[FFmpeg-devel] [PATCH]Make CH_LAYOUT_5POINTx_BACK the normal case

[Justin Ruggles]

Hi,

On 08/24/2011 05:35 PM, Carl Eugen Hoyos wrote:

> Hi!
> 
> Sorry for this late patch.
> 
> AV_CH_LAYOUT_5POINTx_BACK is what every other application expects for 5.0/5.1 
> when reading a wav file which is where FFmpeg's channel layout comes from, so 
> this should be the "normal" case, and AV_CH_LAYOUT_5POINTx the exception.
> 
> I will apply if nobody objects, Carl Eugen


I don't object, because I don't really care, but I wanted to point out
that applications reading WAV (or any other MS format) expect 0x3F as
the channel mask for 5.1 only because, for Microsoft, 0x3F actually
means side channels, not back channels. This oddity was to keep
backwards compatibility with incorrect behavior in older versions of
Windows.

Suggested Reading:
http://msdn.microsoft.com/en-us/windows/hardware/gg463023

-Justin