Add some words about windows cross-compilation

.github/workflows/rust.yml

@@ -10,7 +10,7 @@ env:
   CARGO_TERM_COLOR: always
 
 jobs:
-  build:
+  build-test-lint-linux:
 
     runs-on: ubuntu-latest
 
@@ -34,3 +34,45 @@ jobs:
       run: cargo +nightly-2022-02-16 bench --verbose --features=bench --no-run
     - name: Build examples
       run: cargo build --examples --verbose --features=serde
+
+  build-test-lint-windows:
+    name: Windows - build, test and lint
+    runs-on: windows-latest
+    strategy:
+      matrix:
+        include:
+          - ffmpeg_version: latest
+            ffmpeg_download_url: https://www.gyan.dev/ffmpeg/builds/ffmpeg-release-full-shared.7z
+      fail-fast: false
+    env:
+      FFMPEG_DOWNLOAD_URL: ${{ matrix.ffmpeg_download_url }}
+    steps:
+      - uses: actions/checkout@v2
+      - name: Install dependencies
+        run: |
+          $VCINSTALLDIR = $(& "${env:ProgramFiles(x86)}\Microsoft Visual Studio\Installer\vswhere.exe" -latest -property installationPath)
+          Add-Content $env:GITHUB_ENV "LIBCLANG_PATH=${VCINSTALLDIR}\VC\Tools\LLVM\x64\bin`n"
+          Invoke-WebRequest "${env:FFMPEG_DOWNLOAD_URL}" -OutFile ffmpeg-release-full-shared.7z
+          7z x ffmpeg-release-full-shared.7z
+          mkdir ffmpeg
+          mv ffmpeg-*/* ffmpeg/
+          Add-Content $env:GITHUB_ENV "FFMPEG_DIR=${pwd}\ffmpeg`n"
+          Add-Content $env:GITHUB_PATH "${pwd}\ffmpeg\bin`n"
+      - name: Set up Rust
+        uses: actions-rs/toolchain@v1
+        with:
+          toolchain: stable
+          override: true
+          components: rustfmt, clippy
+      - name: Build
+        run: |
+          cargo build --examples
+      - name: Test
+        run: |
+          cargo test --examples
+      - name: Lint
+        run: |
+          cargo clippy --examples -- -D warnings
+      - name: Check format
+        run: |
+          cargo fmt -- --check

Cargo.lock

@@ -376,9 +376,9 @@ checksum = "e88a8acf291dafb59c2d96e8f59828f3838bb1a70398823ade51a84de6a6deed"
 
 [[package]]
 name = "ffmpeg-next"
-version = "5.0.0"
+version = "5.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "154799d4348e5105d775d72fe53eb32ebb31e7019d963914c687633e894ded92"
+checksum = "70a1fc87054b079ade0b081b023c5fef309cd4bbcb569c09eed2aa39b25a0a11"
 dependencies = [
  "bitflags",
  "ffmpeg-sys-next",
@@ -387,9 +387,9 @@ dependencies = [
 
 [[package]]
 name = "ffmpeg-sys-next"
-version = "5.0.0"
+version = "5.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f81bd9adbcd2903847d680e0d2b0df95f0d514ad5f037a5504e1be1706bd98e0"
+checksum = "6ba12dea33516e30c160ce557c7e43dd857276368eb1cd0eef4fce6529f2dee5"
 dependencies = [
  "bindgen",
  "cc",

Cargo.toml

@@ -35,7 +35,7 @@ lazy_static = "1.4.0"
 rayon = "1.5.0"
 crossbeam = "0.8.0"
 noisy_float = "0.2.0"
-ffmpeg-next = "5.0.0"
+ffmpeg-next = "5.0.2"
 log = "0.4.14"
 env_logger = "0.8.3"
 thiserror = "1.0.24"

README.md

@@ -97,6 +97,42 @@ library (with multithreading), and to make playlists easily.
 See [blissify](https://crates.io/crates/blissify) for a reference
 implementation.
 
+## Cross-compilation
+
+To cross-compile bliss-rs from linux to x86_64 windows, install the
+`x86_64-pc-windows-gnu` target via:
+
+        rustup target add x86_64-pc-windows-gnu
+
+Make sure you have `x86_64-w64-mingw32-gcc` installed on your computer.
+
+Then after downloading and extracting [ffmpeg's prebuilt binaries](https://www.gyan.dev/ffmpeg/builds/),
+running:
+
+        FFMPEG_DIR=/path/to/prebuilt/ffmpeg cargo build --target x86_64-pc-windows-gnu --release
+
+Will produce a `.rlib` library file. If you want to generate a shared `.dll`
+library, add:
+
+        [lib]
+        crate-type = ["cdylib"]
+
+to `Cargo.toml` before compiling, and if you want to generate a `.lib` static
+library, add:
+
+        [lib]
+        crate-type = ["staticlib"]
+
+You can of course test the examples yourself by compiling them as .exe:
+
+        FFMPEG_DIR=/path/to/prebuilt/ffmpeg cargo build --target x86_64-pc-windows-gnu --release --examples
+
+WARNING: Doing all of the above and making it work on windows requires to have
+ffmpeg's dll on your Windows `%PATH%` (`avcodec-59.dll`, etc).
+Usually installing ffmpeg on the target windows is enough, but you can also just
+extract them from `/path/to/prebuilt/ffmpeg/bin` and put them next to the thing
+you generated from cargo (either bliss' dll or executable).
+
 ## Acknowledgements
 
 * This library relies heavily on [aubio](https://aubio.org/)'s