[MEncoder-users] Mencoder Voice De-Sync with MP3 Audio Codec

[Giacomo Comes]

On Tue, Nov 28, 2006 at 03:41:59PM -0800, Gary C. New wrote:
> I am trying to transcode several .MOV files taken with
> our Nikon digital camera to filtered MPEG files.
> 
> The main reason for transcoding is due to a number of
> the .MOV files being taken in a profile (480x640)
> style orientation (opposed to the normal landscape
> view).
> 
> With the help of the mencoder docs and several
> examples found on Google, I was able to figure out the
> necessary video filters to rotate and scale the
> effected videos.
> 
> The only issue that remains is an eventual audio
> de-sync after roughly 5 minutes of play with the
> transcoded file (I have verified the de-sync on
> several machines).
> 
> I am trying to transcode using the lavc codec for mp3
> audio and mpeg2 video.
> 
> mencoder test.mov -oac lavc -ovc lavc -of mpeg
> -mpegopts format=dvd:tsaf -vf
> rotate=1,expand=853:640,scale=640:480,harddup -mc 0
> -noskip -srate 48000 -af lavcresample=48000 -lavcopts
> vcodec=mpeg2video:vrc_buf_size=1835:vrc_maxrate=9800:vbitrate=5000:keyint=18:acodec=mp3:abitrate=192
> -fps 30000/1001 -o test.mpg
> 
> MEncoder dev-CVS-050928-16:38-3.4.2 (C) 2000-2005
> MPlayer Team
> CPU: Intel Pentium 4/Xeon/Celeron Foster (Family: 8,
> Stepping: 4)
> Detected cache-line size is 64 bytes
> CPUflags: Type: 8 MMX: 1 MMX2: 1 3DNow: 0 3DNow2: 0
> SSE: 0 SSE2: 0
> Compiled with runtime CPU detection - WARNING - this
> is not optimal!
> To get best performance, recompile MPlayer with
> --disable-runtime-cpudetection.
> success: format: 0  data: 0x0 - 0x27cbea5c
> Quicktime/MOV file format detected.
> --------------
> MOV track #0: 458 chunks, 13740 samples
> Image size: 640 x 480 (24 bpp)
> Display size: 640 x 480
> Fourcc: jpeg  Codec: 'Photo - JPEG'
> --------------
> MOV track #1: 458 chunks, 0 samples
> Audio bits: 8  chans: 1  rate: 8000
> Fourcc: raw
> --------------
> MOV: longest streams: A: #1 (458 samples)  V: #0
> (13740 samples)
> VIDEO:  [jpeg]  640x480  24bpp  30.000 fps    0.0 kbps
> ( 0.0 kbyte/s)
> [V] filefmt:7  fourcc:0x6765706A  size:640x480 
> fps:30.00  ftime:=0.0333
> input fps will be interpreted as 29.97 instead
> ==========================================================================
> Opening audio decoder: [pcm] Uncompressed PCM audio
> decoder
> AUDIO: 8000 Hz, 1 ch, u8, 64.0 kbit/100.00% (ratio:
> 8000->8000)
> Selected audio codec: [pcm] afm:pcm (Uncompressed PCM)
> ==========================================================================
> 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=640 h=480]
> Opening video filter: [expand w=853 h=640]
> Expand: 853 x 640, -1 ; -1, osd: 0, aspect: 0.000000,
> round: 1
> Opening video filter: [rotate=1]
> ==========================================================================
> Opening video decoder: [ffmpeg] FFmpeg's libavcodec
> codec family
> Selected video codec: [ffmjpeg] vfm:ffmpeg (FFmpeg
> MJPEG decoder)
> ==========================================================================
> Building audio filter chain for 8000Hz/1ch/u8 ->
> 48000Hz/0ch/??...
> Building audio filter chain for 8000Hz/1ch/u8 ->
> 48000Hz/1ch/s16le...
> Writing AVI header...
> Limiting audio preload to 0.4s
> Increasing audio density to 4
> VDec: vo config request - 640 x 480 (preferred csp:
> Planar 422P)
> Could not find matching colorspace - retrying with -vf
> scale...
> Opening video filter: [scale]
> VDec: using Planar 422P as output csp (no 1)
> Movie-Aspect is undefined - no prescaling applied.
> 
> SwScaler: BICUBIC scaler, from Planar 422P to Planar
> 444P using MMX2
> videocodec: libavcodec (640x480 fourcc=3267706d
> [mpg2])
> New_Face failed. Maybe the font path is wrong.
> Please supply the text font file
> (~/.mplayer/subfont.ttf).
> subtitle font: load_sub_face failed.
> INITIAL DELAY of 0 frames  17fps Trem:   0min   0mb 
> A-V:0.000 [0:0]
> Pos: 458.5s  13740f ( 0%)  18fps Trem:   0min   0mb 
> A-V:0.000 [4993:192]
> Flushing video frames
> 
> Writing AVI index...
> 
> Overhead: 1.720% (5112909 / 0)
> Fixing AVI header...
> 
> Video stream: 4993.592 kbit/s  (624198 B/s)  size:
> 286169011 bytes  458.458 secs
>   13740 frames
> 
> Audio stream:  192.000 kbit/s  (24000 B/s)  size:
> 11013120 bytes  458.880 secs
> 
> Before using the "-mc 0 -noskip" options, the A/V
> de-sync was apparent from the very beginning.  Adding
> the "-mc 0 -noskip" options corrected the issue to
> this point where de-sync begins about 5 minutes into
> the video.
> 
> I have also tried using the mp3lame audio codec with
> the same result.
> 
> mencoder test.mov -oac mp3lame -lameopts cbr:br=192
> -ovc lavc -of mpeg -mpegopts format=dvd:tsaf -vf
> rotate=1,expand=853:640,scale=640:480,harddup -mc 0
> -noskip -srate 48000 -af lavcresample=48000 -lavcopts
> vcodec=mpeg2video:vrc_buf_size=1835:vrc_maxrate=9800:vbitrate=5000:keyint=18
> -fps 30000/1001 -o test.mpg
> 
> I would prefer to use an mp3 audio codec.
> 
> Any suggestions?  Your assistance is greatly
> appreciated.

It is true that you should report problems/bugs only if you are using
a recent version of MPlayer, but in this case it looks to me that
the problem is related to some incorrect options more than the 
usage of an old version.

So here is what to try:

1) use rc1 or svn.
2) do not use -fps 30000/1001 but use -ofps 30000/1001 without -mc 0 -noskip
3) if you still have desync add -mc 0/-mc .1/-mc 10
4) report here failure or success.

Giacomo