[FFmpeg-devel] [PATCH] dca: map xxch side channels to AV_CH_SIDE_LEFT/RIGHT instead of REAR.

Nick Brereton nick at nbrereton.net
Tue Jul 10 23:34:49 CEST 2012

On 2012-07-09 11:04, Hendrik Leppkes wrote:

> On Mon, Jul 9, 2012 at 11:44 AM, Benjamin Larsson
> <benjamin at southpole.se>wrote:
>> OK MvH Benjamin Larsson
> I talked to Nick directly, and he'll be looking at the code as soon 
> as
> he
> finds the time to diagnose the other issues i reported, maybe we 
> should
> hold this until then.
> - Hendrik
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In re the first problem, DTS seem to have a greater variety of flavours 
than ffmpeg does; the net result is that I've had to compress some of 
the positions. In this case DCA_XXCH_SIDE_REAR_LEFT/RIGHT (which are 
reserved for the core channels only) are not used and are replaced with 
DCA_XXCH_SIDE_SURROUND_LEFT/RIGHT which I had guessed (wrongly) were 

I think your fix is a reasonable solution in this case; you should also 
make the av_log message on line 2282 an error message.

Are there a proscribed set of allowable speaker configurations for 
XXCH? If there are it might help to clean this up somewhat.

The code that undoes the embedded down-mix is a bit fragile as you've 
noted & in this case gets the wrong channels to remove the down-mix from 
(it winds up eliminating itself instead). I'll try a different solution 
over the weekend.


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