[MEncoder-users] Recoding RM files for iPod

[Ulf Magnusson]

Hi,

I've been trying for a couple of days to recode RM files for viewing
on my iPod. Afters some initial research I came up with the following:

$ mencoder movie.rm -o ipod.mp4                 \
-of lavf -lavfopts format=mp4                   \
-ovc x264 -x264encopts qp=20:keyint=60          \
-oac faac -faacopts mpeg=4:raw:object=2:br=160  \
-srate 48000                                    \
-vf scale=320:240

This produces a file that plays fine in MPlayer, but gives a white
screen with just sound in QuickTime. iTunes refuses to transfer the
file to the iPod, saying "ipod.mp4 was not copied to the iPod <foo>
because it cannot be played on this iPod". For the above, MEncode
prints the following warning:

** MUXER_LAVF *****************************************************************
REMEMBER: MEncoder's libavformat muxing is presently broken and can generate
INCORRECT files in the presence of B frames. Moreover, due to bugs MPlayer
will play these INCORRECT files as if nothing were wrong!
*******************************************************************************

I thought I'd instead try doing the muxing with MP4Box, using the
following (inspired by the script from
http://diveintomark.org/archives/2007/06/07/howto-batch-encode-video-for-ipod-under-linux-2007-edition):

$ mencoder movie.rm -o ipod.avi                \
-ovc x264 -x264encopts qp=20:keyint=60         \
-oac faac -faacopts mpeg=4:object=2:br=160:raw \
-srate 48000                                   \
-vf scale=320:240

$ MP4Box -aviraw video ipod.avi

$ MP4Box -aviraw audio ipod.avi

$ mv ipod_audio.raw ipod.aac

$ mv ipod_video.h264 ipod.h264

$ MP4Box -add ipod.aac:lang=en ipod.mp4

$ MP4Box -add ipod.h264:fps=23.976 ipod.mp4

This gives a file that won't play at all in QuickTime ("An invalid
sample description was found in the movie."), and that iTunes still
refuses to copy to the iPod. It still plays in MPlayer, but without
any sound, and with the following errors:

FAAD: Failed to decode frame: Invalid number of channels
FAAD: Failed to decode frame: Maximum number of bitstream elements exceeded
FAAD: Failed to decode frame: Unexpected channel configuration change
FAAD: Failed to decode frame: Unexpected channel configuration change

The file I'm trying to recode is
http://ocw.mit.edu/ans7870/6/6.046j/f05/lecturenotes/ocw-6.046-07sep2005-220k.rm
.

I'm running out of ideas. Any help appreciated!

/Ulf