feat: add two-pass EBU R128 loudness normalization for audio extraction

config.toml

@@ -6,7 +6,7 @@
 file_a = "/path/to/movie_b.mp4"
 file_b = "/path/to/movie_a.mkv"
 # Window to extract (seconds). This is the ONLY duration needed.
-duration = 90
+duration = 30
 # Start offset in file (seconds, 0 = file start). ffmpeg -ss before -i for fast seek.
 start = 0.0
 out_dir = "extracted"
@@ -20,6 +20,11 @@ channels = 1
 # If extracted wavs already exist, sync test can load them directly:
 # file_a_wav = "extracted/movie_b_audio.wav"
 # file_b_wav = "extracted/movie_a_audio.wav"
+# EBU R128 loudness normalization (two-pass loudnorm)
+normalize = true
+target_lufs = -14       # -14 streaming, -23 broadcast
+target_tp = -1.0        # true peak limit (dBTP)
+target_lra = 11         # loudness range
 
 [sync]
 # Analysis window: null = use full extracted duration; otherwise limit for quick test