Fix bug leading to empty chroma errors

.github/workflows/rust.yml

@@ -24,6 +24,8 @@ jobs:
         override: false
     - name: Packages
       run: sudo apt-get update && sudo apt-get install build-essential yasm libavutil-dev libavcodec-dev libavformat-dev libavfilter-dev libavfilter-dev libavdevice-dev libswresample-dev libfftw3-dev ffmpeg
+    - name: Check format
+      run: cargo fmt -- --check
     - name: Build
       run: cargo build --verbose
     - name: Run tests
@@ -36,8 +38,6 @@ jobs:
       run: cargo build --examples --verbose --features=serde
     - name: Lint
       run: cargo clippy --examples --features=serde -- -D warnings
-    - name: Check format
-      run: cargo fmt -- --check
 
   build-test-lint-windows:
     name: Windows - build, test and lint

CHANGELOG.md

@@ -1,6 +1,7 @@
 #Changelog
 
 ## bliss 0.5.0
+* Fix a bug in `estimate_tuning` that led to empty chroma errors.
 * Remove the unusued Library trait, and extract a few useful functions from
   there (`analyze_paths`, `closest_to_album_group`.
 * Rename `distance` module to `playlist`.

examples/playlist.rs

@@ -83,7 +83,7 @@ fn main() -> Result<()> {
     }
     analyzed_songs.extend_from_slice(&songs);
     let serialized = serde_json::to_string(&analyzed_songs).unwrap();
-    let mut songs_to_chose_from = analyzed_songs
+    let mut songs_to_chose_from: Vec<_> = analyzed_songs
         .into_iter()
         .filter(|x| x == &first_song || paths.contains(&x.path.to_string_lossy().to_string()))
         .collect();

src/chroma.rs

@@ -330,11 +330,14 @@ fn estimate_tuning(
         .map(|(x, y)| (n64(*x), n64(*y)))
         .unzip();
 
+    if pitch.is_empty() {
+        return Ok(0.);
+    }
+
     let threshold: N64 = Array::from(filtered_mag.to_vec())
         .quantile_axis_mut(Axis(0), n64(0.5), &Midpoint)
         .map_err(|e| BlissError::AnalysisError(format!("in chroma: {}", e)))?
         .into_scalar();
-
     let mut pitch = filtered_pitch
         .iter()
         .zip(&filtered_mag)
@@ -486,6 +489,11 @@ mod test {
         assert!(0.000001 > (-0.09999999999999998 - tuning).abs());
     }
 
+    #[test]
+    fn test_chroma_estimate_tuning_empty_fix() {
+        assert!(0. == estimate_tuning(22050, &Array2::zeros((8192, 1)), 8192, 0.01, 12).unwrap());
+    }
+
     #[test]
     fn test_estimate_tuning_decode() {
         let signal = Song::decode(Path::new("data/s16_mono_22_5kHz.flac"))

src/playlist.rs

@@ -39,11 +39,7 @@ pub fn cosine_distance(a: &Array1<f32>, b: &Array1<f32>) -> f32 {
 
 /// Sort `songs` in place by putting songs close to `first_song` first
 /// using the `distance` metric.
-pub fn closest_to_first_song(
-    first_song: &Song,
-    songs: &mut Vec<Song>,
-    distance: impl DistanceMetric,
-) {
+pub fn closest_to_first_song(first_song: &Song, songs: &mut [Song], distance: impl DistanceMetric) {
     songs.sort_by_cached_key(|song| n32(first_song.custom_distance(song, &distance)));
 }