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<div class="moz-cite-prefix">On 3/2/19 10:58 AM, Mark Kendall wrote:<br>
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<div dir="ltr" class="gmail_attr">On Sat, Mar 2, 2019, 3:31
PM Peter Bennett <<a href="mailto:pb.mythtv@gmail.com"
moz-do-not-send="true">pb.mythtv@gmail.com</a>>
wrote:</div>
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> Stuttering occurs right at the start of the program
with mediacodec <br>
> decoder. SW dec is fine. Either avsync method
exhibits this so its <br>
> mediacodec related.<br>
><br>
I am hoping that the direct render fixes it. Mark K said
that he will be <br>
looking into direct render. Anyway I will download some of
that file and <br>
see if I can do anything to understand what is happening,<br>
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<div dir="auto">Has anyone tried increasing the number of
mediacodec video buffers? Its only 8 at the moment. I had
similar problems with VideoToolBox decoding this week and
increasing the buffer count was the key. 8 gives you very
little headroom for the simplest of system glitches.</div>
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<div dir="auto">Direct render is getting there - only problem is
it crashes as soon as it tries to display anything:)</div>
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<div dir="auto">Regards, Mark</div>
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I tried the video that gives the problem. It is H264 interlaced.
Normally, mediacodec on shield should deinterlace it and hand it to
MythTV as progressive. MythTV is seeing this as progressive
switching to interlaced and back to progressive again about once
every second. This causes the OpenGL rendering and deinterlacing to
be re-initialized twice every second. It is not surprising that this
results in jerky playback.<br>
<br>
I will trace through it and see whether ffmpeg is actually switching
it back and forth between interlaced and progressive, and whether
anything can be done about it.<br>
<br>
Regarding the video buffers - I had to set that low value, otherwise
playback would be terminated by android on the shield. Android has
very restrictive memory usage rules, and does not hesitate to shut
down any process that uses more than it thinks is reasonable. 8
buffers seemed to be the best value that worked well. I do not think
the video buffers are the cause of the jerkiness.<br>
<br>
Peter<br>
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