[MPlayer-users] 3GPP for s710a

[Galen]

I'm looking at loading 3GPP (.3gp) files onto a phone, the s710a, which 
I will be getting shortly. Getting them onto the phone and stuff isn't 
a problem. And with an absolutely beautiful 320x240 screen, memory 
stick duo slot, built-in speaker, and 3.5 mm stereo headphone jack, the 
possibilities are pretty good. It supports 3gpp files - MPEG 4. Unless 
you know something I don't about this soon-to-be-released phone, it 
seems that it will only accept .3gp files for on-phone playback, and 
the final (non-beta) version will play them smoothly at full screen. I 
may need to experiment with framerates and stuff, but it should work 
out fine in the end.

I can generate .3gp files no problem with QuickTime. The audio part - 
AAC 32-320 Kbps - is just fine. But as anybody who has tried it knows, 
the Apple MPEG 4 encoder is horrible!!! They also offer h.263 as 
another option, but at least on that implementation, it's no better 
than the Apple MPEG4 default encoder and a bit more blurry. The quality 
for 320x240 at max video bitrate (192 kbps) simply isn't any good. Yet 
other MPEG 4 encoders (Xvid, 3ivx) handle the same video beautifully 
given the same or even lower bitrate. My test scene is a simple, slow 
moving collection of jellyfish.

It seems .3gp is simply a muxing of mpeg-4 compliant audio and video, 
with a few required settings  (i.e. 192 kbps max for the video) and 
options (amr audio, etc) tossed in so I would imagine that it would be 
possible to generate this pretty easily using any number of methods. 
Can mencoder mux a .3gp file from another file? (i.e. .mp4 file w/aac 
audio) Can it encode to a .3gp file from another source? What should I 
be looking for? Are there any "optimal" settings or tips for this sort 
of thing? (Looking for people with experiences - I know the obvious 
mpeg4 encoding stuff, it's those gotchas I'm looking for)

If it helps any, I'm running Mac OS X (10.3) and am looking for a 
solution on that system.

Thanks,

-Galen