[mythtv-users] deinterlacing and non-smooth playback at 1080i

[Seth Daniel]

On Tue, May 22, 2007 at 12:28:23AM +0100, Mark Kendall wrote:
> On 5/21/07, Seth Daniel <mythtv.org at sethdaniel.org> wrote:
>
>> > Does that describe what you're seeing? Best to test with a
>> > clip/channel with a news ticker moving from right to left.
>>
>> I have tons of test material (lots of recordings of various shows that
>> are broadcast @ 1080i).  All exhibit the problem I describe in the first
>> paragraph above.
>
> Seth
>
> I can't remember if you're compiling from source or not, so this may not 
> help:)
>
> The attached patch may help - it's not perfect (it doesn't work 100%
> of the time and it will wreak havoc playing progressive scan content).
> It's against the mythtv-vid branch but shouldn't have any issues with
> other/older versions - and the important stuff is only a couple of
> lines.
>
> With this in place I get perfectly smooth/synced playback at 1080i
> most of the time - still trying to figure out if I can get 100%!
>
> I'll explain it in more detail when I've had some sleep.


It didn't apply cleanly to HEAD svn.  So, I checked out mythtv-vid of
mythtv, applied the patch, and built it.  After some problems with the DB
schema I got it to run.  The sync problem still exists.  I tried with
Bob and w/o any deinterlacing.  FWIW, with Bob I received:

#---START
2007-05-21 19:41:14.042 Using realtime priority.
2007-05-21 19:41:14.044 TV: Changing from None to WatchingPreRecorded
2007-05-21 19:41:14.148 OpenGLVideoSync()
2007-05-21 19:41:14.168 Video sync method can't support double framerate (refresh rate too low for bob deint)
2007-05-21 19:41:14.170 FilterManager: failed to load filter 'none', nosuch filter exists
2007-05-21 19:41:14.170 Couldn't load deinterlace filter none
2007-05-21 19:41:14.175 Video timing method: SGI OpenGL
#---END


Attached is the reject file from patch when I attempted to apply it to
HEAD.

Here is the output when I ran patch:

patching file libs/libmythtv/NuppelVideoPlayer.cpp
Hunk #1 succeeded at 2186 (offset 49 lines).
Hunk #2 succeeded at 2208 (offset 49 lines).
Hunk #3 succeeded at 2217 (offset 49 lines).
patching file libs/libmythtv/vsync.cpp
Hunk #1 succeeded at 311 (offset 5 lines).
Hunk #2 succeeded at 411 (offset 5 lines).
Hunk #3 FAILED at 643.
Hunk #4 succeeded at 702 (offset 54 lines).
Hunk #5 FAILED at 723.
Hunk #6 FAILED at 733.
Hunk #7 succeeded at 797 (offset 56 lines).
Hunk #8 succeeded at 836 (offset 56 lines).
Hunk #9 succeeded at 887 (offset 56 lines).
3 out of 9 hunks FAILED -- saving rejects to file
libs/libmythtv/vsync.cpp.rej
patching file libs/libmythtv/vsync.h
Hunk #4 succeeded at 207 with fuzz 2.

-- 
seth / @sethdaniel.org
I either want less decadence or more chance to participate in it.
-------------- next part --------------
***************
*** 641,647 ****
      unsigned int count;
      X11S(err = gMythGLXGetVideoSyncSGI(&count));
      checkGLSyncError("OpenGLVideoSync::Start(): Frame Number Query", err);
-     X11S(err = gMythGLXWaitVideoSyncSGI(2, (count+1)%2 ,&count));
      checkGLSyncError("OpenGLVideoSync::Start(): A/V Sync", err);
  
      X11S(err = glXMakeCurrent(vo->XJ_disp, None, NULL));
--- 643,649 ----
      unsigned int count;
      X11S(err = gMythGLXGetVideoSyncSGI(&count));
      checkGLSyncError("OpenGLVideoSync::Start(): Frame Number Query", err);
+     X11S(err = gMythGLXWaitVideoSyncSGI(2, 0, &count));
      checkGLSyncError("OpenGLVideoSync::Start(): A/V Sync", err);
  
      X11S(err = glXMakeCurrent(vo->XJ_disp, None, NULL));
***************
*** 721,726 ****
      // Always sync to the next retrace execpt when we are very late.
      if ((m_delay = CalcDelay()) > -(m_refresh_interval/2)) 
      {
          err = gMythGLXWaitVideoSyncSGI(2, (frameNum+1)%2 ,&frameNum);
          checkGLSyncError(msg1, err);
          m_delay = CalcDelay();
--- 723,729 ----
      // Always sync to the next retrace execpt when we are very late.
      if ((m_delay = CalcDelay()) > -(m_refresh_interval/2)) 
      {
+         frameNum += syncToFrameStart ? frameNum % 2 : 0;
          err = gMythGLXWaitVideoSyncSGI(2, (frameNum+1)%2 ,&frameNum);
          checkGLSyncError(msg1, err);
          m_delay = CalcDelay();
***************
*** 730,735 ****
      if (m_delay > 0)
      {
          uint n = m_delay / m_refresh_interval + 1;
          err = gMythGLXWaitVideoSyncSGI((n+1), (frameNum+n)%(n+1), &frameNum);
          checkGLSyncError(msg2, err);
          m_delay = CalcDelay();
--- 733,739 ----
      if (m_delay > 0)
      {
          uint n = m_delay / m_refresh_interval + 1;
+         n += syncToFrameStart ? (n + 1) % 2 : 0;
          err = gMythGLXWaitVideoSyncSGI((n+1), (frameNum+n)%(n+1), &frameNum);
          checkGLSyncError(msg2, err);
          m_delay = CalcDelay();