Fix concat cleanup

utils/CaptionRender.js

@@ -25,6 +25,13 @@ export class CaptionRenderer {
 
     const segmentFiles = [];
 
+    // Helper to clean up intermediate files
+    function cleanupFiles(files) {
+      for (const f of files) {
+        try { fs.unlinkSync(f); } catch (e) { /* ignore */ }
+      }
+    }
+
     // Render each transcript section separately
     for (const [i, section] of originalManuscript.transcript.entries()) {
       const segmentFile = path.join(outDir, `${jobId}_segment_${i}.mp4`);
@@ -85,7 +92,8 @@ export class CaptionRenderer {
     }
 
     // Concatenate all segments together
-    const concatFile = path.join(outDir, `${jobId}_final.mp4`);
+    const resultFile = path.join(outDir, `${jobId}_final.mp4`);
+    const concatFile = path.join(outDir, `${jobId}_combined_final.mp4`);
     const concatList = path.join(outDir, `${jobId}_concat_list.txt`);
 
     fs.writeFileSync(concatList, segmentFiles.map(f => `file '${f}'`).join('\n'));
@@ -97,12 +105,51 @@ export class CaptionRenderer {
       '-c', 'copy',
       '-y', concatFile
     ];
-
     await this.runFFmpeg(concatArgs, controller, onLog);
 
-    return concatFile;
+    // Add background music if present
+    const { bgMusic, bgMusicVolume = 0.25 } = originalManuscript;
+    if (bgMusic) {
+      const finalWithMusic = resultFile; // Overwrite the _final.mp4 file
+      const getDuration = (filePath) => {
+        try {
+          const ffprobeSync = require('child_process').spawnSync;
+          const result = ffprobeSync(ffmpegLocation.replace('ffmpeg', 'ffprobe'), [
+            '-v', 'error',
+            '-show_entries', 'format=duration',
+            '-of', 'default=noprint_wrappers=1:nokey=1',
+            filePath
+          ]);
+          return parseFloat(result.stdout.toString().trim());
+        } catch (e) {
+          return null;
+        }
+      };
+      const videoDuration = getDuration(concatFile);
+      const atrimArg = (videoDuration && !isNaN(videoDuration)) ? `,atrim=end=${videoDuration}` : '';
+
+      const musicArgs = [
+        '-i', concatFile,
+        '-i', bgMusic,
+        '-filter_complex', `[1:a]volume=${bgMusicVolume}${atrimArg}[bgm];[0:a][bgm]amix=inputs=2:duration=first:dropout_transition=2[mixeda]`,
+        '-map', '0:v',
+        '-map', '[mixeda]',
+        '-c:v', 'copy',
+        '-c:a', 'aac',
+        '-y', finalWithMusic
+      ];
+      await this.runFFmpeg(musicArgs, controller, onLog);
+      segmentFiles.push(concatFile);
+    }
+    else {
+      fs.renameSync(concatFile, resultFile);
+    }
+
+    cleanupFiles([...segmentFiles, concatList]);
+    return resultFile;
   }
 
+
   runFFmpeg(args, controller, onLog) {
     console.log('FFMPEG cmd:', args.join(' '));