This option is extremely codec specific and only a few codecs employ it.
Move it to codec private options instead: mpegenc family supports only 3
values, xavs and x264 use 5, and xvid has a different metric entirely.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
The old implementation is unusable due to changes in the Xvid API.
Further fixes by Michael Niedermayer <michaelni@gmx.at>.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
Having a separate section for audio encoders simplifies navigation
and is slightly more consistent with the rest of the manual.
Signed-off-by: Diego Biurrun <diego@biurrun.de>
Channel coupling is an optional AC-3 feature that increases quality by
combining high frequency information from multiple channels into a
single channel. The per-channel high frequency information is sent with
less accuracy in both the frequency and time domains. This allows more
bits to be used for lower frequencies while preserving enough
information to reconstruct the high frequencies.
