don't start playing until the first read in vlc vid handles
use correct buffer len
Fixing typo. memset should zero out the whole struct
add some mutexes
fix locking issue on bad formatted input string

FS-7513: Add new conference profile param video-mode (mux,transcode,passthrough) with passthrough as default
remove transcode-video, decode-video, mix-video flags

FS-7505: clean up and support multiple formats to same extensions {modname=mod_vlc}rtmp://foo.com/flvplayback also move [/tmp]file to be {spool_path=/tmp}

Tested with libav 11.3
./configure --prefix=/opt/av --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --host-cflags= --host-ldflags= --enable-libx264 --enable-libmp3lame --enable-libvorbis --enable-libvpx --enable-libfaac --enable-libspeex --enable-nonfree --enable-vda

WIP av file interface, kind of works, need further tweak & cleanup

made it like a codec mod so we can share the same code in case opus is fully supported in webm
add -lvorbis -lvorbisenc to Makefile
the audio is still completely silence, hope we can find out why