[FFmpeg-devel] [RFC] Channel layouts
Sun Sep 7 16:20:50 CEST 2008
M?ns Rullg?rd wrote:
> Don't forget that the channel layout must specify not only which
> components are present, but also their order. Currently lavc tells
> you neither, making it practically useless for multi-channel audio.
The idea is that the order is the same as the CHANNEL_LAYOUT bits.
I.e. LEFT must be the first channel if it exists, then RIGHT, etc.
Still, this would only be mandatory for codecs (and formats) that
This is IMHO no more strange than that PIX_FMT_YUV always have
the planes in Y,U,V order. From an application perspective i find
this much more convenient. There might be more work in the decoders
though. Still, with float_to_int16_interleave() (that all of the
"popular" multi-channel codecs currently use (AC3, DTS and AAC))
this is just a matter of swizzling a few pointers at setup time.
For other codecs there might be more work involved. However,
that day ffmpeg gets planar audio formats this is even less
> 2.1 and 4.1 are equally, if not more, likely. I have such DVDs, but
> none with x.0 where x > 2.
Just for the record, i've stumbled across 5.0 AC3 in DVB content.
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