Demuxed .mp4 (audio only - AAC) won't play on itunes Options

[wordslashr]

Hi All

I looked around 4 - 5 pages in the AAC forums and I could not locate a solution so I apologize in advance if there's an answer here somewhere...:

Using Yamb (w/the mp4box)I de-muxed an .mp4 A/V stream and extracted the raw AAC and another version with the audio only .mp4. But iTunes did not recognize either version.

But if I encoded the .mp4 video file using fre:ac (great product!) or with Switch audio encoder from NCH I was able to play it in iTunes. Obviously this would degrade the audio by one more lossy generation and I would like to avoid it. Am I missing something with Yamb or is there a product that can de-mux the A/V stream and re-package it into an iTunes compatible .m4a file?

I am not an expert so I thought I would ask here. Any pointers would be greatly appreciated. Thanks.

Gary

[Remedial Sound]

Use the Creation > Click to create an MP4 file... function in YAMB, drag/add the raw aac file you had extracted, then save as mp4. This will "wrap" the raw aac stream in the mp4 container format (no generation loss), and the resulting file should play fine in itunes.

[wordslashr]

Hey Remedial Sound

Much obliged for a quick answer. I'll try it out and post back. Thanks very much.

[Porcus]

Are you able to use a command line? If you want to extract from mp4 video to mp4 audio only, then

ffmpeg -i INFILE.mp4 -acodec copy -vn OUTFILE.mp4

will do the job, without transcoding. (If you prefer, use OUTFILE.m4a instead.)

[Dynamic]

Another thing to watch for is whether iTunes would prefer the extension to be .m4a for the audio-only in an MP4 container.

[wordslashr]

Hi Porcus, I just downloaded ffmpeg, I'll try your command line version as well thanks. Its going to take getting used to again - going back to C prompt Thanks.

[eahm]

You must try this very simple one as well, I've tested it few days ago and everything went fine.
http://mp4ui.sourceforge.net/

[Porcus]

Hi Porcus, I just downloaded ffmpeg, I'll try your command line version as well thanks. Its going to take getting used to again - going back to C prompt Thanks.

I've put
for %%f in (*.mp4) DO ffmpeg.exe -i "%%f" -acodec copy -vn "%%f.m4a"
in a convert_mp4_to_m4a.bat

and similar for webm-to-ogg etc. It takes everything in the folder.


(I get then filename.mp4.m4a, which is OK with me -- it tells me how it was created.)

[wordslashr]

You must try this very simple one as well, I've tested it few days ago and everything went fine.
http://mp4ui.sourceforge.net/

Hi Eahm

I downloaded it, I'll check it out. Thanks very much for the tip.