[FFmpeg-user] Enable all audio channels

Tim Nicholson nichot20 at yahoo.com
Mon Jun 24 08:25:40 CEST 2013

On 23/06/13 19:02, Carl Eugen Hoyos wrote:
> [...]
>> The common case I encounter is to have a single 
>> language in the .mov, as 8 individual mono tracks 
>> of the final audio mixes: Lt, Rt for stereo, and 
>> L, R, C, Lfe, Ls, Rs for 5.1 (in that order).
>> A related question would be how to label these 
>> single mono tracks?
> Just to avoid confusion:
> For me, "order" and "label" are two completely 
> different, partly orthogonal things.
> Is it sufficient if 6 tracks (all being marked 
> as "default") in the right order are in the mov 
> file or is it necessary that all 6 tracks are 
> "labeled" correctly?

Some use cases require "correct" labelling, AFAIK the only way to do
this is using the Qt Pro Properties window*. Achieving it
programatically with standard Apple tools currently seems impossible.
QTKit does not allow you to, and AVFoundation currently only seems to be
able to read the values. So maybe doing it in ffmpeg would be worthwhile.

*directly or via the Scripting Bridge.

> Or in other words:
> If you search for "first track enabled" in 
> libavformat/movenc.c and change the "0x02" in 
> that line to "0xf", does it work?
> Carl Eugen
> [..]


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