Later we use av_channel_layout_copy, but that uninits the struct
unintentionally freeing the possibly allocated u.map pointer.
Signed-off-by: Marton Balint <cus@passwd.hu>
Since the request_channel_layout is used only by a handful of codecs,
move the option to codec private contexts.
Signed-off-by: Anton Khirnov <anton@khirnov.net>
Signed-off-by: James Almer <jamrial@gmail.com>