MP4: Add AtomReader::read_u24

Author: Serial-ATA

lofty/src/mp4/ilst/write.rs

@@ -767,7 +767,7 @@ fn write_data(flags: u32, data: &[u8], writer: &mut AtomWriterCompanion<'_>) ->
 	// Version
 	writer.write_u8(0)?;
 
-	writer.write_uint::<BigEndian>(u64::from(flags), 3)?;
+	writer.write_u24::<BigEndian>(u32::from(flags))?;
 
 	// Locale
 	writer.write_all(&[0; 4])?;

lofty/src/mp4/properties.rs

@@ -652,7 +652,7 @@ where
 					// 15 means the sample rate is stored in the next 24 bits
 					0x0F => {
 						let sample_rate;
-						let explicit_sample_rate = stsd.read_u24::<BigEndian>()?;
+						let explicit_sample_rate = stsd.read_u24()?;
 						if extended_object_type {
 							sample_rate = explicit_sample_rate >> 1;
 							channel_conf = ((explicit_sample_rate >> 4) & 0x0F) as u8;

lofty/src/mp4/read.rs

@@ -54,6 +54,11 @@ where
 		self.reader.read_u16::<BigEndian>()
 	}
 
+	pub(super) fn read_u24(&mut self) -> std::io::Result<u32> {
+		self.remaining_size = self.remaining_size.saturating_sub(3);
+		self.reader.read_u24::<BigEndian>()
+	}
+
 	pub(super) fn read_u32(&mut self) -> std::io::Result<u32> {
 		self.remaining_size = self.remaining_size.saturating_sub(4);
 		self.reader.read_u32::<BigEndian>()