chore: roll ffmpeg binaries to r1001 (#3824)

This patch:
- updates FFMPEG to r1001
- updates README.md with a brief description of binaries build process

Author: aslushnikov

third_party/ffmpeg/README.md

@@ -1,216 +1,5 @@
-# Binary Files
+# FFMPEG
 
-<!-- GEN:toc-top-level -->
-- [Building `ffmpeg-mac`](#building-ffmpeg-mac)
-- [Building `ffmpeg-win64.exe`](#building-ffmpeg-win64exe)
-- [Building `ffmpeg-win32.exe`](#building-ffmpeg-win32exe)
-<!-- GEN:stop -->
-
-## Building `ffmpeg-mac`
-
-> FFMPEG: [`n4.3.1`](https://github.com/FFmpeg/FFmpeg/releases/tag/n4.3.1)
-> libvpx: [`v1.9.0`](https://github.com/webmproject/libvpx/releases/tag/v1.9.0)
-
-I mostly followed steps at https://trac.ffmpeg.org/wiki/CompilationGuide/macOS
-
-1. Clone repo & checkout release tag (we're building release v4.3.1)
-
-```sh
-~$ git clone https://git.ffmpeg.org/ffmpeg.git ffmpeg
-~$ cd ffmpeg
-~/ffmpeg$ git checkout n4.3.1
-```
-
-2. Install brew dependencies
-
-```sh
-~/ffmpeg$ brew install automake fdk-aac git lame libass libtool libvorbis libvpx \
-opus sdl shtool texi2html theora wget x264 x265 xvid nasm
-```
-
-3. Prepare output folders
-
-```sh
-~/ffmpeg$ mkdir -p output/bin
-```
-
-4. Configure with vpx 
-
-```sh
-~/ffmpeg$ ./configure --prefix=$PWD/output \
-                      --pkg-config-flags="--static" \
-                      --bindir=$PWD/output/bin \
-                      --disable-everything \
-                      --enable-ffmpeg \
-                      --enable-protocol=pipe \
-                      --enable-protocol=file \
-                      --enable-parser=mjpeg \
-                      --enable-decoder=mjpeg \
-                      --enable-demuxer=image2pipe \
-                      --enable-filter=pad \
-                      --enable-filter=crop \
-                      --enable-filter=scale \
-                      --enable-muxer=webm \
-                      --enable-encoder=libvpx_vp8 \
-                      --enable-libvpx \
-                      --enable-static
-```
-
-5. Make & install to the `output/bin`
-
-```sh
-~/ffmpeg$ make && make install
-```
-
-## Building `ffmpeg-win64.exe`
-
-> FFMPEG: [`n4.3.1`](https://github.com/FFmpeg/FFmpeg/releases/tag/n4.3.1)
-> libvpx: [`d1a7897`](https://github.com/webmproject/libvpx/commit/d1a78971ebcfd728c9c73b0cfbee69f470d4dc72)
-
-1. Install `MSYS2` from `https://www.msys2.org` and install to `c:\msys64`
-
-2. Launch `c:\msys64\mingw64` to launch a shell with a proper environment.
-
-3. `MSYS2` uses `pacman` to install dependencies. Run the following commands to update & install packages:
-
-```sh
-$ pacman -Syu
-$ pacman -Su
-$ pacman -S make pkgconf diffutils yasm
-$ pacman -S mingw-w64-x86_64-nasm mingw-w64-x86_64-gcc mingw-w64-x86_64-SDL2
-```
-
-notes:
-- `yasm` is needed for `libvpx`
-- the rest is a general compilation toolchain
-
-4. Clone `libvpx` of proper version, compile manually and install to a well-known location (prefix):
-
-```sh
-$ cd /c/
-$ git clone https://chromium.googlesource.com/webm/libvpx
-$ cd libvpx
-$ git checkout d1a78971ebcfd728c9c73b0cfbee69f470d4dc72
-$ ./configure --prefix=/eee64 --target=x86_64-win64-gcc --enable-static --disable-shared --disable-docs --disable-tools --disable-unit-tests --disable-examples
-$ make && make install
-```
-
-Note: `libvpx` has a useful readme: https://chromium.googlesource.com/webm/libvpx/+/master/README
-
-5. Once `libvpx` is compiled, compile `ffmpeg` using the just-compiled `libvpx`:
-
-```sh
-$ cd /c/
-$ git clone git://source.ffmpeg.org/ffmpeg.git
-$ cd ffmpeg
-$ git checkout n4.3.1
-$ ./configure --extra-cflags="-I/eee64/include" \
-              --extra-ldflags="-L/eee64/lib -static" \
-              --prefix=/eee64 \
-              --pkg-config-flags="--static" \
-              --bindir=$PWD/output/bin \
-              --disable-everything \
-              --enable-ffmpeg \
-              --enable-protocol=pipe \
-              --enable-protocol=file \
-              --enable-parser=mjpeg \
-              --enable-decoder=mjpeg \
-              --enable-demuxer=image2pipe \
-              --enable-filter=pad \
-              --enable-filter=crop \
-              --enable-filter=scale \
-              --enable-muxer=webm \
-              --enable-libvpx \
-              --enable-static \
-              --enable-encoder=libvpx_vp8 \
-              --disable-pthreads \
-              --disable-zlib \
-              --disable-iconv \
-              --disable-bzlib \
-              --disable-w32threads
-$ make && make install
-```
-
-note: the following resources helped me to deal with some dynamic dependencies in the resulting `ffmpeg.exe`:
-- https://stackoverflow.com/questions/13768515/how-to-do-static-linking-of-libwinpthread-1-dll-in-mingw
-
-## Building `ffmpeg-win32.exe`
-
-> FFMPEG: [`n4.3.1`](https://github.com/FFmpeg/FFmpeg/releases/tag/n4.3.1)
-> libvpx: [`d1a7897`](https://github.com/webmproject/libvpx/commit/d1a78971ebcfd728c9c73b0cfbee69f470d4dc72)
-
-> NOTE: these steps assume that `ffmpeg-win64.exe` was just built on the machine.
-
-1. Launch `c:\msys64\mingw32` to launch a shell with a proper environment. Not sure if this is required or everything could be done from `mingw64` - but it worked.
-
-2. Update libraries for mingw32
-
-```sh
-$ pacman -Syu
-$ pacman -Su
-```
-
-3. Uninstall the `x86_64` compilers that we installed to build win64 version:
-
-```sh
-$ pacman -R mingw-w64-x86_64-nasm mingw-w64-x86_64-gcc mingw-w64-x86_64-SDL2
-```
-
-4. Install the i686 compilers instead of their x86_64 counterparts:
-
-```sh
-$ pacman -S mingw-w64-i686-nasm mingw-w64-i686-gcc mingw-w64-i686-SDL2
-```
-
-5. Remove all old source folders - we'll re-clone everything later for simplicity
-
-```sh
-$ rm -rf /c/ffmpeg && rm -rf /c/libvpx
-```
-
-6. Clone & compile libvpx. Notice a change: `--target=x86-win32-gcc`
-
-```sh
-$ cd /c/
-$ git clone https://chromium.googlesource.com/webm/libvpx
-$ cd libvpx
-$ ./configure --prefix=/eee32 --target=x86-win32-gcc --enable-static --disable-shared --disable-docs --disable-tools --disable-unit-tests --disable-examples
-$ make && make install
-```
-
-7. Clone & compile ffmpeg
-
-```sh
-$ cd /c/
-$ git clone git://source.ffmpeg.org/ffmpeg.git
-$ cd ffmpeg
-$ git checkout n4.3.1
-$ ./configure --extra-cflags="-I/eee32/include" \
-              --extra-ldflags="-L/eee32/lib -static" \
-              --prefix=/eee32 \
-              --pkg-config-flags="--static" \
-              --bindir=$PWD/output/bin \
-              --disable-everything \
-              --enable-ffmpeg \
-              --enable-protocol=pipe \
-              --enable-protocol=file \
-              --enable-parser=mjpeg \
-              --enable-decoder=mjpeg \
-              --enable-demuxer=image2pipe \
-              --enable-filter=pad \
-              --enable-filter=crop \
-              --enable-filter=scale \
-              --enable-muxer=webm \
-              --enable-libvpx \
-              --enable-static \
-              --enable-encoder=libvpx_vp8 \
-              --disable-pthreads \
-              --disable-zlib \
-              --disable-iconv \
-              --disable-bzlib \
-              --disable-w32threads
-$ make && make install
-```
-
-note: using `-j` for make somehow breaks compilation - so I'd suggest compiling everything in one thread.
+- FFMPEG binary files are produced by [`//browser_patches/ffmpeg`](../../browser_patches/ffmpeg) scripts.
+- To get exact source that produced binary, run executable without arguments and look at the version suffix. It'll be something `n4.3.1-playwright-build-1001` - with the `1001` being the [`ffmpeg/BUILD_NUMBER`](../../browser_patches/ffmpeg/BUILD_NUMBER)