 I  Player(0): Waiting for video buffers...
>
> 2014-04-19 14:25:08.023848 I  AFD: EIA-708 caption service #1 is in the
> Undetermined language.
>
> 2014-04-19 14:25:08.028406 I  Player(0): Enabled deinterlacing
>
> 2014-04-19 14:25:08.058360 I  VDPAU: Added 2 output surfaces (total 4, max
> 4)
>
> 2014-04-19 14:25:08.058196 I  Dec: Selected track #1 (type 5) in the
> Undetermined language(7695972)
>
> 2014-04-19 14:25:10.065231 I  Player(0): Video is 3.33668 frames behind
> audio (too slow), dropping frame to catch up.
>
> 2014-04-19 14:25:10.065720 I  Player(0): Video is 3.44655 frames behind
> audio (too slow), dropping frame to catch up.
>
> 2014-04-19 14:25:10.066074 I  Player(0): Video is 3.27419 frames behind
> audio (too slow), dropping frame to catch up.
>
> 2014-04-19 14:25:10.220057 I  Player(0): Video is 3.16336 frames behind
> audio (too slow), dropping frame to catch up.
>
> 2014-04-19 14:25:10.220476 I  Player(0): Video is 3.24165 frames behind
> audio (too slow), dropping frame to catch up.
>
> 2014-04-19 14:25:10.220844 I  Player(0): Video is 3.05311 frames behind
> audio (too slow), dropping frame to catch up.
>
> 2014-04-19 14:25:10.738573 I  Player(0): FPS:   46.18 Mean: 21654
> Std.Dev:  7665 CPUs: 100%
>
> 2014-04-19 14:25:13.783087 I  Player(0): FPS:   39.11 Mean: 25571
> Std.Dev:  7414 CPUs: 66%
>
>
>
> If I interpret this correctly it is attempting to display frames at 60FPS
> and failing….
>
>
>
> If anyone has a clue how I can hack a change to this to force 29.97 I
> would love to try it.
>

Nice job, Tim.  That's excellent.   I'm one of the many looking for a true
mythtv frontend on a low power system and this sounds like the most
promising option thus far.

Any pointers on systems that have this GPU, if others want to join the
effort?
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