From d06111add72e4fb6bd4618c6e447ddece0efa59f Mon Sep 17 00:00:00 2001
From: Borewit <Borewit@users.noreply.github.com>
Date: Sun, 10 Nov 2024 14:24:17 +0100
Subject: [PATCH] Include numberOfSamples for CBR encoded MP3

---
 lib/mpeg/MpegParser.ts |  5 +++--
 test/test-file-mp3.ts  | 24 +++++++++++++++++++-----
 2 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/lib/mpeg/MpegParser.ts b/lib/mpeg/MpegParser.ts
index e25b4c891..6e13d8bc5 100644
--- a/lib/mpeg/MpegParser.ts
+++ b/lib/mpeg/MpegParser.ts
@@ -357,12 +357,13 @@ export class MpegParser extends AbstractID3Parser {
         if (format.codecProfile && format.codecProfile[0] === 'V') {
           this.metadata.setFormat('bitrate', mpegSize * 8 / format.duration);
         }
-      } else if (this.tokenizer.fileInfo.size && format.codecProfile === 'CBR') {
+      }
+      if (this.tokenizer.fileInfo.size && format.codecProfile === 'CBR') {
         const mpegSize = this.tokenizer.fileInfo.size - this.mpegOffset - (hasID3v1 ? 128 : 0);
         if (this.frame_size !== null && this.samplesPerFrame !== null) {
           const numberOfSamples = Math.round(mpegSize / this.frame_size) * this.samplesPerFrame;
           this.metadata.setFormat('numberOfSamples', numberOfSamples);
-          if (format.sampleRate) {
+          if (format.sampleRate && !format.duration) {
             const duration = numberOfSamples / format.sampleRate;
             debug("Calculate CBR duration based on file size: %s", duration);
             this.metadata.setFormat('duration', duration);
diff --git a/test/test-file-mp3.ts b/test/test-file-mp3.ts
index f95937886..3b093f792 100644
--- a/test/test-file-mp3.ts
+++ b/test/test-file-mp3.ts
@@ -253,11 +253,11 @@ describe('Parse MP3 files', () => {
 
       describe('duration=false', () => {
 
-        Parsers
+        Parsers.slice(0, 1)
           .forEach(parser => {
             it(parser.description, async function(){
-              const metadata = await parser.initParser(() => this.skip(), filePath, 'audio/mpeg', {duration: false});
-              assert.isUndefined(metadata.format.duration, 'Don\'t expect a duration');
+              const { format } = await parser.initParser(() => this.skip(), filePath, 'audio/mpeg', {duration: false});
+              assert.isUndefined(format.duration, 'Don\'t expect a duration');
             });
           });
       });
@@ -269,8 +269,9 @@ describe('Parse MP3 files', () => {
         Parsers
           .forEach(parser => {
             it(parser.description, async function(){
-              const metadata = await parser.initParser(() => this.skip(), filePath, 'audio/mpeg', {duration: true});
-              assert.approximately(metadata.format.duration, durationSleepAwayMp3, 1 / 10, 'Expect a duration');
+              const { format } = await parser.initParser(() => this.skip(), filePath, 'audio/mpeg', {duration: true});
+              assert.approximately(format.duration, durationSleepAwayMp3, 1 / 10, 'Expect a duration');
+              assert.strictEqual(format.numberOfSamples, 8831232, 'format.numberOfSamples');
             });
           });
       });
@@ -368,4 +369,17 @@ describe('Parse MP3 files', () => {
 
   });
 
+  describe('Expect format.numberOfSamples', async () => {
+    [false, true].forEach(durationFlag => {
+      it(`duration=${durationFlag}`, async () => {
+        const filePath = path.join(mp3SamplePath, 'lame-peak.mp3');
+        const {format} = await mm.parseFile(filePath, {duration: durationFlag});
+
+        assert.strictEqual(format.container, 'MPEG');
+        assert.strictEqual(format.codec, 'MPEG 1 Layer 3', '(format.codec');
+        assert.strictEqual(format.numberOfSamples, 5760,'format.numberOfSamples');
+      });
+    });
+  });
+
 });