BCSTM
This document is about the format of CTR Streams (CSTM).
The structure is almost exact to the CTR Wave Format (CWAV).
Overview
The structure of the CSTM is almost exactly the CWAV, except a few differences. The formats can be easily converted between eachother.
These files are either found in rom:\sound\stream\ or they can be inside of a CSAR.
Format
CSTM Header
| OFFSET | SIZE | DESCRIPTION |
|---|---|---|
| 0x000 | 4 | MAGIC "CSTM" |
| 0x004 | 2 | Endianess (0xFEFF=LE / 0xFFFE=BE) |
| 0x00C | 4 | Filesize |
INFO Header
| OFFSET | SIZE | DESCRIPTION |
|---|---|---|
| 0x000 | 4 | Magic "INFO" |
| 0x004 | 4 | Length |
| 0x020 | 1 | Type (00 = PCM8, 01 = PCM16, 02 = DSPADPCM) |
| 0x021 | 1 | Loop Flag |
| 0x022 | 2 | Total Channels |
| 0x024 | 4 | Sample Rate |
| 0x028 | 4 | Unknown |
| 0x02C | 4 | Total samples |
| 0x030 | X | The Channels' Data Pointers |
| X | X | The Channels' Data |
DATA Header
| OFFSET | SIZE | DESCRIPTION |
|---|---|---|
| 0x000 | 4 | Magic "DATA" |
| 0x004 | 4 | Length |
| 0x020 | X | Start of Channels' Data |
Unlike CWAV, if there are 2 channels in a CSTM they alternate every 0x2000 bytes of the DATA partition starting at 0x20. The last section of each channel is usually less than 0x2000, the lengths of these channels is stored in the INFO Header.
Additionally it introduces a new partition called SEEK which comes right before DATA, so a CSTM would be ordered like this:
- CSTM Header
- INFO Partition
- SEEK Partition
- DATA Partition
By default this means that 0x24-0x2B in the CSTM Partition is the SEEK position and length respectively, and DATA position and length follows it (in a CWAV 0x24-0x2B is usually the DATA position and length).
SEEK
| OFFSET | SIZE | DESCRIPTION |
|---|---|---|
| 0x000 | 4 | Magic (SEEK) |
| 0x004 | 4 | Length |