[mythtv] Mediacodec problem with avcodec_flush_buffers

[David Engel]

On Mon, Jul 30, 2018 at 01:26:24PM -0700, Aman Gupta wrote:
> On Mon, Jul 30, 2018 at 1:22 PM David Engel <david at istwok.net> wrote:
> 
> > On Mon, Jul 30, 2018 at 12:59:17PM -0400, Peter Bennett wrote:
> > > On 07/29/2018 11:12 PM, David Engel wrote:
> > > > On Sun, Jul 29, 2018 at 08:55:20PM -0500, David Engel wrote:
> > > > > On Fri, Jul 27, 2018 at 12:35:25PM -0400, Peter Bennett wrote:
> > > > > > On 07/27/2018 10:37 AM, David Engel wrote:
> > > > > > > On Fri, Jul 27, 2018 at 08:09:36AM -0400, Peter Bennett wrote:
> > > > > > > > I think it is only with deinterlace. It may also happen with
> > h264 interlaced
> > > > > > > > content. I do not have much h264 interlaced content to test
> > with.
> > > > > > > I have at least one, 1080i, h264 channel.  I can check it
> > tonight.
> > > > > > >
> > > > > > > David
> > > > > > I have one 2-minute h264 interlaced 1080 file. I tested with that
> > and I do
> > > > > > not see the corrupted frame there when skipping.
> > > > > > Attached is a patch to undo the non-functional workaround for the
> > corrupted
> > > > > > frame in case you want to try it.
> > > > > This is now commit 4287f45f, right?  I just now got a chance to try
> > it
> > > > > and also look into another bug I found.  Do you still want feedback
> > on
> > > > > it?
> > > > Okay, I have some feedback.  Maybe, just maybe, this might help with a
> > > > fix.
> > > >
> > > > The previous behavior I saw was this.  The corruption was very
> > > > prevalent in ff/rew.  It was not very prevalent at all when skipping
> > > > forward and backward.
> > > >
> > > > The new behavior I now see is this.  I never saw any corruption even
> > > > once in ff/rew of a 1-hour and a half-hour show.  The corruption is
> > > > very prevalent now in skipping forward and backward.
> > > >
> > > > In other words, ff/rew was bad before and is now good and skipping was
> > > > good before and is now bad.  Do ff/rew and normal playback still have
> > > > separate GetFrame() calls?  If so, maybe what is being done now for
> > > > one ff/rew frame can be done for skips too and fix the problem.
> > > >
> > > > David
> > > Hi David
> > >
> > > This was expected. I reverted to the original behavior by taking out my
> > > patch, which did not fix the issue and likely made it worse. Aman has
> > > acknowledged the bug and passed it on to NVidia so maybe we can get a
> > patch
> > > from them in due course.
> >
> > Aman, do you have a good connection at Nvidia?  My local ABC station
> > seems to have again started sending streams that show corruption when
> > decoded with MediaCodec (and VDPAU, for that matter), but not when
> > decoded with ffmpeg software.  I have a short sample that I can
> > provide.
> >
> 
> Yes I can forward the bug report and sample if you email them to me. Please
> test the sample with the latest Exoplayer and make sure it reproduces there
> so they can investigate easily.

Excellent.  I have Exoplayer built and running, but I don't see how to
make the demo app play an arbitrary file.  How do I do that?

David
-- 
David Engel
david at istwok.net