Can MP4 video files contain an MP3

[djdust]

Hi all

Quick question really as per above. I'm finding conflicting information online where some sources say you can only use AC3 and AAC audio inside an MP4 container, whereas others say you can have MP3 too. I have a stack of AVI files that I want to batch convert to MP4s that have 320kps MP3 audio and I'd like to retain the audio as is rather than transcoding them. Is this possible and, if so, what tool would people recommend?

Thanks in advance

[El Heggunte]

Yes, the MP4 container does support MP3, MP2, MP1, DTS, ALAC, and ALS.

MP4Box, ffmpeg and L-Smash are able to mux MP3 streams into MP4 files.

[djdust]

Thanks for the clarification. Can they mux the video content of an Xvid too or is a re-encode inevitable?

[hello_hello]

Xvid in an MP4 is fine.
I'd try AnotherGUI with ffmpeg.

I'm pretty sure AnotherGUI includes a preset for remuxing files as MP4, but if not, create one using this command line, save it, open a bunch of AVIs and see what happens.

-i "<SourceFileName>" -y -threads 1 -vcodec copy -acodec copy "<OutputPath><OutputFileName>.mp4"

[djdust]

ok, complete utter thickie here, I've managed to install AnotherGUI and hooked it into ffmpeg but am a bit lost at what to do next.

Is it the "Copy codecs into mp4 container" preset on here I need?

http://www.stuudio.ee/anothergui/presets.html

I exported it as an XML file but cannot get it imported into AnotherGUI at all and don't really have a clue what I'm doing at all. Can someone help?

[djdust]

Ignore above, I think I cracked it. Found the "Copy codecs into MP4 container" preset under COPY. It instantaneously generated the MP4 I was after. Alas, I've now found out this won't work when exported to my iPad via iTunes. I'm assuming from what I've gleaned that this is because an iPad can't play Xvids?

[djdust]

...plus, I've also found the MP4 files I've created that retain the untouched MP3 source are coming out silent on the iPad too. Guess I''m stuck with having to encode videos that are h264 / AAC, in other words, not what I was looking for at all with my first enquiry....

[hello_hello]

The way I understand it Apple devices don't allow players with AC3 audio decoding due to licensing issues, or rather the AC3 decoding need to be licensed, which probably means a non-free player for AC3.

I can't recommending anything although this turned up via Google:
https://itunes.apple.com/au/app/infuse-elegant-video-player/id577130046?mt=8

VLC should play Xvid and MP3.
https://itunes.apple.com/au/app/vlc-for-mobile/id650377962?mt=8

Apple devices seem to have particularly limited support for Xvid. I don't know why.
http://www.apple.com/au/ipad-air-2/specs/
MPEG-4 video up to 2.5 Mbps, 640 by 480 pixels, 30 frames per second, Simple Profile with AAC-LC audio up to 160 Kbps per channel, 48kHz, stereo audio in .m4v, .mp4 and .mov file formats
I've never owned an iAnything but I assume for higher resolutions and audio types other than AAC you'll need a different player. I'd try VLC.

If you want to change the audio to another format...
Create a new preset or copy the one you're using and change it to match the command line below. You just need to remove "copy" after -acodec and add "aac -ac 2. That'll copy the video and convert the audio to AAC. If the audio is multi-channel it'll be downmixed to stereo.
The only problem I had with that conversion is it was stupid slow. It's the AAC encoding that's slow and it's slow on it's own (without video). I don't know why. Maybe a different version of ffmpeg would be okay, or maybe it doesn't like XP, I'm not sure.

-i "<SourceFileName>" -y -threads 1 -vcodec copy -acodec aac -ac 2 "<OutputPath><OutputFileName>.mp4"

[djdust]

Ok, cheers for all the advice.

[djdust]

Hi again, been experimenting a bit more. One question that's probably very daft, why not simply *rename* an AVI file to MP4 instead of using ffmpeg..? It seems to still work in Windows...

[hello_hello]

Software is often clever enough to check the file properly rather than just assume the extension is correct. Linux doesn't even use file extensions (or you don't need to use them). I tried changing an AVI extension to MOV and MPC-HC didn't care, but it's still and AVI. The file extension is more a way of deciding "which program will open the file" when you double click on one.

General (from MediaInfo)
Complete name: E:\test.mov
Format: AVI
Format/Info: Audio Video Interleave
File size: 1.46 GiB
Duration: 2h 2mn
Overall bit rate: 1 707 Kbps
Writing application: VirtualDubMod 1.5.10.2 (build 2540/release)
Writing library: VirtualDubMod build 2540/release

Fooling a program that doesn't understand AVIs or that doesn't officially open them might be a different story.