audio: make native channel count the default instead of stereo downmix

This should work well with most audio APIs, except ALSA. A long-winded
explanation is provided how to make ALSA multichannel output work.

All other AOs should have no such problems. Of course it's possible
that previously unknown issues arise, because I assume that enabling
multichannel audio is actually relatively rare.

This also disables codec downmix by default, which could change the
audio output due to different mixing in the codec and libavresample.

Fixes #1313.

1 files changed, 4 insertions, 4 deletions

diff --git a/DOCS/man/options.rst b/DOCS/man/options.rst
index 7ae04a3b26..4bc7054ba6 100644
--- a/DOCS/man/options.rst
+++ b/DOCS/man/options.rst
@@ -932,7 +932,7 @@ Audio
     ``--dtshd`` and ``--no-dtshd`` are deprecated aliases.
 
 ``--audio-channels=<number|layout>``
-    Request a channel layout for audio output (default: stereo). This  will ask
+    Request a channel layout for audio output (default: auto). This  will ask
     the AO to open a device with the given channel layout. It's up to the AO
     to accept this layout, or to pick a fallback or to error out if the
     requested layout is not supported.
@@ -945,9 +945,9 @@ Audio
     lists speaker names, which can be used to express arbitrary channel
     layouts (e.g. ``fl-fr-lfe`` is 2.1).
 
-    You can use ``--audio-channels=auto`` to disable this. In this case, the AO
-    use the channel layout as the audio filter chain indicates. (``empty`` is
-    an accepted obsolete for ``auto``.)
+    The default is ``--audio-channels=auto``, which tries to play audio using
+    the input file's channel layout. (Or more precisely, the output of the
+    audio filter chain.) (``empty`` is an accepted obsolete alias for ``auto``.)
 
     This will also request the channel layout from the decoder. If the decoder
     does not support the layout, it will fall back to its native channel layout.