Fix: use filter_complex for sequence concatenation to fix sample rate mismatch causing speed up and noise

CloudServer/server.js

@@ -1235,7 +1235,7 @@ function getOrCreateHlsStreamState(streamName) {
     return hlsStreams[streamName];
 }
 
-function buildConcatListFile(seq) {
+function resolveSequenceFiles(seq) {
     ensureSilenceWav();
     const files = [];
 
@@ -1264,24 +1264,23 @@ function buildConcatListFile(seq) {
         for (let i = 0; i < HLS_TAIL_SILENCE_SEC; i++) files.push(silence1sWavPath);
     }
 
-    if (files.length === 0) return null;
-
-    const listPath = path.join(tmpDir, `concat-${Date.now()}-${Math.random().toString(16).slice(2)}.txt`);
-    const content = files
-        .map(p => `file '${p.replace(/\\/g, '/').replace(/'/g, "\\'")}'`)
-        .join('\n');
-    fs.writeFileSync(listPath, content, 'utf8');
-    return listPath;
+    return files;
 }
 
 function buildSequenceWavFile(seq) {
-    const listPath = buildConcatListFile(seq);
-    if (!listPath) return null;
+    const files = resolveSequenceFiles(seq);
+    if (files.length === 0) return null;
 
     const fileName = `sequence-${Date.now()}-${Math.random().toString(16).slice(2)}.wav`;
     const outWavPath = path.join(tempBroadcastDir, fileName);
+    
+    const inputs = files.map(f => `-i "${f}"`).join(' ');
+    const filterResamples = files.map((_, i) => `[${i}:a]aformat=sample_rates=48000:channel_layouts=mono,aresample=48000[a${i}]`).join(';');
+    const filterConcat = files.map((_, i) => `[a${i}]`).join('') + `concat=n=${files.length}:v=0:a=1[a]`;
+    const filterComplex = `${filterResamples};${filterConcat}`;
+
     try {
-        execSync(`ffmpeg -hide_banner -loglevel error -y -f concat -safe 0 -i "${listPath}" -ac 1 -ar 48000 -c:a pcm_s16le "${outWavPath}"`);
+        execSync(`ffmpeg -hide_banner -loglevel error -y ${inputs} -filter_complex "${filterComplex}" -map "[a]" -ac 1 -ar 48000 -c:a pcm_s16le "${outWavPath}"`);
         const buffer = fs.readFileSync(outWavPath);
         const durationSec = getWavDurationSec(buffer) || 0;
         setTimeout(() => {
@@ -1293,15 +1292,16 @@ function buildSequenceWavFile(seq) {
             streamUrl: getManagedMediaUrl('temp', fileName),
             durationSec
         };
-    } finally {
-        try { fs.unlinkSync(listPath); } catch {}
+    } catch (e) {
+        log('ERROR', `buildSequenceWavFile failed: ${e.message}`);
+        return null;
     }
 }
 
 function runFfmpegRtmpPush(streamName, seq) {
     const state = getOrCreateHlsStreamState(streamName);
-    const listPath = buildConcatListFile(seq);
-    if (!listPath) {
+    const files = resolveSequenceFiles(seq);
+    if (files.length === 0) {
         state.status = 'idle';
         state.lastError = 'No playable wav files in sequence';
         return Promise.resolve();
@@ -1315,17 +1315,25 @@ function runFfmpegRtmpPush(streamName, seq) {
 
     if (HLS_PREBUILD) {
         const tmpAacPath = path.join(tmpDir, `prebuild-${Date.now()}-${Math.random().toString(16).slice(2)}.aac`);
+        const inputs = files.map(f => `-i "${f}"`).join(' ');
+        const filterResamples = files.map((_, i) => `[${i}:a]aformat=sample_rates=48000:channel_layouts=mono,aresample=48000[a${i}]`).join(';');
+        const filterConcat = files.map((_, i) => `[a${i}]`).join('') + `concat=n=${files.length}:v=0:a=1[a]`;
+        const filterComplex = `${filterResamples};${filterConcat}`;
+
         const buildArgs = [
             '-hide_banner',
             '-loglevel',
             'error',
-            '-y',
-            '-f',
-            'concat',
-            '-safe',
-            '0',
-            '-i',
-            listPath,
+            '-y'
+        ];
+        
+        files.forEach(f => { buildArgs.push('-i', f); });
+        
+        buildArgs.push(
+            '-filter_complex',
+            filterComplex,
+            '-map',
+            '[a]',
             '-ac',
             '1',
             '-ar',
@@ -1337,7 +1345,7 @@ function runFfmpegRtmpPush(streamName, seq) {
             '-f',
             'adts',
             tmpAacPath
-        ];
+        );
 
         state.status = 'building';
         state.lastStartAt = Date.now();
@@ -1396,7 +1404,6 @@ function runFfmpegRtmpPush(streamName, seq) {
                         state.lastError = (stderr || `ffmpeg exited with code ${code}`).trim();
                         log('ERROR', `HLS push failed for ${streamName}: ${state.lastError}`);
                     }
-                    try { fs.unlinkSync(listPath); } catch {}
                     try { fs.unlinkSync(tmpAacPath); } catch {}
                     resolve();
                 });
@@ -1404,17 +1411,24 @@ function runFfmpegRtmpPush(streamName, seq) {
         });
     }
 
+    const filterResamples = files.map((_, i) => `[${i}:a]aformat=sample_rates=48000:channel_layouts=mono,aresample=48000[a${i}]`).join(';');
+    const filterConcat = files.map((_, i) => `[a${i}]`).join('') + `concat=n=${files.length}:v=0:a=1[a]`;
+    const filterComplex = `${filterResamples};${filterConcat}`;
+
     const args = [
         '-hide_banner',
         '-loglevel',
         'error',
-        '-re',
-        '-f',
-        'concat',
-        '-safe',
-        '0',
-        '-i',
-        listPath,
+        '-re'
+    ];
+    
+    files.forEach(f => { args.push('-i', f); });
+    
+    args.push(
+        '-filter_complex',
+        filterComplex,
+        '-map',
+        '[a]',
         '-ac',
         '1',
         '-ar',
@@ -1426,7 +1440,7 @@ function runFfmpegRtmpPush(streamName, seq) {
         '-f',
         'flv',
         rtmpUrl
-    ];
+    );
 
     state.status = 'pushing';
     state.lastStartAt = Date.now();
@@ -2800,7 +2814,8 @@ app.post('/api/temp-broadcast/publish', (req, res) => {
             const memberName = onlineMembers[idx];
             const ws = getStationWs(memberName);
             enqueueStationAudioTask(memberName, ws, {
-                audioFormat: 'stream',
+                audioFormat: 'wav-stream-live',
+                sourcePath: wavPath,
                 streamUrl,
                 durationSec,
                 priority,