Adjustments to audio parsing

Signed-off-by: Hans Kokx <hans.d.kokx@gmail.com>

packages/wolf_3d_data/lib/src/wl_parser.dart

@@ -323,10 +323,11 @@ abstract class WLParser {
       }
     }
 
-    // --- THE FIX: Accurate Historical Chunk Indices ---
-    // WL1 (Shareware) has exactly 234 sound effects before the music.
-    // WL6 (Retail) has exactly 261 sound effects before the music.
-    int musicStartIndex = (version == GameVersion.shareware) ? 234 : 261;
+    // In Wolf3D v1.4 (Shareware and Retail), Music ALWAYS starts at chunk 261.
+    // Chunks 0-86: PC Sounds
+    // Chunks 87-173: AdLib Sounds
+    // Chunks 174-260: Digitized Sounds
+    int musicStartIndex = 261;
 
     List<AdLibSound> adLib = allAudioChunks
         .take(musicStartIndex)

packages/wolf_3d_synth/lib/src/opl2_emulator.dart

@@ -56,6 +56,9 @@ class Opl2Emulator {
       int channelIdx = reg - 0xB0;
       Opl2Channel channel = channels[channelIdx];
 
+      // Track the previous key state to prevent constant phase resetting
+      bool wasKeyOn = channel.keyOn;
+
       // Extract the bits using bitwise masks
       channel.keyOn = (data & 0x20) != 0; // Bit 5
       channel.block = (data & 0x1C) >> 2; // Bits 2-4
@@ -65,8 +68,8 @@ class Opl2Emulator {
       channel.fNum = (channel.fNum & 0xFF) | fNumHigh;
       channel.updateFrequency();
 
-      // When a new note is struck, we reset the phase counter to 0
-      if (channel.keyOn) {
+      // ONLY reset the phase if the note was just struck
+      if (!wasKeyOn && channel.keyOn) {
         channel.phase = 0.0;
       }
     }