cross compilation support

Author: paulrouget

README.md

@@ -13,26 +13,37 @@ erased by the script (see `maybe_clean_module` function).
 Usage:
 -----
 
+To do a non-cross-compile build:
+
 ```
 $ ./build.sh
 ```
 
-Build for Mac x86 on Mac Arm:
+5 supported targets:
+
+- `linux-x86_64`
+- `linux-i686`
+- `windows-x86_64`
+- `windows-i686`
+- `mac-x86_64`
+- `mac-arm64`
 
 ```
-$ arch -x86_64 ./build.sh
+$ ./build.sh <target>
 ```
 
-Compilation result will be under the `dist/ffmpeg` directory.
+Compilation result will be under the `dist/<os>/<arch>/ffmpeg` directory.
 To rebuild a dependency or ffmpeg itself, `rm -rf` the relevant
-directory in `dist`.
+directory in `dist/<o>/<target>/`.
 
 Todo:
 ----
-- Windows, Mac Intel
+- Windows i686
+- Linux i686
+- Mac Intel
+- Tests
 - test MP3 support (no lame?)
-- remove dependency on libc++ (x265)
-- no ffplay
+- remove dependency on libc++ (x265) and libvdso (linux)
 - re-enable xvid: --enable-libxvid
 - --enable-sdl2 --enable-ffplay
-
+- presets? dist/windows/i686/ffmpeg/share/ffmpeg/