Interpret Footage: looped footage lasts its loops on new and re-timed layers (fixes #1045)

crates/engine/src/commands/file_more.rs

@@ -771,9 +771,9 @@ fn interpret(s: &mut Session, p: &Value) -> Result<Value> {
     s.edit("Interpret Footage", None, |proj, _| {
         for (i, g) in items.iter().zip(&guesses) {
             let Some(ItemKind::Footage(f)) = proj.item_mut(*i).map(|x| &mut x.kind) else { continue };
-            let old = f.duration;
+            let old = f.looped_duration();
             it.apply(f, *g);
-            let new = f.duration;
+            let new = f.looped_duration();
             if new == old {
                 continue;
             }

crates/engine/src/commands/layer.rs

@@ -283,7 +283,7 @@ fn add_item(s: &mut Session, p: &Value) -> Result<Value> {
                 &serde_json::json!({"comp": cid.0, "item": item.0, "time": f_p(p, "time"), "index": p.get("index"), "position": p.get("position")}),
             );
         }
-        ItemKind::Footage(f) => (LayerSource::Footage { item }, (f.width, f.height), Some(f.duration)),
+        ItemKind::Footage(f) => (LayerSource::Footage { item }, (f.width, f.height), Some(f.looped_duration())),
         ItemKind::Solid(so) => (LayerSource::Solid { item }, (so.width, so.height), None),
         ItemKind::Folder => return Err(bad("layer.addItem", "folders can't be layers")),
     };
@@ -972,7 +972,7 @@ fn slip(s: &mut Session, p: &Value) -> Result<Value> {
         }
         let dur = match &l.source {
             LayerSource::Footage { item } => match s.project.item(*item).map(|i| &i.kind) {
-                Some(ItemKind::Footage(f)) if f.kind != effectcraft_project::FootageKind::Still => Some(Tick(f.duration.0 * f.loop_count.max(1) as i64)),
+                Some(ItemKind::Footage(f)) if f.kind != effectcraft_project::FootageKind::Still => Some(f.looped_duration()),
                 _ => None,
             },
             LayerSource::Comp { item } => s.project.comp(*item).map(|c| c.duration),

crates/engine/src/tests_menu_cmds.rs

@@ -1464,3 +1464,19 @@ fn interpret_footage_loop_from_form_float() {
         _ => panic!(),
     }
 }
+
+/// Looped video footage lasts its loops: a 2 s clip looped 3 times is a 6 s layer, and a layer
+/// that ran to the clip's end is re-timed when the loop count changes (#1045).
+#[test]
+fn interpret_footage_loop_extends_video_layers() {
+    let mut s = comp();
+    let p = s.execute("file.importPlaceholder", json!({"name": "Clip", "width": 320, "height": 240, "duration": 2})).unwrap()["item"].as_u64().unwrap();
+    let before = s.execute("layer.addItem", json!({"item": p})).unwrap()["layer"].as_u64().unwrap();
+    s.state.project_selection = vec![effectcraft_project::ItemId(p)];
+    s.execute("file.interpretFootage", json!({"loop": 3.0})).unwrap();
+    let after = s.execute("layer.addItem", json!({"item": p})).unwrap()["layer"].as_u64().unwrap();
+    let out = |s: &Session, l: u64| s.active_comp().unwrap().layer(effectcraft_project::LayerId(l)).unwrap().out_point.seconds();
+    assert_eq!(out(&s, after), 6.0, "a new layer plays every loop");
+    assert_eq!(out(&s, before), 6.0, "a layer that ran to the clip's end still does");
+    assert_eq!(s.project.item(effectcraft_project::ItemId(p)).unwrap().duration(), Some(Tick::from_seconds_f64(6.0)));
+}

crates/project/src/lib.rs

@@ -1158,6 +1158,11 @@ impl Footage {
         self.linear_light && !self.preserve_rgb
     }
 
+    /// How long the footage plays: its duration times Interpret Footage ▸ Loop.
+    pub fn looped_duration(&self) -> Tick {
+        Tick(self.duration.0.saturating_mul(self.loop_count.max(1) as i64))
+    }
+
     /// Source time as the footage's timecode: its frame `frame` from Start Timecode
     /// (`0:00:41:20`), as the Footage panel shows it.
     pub fn timecode(&self, frame: i64) -> String {
@@ -1281,7 +1286,7 @@ impl Item {
     pub fn duration(&self) -> Option<Tick> {
         match &self.kind {
             ItemKind::Comp(c) => Some(c.duration),
-            ItemKind::Footage(f) if f.kind != FootageKind::Still => Some(f.duration),
+            ItemKind::Footage(f) if f.kind != FootageKind::Still => Some(f.looped_duration()),
             _ => None,
         }
     }