Welcome to the MacNN Forums.

atomico37 · Apr 17, 2003, 06:08 PM

and if it can't what can i use to convert? i'm in a bind, cause the new mp3 player i'm getting plays videos on a built in screen. but only avi.

-patrick

bradoesch · Apr 17, 2003, 07:18 PM

I think you'll need a program to demux the audio of the MPG. QuickTime should be able to handle converting the video. Then add the audio.

Uncle Skeleton · Apr 17, 2003, 08:36 PM

what you want is ffmpegX (or another of the dozens of applescript studio gui's for ffmpeg). it can read mpeg video and audio, and compress to divx-compatible "avi" with mp3 audio, which is not really avi but it's what your device will be expecting. Make sure not to use anything that says "DivX 3" or MSMPEG4, because no hardware devices will ever support that. You want something equivalent to "DivX 4/5" or "OpenDivx".

C.J. Moof · Apr 18, 2003, 09:26 AM

Just yesterday I converted an MPEG-1 muxed video to divx via ffmpeg- used the Divx (NTSC) quick preset. It played just fine.

C.J. Moof · Apr 18, 2003, 07:11 PM

Actually, I lied. I bet that movie didn't have audio.... I was processing it on an Xserve, so I didn't realize there was no sound.

You'll want to use bbdemux to split the A and V, process the V via ffmpeg, and the audio via SoundApp, Add Scaled (audo TO video), save as.

Uncle Skeleton · Apr 18, 2003, 10:26 PM

Originally posted by C.J. Moof:
Actually, I lied. I bet that movie didn't have audio.... I was processing it on an Xserve, so I didn't realize there was no sound.

You'll want to use bbdemux to split the A and V, process the V via ffmpeg, and the audio via SoundApp, Add Scaled (audo TO video), save as.

the original poster wanted an "avi", not a mov, which is the only thing that QTPro saves things as

dampeoples · Apr 18, 2003, 10:52 PM

Originally posted by Uncle Skeleton:
the original poster wanted an "avi", not a mov, which is the only thing that QTPro saves things as

now i'm confused. My QT Pro has an option to export to .avi

Uncle Skeleton · Apr 19, 2003, 04:17 AM

Export is different than Save. Export implies re-encoding the video to another format (although now there is one exception that if it's already in Apple's mpeg-4 codec you can export with 'passthrough' to mp4). Saving, which is what Mr Moof described, means leaving the data alone and saving it either to a new file or to the same file. QTPro only saves mov files (not even mp4, which is a huge dissapointment to me).

Now that I'm here, Moof, I should also clarify something you mentioned. Never scale the audio track. You mentioned "add scaled audio TO video", when you should have said "video TO audio". The reasons for this are many. First of all, scaling the audio changes the pitch slightly. Secondly, it changes the sample rate to something that is not one of the quantum rates supported by the sound card. this means that it has to be resampled back to a supported rate during playback by the CPU, which takes a surprising amount of processing time (something like 20% of 400mhz). Lastly, there is circumstantial evidence that scaled audio contributes to a "soft" sync problem, where the sound gradually drifts out of sync, but pausing and resuming fixes it (until it drifts out again). So in conclusion, try "Add" first, and if that doesn't work, "Add Scaled" the VIDEO to the AUDIO

dampeoples · Apr 19, 2003, 08:08 AM

Originally posted by Uncle Skeleton:
~snip~

As always, U.S. has schooled us, thanks for the clarification