[FFmpeg-devel] [PATCH] avfilter/af_amerge: add reorder_inputs option to be able to turn off reordering

[Marton Balint]

On Sun, 4 Sep 2016, Nicolas George wrote:

> Le nonidi 19 fructidor, an CCXXIV, Marton Balint a écrit :
>> Some source files might have a mono track, and a stereo track. If I merge
>> these, the order will change, because mono is handled as center.
>
> And this is completely correct. What would you want instead?

The order of the channels to remain unchanged regardless of the input 
channel layout (which is often guessed only). Filtering in ffmpeg is 
unfortunately forcing you to use channel layouts, even if you don't want 
to, even if you only want to say: this track has 2 channels, that stream 
track has 1 channels. Don't assume anything else.

Another example: You have a file, with mono tracks. Some tracks have 
correct metadata describing the channel layout of the files, others don't. 
You wan't the channels in file-order, regardless of the correctness of the 
input channel layout metadata in the file.

Regards,
Marton