[MEncoder-users] Revived: audio sync problems encoding from vob

[Christopher M. Jones]

I'm trying to reencode a vob copied using cpdvd. The reason I'm trying
to reencode is that dvdauthor is giving me this error:

ERR:  SCR moves backwards, remultiplex input.

Problem is, whenever I try to reencode or remultiplex I get audio sync
issues, or else I get other errors that also result in dvdauthor
refusing to process the file. I've tried splitting the video and audio,
then remuxing it. I've tried creating an avi and using avisync, but that
gives me odd patches of noise throughout the file.

Here is the source info, as reported by mencoder:

MEncoder 2:0.99+1.0pre7try2+cvs20060117-0ubuntu8 (C) 2000-2006 MPlayer
Team
CPU: Intel Pentium 4/Celeron 4 Northwood; Pentium 4 EE/Xeon
Prestonia,Gallatin (Family: 15, Stepping: 4)
CPUflags: Type: 15 MMX: 1 MMX2: 1 3DNow: 0 3DNow2: 0 SSE: 1 SSE2: 1
Compiled with runtime CPU detection.
91 audio & 204 video codecs
success: format: 0  data: 0x0 - 0x40000000
MPEG-PS file format detected.
VIDEO:  MPEG2  720x480  (aspect 3)  29.970 fps  9800.0 kbps (1225.0
kbyte/s)
[V] filefmt:2  fourcc:0x10000002  size:720x480  fps:29.97  ftime:=0.0334
==========================================================================
Opening audio decoder: [liba52] AC3 decoding with liba52
Using SSE optimized IMDCT transform
AC3: 5.1 (3f+2r+lfe)  48000 Hz  448.0 kbit/s
Using MMX optimized resampler
AUDIO: 48000 Hz, 2 ch, s16le, 448.0 kbit/29.17% (ratio: 56000->192000)
Selected audio codec: [a52] afm: liba52 (AC3-liba52)
==========================================================================
PACKET SIZE: 2048 bytes
Opening video filter: [expand osd=1]
Expand: -1 x -1, -1 ; -1, osd: 1, aspect: 0.000000, round: 1
Opening video filter: [harddup]
Opening video filter: [scale w=720 h=480]
==========================================================================
Opening video decoder: [mpegpes] MPEG 1/2 Video passthrough
VDec: vo config request - 720 x 480 (preferred colorspace: Mpeg PES)
The selected video_out device is incompatible with this codec.
Try adding the scale filter, e.g. -vf spp,scale instead of -vf spp.
VDecoder init failed :(
Opening video decoder: [libmpeg2] MPEG 1/2 Video decoder
libmpeg2-v0.4.0b
Selected video codec: [mpeg12] vfm: libmpeg2 (MPEG-1 or 2 (libmpeg2))
==========================================================================

I have tried a number of different lines, too many for me to dig out of
my shell history. Here is one example of something I tried:

 mencoder -oac lavc -ovc lavc -of mpeg -mpegopts format=dvd:telecine -vf
scale=720:480,harddup -lavcopts
vcodec=mpeg2video:acodec=ac3:abitrate=448:aspect=16/9 -ofps 24000/1001
-mc 0   -o 01_firstcontact.2.mpg VTS_01_1.VOB

This gives me the following:

Building audio filter chain for 48000Hz/2ch/s16le -> 0Hz/0ch/??...
Building audio filter chain for 48000Hz/2ch/s16le ->
48000Hz/2ch/s16le...
Limiting audio preload to 0.4s
Increasing audio density to 4
VDec: vo config request - 720 x 480 (preferred colorspace: Planar YV12)
VDec: using Planar YV12 as output csp (no 0)
Movie-Aspect is 1.78:1 - prescaling to correct movie aspect.
SwScaler: using unscaled Planar YV12 -> Planar YV12 special converter
videocodec: libavcodec (720x480 fourcc=3267706d [mpg2])
Writing header...2f ( 0%)  0.00fps Trem:   0min   0mb  A-V:0.000 [0:0]

ENABLED SOFT TELECINING, FPS=29.97, INITIAL PATTERN IS TFF:0, RFF:0

1 duplicate frame(s)!
Pos:   0.1s      4f ( 0%)  3.25fps Trem:   0min   0mb  A-V:0.000 [0:0]
1 duplicate frame(s)!
Pos:   0.5s     11f ( 0%)  7.90fps Trem:   0min   0mb  A-V:0.000 [0:0]
demux_mpg: 24000/1001fps progressive NTSC content detected, switching
framerate.
Pos:   8.8s    211f ( 0%)  2.91fps Trem: 247min   0mb  A-V:0.000
[1141:448]

...with many messages like this:

ERROR: SCR: 949320786, APTS: 944455680, DELTA=-0.053 secs,
COMPENSATE=2956, BR: 56000, lens: 2016/2016, frames: 2

So I tried simply copying the video:

 mencoder -oac lavc -ovc copy -of mpeg -mpegopts format=dvd:telecine -vf
scale=720:480,harddup -lavcopts
vcodec=mpeg2video:acodec=ac3:abitrate=448:aspect=16/9 -ofps 24000/1001
-mc 0   -o 01_firstcontact.2.mpg VTS_01_1.VOB

...which gives me

PACKET SIZE: 2048 bytes
videocodec: framecopy (720x480 24bpp fourcc=10000002)
Building audio filter chain for 48000Hz/2ch/s16le -> 0Hz/0ch/??...
Building audio filter chain for 48000Hz/2ch/s16le ->
48000Hz/2ch/s16le...
Limiting audio preload to 0.4s
Increasing audio density to 4
Writing header...

ERROR! FRAMERATE IS INVALID: 4, disabling telecining
INITIAL DELAY of 0 frames  0.00fps Trem:   0min   0mb  A-V:0.000 [0:0]
Pos:   0.5s     11f ( 0%)  0.00fps Trem:   0min   0mb  A-V:0.000 [0:0]
demux_mpg: 24000/1001fps progressive NTSC content detected, switching
framerate.
Pos:  85.3s   2046f ( 4%) 178.41fps Trem:   4min 915mb  A-V:0.000
[3501:448]

...and audio is out of sync. Finally, I tried simply copying the audio:

 mencoder -oac copy -ovc lavc -of mpeg -mpegopts format=dvd:telecine -vf
scale=720:480,harddup -lavcopts
vcodec=mpeg2video:acodec=ac3:abitrate=448:aspect=16/9 -ofps 24000/1001
-mc 0   -o 01_firstcontact.2.mpg VTS_01_1.VOB

This gives me a file which is synced when played by mplayer, but which
dvdauthor won't process. dvdauthor gives me the following error:

WARN: audio sector out of range: -56910 (vobu #176, pts 762.862)

Let me just say that I did read the documentation, but I'm new to this.
So, there is probably much I missed, or didn't understand. There's a lot
there, and I have to say I'm a bit overwhelmed by all the variables. I'm
hoping that someone can give me the magic bullet, offer a different
approach, or tell me its time to scrap this project.