[mythtv-commits] Ticket #12047: mythplayer picks the wrong fps for 1080i matroska, degrading to 1xHW deint

[MythTV]

#12047: mythplayer picks the wrong fps for 1080i matroska, degrading to 1xHW deint
-------------------------------------+--------------------------------
 Reporter:  angela.schmid@…          |          Owner:
     Type:  Patch - Bug Fix          |         Status:  infoneeded_new
 Priority:  major                    |      Milestone:  0.28
Component:  MythTV - Video Playback  |        Version:  Master Head
 Severity:  high                     |     Resolution:
 Keywords:  deinterlace mkv 1080i    |  Ticket locked:  0
-------------------------------------+--------------------------------

Comment (by angela.schmid@…):

 Patch didn't compile on 0.27 and master:
 {{{
 avformatdecoder.cpp: In member function ‘float
 AvFormatDecoder::normalized_fps(AVStream*, AVCodecContext*)’:
 avformatdecoder.cpp:1351:13: error: ‘st’ was not declared in this scope
 }}}

 Changed 'st' to 'stream' and tested on 0.27-fixes.

 The patch works for media as the one shown above.

 I didn't had good luck with lossless_cut (uses mkvmerge) and 1080i
 material with minimal glitches, so I changed my workflow in the meantime
 and use ts-doctor (which at the end produces correct total times and
 proper FFWD) and avconv.

 I don't have the original chinese wall recording anymore and the resulting
 mkv has been converted with the following:

 {{{
 avconv -y -i input-tsdoctor.mpg -r 25 -c:v libx264  -flags
 +ilme+ildct+loop -cmp chroma -deblock 0:0 -r 25 -bt 256k -coder 0
 -me_method full -me_range 16 -subq 5 -partitions
 +parti4x4+parti8x8+partp8x -g 250 -keyint_min 25 -trellis 2 -sc_threshold
 40 -i_qfactor 0.71 -b_strategy 1 -qcomp 0.6 -qdiff 4 -refs 2 -direct-pred
 1 -wpredp 2 -rc_lookahead 30 -profile:v baseline -level 30 -bf 0 -coder 0
 -crf 22 -qmin 2 -qmax 30 -b:v 5000K -c:a copy -ar 44100 -ac 2 -b:a 128K
 -map 0:0 -map 0:a:0 -sn -f matroska output.mkv
 }}}

 which produces MBAFF
 {{{
 General
 Unique ID                                :
 63265251044264927949292968836987650338
 (0x2F9871B35334230A54E4639435FC8122)
 Complete name                            : Die sieben Wunder Chinas S01E06
 Die Verbotene Stadt.mkv
 Format                                   : Matroska
 Format version                           : Version 2
 File size                                : 1.69 GiB
 Duration                                 : 23mn 59s
 Overall bit rate                         : 10.1 Mbps
 Writing application                      : Lavf53.21.1
 Writing library                          : Lavf53.21.1

 Video
 ID                                       : 1
 Format                                   : AVC
 Format/Info                              : Advanced Video Codec
 Format profile                           : Main at L3.0
 Format settings, CABAC                   : No
 Format settings, ReFrames                : 2 frames
 Codec ID                                 : V_MPEG4/ISO/AVC
 Duration                                 : 23mn 59s
 Bit rate                                 : 9 489 Kbps
 Width                                    : 1 920 pixels
 Height                                   : 1 080 pixels
 Display aspect ratio                     : 16:9
 Frame rate mode                          : Constant
 Frame rate                               : 25.000 fps
 Color space                              : YUV
 Chroma subsampling                       : 4:2:0
 Bit depth                                : 8 bits
 Scan type                                : MBAFF
 Bits/(Pixel*Frame)                       : 0.183
 Stream size                              : 1.59 GiB (94%)
 Writing library                          : x264 core 120 r2151 a3f4407
 Encoding settings                        : cabac=0 / ref=2 / deblock=1:0:0
 / analyse=0x1:0x1 / me=umh / subme=5 / psy=1 / psy_rd=1.00:0.00 /
 mixed_ref=0 / me_range=16 / chroma_me=1 / trellis=2 / 8x8dct=0 / cqm=0 /
 deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=0 / threads=12 /
 sliced_threads=0 / nr=0 / decimate=1 / interlaced=tff / bluray_compat=0 /
 constrained_intra=0 / bframes=0 / weightp=0 / keyint=250 / keyint_min=25 /
 scenecut=40 / intra_refresh=0 / rc_lookahead=30 / rc=crf / mbtree=1 /
 crf=22.0 / qcomp=0.60 / qpmin=2 / qpmax=30 / qpstep=4 / ip_ratio=1.41 /
 aq=1:1.00
 Default                                  : Yes
 Forced                                   : No
 }}}

 Your patch produces for MBAFF media the wrong FPS, interlacing is detected
 correctly:
 {{{
 CoreContext avformatdecoder.cpp:1256 (normalized_fps) - AFD: Selected FPS
 is 12.5 (avg 12.5 codec 25 container 1000 estimated 25 ticks_per_frame 2)
 CoreContext mythplayer.cpp:1748 (SetFrameInterval) - Player(6):
 SetFrameInterval ps:1 scan:3
 CoreContext mythplayer.cpp:670 (detectInterlace) - Player(6):
 detectInterlace(Detect Scan, Interlaced Scan, 12.5, 1080) ->Interlaced
 Scan
 }}}

 For MBAFF no patch is needed, my patch does not interfere.

 OT:
 I searched for other tools other than mediainfo to inspect the interlace
 status, but couldn't find one showing interlacing for MBAFF media, any
 suggestions.

 OT:
 Is MBAFF good, or should I use another avconv command, any suggestions.

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Ticket URL: <https://code.mythtv.org/trac/ticket/12047#comment:3>
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