[FFmpeg-devel] [PATCH] avformat/asfenc: write group_mutual_exclusion_objects on multiple languages

[Marton Balint]

On Sun, 14 Feb 2016, Michael Niedermayer wrote:

> On Sun, Feb 07, 2016 at 11:02:56PM +0100, Marton Balint wrote:
>> Improves streaming compatibility with Windows Media Services. Also tested for
>> compatilbility in Windows Media Player, Windows Media ASF Viewer and VLC.
>>

[..]

> would this make a subtitle and a audio track exclude each other ?
> one can want a subtitle ad audio stream of the same language as well
> as different languages play at teh same time

You're right, on the other hand probably there won't be a proper default 
excusion policy which suits every use case.

There is another way to exclude streams, using the advanced 
mutual exclusion object which define groups from which only one of the 
streams can be selected.

I can put all audio streams into such a group, but in this case the 
exclusion type (language based) may not reflect the reality in case of 
multiple bitrates of the same language. Also AFAIK ASF can have multiple 
streams of the same type as well for fancy multi-video streams.

Obviously I can create an option "exclusion_policy" which controls the 
behaviour, the reason why I did not do that is because I thought subtitles 
in ASF are very rare anyway and writing language exclusions is usually 
what the user wants.

So which approach do you prefer? Adding an option for this? What would be 
the default? Or writing advanced mutual exclusion objects based on some 
other logic?

Thanks,
Marton