bit-depth for ALAC and getter for wav

src/iff/wav/properties.rs

@@ -91,6 +91,11 @@ impl WavProperties {
 		self.sample_rate
 	}
 
+	/// Bits per sample
+	pub fn bit_depth(&self) -> u8 {
+		self.bit_depth
+	}
+
 	/// Channel count
 	pub fn channels(&self) -> u8 {
 		self.channels

src/mp4/properties.rs

@@ -32,6 +32,7 @@ pub struct Mp4Properties {
 	overall_bitrate: u32,
 	audio_bitrate: u32,
 	sample_rate: u32,
+	bit_depth: Option<u8>,
 	channels: u8,
 }
 
@@ -42,7 +43,7 @@ impl From<Mp4Properties> for FileProperties {
 			overall_bitrate: Some(input.overall_bitrate),
 			audio_bitrate: Some(input.audio_bitrate),
 			sample_rate: Some(input.sample_rate),
-			bit_depth: None,
+			bit_depth: input.bit_depth,
 			channels: Some(input.channels),
 		}
 	}
@@ -56,6 +57,7 @@ impl Mp4Properties {
 		overall_bitrate: u32,
 		audio_bitrate: u32,
 		sample_rate: u32,
+		bit_depth: Option<u8>,
 		channels: u8,
 	) -> Self {
 		Self {
@@ -64,6 +66,7 @@ impl Mp4Properties {
 			overall_bitrate,
 			audio_bitrate,
 			sample_rate,
+			bit_depth,
 			channels,
 		}
 	}
@@ -88,6 +91,11 @@ impl Mp4Properties {
 		self.sample_rate
 	}
 
+	/// Bits per sample
+	pub fn bit_depth(&self) -> Option<u8> {
+		self.bit_depth
+	}
+
 	/// Channel count
 	pub fn channels(&self) -> u8 {
 		self.channels
@@ -201,6 +209,7 @@ where
 		overall_bitrate: 0,
 		audio_bitrate: 0,
 		sample_rate: 0,
+		bit_depth: None,
 		channels: 0,
 	};
 
@@ -337,15 +346,20 @@ where
 		if alac.ident == AtomIdent::Fourcc(*b"alac") {
 			properties.codec = Mp4Codec::ALAC;
 
-			// Skipping 13 bytes
+			// Skipping 9 bytes
 			// Version (4)
 			// Samples per frame (4)
 			// Compatible version (1)
+			data.seek(SeekFrom::Current(9))?;
+
 			// Sample size (1)
+			properties.bit_depth = Some(data.read_u8()?);
+
+			// Skipping 3 bytes
 			// Rice history mult (1)
 			// Rice initial history (1)
 			// Rice parameter limit (1)
-			data.seek(SeekFrom::Current(13))?;
+			data.seek(SeekFrom::Current(3))?;
 
 			properties.channels = data.read_u8()?;
 

tests/properties.rs

@@ -46,6 +46,17 @@ const MP4_PROPERTIES: Mp4Properties = Mp4Properties::new(
 	135,
 	124,
 	48000,
+	None,
+	2,
+);
+
+const ALAC_PROPERTIES: Mp4Properties = Mp4Properties::new(
+	Mp4Codec::ALAC,
+	Duration::from_millis(1428),
+	331,
+	124,
+	48000,
+	Some(16),
 	2,
 );
 
@@ -126,6 +137,14 @@ fn mp4_properties() {
 	)
 }
 
+#[test]
+fn alac_properties() {
+	assert_eq!(
+		get_properties::<Mp4File>("tests/files/assets/b.m4a").bit_depth(),
+		ALAC_PROPERTIES.bit_depth()
+	)
+}
+
 #[test]
 fn opus_properties() {
 	assert_eq!(