[MPlayer-users] mencoder mkv 2 avi, motion is unsmooth due to "skipping frame", or a-v desync with -mc 0 -noskip

[Ferry de Jong]

A progressive matroska VIDEO:  [avc1]  1920x800  24bpp  23.976 fps
file plays with smooth video and well synched A/V in mplayer.

When I convert it to AVI (-lavc) with mencoder (version below,
1.0rc2 behaves the same) a "Skipping frame!" every 2.4 seconds
for the entire length of the video stream. (see below for mencoder output)

The resulting avi/fmp4 plays but video motion is not smooth due to
the skipped frames, the motion jumps at the exact moments of the skipped frames.
When I encode with -mc 0 -noskip, the video is smooth again but A/V desyncs
gradually over time.

I've seen this issue with several 23.976 fps matroska files.
Is there a way to get a smooth playing avi file with the audio
still in-sync? Am I using wrong command line parameters?

BFRAMES1=vmax_b_frames=2:vb_strategy=1:b_sensitivity=40
LAVCOPTS1=vcodec=mpeg4:vpass=1:autoaspect:vbitrate=1200:$BFRAMES1:mbd=2:trell:v4mv:turbo

mencoder $MYFILE.mkv \
  -vf-add scale=1024:576 \
  -channels 6 \
  -aid 0 \
  -oac copy \
  -ovc lavc \
  -lavcopts $LAVCOPTS1 \
  -endpos 1:00 \
  -o test.avi


-mc0 -noskip #added for the other encoding attempt that de-syncs.




MEncoder dev-SVN-r27464-4.3 (C) 2000-2008 MPlayer Team
CPU: AMD Athlon(tm) 64 Processor 3000+ (Family: 15, Model: 47, Stepping: 0)
CPUflags: Type: 15 MMX: 1 MMX2: 1 3DNow: 1 3DNow2: 1 SSE: 1 SSE2: 1
Compiled for x86 CPU with extensions: MMX MMX2 3DNow 3DNowEx SSE SSE2

success: format: 0  data: 0x0 - 0x2f694346
[mkv] Track ID 1: video (V_MPEG4/ISO/AVC) "MPEG-4/AVC, 9222 kbps", -vid 0
[mkv] Track ID 2: audio (A_DTS) "DTS, 5.1, 1536 kbps (transcoded from LPCM)", -aid 0, -alang eng
[mkv] Track ID 3: subtitles (S_TEXT/ASS) "Hungarian", -sid 0, -slang und
[mkv] Track ID 4: subtitles (S_TEXT/ASS) "Italian", -sid 1, -slang und
[mkv] Track ID 5: subtitles (S_TEXT/ASS) "Polish", -sid 2, -slang pol
[mkv] Track ID 6: subtitles (S_TEXT/ASS) "Portuguese", -sid 3, -slang por
[mkv] Track ID 7: subtitles (S_TEXT/ASS) "Romanian", -sid 4, -slang rum
[mkv] Track ID 8: subtitles (S_TEXT/ASS) "Serbian", -sid 5, -slang scc
[mkv] Track ID 9: subtitles (S_TEXT/ASS) "Slovenian", -sid 6, -slang slv
[mkv] Track ID 10: subtitles (S_TEXT/ASS) "Spanish", -sid 7, -slang spa
[mkv] Track ID 11: subtitles (S_TEXT/ASS) "Swedish", -sid 8, -slang swe
[mkv] Track ID 12: subtitles (S_TEXT/ASS) "Turkish", -sid 9, -slang tur
[mkv] Track ID 13: subtitles (S_TEXT/ASS) "Brazilian", -sid 10, -slang por
[mkv] Track ID 14: subtitles (S_TEXT/ASS) "Croatian", -sid 11, -slang scr
[mkv] Track ID 15: subtitles (S_TEXT/ASS) "Czech", -sid 12, -slang cze
[mkv] Track ID 16: subtitles (S_TEXT/ASS) "Danish", -sid 13, -slang dan
[mkv] Track ID 17: subtitles (S_TEXT/ASS) "Dutch", -sid 14, -slang dut
[mkv] Track ID 18: subtitles (S_TEXT/ASS) "English", -sid 15, -slang eng
[mkv] Track ID 19: subtitles (S_TEXT/ASS) "Finnish", -sid 16, -slang fin
[mkv] Track ID 20: subtitles (S_TEXT/ASS) "French", -sid 17, -slang fre
[mkv] Track ID 21: subtitles (S_TEXT/ASS) "German", -sid 18, -slang ger
[mkv] Will play video track 1.
Matroska file format detected.
VIDEO:  [avc1]  1920x800  24bpp  23.976 fps    0.0 kbps ( 0.0 kbyte/s)
[V] filefmt:31  fourcc:0x31637661  size:1920x800  fps:23.976  ftime:=0.0417
==========================================================================
Requested audio codec family [dts] (afm=libdca) not available.
Enable it at compilation.
Opening audio decoder: [ffmpeg] FFmpeg/libavcodec audio decoders
AUDIO: 48000 Hz, 6 ch, s16le, 1536.0 kbit/33.33% (ratio: 192000->576000)
Selected audio codec: [ffdca] afm: ffmpeg (FFmpeg DTS)
==========================================================================
Opening video filter: [expand osd=1]
Expand: -1 x -1, -1 ; -1, osd: 1, aspect: 0.000000, round: 1
Opening video filter: [scale w=1024 h=576]

Writing header...4f ( 0%)  0.00fps Trem:   0min   0mb  A-V:0.013 [0:0]
ODML: vprp aspect is 16384:6828.
Pos:   0.1s      5f ( 0%)  0.00fps Trem:   0min   0mb  A-V:0.017 [0:0]
1 duplicate frame(s)!
Pos:   1.6s     40f ( 0%) 18.81fps Trem:   0min   0mb  A-V:0.084 [51:1536]
Skipping frame!
Pos:   3.9s     97f ( 0%) 20.24fps Trem:   0min   0mb  A-V:0.084 [1091:1536]
Skipping frame!
Pos:   6.3s    155f ( 0%) 15.29fps Trem: 127min 2549mb  A-V:0.084 [2794:1536]
Skipping frame!
Pos:   8.7s    213f ( 0%) 14.04fps Trem: 147min 2579mb  A-V:0.084 [2587:1536]
Skipping frame!
Pos:  11.1s    273f ( 0%) 11.37fps Trem: 203min 2641mb  A-V:0.084 [2250:1536]
Skipping frame!
Pos:  13.6s    332f ( 0%) 10.84fps Trem: 213min 2480mb  A-V:0.084 [2009:1536]
Skipping frame!
Pos:  15.9s    390f ( 0%) 10.89fps Trem: 210min 2334mb  A-V:0.084 [1887:1536]
Skipping frame!
Pos:  18.3s    447f ( 0%) 10.88fps Trem: 200min 2225mb  A-V:0.084 [1877:1536]
Skipping frame!
Pos:  20.7s    506f ( 0%) 11.10fps Trem: 204min 2373mb  A-V:0.084 [1967:1536]