Ticket #8076: sbl.diff

scummvm/scumm/sound.cpp

@@ -248 +248 @@
                 else if (READ_UINT32_UNALIGNED(ptr) == MKID('SBL ')) {
                         debug(2, "Using SBL sound effect");
         
-                        // TODO - Figuring out how the SBL chunk works. Here's an
-                        // example:
+                        // TODO - Figuring out how the SBL chunk works. Here's
+                        // an example:
                         //
                         // 53 42 4c 20 00 00 11 ae  |SBL ....|
                         // 41 55 68 64 00 00 00 03  |AUhd....|
@@ -259 +259 @@
                         // 7e 7f 7f 80 80 7f 7f 7f  |~.......|
                         // 7f 80 80 7f 7e 7d 7d 7e  |....~}}~|
                         // 7e 7e 7e 7e 7e 7e 7e 7f  |~~~~~~~.|
-                        // 7f 7f 7f 80 80 80 80 80  |........|
-                        // 80 81 80 80 7f 7f 80 85  |........|
-                        // 8b 8b 83 78 72 6d 6f 75  |...xrmou|
-                        // 7a 78 77 7d 83 84 83 81  |zxw}....|
                         //
-                        // The length of the AUhd chunk always seems to be 3 bytes.
-                        // Let's skip that for now.
+                        // The length of the AUhd chunk always seems to be 3
+                        // bytes. Let's skip that for now.
                         //
-                        // The starting offset, length and sample rate is all pure
-                        // guesswork. The result sounds reasonable to me, but I've
-                        // never heard the original.
-        
+                        // The starting offset, length and sample rate is all
+                        // pure guesswork. The result sounds reasonable to me,
+                        // but I've never heard the original.
+                        //
+                        // I've since discovered that the non-interactive
+                        // Sam & Max demo also uses SBL sound effects, but
+                        // with different sub-chunks. Example:
+                        //
+                        // 53 42 4c 20 00 01 15 6e  |SBL ...n|
+                        // 57 56 68 64 00 00 00 03  |WVhd....|
+                        // 00 00 80 57 56 64 74 00  |...WVdt.|
+                        // 01 15 5b 01 56 15 01 a6  |..[.V...|
+                        // 00 80 80 80 80 80 80 80  |........|
+                        // 80 80 80 80 80 80 80 80  |........|
+                        // 80 80 80 80 80 80 80 80  |........|
+                        // 80 80 80 80 80 80 80 80  |........|
+                        //
+                        // I'm going to assume that the sample frequency is
+                        // the only important difference between the two.
+
+                        if (READ_UINT32_UNALIGNED(ptr + 8) == MKID('WVhd'))
+                                rate = 11025;
+                        else
+                                rate = 8000;
+
                         size = READ_BE_UINT32_UNALIGNED(ptr + 4) - 27;
-                        rate = 8000;
         
                         // Allocate a sound buffer, copy the data into it, and play
                         char *sound = (char*)malloc(size);