Move av_log callback handling from vd_ffmpeg.c to a new file
av_log.c and install the callback immediately when starting the
program. Main functionality improvements of the new code:
- The old version only installed the callback when opening an FFmpeg
video decoder. If nothing had triggered that then av_log() messages
from other sources (libavformat, audio decoding, swscale usage)
bypassed MPlayer's output system completely. Now the callback is
always installed.
- Current av_log message severity levels are handled correctly. The
old code used MSGL_ERR for some messages that should be MSGL_V.
- Message type is now set for libavformat contexts
(MSGT_DEMUXER / MSGT_MUXER).
- The old code did "mp_msg_test(type, mp_level)" before actually
determining the type, so that it always used MSGT_FIXME. This led
to some messages being incorrectly dropped in case the user
had specified module-specific verbosity levels. The old check in
question was originally motivated by performance problems when
there were a lot of callbacks; however it's not clear whether the
part about it skipping the type determination was intentional (most
of the performance problems must have come from the way the
original code used snprintf) and in my tests current FFmpeg
libraries have not generated unreasonable amounts of callbacks
anyway.
Uoti Urpala