[mythtv-users] Deinterlace stopped working in latest SVN trunk

Thu May 31 03:04:44 UTC 2007

On Wed, May 30, 2007 at 05:21:38PM +1000, Matt Doran wrote:
> Brad Templeton wrote:
> > I decided to upgrade to the lastest SVN trunk after about 6 months
> > from the last one (also a .21 but protocol 32) and now I find
> > my deinterlace is not operating, no matter whether I set it to bob,
> > linear blend or kernel.   It was bob before and worked.  No error message
> > (on the system in question) about not having enough framerate for bob,
> > or any other diagnostic.
> >
> > This is on 1080i content being sent to a 720p screen.
> >
> > Don't see anything about deinterlace in the change logs -- did something
> > change recently regarding this?
> > _______________________________________________
> >
> >   
> I recently got this working.  It's a bit tricky.  I don't know what has 
> changed, because I've only tried to get bob working since using trunk.
> 
> It's worth running your frontend with verbose playback logging (e.g. 
> mythfrontend -v playback).  This should give you information about why 
> bob deinterlacing isn't working.

It's all deinterlacing.   Debug tracks indicate Myth is getting
confused by the streams (which I think are ordinary) and deciding
there are progressive frames in the middle and turns off the deinterlacer.

Here is a sequence from last weekend's 1080i broadcast of "Chicago"

    2007-05-30 19:49:32.106 Using OpenGLVideoSync
    2007-05-30 19:49:32.118 Avg read interval was 199 msec. 128K block size
    2007-05-30 19:49:32.119 Using audio as timebase
    2007-05-30 19:49:32.119 Video timing method: SGI OpenGL
    2007-05-30 19:49:32.119 Refresh rate: 16671, frame interval: 33366
    2007-05-30 19:49:32.134 NVP: Waiting for prebuffer.. 0 AALLAAAAAAAAAAAAAAAAAAAAAAAAAAA
    2007-05-30 19:49:32.185 Avg read interval was 181 msec. 160K block size
    2007-05-30 19:49:32.267 Avg read interval was 182 msec. 192K block size
    2007-05-30 19:49:32.284 NVP: Waiting for prebuffer.. 1 AAULUULAAAAAAAAAAAAAAAAAAAAAAAA
    2007-05-30 19:49:32.364 Avg read interval was 182 msec. 224K block size
    2007-05-30 19:49:32.434 NVP: Waiting for prebuffer.. 2 AAUUUUUUULUULAAAAAAAAAAAAAAAAAA
    2007-05-30 19:49:32.473 Avg read interval was 184 msec. 256K block size
    2007-05-30 19:49:32.500 NVP: progressive frame seen after 2 interlaced  frames
    2007-05-30 19:49:32.560 Disabled deinterlacing
    2007-05-30 19:49:32.646 Avg read interval was 189 msec. 288K block size
    2007-05-30 19:49:32.791 NVP: interlaced frame seen after 9 progressive frames
    2007-05-30 19:49:32.857 Enabled deinterlacing
    2007-05-30 19:49:32.940 Dec: Selected track #1 in the Unknown language(0)
    2007-05-30 19:49:33.040 NVP: progressive frame seen after 7 interlaced  frames
    2007-05-30 19:49:33.107 Disabled deinterlacing
    2007-05-30 19:49:33.116 Avg read interval was 195 msec. 320K block size
    2007-05-30 19:49:33.290 NVP: interlaced frame seen after 7 progressive frames
    2007-05-30 19:49:33.373 NVP: progressive frame seen after 2 interlaced  frames
    2007-05-30 19:49:33.736 NVP: interlaced frame seen after 9 progressive frames
    2007-05-30 19:49:33.820 Enabled deinterlacing
    2007-05-30 19:49:33.884 Avg read interval was 198 msec. 352K block size
    2007-05-30 19:49:34.002 NVP: progressive frame seen after 7 interlaced  frames
    2007-05-30 19:49:34.069 Disabled deinterlacing
    2007-05-30 19:49:34.169 NVP: interlaced frame seen after 5 progressive frames
    2007-05-30 19:49:34.235 NVP: progressive frame seen after 2 interlaced  frames
    2007-05-30 19:49:34.600 NVP: interlaced frame seen after 9 progressive frames
    2007-05-30 19:49:34.683 Enabled deinterlacing
    2007-05-30 19:49:34.867 NVP: progressive frame seen after 7 interlaced  frames
    2007-05-30 19:49:34.932 Disabled deinterlacing

Chicago seems worse than usual but here's from an old episode of
Heroes (1080i) 

    2007-05-30 19:54:03.631 NVP: progressive frame seen after 4 interlaced  frames
    2007-05-30 19:54:03.714 Set video sync frame interval to 33366
    2007-05-30 19:54:03.714 Disabled deinterlacing
    2007-05-30 19:54:04.382 NVP: interlaced frame seen after 19 progressive frames
    2007-05-30 19:54:04.465 Set video sync frame interval to 33366
    2007-05-30 19:54:04.465 Enabled deinterlacing
    2007-05-30 19:54:04.562 NVP: progressive frame seen after 4 interlaced  frames
    2007-05-30 19:54:04.628 Set video sync frame interval to 33366
    2007-05-30 19:54:04.628 Disabled deinterlacing
    'video_output' mean = '40868.76', std. dev. = '8893.10', fps = '24.47'
    'video_output' mean = '41528.50', std. dev. = '8278.04', fps = '24.08'
    2007-05-30 19:54:11.529 NVP: Video is 3.02059 frames ahead of audio,
                            doubling video frame interval to slow down.
    'video_output' mean = '41870.25', std. dev. = '8615.11', fps = '23.88'
    2007-05-30 19:54:17.295 NVP: interlaced frame seen after 307 progressive frames
    2007-05-30 19:54:17.378 Set video sync frame interval to 33366
    2007-05-30 19:54:17.379 Enabled deinterlacing
    2007-05-30 19:54:18.822 NVP: progressive frame seen after 44 interlaced  frames
    2007-05-30 19:54:18.888 Set video sync frame interval to 33366
    2007-05-30 19:54:18.889 Disabled deinterlacing
    2007-05-30 19:54:18.974 NVP: interlaced frame seen after 5 progressive frames
    2007-05-30 19:54:19.057 Set video sync frame interval to 33366
    2007-05-30 19:54:19.057 Enabled deinterlacing
    'video_output' mean = '38185.15', std. dev. = '7837.27', fps = '26.19'
    2007-05-30 19:54:20.816 NVP: progressive frame seen after 54 interlaced  frames
    2007-05-30 19:54:20.883 Set video sync frame interval to 33366
    2007-05-30 19:54:20.883 Disabled deinterlacing
    'video_output' mean = '36910.88', std. dev. = '7177.23', fps = '27.09'
    'video_output' mean = '41538.65', std. dev. = '8315.99', fps = '24.07'
    2007-05-30 19:54:29.212 NVP: Video is 3.00779 frames ahead of audio,
                            doubling video frame interval to slow down.
    2007-05-30 19:54:29.911 NVP: interlaced frame seen after 219 progressive frames
    2007-05-30 19:54:29.993 Set video sync frame interval to 33366
    2007-05-30 19:54:29.994 Enabled deinterlacing

Longer gaps (of both types) and it doesn't look as bad.   Since I don't
think these broadcasts actually have these long runs of progressive frames,
myth is somehow misinterpreting, I fear.

Note this is with linearblend, not with bob, though I think it's the same
there.