Test it and find out.
Hi, I have a Sony E353 walkman mp3 player (also plays ogg, aac, flac, etc) anyway, I was thinking of converting my library to AAC 156kbps VBR but I was wondering if that or LAME q3 would drain the battery more, at identical bitrates, let's say 128 CBR for both AAC and LAME Mp3 (I'm using version 3.98.4) which would be a bigger drain on the battery?
Don't know about the Sony walkman, but on a Nokia N79, testing the CPU usage I got this (most to least CPU usage):OGG Vorbis>>>>>AAC>>MP3>FLAC
Are these occurrences more or less even across the board?
There's no database I know of, where you can see how particular formats on particular players perform. No companies have done tests like this on their players. So, the only way to get that information would be to hope someone with your same player has done the tests (and hope their claimed results are accurate), or to do the tests yourself.
I'm skeptical that which format your music is in has any impact on battery life beyond a few percentage points. All my computer experience tells me otherwise.