1This directory contains files used in gecko builds from FFmpeg
2(http://ffmpeg.org). The current files are from FFmpeg as of
3revision n3.1.1-6-g86f9228
4All source files match their path from the library's source archive.
5
6Currently, we only use the vp8 and vp9 portion of the library, and only on x86
7based platforms. If this changes, configuration files will most likely
8need to be updated.
9
10AVX2 must be disabled on Linux due to the use of yasm 1.1 on the build bots.
11Once yasm is upgraded to 1.2 or later, AVX2 code could be re-enabled.
12Add --disable-avx2 to configure on those platforms.
13
14configuration files were generated as follow using the configure script:
15./configure --disable-everything --disable-protocols --disable-demuxers --disable-muxers --disable-filters --disable-programs --disable-doc --disable-parsers --enable-parser=vp8 --enable-parser=vp9 --enable-decoder=vp8 --enable-decoder=vp9 --disable-static --enable-shared --disable-debug --disable-sdl --disable-libxcb --disable-securetransport --disable-iconv --disable-swresample --disable-swscale --disable-avdevice --disable-avfilter --disable-avformat --disable-d3d11va --disable-dxva2 --disable-vaapi --disable-vda --disable-vdpau --disable-videotoolbox --enable-asm --enable-yasm
16
17config*:
18replace: /HAVE_(MALLOC_H|ARC4RANDOM|LOCALTIME_R|MEMALIGN|POSIX_MEMALIGN)/d
19
20config_unix64.h/config_unix64.asm:
21replace: s/HAVE_SYSCTL 1/HAVE_SYSCTL 0
22
23config_win32/64.h/asm:
24add to configure command: --toolchain=msvc
25
2623 Sept 2016: libavcodec/pthread_frame.c has been patched so as to avoid
27generating large numbers of warnings from TSan (Thread Sanitizer) when
28decoding vp9 streams.  This will likely be fixed upstream sometime soon.
29When resyncing with upstream, first un-apply the patch shown at
30https://bugzilla.mozilla.org/show_bug.cgi?id=1274256#c60, then resync,
31then assess whether the patch is still necessary.
32