feat: improve audio stream selection and caching

apply_sync.py

@@ -75,7 +75,8 @@ def _codec_args(codec: str, out_idx: int) -> list[str]:
 
 
 def build_ffmpeg_cmd(file_a: str, file_b: str, lag_sec: float, out_path: str) -> list[str]:
-    """Build ffmpeg command to mux A video + A audio + delayed B audio streams."""
+    """Build ffmpeg command to mux A video + all A audio + all delayed B audio streams."""
+    a_streams = probe_audio_streams(file_a)
     b_streams = probe_audio_streams(file_b)
 
     lag_ms = lag_sec * 1000
@@ -99,22 +100,22 @@ def build_ffmpeg_cmd(file_a: str, file_b: str, lag_sec: float, out_path: str) ->
     if filters:
         cmd += ["-filter_complex", ";".join(filters)]
 
-    # Map: video from A, all audio from A, all delayed B audio
+    # Map: video from A, ALL audio from A, all delayed B audio
     cmd += ["-map", "0:v", "-map", "0:a"]
     for i in range(len(b_streams)):
         cmd += ["-map", f"[d{i}]"]
 
     # Codecs: copy video + A's audio, re-encode B's filtered audio with same codec
-    n_a_audio = len(probe_audio_streams(file_a))
+    n_a = len(a_streams)
     cmd += ["-c:v", "copy"]
-    for i in range(n_a_audio):
+    for i in range(n_a):
         cmd += [f"-c:a:{i}", "copy"]
     for i, s in enumerate(b_streams):
-        cmd += _codec_args(s["codec"], n_a_audio + i)
+        cmd += _codec_args(s["codec"], n_a + i)
 
-    # Language metadata for B audio streams (they become the last N audio streams in output)
+    # Language metadata for B audio streams (they start after A's streams)
     for i, s in enumerate(b_streams):
-        out_audio_idx = n_a_audio + i  # 0-based index in output audio streams
+        out_audio_idx = n_a + i
         if set_german and i == 0:
             cmd += [f"-metadata:s:a:{out_audio_idx}", "language=ger"]
         elif s["language"] not in ("und", "unknown", ""):
@@ -183,14 +184,6 @@ def main():
 
     print(f"\nSynced output: {out_path}")
 
-    # Auto-launch verify_sync in full mode
-    verify_script = os.path.join(os.path.dirname(os.path.abspath(__file__)), "verify_sync.py")
-    if os.path.exists(verify_script):
-        verify_cmd = [sys.executable, verify_script, "--config", args.config or "config.toml",
-                      "--lag", f"{args.lag:.6f}", "--mode", "full"]
-        print(f"Launching verify: {' '.join(verify_cmd)}")
-        subprocess.Popen(verify_cmd)
-
     sys.exit(0)