MP4 (AAC / M4A) gapless?

[scarfy]

There seems to be a lot of questions about this, but I've not seen an answer yet.

 

Does anyone know how to get gapless playback to work with MP4s when using Poweramp?

 

I ripped a few CDs using Nero AAC, which played back fine in Poweramp. However, the playback wasn't gapless. There is a small break of a few milliseconds between songs, which, when listening to an album where one track seamlessly transitions to another, is quite disruptive to listen to (at first I thought that Poweramp was hiccuping on the tracks).

 

Are there any tags I can add to the files?

 

The reason I'm interested is that right now I have most of my music in OGG. However, I've notice that the battery takes quite a beating from playing these, compared to MP4 (because the CPU usage is much higher). It's not dreadful of course, but could be better. An example:

 

2 hours of playing back MP4 audio shows a total CPU usage of 13m in Android.

1.5 hours of playing back OGG audio shows a total CPU usage of 20m (some quick maths suggests this would be almost double that of MP4).

 

The OGGs are encoded at q6 (~192kps), whereas the MP4 are ripped at 0.5 (~160kps). I'm not sure that the extra 32kps accounts for double the CPU usage, but maybe I'm wrong

 

Tags? Ripping suggestions..?

 

Thanks,

 

Steve

 

[scarfy]

Ah, I finally found the answer to it, myself.

 

Turns out that gapless isn't a part of the AAC standard (huh?!) and it's up to the individual playback software to support it.

 

http://wiki.hydrogenaudio.org/index.php?title=AAC_FAQ#Do_AAC_encoded_files_play_back_gaplessly.3F

 

Maybe we should request that Poweramp support it