I need to know if there´s any software for AAC like mp3gain, I mean something to control gain of MP4 files.
Thanks.

The only program that can do this (that I'm aware of) is foobar2000. I think Winamp can playback AAC with ReplayGain (with plugins), but I don't think it can calculate it.

Thanks kl33per, I´ll check it out.
It´s a pain in the ass having a lot of mp3gained mp3s, relpaygained mpcs and vorbisgained oggs and then volume goes to hell when you play an mp4 .

afaik itunes can set some private postgain infos in the .mp4 container, maybe this can be reverse engineered?

Yes, I read about this somewhere too. This would be a very nice thing to have. I miss replaygain a lot when I use AAC.

It's track gain, though. Not album gain. It's called Sound Check in iTunes and on the iPod.

It already has been, for use with foo_pod, a foobar to iPod component. See: http://www.hydrogenaudio.org/forums/index....ST&f=33&t=19156

wow now we would only need faad2 to be able to offer using this value during decoding

menno?

what if i have an itunes file with this value and still apply replaygain to it with foobar?? will it be messed up?

No, the SoundCheck and ReplayGain metadata items are separate and don't conflict, so you can have a file with both in it.

i dont want any quicktime crap in my files, i have some m4s from allofmp3.com supposedly itunes compatible... so is there a way to find if they have soundcheck and possibly get rid of it?

Brilliant reasoning. "It's related to QuickTime, so even though it's completely harmless, it must suck"


Well, I personally applaud Apple for creating SoundCheck. It's the first initiative similar to ReplayGain to be implemented by one of the big players. You don't see Microsoft implementing it on WMA, or Xiph oficially implementing it on Vorbis. Not even Ahead, that is highly praised in these forums and have several developers participating here, implemented volume leveling techniques on their AAC encoder.

the fact is that i dont want to feel forced to use quicktime for soundcheck, i want replaygain i can use with winamp and foobar. i dont like useless stuff no matter its from quicktime or else, thats my choice, i didnt mean it was crap, just a way of saying...

i would be glad to keep soundcheck but i dont see myself buying an expensive ipod just for soundcheck, so i would just rather wait if another company can use the technology. Anybody trying to use soundcheck besides mac would result in copyright infrigement?? if not, well, ill keep my mouth shut, so is it possible?

Winamp doesn't recognize either foobar's RG tags in MP4 or SoundCheck.







Hardly. It's just a value stored in an MP4 atom. And I doubt they can patent it, given ReplayGain is previous art.

I also applaud Apple for trying to implement something like ReplayGain. Its a start for major players to support some type of volume leveling. Maybe Winamp will follow next but I hope that we don't get all these big players creating their own volume leveling standard...this would just create a mess of incompatibility. I used Apple's feedback about SoundCheck and told them about ReplayGain (which I'm sure they already knew about) since their SoundCheck isn't fool-proof and often makes songs louder than others and because its overall inconsistant. I went ahead and told them to try using ReplayGain instead because it's proven to work and the code is free and available for use. Plus there is no album gain since SoundCheck works like track-gain and boosts all songs to the same level (when it works). But I bet they still stay stubborn and still use their inferior SoundCheck technique. But I guess if you are an iTunes user, SoundCheck is better than nothing. But I'd love to see ReplayGain recognized by a big player such as iTunes or Winamp to give the standard a push so more players will recognize it and support it finally.