WavPack: Stop overwriting custom sample rates

When a custom sample rate (or multiplier) was encountered, it would accidentally be overwritten with 0, causing incorrect duration and bitrate values.

This was due to us reading the metadata sub blocks first (when necessary) and then immediately overwriting the sample rate with the value from the block header (which is 0 in the presence of a custom sample rate).

Author: Serial-ATA

CHANGELOG.md

@@ -28,6 +28,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
     to encounter in the wild. Now we will just tag whichever tag happens to be latest in the stream and
     use it, they **will not be merged**.
 
+## Fixed
+- **WavPack**: Custom sample rates will no longer be overwritten
+  - When a custom sample rate (or multiplier) was encountered, it would accidentally be overwritten with 0, causing
+    incorrect duration and bitrate values.
+
 ## [0.15.0] - 2023-07-11
 
 ## Added

src/wavpack/properties.rs

@@ -131,22 +131,24 @@ where
 		let block_header;
 		match parse_wv_header(reader) {
 			Ok(header) => block_header = header,
+			Err(e) if parse_mode == ParsingMode::Strict => return Err(e),
 			_ => break,
 		}
 
 		let flags = block_header.flags;
 		let sample_rate_idx = ((flags >> 23) & 0xF) as usize;
+		properties.sample_rate = SAMPLE_RATES[sample_rate_idx];
 
 		// In the case of non-standard sample rates and DSD audio, we need to actually read the
 		// block to get the sample rate
-		if properties.sample_rate == 0 || flags & FLAG_DSD == FLAG_DSD {
+		if sample_rate_idx == 15 || flags & FLAG_DSD == FLAG_DSD {
 			let mut block_contents = try_vec![0; (block_header.block_size - 24) as usize];
 			if reader.read_exact(&mut block_contents).is_err() {
 				parse_mode_choice!(
-						parse_mode,
-						STRICT: decode_err!(@BAIL WavPack, "Block size mismatch"),
-						DEFAULT: break
-					);
+					parse_mode,
+					STRICT: decode_err!(@BAIL WavPack, "Block size mismatch"),
+					DEFAULT: break
+				);
 			}
 
 			if let Err(e) = get_extended_meta_info(parse_mode, &block_contents, &mut properties)
@@ -183,9 +185,6 @@ where
 			total_samples = block_header.total_samples;
 			properties.bit_depth = ((((flags & BYTES_PER_SAMPLE_MASK) + 1) * 8) - ((flags & BIT_DEPTH_SHIFT_MASK) >> BIT_DEPTH_SHL)) as u8;
 
-			let sample_rate = SAMPLE_RATES[sample_rate_idx];
-			properties.sample_rate = sample_rate;
-
 			properties.version = block_header.version;
 			properties.lossless = flags & FLAG_HYBRID_COMPRESSION == 0;
 
@@ -216,20 +215,22 @@ where
 		offset += u64::from(block_header.block_size + 8);
 	}
 
-	if total_samples > 0 && properties.sample_rate > 0 {
-		let length = f64::from(total_samples) * 1000. / f64::from(properties.sample_rate);
-		properties.duration = Duration::from_millis((length + 0.5) as u64);
-		properties.audio_bitrate = (stream_length as f64 * 8. / length + 0.5) as u32;
-
-		let file_length = reader.seek(SeekFrom::End(0))?;
-		properties.overall_bitrate = (file_length as f64 * 8. / length + 0.5) as u32;
-	} else {
-		parse_mode_choice!(
-			parse_mode,
-			STRICT: decode_err!(@BAIL WavPack, "Unable to calculate duration (sample count == 0 || sample rate == 0)"),
-		);
+	if total_samples == 0 || properties.sample_rate == 0 {
+		if parse_mode == ParsingMode::Strict {
+			decode_err!(@BAIL WavPack, "Unable to calculate duration (sample count == 0 || sample rate == 0)")
+		}
+
+		// We aren't able to determine the duration/bitrate, just early return
+		return Ok(properties);
 	}
 
+	let length = f64::from(total_samples) * 1000. / f64::from(properties.sample_rate);
+	properties.duration = Duration::from_millis((length + 0.5) as u64);
+	properties.audio_bitrate = (stream_length as f64 * 8. / length + 0.5) as u32;
+
+	let file_length = reader.seek(SeekFrom::End(0))?;
+	properties.overall_bitrate = (file_length as f64 * 8. / length + 0.5) as u32;
+
 	Ok(properties)
 }
 
@@ -245,7 +246,7 @@ struct WVHeader {
 	flags: u32,
 }
 
-// TODO: for now, all errors are just discarded
+// NOTE: Any error here is ignored unless using `ParsingMode::Strict`
 fn parse_wv_header<R>(reader: &mut R) -> Result<WVHeader>
 where
 	R: Read + Seek,