3GP with mpeg-4 video

[sith33]

It'd be great to have the ability to generate 3GPP files with mpeg4 for the video codec (and still with AMR for audio). A preset similar to quicktime pro's "3GPP (Mobile MP4)" setting would be fantastic.

[major]

Adding in to-do list.

[oscord]

I beleive there's a bug in ffmpegx 0.0.9s. Whenever you create a 3gp movie with AMR_NB audio and h.263 video - audio track is all "messed up". If I create an amr audio file and 3gp video file separately, they'd be both fine. Combining them together later is a pain for 3gp. (a/v sync problems).
I took a liberty to extract the ffmpeg binary from ffmpegx and ran it with normal 3gp settings (-acodec amr_nb -ac 1 -ar 8000 -ab 8 -vodec h263 -s 176x144 -r 5 -b 35 -f 3gp) - same problem.
It seems that ffmpeg wasn't compiled properlym something to do with 3gp container of AMR coderc? I have compiled it myself numerous times for P4, never for Mac... If anyone got proper 3gp (mpeg4/h.263 with amr_nb) out of ffmpegx please advise.

Thanks.

[major]

I will check that, did you try if QT6 vs QT7 makes any difference in playback?

[oscord]

Yes, I have tried with different players- same problem.
At about 3Hz frequency there's a clicking sound - it seems only 3 (maybe more) audio samples were fit into each frame(1sec long) when 3gp was made. Usually there're lots and lots (usually 50 per second with AMR_NB) of audio samples and few video (depends on fps) ones every frame.
It has happened to me before with amr_nb codec and older ffmpeg 48...

Thanks and good luck.