[MPlayer-users] mencoder -lameopts mode=3 with multiple input files only handles first file correctly -- bug?

[Julian Mehnle]

Hi all,

I'm having a problem with audio sample rate conversion using 
`mencoder -srate` on more than one input file.  Let me demonstrate the 
issue first.

I have two AVI files with PCM stereo audio in them.  I then join them, 
encoding audio to MP3 mono in the process, as follows:

  $ mencoder \
        -of avi -ovc copy \
        -oac mp3lame -lameopts mode=3:cbr:br=64 \
        -o video1+2.mp3-mono.avi \
        video1.pcm-stereo.avi video2.pcm-stereo.avi

This gives me a joined file where the first part has correctly encoded 
audio as MP3 mono and the second part has MP3 audio with double the speed 
(and half the length)!  mencoder also seems to try syncing A/V by 
dropping a lot of video frames while encoding the second input file.

If you want to reproduce it using the files I used, try these:

  http://julian.io.link-m.de/tmp/mencoder/

(I also put a log of the mencoder output there, which shows the video 
frame dropping.)

It seems there is a bug in mencoder and/or the mp3lame module that causes 
them to get confused about MP3 encoding mode and/or sample rate on all 
but the first input file.

-Julian
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