55
edits
Changes
no edit summary
Line 1:
Line 1:
AST files contain PCM16 (16-bit signed) sound data. They're used in Super Mario Galaxy for musics, and possibly in other games.
AST files contain PCM16 (16-bit signed) sound data. They're used in Super Mario Galaxy for musics, and possibly in other games.
−They contain an header followed by a BLCK chunk.<br>
+They contain an header followed by BLCK chunks.<br>
All the data in those files are big-endian, except where mentioned.<br>
All the data in those files are big-endian, except where mentioned.<br>
All the offsets are absolute (from begining of file), except where mentioned.<br>
All the offsets are absolute (from begining of file), except where mentioned.<br>
Line 30:
Line 30:
|-
|-
| 0x000C
| 0x000C
−| 4
+| 2
−| Unknown
+| Number of blocks per chunk
+|-
+| 0x000E
+| 2
+| Unknown (0xFFFF)
|-
|-
| 0x0010
| 0x0010
Line 51:
Line 55:
| 0x0020
| 0x0020
| 4
| 4
−| Block size? (typically 0x2760)
+| Block size (typically 0x2760)
|-
|-
| 0x0024
| 0x0024
Line 60:
Line 64:
=== BLCK chunk ===
=== BLCK chunk ===
−The BLCK chunk directly follows the AST header. It contains a 32-byte header, followed by the PCM16 sound data.<br>
+The BLCK chunks directly follow the AST header. They contain a 32-byte header, followed by PCM16 sound data.<br>
−Here's a description of it:
+Here's a description of them:
{| class="wikitable"
{| class="wikitable"
Line 76:
Line 80:
| 0x0004
| 0x0004
| 4
| 4
−| Block size? (typically 0x2760)
+| Block size (typically 0x2760)
|-
|-
| 0x0008
| 0x0008
Line 84:
Line 88:
| 0x0020
| 0x0020
| variable
| variable
−| PCM16 data
+| PCM16 data blocks
|}
|}
+
+The data is divided into blocks. The number of blocks is defined by entry 0x000C in AST header.<br>
+The length of the blocks is defined by entry 0x0020 in AST header.<br>
WARNING: The PCM16 data is stored in BIG-ENDIAN! Don't forget to byteswap each sample you read or your sound will be pure junk!<br>
WARNING: The PCM16 data is stored in BIG-ENDIAN! Don't forget to byteswap each sample you read or your sound will be pure junk!<br>
Note: there's sound data for one channel only. Stereo mixing is performed by the Wii's DSP.
Note: there's sound data for one channel only. Stereo mixing is performed by the Wii's DSP.
+
+=== AST file structure ===
+
+{| class="wikitable"
+|-
+! Element
+! Size
+|-
+| AST header
+| 64 bytes
+|-
+| BLCK chunk header
+| 32 bytes
+|-
+| PCM16 block 1
+| N
+|-
+| PCM16 block 2
+| N
+|-
+| ...
+|
+|-
+| PCM16 block N'
+| N
+|-
+| BLCK chunk header
+| 32 bytes
+|-
+| PCM16 block 1
+| N
+|-
+| PCM16 block 2
+| N
+|-
+| ...
+|
+|-
+| PCM16 block N'
+| N
+|-
+| BLCK chunk header
+| 32 bytes
+|-
+| ...
+|
+|}
+
+Where:
+- N is the number of blocks per BLCK chunk (entry 0x000C in AST header)
+- N' is the block size (entry 0x0020 in AST header)