FLAC within mp4 and/or mkv

2009-03-23 16:38:16

I have been trying to get to grip with the various media containers and encoders for a while now, and when I read this about MP3HD being lossless and being backward compatible with mp3 for older players, it got me thinking.

A lot of music players can play .MP4 (generally AAC from what I can understand) and mp4 as a container can include various media streams. I was wondering whether .MP4 could contain and MP3 or MP4 (AAC) and FLAC encoded audio streams? If they could, then could the audio players not play the file just as an MP4 (AAC) if it could not decode FLAC, or a full quality FLAC if it can?

If the MP4 container can't work like this, would such a format be possible with the .MKV container?

FLAC within mp4 and/or mkv

Reply #1 – 2009-03-24 02:42:41

i've seen flac inside mkv high-definition scene releases before.

try it out, this software will give u a hand http://www.bunkus.org/videotools/mkvtoolnix/

FLAC within mp4 and/or mkv

Reply #2 – 2009-03-24 10:19:55

mkv can contain many audio tracks, but you will have to select a default track and maybe need to select the track you want to playback. I don't really know what a player would do if it didn't support the codec of the default track, but I suppose I might just refuse to play it. You can somewhat easily test it though

Edit: And yes flac is supported in mkv's - Actually most formats are

The mp4-format is more restricted. From what I know, you can't just mux any track into it. Some players might support it though as it is just a container, but FLAC (and even AC3) are not officially supported by most applications. Still there's room for experiment

I cannot say for sure that I'm correct, but I don't think I'm that off

FLAC within mp4 and/or mkv

Reply #3 – 2009-03-24 11:11:23

It depends on what is playing it as to what audio formats are supported in a particular container. I.e. the PS3 can support AVC video inside an m2ts container even though technically it's an MPEG2 transport stream (I think)....alongside AC3 audio but not AAC.

FLAC within mp4 and/or mkv

Reply #4 – 2009-03-25 03:56:26

vlc has no problems handling multiple audio tracks for a mkv movie, so i see no reason why it wouldnt handle two flacs inside an .mkv,

if you wanted you could have each audio channel assigned as a track (for 5.1 mixes etc), but i dont know if u can use vlc to play multiple tracks at once (ie all the tracks in the container at once).