#1417: WAV markers show on the audio layer

A WAV's markers were never read, so its audio layer showed none. The importer
now reads the file's cue points (`cue ` chunk named by `LIST/adtl` `labl` and
`note`, sized by `ltxt`) and Adobe's XMP markers (`_PMX` chunk, `xmpDM:markers`
entries as elements or attributes, in frames of the track's `xmpDM:frameRate`).
A marker present in both encodings is listed once. The reader is bounds-checked
and caps the marker count and XMP size.

- `Footage.markers` (optional in the file format) holds them at footage time; a
  layer made from the footage starts with them.
- Layer ▸ Markers ▸ Update Markers From Source also works on footage layers.
- Markers from a file have no label colour.

Tests: reader unit tests (cue, note, ltxt, both XMP forms, both encodings,
truncated and hostile files), a probe test, and an end-to-end test through the
fully wired session. Not checked against a WAV written by Adobe's tools.

Claude-Session: https://claude.ai/code/session_013fTnVxnXTv2MBW6uj2PPyU
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

Cargo.lock

@@ -1443,6 +1443,7 @@ name = "effectcraft-media"
 version = "0.12.0"
 dependencies = [
  "craft-docpath",
+ "effectcraft-color",
  "effectcraft-model",
  "effectcraft-pdf",
  "effectcraft-project",

crates/engine/src/commands/markers.rs

@@ -296,8 +296,9 @@ fn convert(s: &mut Session, p: &Value) -> Result<Value> {
     Ok(Value::Null)
 }
 
-/// Layer ▸ Markers ▸ Update Markers From Source: copy a precomp's composition markers onto the
-/// layer (layer time is the nested comp's time), skipping ones already there.
+/// Layer ▸ Markers ▸ Update Markers From Source: copy a precomp's composition markers, or the
+/// markers a footage file carries (a WAV's cue points), onto the layer (layer time is the source's
+/// time), skipping ones already there.
 fn update_from_source(s: &mut Session, p: &Value) -> Result<Value> {
     let (cid, ids) = layers_p(s, p)?;
     let src: Vec<(LayerId, Vec<Marker>)> = {
@@ -307,13 +308,17 @@ fn update_from_source(s: &mut Session, p: &Value) -> Result<Value> {
                 let l = comp.layer(*id)?;
                 match &l.source {
                     LayerSource::Comp { item } => Some((*id, s.project.comp(*item)?.markers.clone())),
+                    LayerSource::Footage { item } => match &s.project.item(*item)?.kind {
+                        effectcraft_project::ItemKind::Footage(f) => Some((*id, f.markers.clone())),
+                        _ => None,
+                    },
                     _ => None,
                 }
             })
             .collect()
     };
     if src.is_empty() {
-        return Err(bad("layer.updateMarkersFromSource", "select a precomposition layer"));
+        return Err(bad("layer.updateMarkersFromSource", "select a precomposition or footage layer"));
     }
     let n = s.edit("Update Markers From Source", None, |proj, _| {
         let c = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
@@ -339,10 +344,10 @@ fn update_from_source(s: &mut Session, p: &Value) -> Result<Value> {
 fn has_precomp_layer(s: &Session) -> std::result::Result<(), String> {
     has_layers(s)?;
     let c = s.active_comp().ok_or("no composition")?;
-    if s.state.selected_layers.iter().filter_map(|l| c.layer(*l)).any(|l| matches!(l.source, LayerSource::Comp { .. })) {
+    if s.state.selected_layers.iter().filter_map(|l| c.layer(*l)).any(|l| matches!(l.source, LayerSource::Comp { .. } | LayerSource::Footage { .. })) {
         Ok(())
     } else {
-        Err("select a precomposition layer".into())
+        Err("select a precomposition or footage layer".into())
     }
 }
 

crates/host/tests/wav_markers.rs

@@ -0,0 +1,75 @@
+//! Markers a WAV file carries, through the fully wired session (media import included): the
+//! layer made from the file starts with them, and Update Markers From Source copies them again.
+
+use effectcraft_project::LayerSource;
+use serde_json::json;
+
+/// A one-second mono 8 kHz WAV with two named cue points (a `cue ` chunk and a `LIST` `adtl`).
+fn marker_wav() -> Vec<u8> {
+    fn chunk(id: &[u8; 4], body: &[u8]) -> Vec<u8> {
+        let mut v = id.to_vec();
+        v.extend((body.len() as u32).to_le_bytes());
+        v.extend(body);
+        if body.len() % 2 == 1 {
+            v.push(0);
+        }
+        v
+    }
+    let mut fmt = Vec::new();
+    fmt.extend(1u16.to_le_bytes());
+    fmt.extend(1u16.to_le_bytes());
+    fmt.extend(8000u32.to_le_bytes());
+    fmt.extend(16000u32.to_le_bytes());
+    fmt.extend(2u16.to_le_bytes());
+    fmt.extend(16u16.to_le_bytes());
+    let points = [(1u32, 0u32, "Intro"), (2, 4000, "Middle")];
+    let mut cue = (points.len() as u32).to_le_bytes().to_vec();
+    let mut adtl = b"adtl".to_vec();
+    for (id, at, name) in points {
+        for v in [id, 0] {
+            cue.extend(v.to_le_bytes());
+        }
+        cue.extend(b"data");
+        for v in [0, 0, at] {
+            cue.extend(u32::to_le_bytes(v));
+        }
+        let mut labl = id.to_le_bytes().to_vec();
+        labl.extend(name.as_bytes());
+        labl.push(0);
+        adtl.extend(chunk(b"labl", &labl));
+    }
+    let mut body = b"WAVE".to_vec();
+    for c in [chunk(b"fmt ", &fmt), chunk(b"data", &[0; 16000]), chunk(b"cue ", &cue), chunk(b"LIST", &adtl)] {
+        body.extend(c);
+    }
+    let mut file = b"RIFF".to_vec();
+    file.extend((body.len() as u32).to_le_bytes());
+    file.extend(body);
+    file
+}
+
+/// A WAV's cue points become markers on the layer made from it, named as in the file, and
+/// Update Markers From Source brings back one that was deleted (through the fully wired session,
+/// media import included).
+#[test]
+fn a_wav_layer_starts_with_the_markers_in_its_file() {
+    let mut s = effectcraft_host::session();
+    s.execute_checked("comp.new", json!({"name": "C", "width": 64, "height": 48, "frameRate": 30, "duration": 2})).unwrap();
+    let dir = std::env::temp_dir().join(format!("effectcraft-host-wav-markers-{}", std::process::id()));
+    std::fs::create_dir_all(&dir).unwrap();
+    let path = dir.join("cues.wav");
+    std::fs::write(&path, marker_wav()).unwrap();
+    let r = s.execute_checked("file.import", json!({"paths": [path.to_string_lossy()], "addToComp": true})).unwrap();
+    assert_eq!(r["errors"], json!([]), "{r}");
+    let layer = s.active_comp().unwrap().layers.iter().find(|l| matches!(l.source, LayerSource::Footage { .. })).unwrap().id.0;
+    let list = s.execute_checked("markers.list", json!({"layer": layer})).unwrap();
+    let marks: Vec<(String, f64)> =
+        list.as_array().unwrap().iter().map(|m| (m["comment"].as_str().unwrap().to_string(), m["time"].as_f64().unwrap())).collect();
+    assert_eq!(marks, [("Intro".to_string(), 0.0), ("Middle".to_string(), 0.5)]);
+    s.execute_checked("markers.delete", json!({"layer": layer, "index": 0})).unwrap();
+    s.execute_checked("layer.select", json!({"layers": [layer]})).unwrap();
+    assert_eq!(s.execute_checked("layer.updateMarkersFromSource", json!({})).unwrap()["added"], 1);
+    let list = s.execute_checked("markers.list", json!({"layer": layer})).unwrap();
+    assert_eq!(list.as_array().unwrap().len(), 2);
+    let _ = std::fs::remove_dir_all(&dir);
+}

crates/media/Cargo.toml

@@ -12,6 +12,7 @@ workspace = true
 [dependencies]
 craft-docpath = { workspace = true }
 effectcraft-time = { workspace = true }
+effectcraft-color = { workspace = true }
 effectcraft-project = { workspace = true }
 effectcraft-raster = { workspace = true }
 effectcraft-render = { workspace = true }

crates/media/src/lib.rs

@@ -25,6 +25,7 @@ pub use layered::vector_doc;
 mod pool;
 mod probe;
 mod stream;
+mod wav_markers;
 mod webp_anim;
 
 pub use pool::{DEFAULT_BUDGET, MediaPool, PoolStats};

crates/media/src/probe.rs

@@ -98,8 +98,11 @@ pub fn probe_bytes(path: &str, bytes: Arc<[u8]>) -> Result<Footage> {
     let name = Path::new(path).file_name().map(|n| n.to_string_lossy().to_string()).unwrap_or_else(|| path.to_string());
     let turn = video_turn(&bytes);
     let rate = video_rate(&bytes);
+    // A WAV's cue points and XMP markers become the footage's markers.
+    let markers = crate::wav_markers::read(&bytes);
     let src = filmcraft_codecs::open_bytes(&name, bytes)?;
     let mut f = footage_from_info(path, src.info());
+    f.markers = markers;
     turn_footage(&mut f, turn);
     correct_rate(&mut f, rate);
     Ok(f)

crates/media/src/wav_markers.rs

@@ -0,0 +1,350 @@
+//! Markers a WAV file carries, read from its RIFF chunks.
+//!
+//! Two encodings are read and merged:
+//! - **Cue points** (the standard): a `cue ` chunk with one point per marker, named by `labl` (or
+//!   `note`) sub-chunks of a `LIST` `adtl` chunk, and given a length by `ltxt`.
+//! - **XMP** (Adobe's tools): an `_PMX` chunk holding an XMP packet whose `xmpDM:markers` list has
+//!   one entry per marker (`xmpDM:startTime`, `xmpDM:duration`, `xmpDM:name`), counted in frames
+//!   of `xmpDM:frameRate` (`f44100` for samples at 44.1 kHz).
+//!
+//! The file is untrusted input: every read is bounds-checked, sizes use checked arithmetic, and
+//! the number of markers and the size of the XMP packet are capped.
+
+use effectcraft_color::Label;
+use effectcraft_project::Marker;
+use effectcraft_time::Tick;
+
+/// Most markers read from one file.
+pub const MAX_MARKERS: usize = 10_000;
+/// Largest XMP packet read (bytes).
+const MAX_XMP: usize = 4 << 20;
+
+fn u32_at(b: &[u8], at: usize) -> Option<u32> {
+    let s = b.get(at..at.checked_add(4)?)?;
+    Some(u32::from_le_bytes(s.try_into().ok()?))
+}
+
+/// The text of a NUL-terminated label (the rest of the chunk), lossily decoded.
+fn label(b: &[u8]) -> String {
+    let end = b.iter().position(|&c| c == 0).unwrap_or(b.len());
+    String::from_utf8_lossy(b.get(..end).unwrap_or_default()).trim().to_string()
+}
+
+fn secs(frames: f64, rate: f64) -> Tick {
+    if rate > 0.0 && frames.is_finite() { Tick::from_seconds_f64((frames / rate).max(0.0)) } else { Tick::ZERO }
+}
+
+/// Whether `bytes` start a RIFF/WAVE file.
+pub fn is_wav(bytes: &[u8]) -> bool {
+    matches!(bytes.get(0..4), Some(b"RIFF" | b"RF64")) && bytes.get(8..12) == Some(b"WAVE")
+}
+
+/// The chunks of a WAVE file as `(id, body)`, stopping at the first one that doesn't fit.
+fn chunks(bytes: &[u8]) -> Vec<([u8; 4], &[u8])> {
+    let mut out = Vec::new();
+    let mut at = 12usize;
+    while let Some(head) = bytes.get(at..at.saturating_add(8)) {
+        let (Ok(id), Some(size)) = (<[u8; 4]>::try_from(&head[..4]), u32_at(head, 4)) else { break };
+        let start = at.saturating_add(8);
+        let Some(end) = start.checked_add(size as usize) else { break };
+        let Some(body) = bytes.get(start..end) else { break };
+        out.push((id, body));
+        // Chunks are padded to an even size.
+        at = end.saturating_add(end & 1);
+    }
+    out
+}
+
+/// The markers `bytes` carry, in time order (empty for anything that isn't a WAV with markers).
+pub fn read(bytes: &[u8]) -> Vec<Marker> {
+    if !is_wav(bytes) {
+        return Vec::new();
+    }
+    let chunks = chunks(bytes);
+    let rate = chunks.iter().find(|(id, _)| id == b"fmt ").and_then(|(_, b)| u32_at(b, 4)).map_or(0.0, f64::from);
+    let mut out = cue_markers(&chunks, rate);
+    if let Some((_, xmp)) = chunks.iter().find(|(id, _)| id == b"_PMX") {
+        for m in xmp_markers(xmp, rate) {
+            // Tools that write both encodings repeat each marker.
+            if !out.iter().any(|o| o.comment == m.comment && o.time == m.time) {
+                out.push(m);
+            }
+        }
+    }
+    out.truncate(MAX_MARKERS);
+    out.sort_by_key(|m| m.time);
+    out
+}
+
+/// Cue points named and sized by the `adtl` list.
+fn cue_markers(chunks: &[([u8; 4], &[u8])], rate: f64) -> Vec<Marker> {
+    let Some((_, cue)) = chunks.iter().find(|(id, _)| id == b"cue ") else { return Vec::new() };
+    let count = (u32_at(cue, 0).unwrap_or(0) as usize).min(MAX_MARKERS);
+    // Cue id -> (name, length in samples).
+    let mut names: Vec<(u32, String)> = Vec::new();
+    let mut lengths: Vec<(u32, u32)> = Vec::new();
+    for (_, list) in chunks.iter().filter(|(id, b)| id == b"LIST" && b.get(0..4) == Some(b"adtl")) {
+        let mut at = 4usize;
+        while let Some(head) = list.get(at..at.saturating_add(8)) {
+            let (Ok(id), Some(size)) = (<[u8; 4]>::try_from(&head[..4]), u32_at(head, 4)) else { break };
+            let start = at.saturating_add(8);
+            let Some(end) = start.checked_add(size as usize) else { break };
+            let Some(body) = list.get(start..end) else { break };
+            if let Some(cue_id) = u32_at(body, 0) {
+                match &id {
+                    b"labl" | b"note" => {
+                        let text = label(body.get(4..).unwrap_or_default());
+                        // A `labl` is the name; a `note` only when there is none.
+                        let known = names.iter().any(|(c, _)| *c == cue_id);
+                        if &id == b"labl" || !known {
+                            names.retain(|(c, _)| *c != cue_id);
+                            names.push((cue_id, text));
+                        }
+                    }
+                    b"ltxt" => lengths.push((cue_id, u32_at(body, 4).unwrap_or(0))),
+                    _ => {}
+                }
+            }
+            at = end.saturating_add(end & 1);
+        }
+    }
+    let mut out = Vec::new();
+    for i in 0..count {
+        let Some(point) = cue.get(4usize.saturating_add(i.saturating_mul(24))..) else { break };
+        let (Some(id), Some(offset)) = (u32_at(point, 0), u32_at(point, 20)) else { break };
+        let comment = names.iter().find(|(c, _)| *c == id).map(|(_, t)| t.clone()).unwrap_or_default();
+        let length = lengths.iter().find(|(c, _)| *c == id).map_or(0, |(_, l)| *l);
+        out.push(Marker { time: secs(f64::from(offset), rate), duration: secs(f64::from(length), rate), comment, label: Label::None, ..Default::default() });
+    }
+    out
+}
+
+/// The text of `name` in an XMP entry, as an attribute (`name="v"`) or an element
+/// (`<name>v</name>`).
+fn xmp_value(entry: &str, name: &str) -> Option<String> {
+    let attr = format!("{name}=\"");
+    if let Some(i) = entry.find(&attr) {
+        let rest = entry.get(i + attr.len()..)?;
+        return Some(unescape(rest.get(..rest.find('"')?)?));
+    }
+    let open = format!("<{name}>");
+    let i = entry.find(&open)?;
+    let rest = entry.get(i + open.len()..)?;
+    Some(unescape(rest.get(..rest.find('<')?)?))
+}
+
+fn unescape(s: &str) -> String {
+    let mut out = String::with_capacity(s.len());
+    let mut rest = s;
+    while let Some(i) = rest.find('&') {
+        out.push_str(rest.get(..i).unwrap_or_default());
+        let tail = rest.get(i..).unwrap_or_default();
+        let Some(semi) = tail.find(';').filter(|&n| n <= 10) else {
+            out.push('&');
+            rest = tail.get(1..).unwrap_or_default();
+            continue;
+        };
+        let ent = tail.get(1..semi).unwrap_or_default();
+        match ent {
+            "amp" => out.push('&'),
+            "lt" => out.push('<'),
+            "gt" => out.push('>'),
+            "quot" => out.push('"'),
+            "apos" => out.push('\''),
+            _ => {
+                let code = ent.strip_prefix("#x").and_then(|h| u32::from_str_radix(h, 16).ok()).or_else(|| ent.strip_prefix('#').and_then(|d| d.parse().ok()));
+                match code.and_then(char::from_u32) {
+                    Some(c) => out.push(c),
+                    None => out.push_str(tail.get(..=semi).unwrap_or_default()),
+                }
+            }
+        }
+        rest = tail.get(semi + 1..).unwrap_or_default();
+    }
+    out.push_str(rest);
+    out.trim().to_string()
+}
+
+/// A frame rate as XMP writes it: `f44100`, or `f30000s1001` (rate over scale).
+fn xmp_rate(text: &str) -> Option<f64> {
+    let t = text.trim().strip_prefix('f')?;
+    let (num, den) = t.split_once('s').unwrap_or((t, "1"));
+    let (n, d): (f64, f64) = (num.parse().ok()?, den.parse().ok()?);
+    (n > 0.0 && d > 0.0).then_some(n / d)
+}
+
+/// The markers of an XMP packet's `xmpDM:markers` entries.
+fn xmp_markers(packet: &[u8], file_rate: f64) -> Vec<Marker> {
+    let text = String::from_utf8_lossy(packet.get(..packet.len().min(MAX_XMP)).unwrap_or_default());
+    let mut out = Vec::new();
+    // The frame rate belongs to the track an entry follows.
+    let mut rate = file_rate;
+    for entry in text.split("<rdf:li").skip(1) {
+        if let Some(r) = xmp_value(entry, "xmpDM:frameRate").as_deref().and_then(xmp_rate) {
+            rate = r;
+        }
+        let Some(start) = xmp_value(entry, "xmpDM:startTime").and_then(|v| v.trim().parse::<f64>().ok()) else { continue };
+        let length = xmp_value(entry, "xmpDM:duration").and_then(|v| v.trim().parse::<f64>().ok()).unwrap_or(0.0);
+        let comment = xmp_value(entry, "xmpDM:name").unwrap_or_default();
+        out.push(Marker { time: secs(start, rate), duration: secs(length, rate), comment, label: Label::None, ..Default::default() });
+        if out.len() >= MAX_MARKERS {
+            break;
+        }
+    }
+    out
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn chunk(id: &[u8; 4], body: &[u8]) -> Vec<u8> {
+        let mut v = id.to_vec();
+        v.extend((body.len() as u32).to_le_bytes());
+        v.extend(body);
+        if body.len() % 2 == 1 {
+            v.push(0);
+        }
+        v
+    }
+
+    fn fmt(rate: u32) -> Vec<u8> {
+        let mut b = Vec::new();
+        b.extend(1u16.to_le_bytes()); // PCM
+        b.extend(1u16.to_le_bytes()); // mono
+        b.extend(rate.to_le_bytes());
+        b.extend((rate * 2).to_le_bytes());
+        b.extend(2u16.to_le_bytes());
+        b.extend(16u16.to_le_bytes());
+        chunk(b"fmt ", &b)
+    }
+
+    fn wav(chunks: &[Vec<u8>]) -> Vec<u8> {
+        let body: Vec<u8> = chunks.iter().flatten().copied().collect();
+        let mut v = b"RIFF".to_vec();
+        v.extend((body.len() as u32 + 4).to_le_bytes());
+        v.extend(b"WAVE");
+        v.extend(body);
+        v
+    }
+
+    fn cue(points: &[(u32, u32)]) -> Vec<u8> {
+        let mut b = (points.len() as u32).to_le_bytes().to_vec();
+        for (id, offset) in points {
+            b.extend(id.to_le_bytes());
+            b.extend(0u32.to_le_bytes());
+            b.extend(b"data");
+            b.extend(0u32.to_le_bytes());
+            b.extend(0u32.to_le_bytes());
+            b.extend(offset.to_le_bytes());
+        }
+        chunk(b"cue ", &b)
+    }
+
+    fn labl(id: &[u8; 4], cue_id: u32, text: &str) -> Vec<u8> {
+        let mut b = cue_id.to_le_bytes().to_vec();
+        b.extend(text.as_bytes());
+        b.push(0);
+        chunk(id, &b)
+    }
+
+    fn adtl(subs: &[Vec<u8>]) -> Vec<u8> {
+        let mut b = b"adtl".to_vec();
+        b.extend(subs.iter().flatten());
+        chunk(b"LIST", &b)
+    }
+
+    #[test]
+    fn cue_points_are_named_by_the_adtl_list_and_timed_in_samples() {
+        let file = wav(&[
+            fmt(44100),
+            chunk(b"data", &[0; 8]),
+            cue(&[(2, 88200), (1, 22050)]),
+            adtl(&[labl(b"labl", 1, "SEQ01_Prologue"), labl(b"labl", 2, "SEQ02_Vallee_P1_Agriculture")]),
+        ]);
+        let m = read(&file);
+        assert_eq!(m.len(), 2);
+        assert_eq!((m[0].comment.as_str(), m[0].time), ("SEQ01_Prologue", Tick::from_seconds_f64(0.5)));
+        assert_eq!((m[1].comment.as_str(), m[1].time), ("SEQ02_Vallee_P1_Agriculture", Tick::from_seconds_f64(2.0)));
+    }
+
+    #[test]
+    fn a_note_names_a_cue_only_when_it_has_no_label_and_ltxt_gives_a_length() {
+        let mut ltxt = 1u32.to_le_bytes().to_vec();
+        ltxt.extend(44100u32.to_le_bytes());
+        ltxt.extend([0; 16]);
+        let file = wav(&[
+            fmt(44100),
+            cue(&[(1, 0), (2, 44100)]),
+            adtl(&[labl(b"note", 1, "from note"), chunk(b"ltxt", &ltxt), labl(b"labl", 2, "named"), labl(b"note", 2, "ignored")]),
+        ]);
+        let m = read(&file);
+        assert_eq!((m[0].comment.as_str(), m[0].duration), ("from note", Tick::from_seconds_f64(1.0)));
+        assert_eq!(m[1].comment, "named");
+    }
+
+    const XMP_ELEMENTS: &str = r#"<x:xmpmeta><rdf:RDF><rdf:Description><xmpDM:Tracks><rdf:Bag><rdf:li rdf:parseType="Resource"><xmpDM:trackName>Markers</xmpDM:trackName><xmpDM:trackType>Cue</xmpDM:trackType><xmpDM:frameRate>f44100</xmpDM:frameRate><xmpDM:markers><rdf:Seq><rdf:li rdf:parseType="Resource"><xmpDM:startTime>44100</xmpDM:startTime><xmpDM:duration>0</xmpDM:duration><xmpDM:name>One &amp; Two</xmpDM:name></rdf:li><rdf:li rdf:parseType="Resource"><xmpDM:startTime>132300</xmpDM:startTime><xmpDM:duration>22050</xmpDM:duration><xmpDM:name>Three</xmpDM:name></rdf:li></rdf:Seq></xmpDM:markers></rdf:li></rdf:Bag></xmpDM:Tracks></rdf:Description></rdf:RDF></x:xmpmeta>"#;
+
+    #[test]
+    fn xmp_markers_are_read_as_elements_in_frames_of_the_track_rate() {
+        let file = wav(&[fmt(48000), chunk(b"_PMX", XMP_ELEMENTS.as_bytes())]);
+        let m = read(&file);
+        assert_eq!(m.len(), 2);
+        // 44100 frames at f44100 is one second, whatever the file's own rate.
+        assert_eq!((m[0].comment.as_str(), m[0].time), ("One & Two", Tick::from_seconds_f64(1.0)));
+        assert_eq!((m[1].comment.as_str(), m[1].time, m[1].duration), ("Three", Tick::from_seconds_f64(3.0), Tick::from_seconds_f64(0.5)));
+    }
+
+    #[test]
+    fn xmp_markers_are_read_as_attributes_and_use_the_file_rate_without_a_track_rate() {
+        let xmp = r#"<rdf:Seq><rdf:li xmpDM:startTime="24000" xmpDM:duration="0" xmpDM:name="Attr &#233;"/></rdf:Seq>"#;
+        let m = read(&wav(&[fmt(48000), chunk(b"_PMX", xmp.as_bytes())]));
+        assert_eq!((m[0].comment.as_str(), m[0].time), ("Attr é", Tick::from_seconds_f64(0.5)));
+    }
+
+    #[test]
+    fn a_marker_in_both_encodings_is_listed_once() {
+        let xmp = r#"<rdf:li xmpDM:startTime="44100" xmpDM:name="Same"/><rdf:li xmpDM:startTime="88200" xmpDM:name="Only XMP"/>"#;
+        let file = wav(&[fmt(44100), cue(&[(1, 44100)]), adtl(&[labl(b"labl", 1, "Same")]), chunk(b"_PMX", xmp.as_bytes())]);
+        let names: Vec<String> = read(&file).into_iter().map(|m| m.comment).collect();
+        assert_eq!(names, ["Same", "Only XMP"]);
+    }
+
+    #[test]
+    fn importing_a_wav_puts_its_markers_on_the_footage() {
+        let file = wav(&[
+            fmt(44100),
+            chunk(b"data", &[0; 4 * 44100]),
+            cue(&[(1, 0), (2, 44100)]),
+            adtl(&[labl(b"labl", 1, "SEQ01_Prologue"), labl(b"labl", 2, "SEQ02_Vallee_P1_Agriculture")]),
+        ]);
+        let f = crate::probe::probe_bytes("markers.wav", file.into()).expect("probe");
+        assert!(f.has_audio);
+        let names: Vec<&str> = f.markers.iter().map(|m| m.comment.as_str()).collect();
+        assert_eq!(names, ["SEQ01_Prologue", "SEQ02_Vallee_P1_Agriculture"]);
+        assert_eq!(f.markers[1].time, Tick::from_seconds_f64(1.0));
+    }
+
+    #[test]
+    fn damaged_or_hostile_files_read_as_far_as_they_go_without_panicking() {
+        assert!(read(b"").is_empty());
+        assert!(read(b"RIFF").is_empty());
+        assert!(read(b"not a wav file at all").is_empty());
+        let good = wav(&[fmt(44100), cue(&[(1, 44100)]), adtl(&[labl(b"labl", 1, "Kept")])]);
+        // Every truncation is safe.
+        for n in 0..good.len() {
+            let _ = read(&good[..n]);
+        }
+        // A cue count far beyond the chunk, and chunk sizes past the end of the file.
+        let mut huge = 0xFFFF_FFFFu32.to_le_bytes().to_vec();
+        huge.extend([0; 24]);
+        let m = read(&wav(&[fmt(44100), chunk(b"cue ", &huge)]));
+        assert!(m.len() <= 1);
+        let mut lying = good.clone();
+        lying.extend(b"LIST\xff\xff\xff\xffadtl");
+        assert_eq!(read(&lying).len(), 1);
+        // No sample rate: times are zero, not a division by zero.
+        let m = read(&wav(&[cue(&[(1, 44100)])]));
+        assert_eq!(m[0].time, Tick::ZERO);
+    }
+}

crates/project/src/build.rs

@@ -854,6 +854,14 @@ pub fn layer(project: &mut Project, comp: &Comp, name: &str, source: LayerSource
             _ => {}
         }
     }
+    // A footage layer starts with the markers its file carries (layer time is footage time).
+    let footage_markers = match &source {
+        LayerSource::Footage { item } => match project.item(*item).map(|i| &i.kind) {
+            Some(crate::ItemKind::Footage(f)) => f.markers.clone(),
+            _ => vec![],
+        },
+        _ => vec![],
+    };
     let has_audio = matches!(&source, LayerSource::Footage { item } if matches!(project.item(*item).map(|i| &i.kind), Some(crate::ItemKind::Footage(f)) if f.has_audio))
         || matches!(source, LayerSource::Comp { .. });
     if has_audio {
@@ -883,7 +891,7 @@ pub fn layer(project: &mut Project, comp: &Comp, name: &str, source: LayerSource
         preserve_transparency: false,
         track_matte: None,
         parent: None,
-        markers: vec![],
+        markers: footage_markers,
         markers_locked: false,
         environment: false,
         environment_background: false,

crates/project/src/lib.rs

@@ -1172,6 +1172,10 @@ pub struct Footage {
     /// timecode isn't read). It only relabels source time, as in After Effects.
     #[serde(default, skip_serializing_if = "Option::is_none")]
     pub start_timecode: Option<i64>,
+    /// Markers the file carries (a WAV's cue points and XMP markers), at footage time. A layer
+    /// made from the footage starts with them, and Update Markers From Source copies new ones.
+    #[serde(default, skip_serializing_if = "Vec::is_empty")]
+    pub markers: Vec<Marker>,
 }
 
 fn is_default<T: Default + PartialEq>(v: &T) -> bool {
@@ -1207,6 +1211,7 @@ impl Default for Footage {
             page: 0,
             alphabetical: false,
             start_timecode: None,
+            markers: vec![],
         }
     }
 }