Native H.264 decoding using FFMPEG over CLI/IPC

Cargo.lock

@@ -2399,6 +2399,15 @@ dependencies = [
  "simd-adler32",
 ]
 
+[[package]]
+name = "ffmpeg-sidecar"
+version = "1.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4bd1e249e0ceeb0f5c9f84a3c6941c3bde3ebc2815f4b94531a7e806af61c4c0"
+dependencies = [
+ "anyhow",
+]
+
 [[package]]
 name = "filetime"
 version = "0.2.23"
@@ -6183,6 +6192,7 @@ dependencies = [
  "criterion",
  "crossbeam",
  "econtext",
+ "ffmpeg-sidecar",
  "indicatif",
  "itertools 0.13.0",
  "parking_lot",

Cargo.toml

@@ -176,6 +176,7 @@ econtext = "0.2" # Prints error contexts on crashes
 ehttp = "0.5.0"
 enumset = "1.0.12"
 env_logger = { version = "0.10", default-features = false }
+ffmpeg-sidecar = "1.1.2"
 fixed = { version = "<1.28", default-features = false } # 1.28+ is MSRV 1.79+
 flatbuffers = "23.0"
 futures-channel = "0.3"

crates/store/re_video/Cargo.toml

@@ -23,11 +23,14 @@ features = ["all"]
 
 
 [features]
-default = ["av1"]
+default = ["av1", "ffmpeg"]
 
 ## Native AV1 decoding.
 av1 = ["dep:dav1d"]
 
+## Decode H.264 using ffmpeg over CLI.
+ffmpeg = ["dep:ffmpeg-sidecar"]
+
 ## Enable faster native video decoding with assembly.
 ## You need to install [nasm](https://nasm.us/) to compile with this feature.
 nasm = [
@@ -61,7 +64,11 @@ dav1d = { workspace = true, optional = true, default-features = false, features
   "bitdepth_8",
 ] }
 
+ffmpeg-sidecar = { workspace = true, optional = true }
+
+
 [dev-dependencies]
+# For the `frames` example:
 indicatif.workspace = true
 criterion.workspace = true
 

crates/store/re_video/examples/frames.rs

@@ -14,6 +14,8 @@ use indicatif::ProgressBar;
 use parking_lot::Mutex;
 
 fn main() {
+    re_log::setup_logging();
+
     // frames <video.mp4>
     let args: Vec<_> = std::env::args().collect();
     let Some(video_path) = args.get(1) else {
@@ -88,8 +90,18 @@ fn write_video_frames(
                 .create(true)
                 .truncate(true)
                 .open(output_dir.join(format!("{i:0width$}.ppm")))
-                .expect("failed to open file");
-            write_binary_ppm(&mut file, frame.width, frame.height, &frame.data);
+                .expect("failed to oformatpen file");
+            match frame.format {
+                re_video::PixelFormat::Rgb8Unorm => {
+                    write_ppm_rgb24(&mut file, frame.width, frame.height, &frame.data);
+                }
+                re_video::PixelFormat::Rgba8Unorm => {
+                    write_ppm_rgba32(&mut file, frame.width, frame.height, &frame.data);
+                }
+                re_video::PixelFormat::Yuv { .. } => {
+                    re_log::error_once!("YUV frame writing is not not supported");
+                }
+            }
         }
     }
 }
@@ -98,7 +110,24 @@ fn num_digits(n: usize) -> usize {
     (n as f64).log10().floor() as usize + 1
 }
 
-fn write_binary_ppm(file: &mut File, width: u32, height: u32, rgba: &[u8]) {
+fn write_ppm_rgb24(file: &mut File, width: u32, height: u32, rgb: &[u8]) {
+    assert_eq!(width as usize * height as usize * 3, rgb.len());
+
+    let header = format!("P6\n{width} {height}\n255\n");
+
+    let mut data = Vec::with_capacity(header.len() + width as usize * height as usize * 3);
+    data.extend_from_slice(header.as_bytes());
+
+    for rgb in rgb.chunks(3) {
+        data.extend_from_slice(&[rgb[0], rgb[1], rgb[2]]);
+    }
+
+    file.write_all(&data).expect("failed to write frame data");
+}
+
+fn write_ppm_rgba32(file: &mut File, width: u32, height: u32, rgba: &[u8]) {
+    assert_eq!(width as usize * height as usize * 4, rgba.len());
+
     let header = format!("P6\n{width} {height}\n255\n");
 
     let mut data = Vec::with_capacity(header.len() + width as usize * height as usize * 3);

crates/store/re_video/src/decode/async_decoder.rs

@@ -57,7 +57,7 @@ impl AsyncDecoder {
         let comms = Comms::default();
 
         let thread = std::thread::Builder::new()
-            .name("av1_decoder".into())
+            .name(format!("decoer thread for {debug_name}"))
             .spawn({
                 let comms = comms.clone();
                 move || {

crates/store/re_video/src/decode/av1.rs

@@ -232,7 +232,7 @@ fn output_picture(
         width: picture.width(),
         height: picture.height(),
         format,
-        timestamp: Time(picture.timestamp().unwrap_or(0)),
+        composition_timestamp: Time(picture.timestamp().unwrap_or(0)),
         duration: Time(picture.duration()),
     };
     on_output(Ok(frame));