Lossless MPEG-4 AVI to MP4 on Mac OS X?

[elmimmo]

How can I losslessly convert a DivX/XVid/3ivX AVI to an MP4 container, leaving the video track untouched?

I have indeed searched, this forum and Google and found nothing. Maybe it is that the search terms are too short and generic.

[nm]

You mean remuxing. MP4Box does this. You'll probably need to encode the audio track to AAC though.

[elmimmo]

MP4Box does this.

Thanks! Since I still have to see how to get the audio transcoded, I tried making an MP4 with only a video track:

$ MP4Box -add in.avi#video out.mp4
AVI XVID video import - 704 x 396 @ 29.9700 FPS - 82713 Frames
Indicated Profile: Advanced Simple Profile @ Level 5
Has B-Frames (3 max consecutive B-VOPs - packed bitstream)
Import results: 82713 VOPs (966 Is - 30617 Ps - 51130 Bs)
Removed Frames: 0 VFW delay frames - 29240 N-VOPs
Converting to ISMA Audio-Video MP4 file...
Saving to ./out.mp4: 0.500 secs Interleaving

The MP4 plays fine in MPlayer and VLC. QuickTime does not like it though. "The movie does not contain valid data" (translated from Spanish).

Any idea what is lacking?

[elmimmo]

Has B-Frames (3 max consecutive B-VOPs - packed bitstream)

Mmm… Is it that? I have found sources on Google that state QuickTime does not support B-frames, but I cannot relate the statement to a particular version.

Should those b-frames be the reason, is there a way to "mince" them?

[smok3]

i think the limit is still there, no b-frames for mpeg-4 ASP (and a lot of other no-s).

[elmimmo]

i think the limit is still there, no b-frames for mpeg-4 ASP (and a lot of other no-s).

Mmm… bummer.

Is there, still, a way to "flatten" those "b-frames and other no-s" only, so that the process takes less time that simply transcoding the whole video track again?

[smok3]

no, you will have to transcode.