[mythtv-commits] Ticket #7644: Playback of interlaced TV broken (from r22881)

[MythTV]

#7644: Playback of interlaced TV broken (from r22881)
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 Reporter:  Davin McCall <davmac@…>           |       Owner:  janne  
     Type:  defect                            |      Status:  new    
 Priority:  critical                          |   Milestone:  unknown
Component:  MythTV - Video Playback           |     Version:  head   
 Severity:  high                              |     Mlocked:  0      
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Comment(by anonymous):

 Replying to [ticket:7644 Davin McCall <davmac@…>]:
 > Playback of interlaced TV (live TV or recording) is broken. Video plays
 too quickly and goes out of sync with audio. This occurs since r22881,
 however, that change is not actually faulty, it just exposes an additional
 bug.
 >
 > The problem is that m_double_framerate (in
 mythtv/libs/libmythtv/NuppelVideoPlayer.cpp) doesn't get set correctly
 when an interlaced scan mode is set, since it is initialized to interlaced
 and SetScanType returns without correctly setting m_double_framerate if
 the scan type matches the current type.
 >
 > As a result m_double_framerate is false and the AVSync method doesn't
 recognize that two fields need to be displayed each frame interval.

 I, too, have seen this problem on select ATSC broadcast channels.  The
 problem was not present in release 0.21, and has been visible since
 upgrading to 0.22 yesterday.  I'll try applying the patch and report on
 whether it works.

 Here are the statistics reported by FFMPEG for a clip exhibiting problem:

 [scott at eowyn myth_playback_issue]$ ffmpeg -vstats -i
 5071_20091120160000.mpg
 FFmpeg version 0.5-30.fc9, Copyright (c) 2000-2009 Fabrice Bellard, et al.
   configuration: --prefix=/usr --libdir=/usr/lib --shlibdir=/usr/lib
 --mandir=/usr/share/man --enable-shared --enable-gpl --enable-postproc
 --enable-swscale --enable-avfilter --enable-avfilter-lavf --enable-
 pthreads --enable-x11grab --enable-vdpau --disable-avisynth --disable-
 libamr-nb --disable-libamr-wb --enable-libdc1394 --enable-libfaac
 --enable-libfaad --enable-libfaadbin --enable-libgsm --enable-libmp3lame
 --enable-libspeex --enable-libtheora --enable-libvorbis --enable-libx264
 --enable-libxvid --extra-cflags=-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2
 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m32 -march=i386
 -mtune=generic -fasynchronous-unwind-tables --disable-stripping --extra-
 cflags=-I/usr/include/nvidia-graphics --extra-ldflags=-L/usr/lib/nvidia-
 graphics
   libavutil     49.15. 0 / 49.15. 0
   libavcodec    52.20. 0 / 52.20. 0
   libavformat   52.31. 0 / 52.31. 0
   libavdevice   52. 1. 0 / 52. 1. 0
   libavfilter    0. 4. 0 /  0. 4. 0
   libswscale     0. 7. 1 /  0. 7. 1
   libpostproc   51. 2. 0 / 51. 2. 0
   built on Mar 17 2009 07:05:36, gcc: 4.3.0 20080428 (Red Hat 4.3.0-8)

 Seems stream 0 codec frame rate differs from container frame rate: 119.88
 (120000/1001) -> 59.94 (60000/1001)
 Input #0, mpegts, from '5071_20091120160000.mpg':
   Duration: 00:59:56.35, start: 50395.716533, bitrate: 11657 kb/s
   Program 1
     Stream #0.0[0x31]: Video: mpeg2video, yuv420p, 1280x720 [PAR 1:1 DAR
 16:9], 17808 kb/s, 59.94 tbr, 90k tbn, 119.88 tbc
     Stream #0.1[0x34](eng): Audio: ac3, 48000 Hz, 5.1, s16, 384 kb/s
     Stream #0.2[0x35](spa): Audio: ac3, 48000 Hz, mono, s16, 96 kb/s
     Stream #0.3[0x36](fre): Audio: ac3, 0 channels, s16
 At least one output file must be specified

-- 
Ticket URL: <http://svn.mythtv.org/trac/ticket/7644#comment:1>
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