Checking in FFmpeg sources.

third_party/ffmpeg/README.chromium

+Contains the sources used to compile FFmpeg binaries used by Google Chrome and
+Chromium.
+
+The FFmpeg source is from Alexander Strange's ffmpeg-mt branch:
+  git://gitorious.org/~astrange/ffmpeg/ffmpeg-mt.git
+  Commit: 42b521db9177ed2d4e62845659fdcd44c59757f9
+
+The libswscale source is from the public libswscale repository:
+  git://git.ffmpeg.org/libswscale
+  Commit: 69fc1002e2c92aac84dccc5047141feefc94b309
+
+Since FFmpeg is sandboxed inside the render process, we're only interested in
+building the absolute minimum.
+
+Example configure flags suitable for Chromium (Ogg+Theora+Vorbis), which will
+build and install to the directory ./chromium-ffmpeg:
+  ./configure --disable-ffmpeg --disable-ffplay --disable-ffserver             \
+              --enable-shared --disable-static --disable-debug                 \
+              --enable-pthreads --disable-network --disable-encoders           \
+              --disable-decoders --disable-hwaccels --disable-muxers           \
+              --disable-demuxers --disable-parsers --disable-bsfs              \
+              --disable-protocols --disable-devices --disable-filters          \
+              --enable-decoder=theora --enable-decoder=vorbis                  \
+              --enable-demuxer=ogg                                             \
+              --prefix=./chromium-ffmpeg
+
+If building on Windows with Chromium's MinGW/MSYS environment, add the following:
+              --cc=gcc-sjlj --enable-memalign-hack
+
+To build:
+  make
+
+To install:
+  make install
+
+Copy the resulting avcodec-52.dll, avformat-52.dll and avutil-50.dll alongside
+chrome.exe.