M9.15: mpeg2v 1080i decode benchmark test

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/mpeg2v/tests/common/mod.rs

@@ -21,6 +21,15 @@ pub struct Spec {
     pub pix_fmt: &'static str,
 }
 
+/// 1080i 4:2:0 (decode benchmark; Main@High).
+pub const HD1080I: Spec = Spec {
+    name: "m2v_1080i",
+    lavfi: "testsrc2=size=1920x1080:rate=50,tinterlace=mode=interleave_top,setfield=tff",
+    frames: 25,
+    enc: &["-c:v", "mpeg2video", "-flags", "+ilme+ildct", "-bf", "2", "-g", "12", "-b:v", "25M", "-maxrate", "25M", "-bufsize", "9M"],
+    pix_fmt: "yuv420p",
+};
+
 pub fn path(spec: &Spec) -> PathBuf {
     fixture_dir().join(format!("{}.{}", spec.name, if spec.enc.contains(&"mpeg1video") { "m1v" } else { "m2v" }))
 }

crates/mpeg2v/tests/oracle.rs

@@ -136,15 +136,6 @@ const SPECS: &[Spec] = &[
     },
 ];
 
-/// 1080i 4:2:0 (decode benchmark; Main@High).
-pub const HD1080I: Spec = Spec {
-    name: "m2v_1080i",
-    lavfi: "testsrc2=size=1920x1080:rate=50,tinterlace=mode=interleave_top,setfield=tff",
-    frames: 25,
-    enc: &["-c:v", "mpeg2video", "-flags", "+ilme+ildct", "-bf", "2", "-g", "12", "-b:v", "25M", "-maxrate", "25M", "-bufsize", "9M"],
-    pix_fmt: "yuv420p",
-};
-
 /// Tolerance against ffmpeg (whose integer IDCT differs from our IEEE 1180-accurate one, and the
 /// difference propagates through prediction): per frame max |Δ| ≤ 4 and PSNR ≥ 58 dB; overall
 /// at most 3 % of samples differ at all.

crates/mpeg2v/tests/perf.rs

@@ -0,0 +1,37 @@
+//! Decode speed (ignored; run with `cargo test --release -p filmcraft-mpeg2v --test perf --
+//! --ignored --nocapture`). Uses the 1080i fixture of `tests/oracle.rs` (ffmpeg-encoded, 25 Mb/s).
+
+mod common;
+
+use common::*;
+
+#[test]
+#[ignore]
+fn perf_1080i_decode_fps() {
+    let ff = filmcraft_testkit::require_ffmpeg!();
+    let f = make(&ff, &HD1080I).expect("fixture");
+    let es = std::fs::read(&f).unwrap();
+    let aus = filmcraft_mpeg2v::access_units(&es);
+    for threads in [false, true] {
+        let mut best = f64::MAX;
+        let mut frames = 0;
+        for _ in 0..5 {
+            let mut d = filmcraft_mpeg2v::Decoder::new();
+            d.set_threads(threads);
+            let t0 = std::time::Instant::now();
+            let mut n = 0;
+            for (i, r) in aus.iter().enumerate() {
+                n += d.decode(&es[r.clone()], i as i64).unwrap().len();
+            }
+            n += d.flush().len();
+            best = best.min(t0.elapsed().as_secs_f64());
+            frames = n;
+        }
+        println!(
+            "1080i25 MPEG-2 (4:2:0, 25 Mb/s, IBBP): {frames} frames in {:.1} ms = {:.1} fps ({})",
+            best * 1e3,
+            frames as f64 / best,
+            if threads { "slice rows on rayon" } else { "single thread" }
+        );
+    }
+}