[vlc-devel] [RFC] audio: let VLC decode more than 9 audio channels
emeric.grange at gmail.com
Mon Oct 12 17:06:18 CEST 2015
2015-10-07 6:36 GMT+02:00 Ilkka Ollakka <ileoo at videolan.org>:
> I think biggest issue has been, that nobody has yet tought should those
> extra channels be mapped somehow/mixed to other channes when playing
> back, or just ignored (in channelmixers). And is there any actual
> channelmappings between 8.1 and 16 channels?
Yes there are several other speaker configuration, like 9.1 and 10.1
mentioned by Dolby Auro 3D for "small rooms", and for Cinemas there is
11.1, 12.2, 13.1, 22.2 and probably others. Agreed, documentation is
hard to get for these very unusual configurations.
I think the best "consumer grade" Dolby amplifier has 12 channels.
The WAVEFORMATEX structure defines 18 speakers.
Also to answer Rémis, the 16 channels configuration is used for "Third
>> diff --git a/include/vlc_es.h b/include/vlc_es.h
>> index 97cdb78..bf0bc11 100644
>> --- a/include/vlc_es.h
>> +++ b/include/vlc_es.h
>> @@ -108,13 +108,28 @@ struct audio_format_t
>> #define AOUT_CHAN_REARRIGHT 0x40
>> #define AOUT_CHAN_MIDDLELEFT 0x100
>> #define AOUT_CHAN_MIDDLERIGHT 0x200
>> -#define AOUT_CHAN_LFE 0x1000
>> +#define AOUT_CHAN_SIDE_LEFT 0x100
>> +#define AOUT_CHAN_SIDE_RIGHT 0x200
> I think you should start that side_left from 0x1000 or is it
> intentionally same as chan_middleleft?
Definitely my mistake.
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