Allowed audio codecs for MPEG4 AVC

[Anakunda]

Hello, is there a strict specification for allowed/sugested audio codecs for AVC video in either MP4 or MKV container (does these two differ in audio codec restrictions?), and if so is Vorbis and FLAC or another lossless format supported as wide as AAC or AC3 by HW devices like BluRay players or Home Media Centers? In another words if I switch from AC3 to Vorbis or FLAC if I may expect some playback issues on HW player, or Windows Media player without 3rd party codecs installed.

[shon3i]

H264/AVC is only codec, and not dictate with what codec will be combined. You practically answered yourself, different containers allowed different combinations, but also, different players can play different combinations. So you should use video or audio codec and container that meet your players.

[Anakunda]

That I know, but rather I'd like to know if there's some standard that HW or SW players must obey, ie. if HW player of any kind features H264 (mkv) playback, then if there's some obligatory list of audio codecs that he HW player must support, the same about SW players like WMP. AC3 and AAC are most likely obligatory, but maybe there's more obligatory audio formats like Vorbis, or FLAC?

[mp3dom]

Software players potentially can load anything. There are internal or external decoders for that. Hardware players are a bit more restricted. In general MP4 based of AVC+AAC audio have very good compatibility. About AVC, hardware players can have limitations in profile/level. There's no precise rule.

[Blue_MiSfit]

You'll probably find that the vast majority of H.264 MP4 files targeted at hardware devices have AAC audio.

Transport Streams most often will contain Dolby Digital audio, though you occasionally see MPEG-1 Layer 2 (MP2), or PCM. SOMETIMES the more exotic Dolby Digital Plus.

Derek