Validate WAV audio metadata

scripts/verify-audio-asset-data.mjs

@@ -195,6 +195,28 @@ function validateAudioFile(errors, context, path) {
   if (path.toLowerCase().endsWith('.wav')) {
     if (bytes.subarray(0, 4).toString('ascii') !== 'RIFF' || bytes.subarray(8, 12).toString('ascii') !== 'WAVE') {
       errors.push(`${context} at "${path}" does not have a WAV header`);
+      return;
+    }
+
+    const metadata = readWavMetadata(bytes);
+    if (!metadata) {
+      errors.push(`${context} at "${path}" is missing readable WAV fmt/data chunks`);
+      return;
+    }
+    if (metadata.audioFormat !== 1) {
+      errors.push(`${context} at "${path}" should be PCM WAV audio, got format ${metadata.audioFormat}`);
+    }
+    if (metadata.channels < 1 || metadata.channels > 2) {
+      errors.push(`${context} at "${path}" should be mono or stereo WAV audio, got ${metadata.channels} channels`);
+    }
+    if (metadata.sampleRate < 22050) {
+      errors.push(`${context} at "${path}" should use at least 22050 Hz WAV audio, got ${metadata.sampleRate} Hz`);
+    }
+    if (![16, 24, 32].includes(metadata.bitsPerSample)) {
+      errors.push(`${context} at "${path}" should use 16/24/32-bit WAV audio, got ${metadata.bitsPerSample}-bit`);
+    }
+    if (metadata.dataSize <= 0) {
+      errors.push(`${context} at "${path}" does not contain WAV sample data`);
     }
     return;
   }
@@ -211,6 +233,39 @@ function validateAudioFile(errors, context, path) {
   errors.push(`${context} at "${path}" uses an unsupported audio extension`);
 }
 
+function readWavMetadata(bytes) {
+  let offset = 12;
+  let format;
+  let dataSize = 0;
+
+  while (offset + 8 <= bytes.length) {
+    const chunkType = bytes.subarray(offset, offset + 4).toString('ascii');
+    const chunkSize = bytes.readUInt32LE(offset + 4);
+    const dataOffset = offset + 8;
+    if (dataOffset + chunkSize > bytes.length) {
+      return undefined;
+    }
+
+    if (chunkType === 'fmt ' && chunkSize >= 16) {
+      format = {
+        audioFormat: bytes.readUInt16LE(dataOffset),
+        channels: bytes.readUInt16LE(dataOffset + 2),
+        sampleRate: bytes.readUInt32LE(dataOffset + 4),
+        bitsPerSample: bytes.readUInt16LE(dataOffset + 14)
+      };
+    } else if (chunkType === 'data') {
+      dataSize += chunkSize;
+    }
+
+    offset = dataOffset + chunkSize + (chunkSize % 2);
+  }
+
+  if (!format || dataSize <= 0) {
+    return undefined;
+  }
+  return { ...format, dataSize };
+}
+
 function lineForIndex(source, index) {
   return source.slice(0, index).split(/\r?\n/).length;
 }