support duration extraction from WAV files

Cargo.toml

@@ -47,6 +47,7 @@ toml = "0.8"
 tree_magic_mini = { version = "3.0", features = [ "tree_magic_db" ] }
 update-informer = { version = "1.1.0", optional = true }
 wana_kana = "3.0"
+wavers = "1.1"
 zip = "0.6"
 
 [target.'cfg(unix)'.dependencies]

src/util/duration/mod.rs

@@ -3,6 +3,7 @@ use std::io;
 mod mkv;
 mod mp3;
 mod mp4;
+mod wav;
 
 use std::path::Path;
 
@@ -11,6 +12,7 @@ use mp3_metadata::MP3Metadata;
 use mkv::MkvDurationExtractor;
 use mp3::Mp3DurationExtractor;
 use mp4::Mp4DurationExtractor;
+use wav::WavDurationExtractor;
 
 #[derive(PartialEq, Eq, Clone, Debug)]
 pub struct Duration {
@@ -22,10 +24,11 @@ pub trait DurationExtractor {
     fn try_read_duration(&self, path: &Path, mp3_metadata: &Option<MP3Metadata>) -> io::Result<Option<Duration>>;
 }
 
-const EXTRACTORS: [&dyn DurationExtractor; 3] = [
+const EXTRACTORS: [&dyn DurationExtractor; 4] = [
     &Mp3DurationExtractor,
     &Mp4DurationExtractor,
     &MkvDurationExtractor,
+    &WavDurationExtractor,
 ];
 
 pub fn get_duration<T: AsRef<Path>>(path: T, mp3_metadata: &Option<MP3Metadata>) -> Option<Duration> {

src/util/duration/wav.rs

@@ -0,0 +1,47 @@
+use std::io;
+use std::path::Path;
+
+use mp3_metadata::MP3Metadata;
+
+use wavers::Wav;
+
+use crate::util::duration::DurationExtractor;
+use crate::util::Duration;
+
+pub struct WavDurationExtractor;
+
+impl DurationExtractor for WavDurationExtractor {
+    fn supports_ext(&self, ext_lowercase: &str) -> bool {
+        "wav" == ext_lowercase
+    }
+
+    fn try_read_duration(
+        &self,
+        path: &Path,
+        _: &Option<MP3Metadata>,
+    ) -> io::Result<Option<Duration>> {
+        let wav: Wav<i16> = Wav::from_path(path).map_err(|err| io::Error::new(io::ErrorKind::InvalidData, err))?;
+        Ok(Some(Duration { length: wav.duration() as usize }))
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use crate::util::duration::DurationExtractor;
+    use crate::util::Duration;
+    use std::error::Error;
+    use std::path::PathBuf;
+
+    #[test]
+    fn test_success() -> Result<(), Box<dyn Error>> {
+        let path_string =
+            std::env::var("CARGO_MANIFEST_DIR")? + "/resources/test/" + "audio/silent.wav";
+        let path = PathBuf::from(path_string);
+        assert_eq!(
+            WavDurationExtractor.try_read_duration(&path, &None)?,
+            Some(Duration { length: 15 }),
+        );
+        Ok(())
+    }
+}