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use bindgen::{self, callbacks, CargoCallbacks};
use num_cpus as ncpus;
use once_cell::sync::Lazy;
use pkg_config as pkgconfig;
use std::{collections::HashSet, env, fs, path, process::Command};
/// All the libs that FFmpeg has
static LIBS: Lazy<[&str; 8]> = Lazy::new(|| {
[
"avcodec",
"avdevice",
"avfilter",
"avformat",
"avutil",
"postproc",
"swresample",
"swscale",
]
});
/// Whitelist of the headers we want to generate bindings
static HEADERS: Lazy<[&str; 64]> = Lazy::new(|| {
[
"libavcodec/avcodec.h",
"libavcodec/avfft.h",
"libavcodec/dv_profile.h",
"libavcodec/vaapi.h",
"libavcodec/vorbis_parser.h",
"libavdevice/avdevice.h",
"libavfilter/avfilter.h",
"libavfilter/buffersink.h",
"libavfilter/buffersrc.h",
"libavformat/avformat.h",
"libavformat/avio.h",
"libavutil/adler32.h",
"libavutil/aes.h",
"libavutil/audio_fifo.h",
"libavutil/avstring.h",
"libavutil/avutil.h",
"libavutil/base64.h",
"libavutil/blowfish.h",
"libavutil/bprint.h",
"libavutil/buffer.h",
"libavutil/camellia.h",
"libavutil/cast5.h",
"libavutil/channel_layout.h",
"libavutil/cpu.h",
"libavutil/crc.h",
"libavutil/dict.h",
"libavutil/display.h",
"libavutil/downmix_info.h",
"libavutil/error.h",
"libavutil/eval.h",
"libavutil/fifo.h",
"libavutil/file.h",
"libavutil/frame.h",
"libavutil/hash.h",
"libavutil/hmac.h",
"libavutil/imgutils.h",
"libavutil/lfg.h",
"libavutil/log.h",
"libavutil/macros.h",
"libavutil/mathematics.h",
"libavutil/md5.h",
"libavutil/mem.h",
"libavutil/motion_vector.h",
"libavutil/murmur3.h",
"libavutil/opt.h",
"libavutil/parseutils.h",
"libavutil/pixdesc.h",
"libavutil/pixfmt.h",
"libavutil/random_seed.h",
"libavutil/rational.h",
"libavutil/replaygain.h",
"libavutil/ripemd.h",
"libavutil/samplefmt.h",
"libavutil/sha.h",
"libavutil/sha512.h",
"libavutil/stereo3d.h",
"libavutil/threadmessage.h",
"libavutil/time.h",
"libavutil/timecode.h",
"libavutil/twofish.h",
"libavutil/xtea.h",
"libpostproc/postprocess.h",
"libswresample/swresample.h",
"libswscale/swscale.h",
]
});
static PATH: Lazy<String> = Lazy::new(|| env::var("PATH").unwrap());
static OUT_DIR: Lazy<String> = Lazy::new(|| env::var("OUT_DIR").unwrap());
static FFMPEG_DIR: Lazy<String> = Lazy::new(|| format!("{}/ffmpeg", env::var("OUT_DIR").unwrap()));
static BINDING_FILE_PATH: Lazy<String> =
Lazy::new(|| format!("{}/binding.rs", env::var("OUT_DIR").unwrap()));
static NUM_CPUS: Lazy<usize> = Lazy::new(ncpus::get);
/// Filter out all symbols in the HashSet, and for others things it will act
/// exactly the same as `CargoCallback`.
#[derive(Debug)]
struct FilterCargoCallbacks(CargoCallbacks, HashSet<String>);
impl callbacks::ParseCallbacks for FilterCargoCallbacks {
fn will_parse_macro(&self, _name: &str) -> callbacks::MacroParsingBehavior {
if self.1.contains(_name) {
callbacks::MacroParsingBehavior::Ignore
} else {
callbacks::MacroParsingBehavior::Default
}
}
fn include_file(&self, _filename: &str) {
self.0.include_file(_filename);
}
}
fn probe_system_ffmpeg() -> Result<(), String> {
match (&*LIBS)
.iter()
.map(|name| "lib".to_owned() + name)
.find(|libname| {
pkgconfig::Config::new()
.statik(true)
// Remove side effect
.cargo_metadata(false)
.probe(&libname)
.is_err()
}) {
Some(libname) => Err(format!("{} not found", libname)),
None => Ok(()),
}
}
fn main() {
println!("cargo:rerun-if-changed=build.rs");
println!("cargo:rerun-if-env-changed=DOCS_RS");
println!("cargo:rerun-if-env-changed=PKG_CONFIG_PATH");
// If it's a documentation generation from docs.rs, just copy the bindings
// generated locally to `OUT_DIR`. We do this because the building
// environment of docs.rs doesn't have an network connection, so we cannot
// git clone the FFmpeg. And they also have a limitation on crate's size:
// 10MB, which is not enough to fit in FFmpeg source files. So the only
// thing we can do is copying the locally generated binding files to the
// `OUT_DIR`.
if env::var("DOCS_RS").is_ok() {
fs::copy("src/binding.rs", &*BINDING_FILE_PATH)
.expect("Prebuilt binding file failed to be copied.");
return;
}
if env::var("PKG_CONFIG_PATH").is_err() {
// If no system FFmpeg found, download and build one
if let Err(msg) = probe_system_ffmpeg() {
eprintln!("{}! Try to git clone an FFmpeg and build.", msg);
// All outputs are stored in ./ffmpeg/build/{bin, lib, share, include}
// If no prebuilt FFmpeg libraries provided, we custom build a FFmpeg.
env::set_var(
"PKG_CONFIG_PATH",
format!("{}/build/lib/pkgconfig", *FFMPEG_DIR),
);
env::set_var("PATH", format!("{}/build/bin:{}", *FFMPEG_DIR, *PATH));
// Check if FFmpeg is not get cloned.
if !path::PathBuf::from(format!("{}/fftools", &*FFMPEG_DIR)).is_dir() {
Command::new("git")
.current_dir(&*OUT_DIR)
.args(["clone", "https://github.com/ffmpeg/ffmpeg", "--depth", "1"].iter())
.spawn()
.expect("FFmpeg submodule failed to clone.")
.wait()
.expect("FFmpeg submodule failed to clone.");
}
// Corresponding to the shell script below:
// ./configure \
// --prefix="$PWD/build" \
// --extra-cflags="-I$PWD/build/include" \
// --extra-ldflags="-L$PWD/build/lib" \
// --bindir="$PWD/build/bin" \
// --pkg-config-flags="--static" \
// --extra-libs="-lpthread -lm" \
// --enable-gpl \
// --enable-libass \
// --enable-libfdk-aac \
// --enable-libfreetype \
// --enable-libmp3lame \
// --enable-libopus \
// --enable-libvorbis \
// --enable-libvpx \
// --enable-libx264 \
// --enable-libx265 \
// --enable-nonfree
Command::new(format!("{}/configure", *FFMPEG_DIR))
.current_dir(&*FFMPEG_DIR)
.env(
"PKG_CONFIG_PATH",
format!("{}/build/lib/pkgconfig", *FFMPEG_DIR),
)
.args(
[
format!(r#"--prefix={}/build"#, *FFMPEG_DIR),
format!(r#"--extra-cflags=-I{}/build/include"#, *FFMPEG_DIR),
format!(r#"--extra-ldflags=-L{}/build/lib"#, *FFMPEG_DIR),
format!(r#"--bindir={}/build/bin"#, *FFMPEG_DIR),
]
.iter(),
)
.args(
[
"--pkg-config-flags=--static",
"--extra-libs=-lpthread -lm",
"--enable-gpl",
"--enable-libass",
"--enable-libfdk-aac",
"--enable-libfreetype",
"--enable-libmp3lame",
"--enable-libopus",
"--enable-libvorbis",
"--enable-libvpx",
"--enable-libx264",
"--enable-libx265",
"--enable-nonfree",
]
.iter(),
)
.spawn()
.expect("FFmpeg build process: configure failed!")
.wait()
.expect("FFmpeg build process: configure failed!");
Command::new("make")
.current_dir(&*FFMPEG_DIR)
.arg(format!("-j{}", *NUM_CPUS))
.spawn()
.expect("FFmpeg build process: make compile failed!")
.wait()
.expect("FFmpeg build process: make compile failed!");
Command::new("make")
.current_dir(&*FFMPEG_DIR)
.arg(format!("-j{}", *NUM_CPUS))
.arg("install")
.spawn()
.expect("FFmpeg build process: make install failed!")
.wait()
.expect("FFmpeg build process: make install failed!");
/* Commented because it's not needed, we are not using any specific shell.
Command::new("hash")
.current_dir(&*FFMPEG_DIR)
.arg("-r")
.spawn()
.expect("FFmpeg build process: clear hash cache failed!")
.wait()
.expect("FFmpeg build process: clear hash cache failed!");
*/
}
}
// We currently only support building with static libraries.
// Probe libraries
// TODO if not enabled, we should not probe it. Should modify probe_system_ffmpeg() too.
let include_paths = (&*LIBS)
.iter()
.map(|name| "lib".to_owned() + name)
.map(|libname| {
pkgconfig::Config::new()
.statik(true)
.cargo_metadata(true)
.probe(&libname)
.unwrap_or_else(|_| panic!(format!("{} not found!", libname)))
.include_paths
})
.fold(HashSet::new(), |mut acc, paths| {
paths.into_iter().for_each(|path| {
acc.insert(path);
});
acc
});
// Because the strange `FP_*` in `math.h` https://github.com/rust-lang/rust-bindgen/issues/687
let filter_callback = FilterCargoCallbacks(
CargoCallbacks,
vec![
"FP_NAN".to_owned(),
"FP_INFINITE".to_owned(),
"FP_ZERO".to_owned(),
"FP_SUBNORMAL".to_owned(),
"FP_NORMAL".to_owned(),
]
.into_iter()
.collect(),
);
// Bindgen the headers
(&*HEADERS)
.iter()
// map header short path to full path
.map(|header| {
include_paths
.iter()
.find_map(|path| {
let full_path = path.join(header);
fs::metadata(&full_path).ok().map(|_| full_path)
})
.unwrap()
})
.fold(
bindgen::builder()
// Add clang path, for `#include` header finding in bindgen process.
.clang_args(
include_paths
.iter()
.map(|path| "-I".to_owned() + path.to_str().unwrap()),
)
.parse_callbacks(Box::new(filter_callback)),
|builder, header| builder.header(header.to_str().unwrap()),
)
.generate()
.expect("Binding generation failed.")
// Is it correct to generate binding to one file? :-/
.write_to_file(&*BINDING_FILE_PATH)
.expect("Cannot write binding to file!")
}