BS.1770 true-peak

scripts/run-ebu-true-peak-tests.mjs

@@ -0,0 +1,126 @@
+import { readFile, readdir, stat } from 'node:fs/promises'
+import { basename, join, resolve } from 'node:path'
+import { createRequire } from 'node:module'
+
+const require = createRequire(import.meta.url)
+const { lufsmeter } = require('../native/build/Release/visualizer_dsp.node')
+
+const sourcePath = process.argv[2]
+if (!sourcePath) {
+  console.error('Usage: npm run test:lufsmeter-ebu -- /path/to/extracted-ebu-loudness-test-set')
+  process.exit(2)
+}
+
+async function collectFiles(path) {
+  const details = await stat(path)
+  if (details.isFile()) return [path]
+  if (!details.isDirectory()) return []
+
+  const files = []
+  for (const entry of await readdir(path, { withFileTypes: true })) {
+    files.push(...await collectFiles(join(path, entry.name)))
+  }
+  return files
+}
+
+function decodeWave(buffer) {
+  if (buffer.length < 12 || buffer.toString('ascii', 0, 4) !== 'RIFF'
+    || buffer.toString('ascii', 8, 12) !== 'WAVE') {
+    throw new Error('not a RIFF/WAVE file')
+  }
+
+  let format = null
+  let data = null
+  for (let offset = 12; offset + 8 <= buffer.length;) {
+    const chunkId = buffer.toString('ascii', offset, offset + 4)
+    const chunkSize = buffer.readUInt32LE(offset + 4)
+    const chunkOffset = offset + 8
+    if (chunkOffset + chunkSize > buffer.length) throw new Error(`truncated ${chunkId} chunk`)
+
+    if (chunkId === 'fmt ') {
+      if (chunkSize < 16) throw new Error('invalid fmt chunk')
+      let formatTag = buffer.readUInt16LE(chunkOffset)
+      if (formatTag === 0xfffe && chunkSize >= 40) {
+        formatTag = buffer.readUInt16LE(chunkOffset + 24)
+      }
+      format = {
+        formatTag,
+        channels: buffer.readUInt16LE(chunkOffset + 2),
+        sampleRate: buffer.readUInt32LE(chunkOffset + 4),
+        blockAlign: buffer.readUInt16LE(chunkOffset + 12),
+        bitsPerSample: buffer.readUInt16LE(chunkOffset + 14),
+      }
+    } else if (chunkId === 'data') {
+      data = buffer.subarray(chunkOffset, chunkOffset + chunkSize)
+    }
+    offset = chunkOffset + chunkSize + (chunkSize % 2)
+  }
+
+  if (!format || !data) throw new Error('missing fmt or data chunk')
+  if (format.channels < 1 || format.blockAlign < 1 || format.sampleRate < 1) {
+    throw new Error('invalid WAVE format')
+  }
+
+  const bytesPerSample = Math.ceil(format.bitsPerSample / 8)
+  const frameCount = Math.floor(data.length / format.blockAlign)
+  const left = new Float32Array(frameCount)
+  const right = new Float32Array(frameCount)
+  const readSample = (offset) => {
+    if (format.formatTag === 3 && format.bitsPerSample === 32) return data.readFloatLE(offset)
+    if (format.formatTag !== 1) throw new Error(`unsupported WAVE format tag ${format.formatTag}`)
+    if (format.bitsPerSample === 16) return data.readInt16LE(offset) / 0x8000
+    if (format.bitsPerSample === 24) return data.readIntLE(offset, 3) / 0x800000
+    if (format.bitsPerSample === 32) return data.readInt32LE(offset) / 0x80000000
+    throw new Error(`unsupported PCM depth ${format.bitsPerSample}`)
+  }
+
+  for (let frame = 0; frame < frameCount; frame += 1) {
+    const frameOffset = frame * format.blockAlign
+    left[frame] = readSample(frameOffset)
+    right[frame] = format.channels > 1 ? readSample(frameOffset + bytesPerSample) : left[frame]
+  }
+  return { sampleRate: format.sampleRate, left, right }
+}
+
+function expectedDbtp(caseNumber) {
+  if (caseNumber >= 15 && caseNumber <= 18) return -6
+  if (caseNumber === 19) return 3
+  return 0
+}
+
+const files = await collectFiles(resolve(sourcePath))
+const cases = new Map()
+for (const file of files) {
+  const match = basename(file).match(/3341[-_ ](1[5-9]|2[0-3])(?:\D|$)/i)
+  if (match && /\.wav(?:\.wav)?$/i.test(file)) cases.set(Number(match[1]), file)
+}
+
+const missing = []
+for (let caseNumber = 15; caseNumber <= 23; caseNumber += 1) {
+  if (!cases.has(caseNumber)) missing.push(caseNumber)
+}
+if (missing.length > 0) {
+  console.error(`Could not find EBU Tech 3341 WAV cases: ${missing.join(', ')}`)
+  process.exit(2)
+}
+
+let failed = false
+for (let caseNumber = 15; caseNumber <= 23; caseNumber += 1) {
+  const file = cases.get(caseNumber)
+  try {
+    const wave = decodeWave(await readFile(file))
+    lufsmeter.setSampleRate(wave.sampleRate)
+    lufsmeter.reset()
+    lufsmeter.pushSamples(wave.left, wave.right)
+    const actual = lufsmeter.getSnapshot().maxTruePeakDb
+    const expected = expectedDbtp(caseNumber)
+    const passed = actual >= expected - 0.4 && actual <= expected + 0.2
+    console.log(`${passed ? 'PASS' : 'FAIL'}  EBU 3341-${caseNumber}: ${actual.toFixed(3)} dBTP (expected ${expected}, +0.2/-0.4)`)
+    failed ||= !passed
+  } catch (error) {
+    failed = true
+    console.error(`FAIL  EBU 3341-${caseNumber}: ${error instanceof Error ? error.message : String(error)}`)
+  }
+}
+
+process.exit(failed ? 1 : 0)

scripts/run-tests.mjs

@@ -19,6 +19,7 @@ const testScripts = [
   'test:spectrum-native',
   'test:spectrogram-native',
   'test:vectorscope-native',
+  'test:lufsmeter-native',
 ]
 
 const npmCommand = process.platform === 'win32' ? 'npm.cmd' : 'npm'