BCWAV

From 3dbrew
Jump to: navigation, search

This document is about the format of Banner's CTR Wave files (BCWAV).

The structure is very similar to Microsoft's Wave file.

Banner CWAV total channels must be 2, and the length of the audio must be 3 seconds or less, otherwise the sound will play incorrectly (beeping/clicking) or the model may fail to load.

Overview[edit]

Microsoft's WAV structure is RIFF Header which defines the data inside which is WAVE, then the media player expects a "fmt " chunk and a "data" chunk. Nintendo's format uses a CWAV header (no need for a general structure for media, only wave), which points to an INFO struct (the equivalent to fmt) and a DATA struct (the equivalent to data).

Header[edit]

OFFSET SIZE DESCRIPTION
0x000 4 Magic (CWAV)
0x004 2 Endianness (0xFEFF = little, 0xFFFE = big)
0x006 2 Header Size (0x40 due to Info Block alignment)
0x008 4 Version (0x02010000)
0x00C 4 File Size
0x010 2 Number of Blocks (2)
0x012 2 Reserved
0x014 12 Info Block Sized Reference (Offset relative to start of file)
0x020 12 Data Block Sized Reference (Offset relative to start of file)

Block Header[edit]

OFFSET SIZE DESCRIPTION
0x000 4 Magic
0x004 4 Size

Block Types[edit]

MAGIC TYPE
INFO Info Block
DATA Data Block

Info Block[edit]

OFFSET SIZE DESCRIPTION
0x000 8 Block Header
0x008 1 Encoding
0x009 1 Loop (0 = don't loop, 1 = loop)
0x00A 2 Padding
0x00C 4 Sample Rate
0x010 4 Loop Start Frame
0x014 4 Loop End Frame
0x018 4 Reserved
0x01C X Channel Info Reference Table
X X Channel Info Entries

If encoding is DSP ADPCM:

OFFSET SIZE DESCRIPTION
X X DSP ADPCM Info Entries

If encoding is IMA ADPCM:

OFFSET SIZE DESCRIPTION
X X IMA ADPCM Info Entries

The info block is aligned to 0x20 bytes.

Encoding[edit]

VALUE DESCRIPTION
0 PCM8
1 PCM16
2 DSP ADPCM
3 IMA ADPCM

Channel Info[edit]

OFFSET SIZE DESCRIPTION
0x000 8 Samples Reference (Offset relative to Data Block Data field)
0x008 8 ADPCM Info Reference (Offset relative to Samples Reference field)
0x010 4 Reserved
DSP ADPCM Info[edit]
OFFSET SIZE DESCRIPTION
0x000 32 Param
0x020 6 Context
0x026 6 Loop Context
0x02C 2 Padding
DSP ADPCM Param[edit]
OFFSET SIZE DESCRIPTION
0x000 32 16-bit Coefficients
DSP ADPCM Context[edit]
OFFSET SIZE DESCRIPTION
0x000 1 4-bit Predictor + 4-bit Scale
0x001 1 Reserved
0x002 2 Previous Sample
0x004 2 Second Previous Sample
IMA ADPCM Info[edit]
OFFSET SIZE DESCRIPTION
0x000 4 Context
0x004 4 Loop Context
IMA ADPCM Context[edit]
OFFSET SIZE DESCRIPTION
0x000 2 Data
0x002 1 Table Index
0x003 1 Padding

Data Block[edit]

OFFSET SIZE DESCRIPTION
0x000 8 Block Header
0x008 Block Header Size Value - 8 Data

The data block is aligned to 0x20 bytes, as well as the data field's actual sample data.

Reference Table[edit]

OFFSET SIZE DESCRIPTION
0x000 4 Count
0x004 Count * 8 References (Offsets relative to Count field)

Sized Reference[edit]

OFFSET SIZE DESCRIPTION
0x000 8 Reference
0x008 4 Size

Reference[edit]

OFFSET SIZE DESCRIPTION
0x000 2 Type ID
0x002 2 Padding
0x004 4 Offset ("null" = 0xFFFFFFFF)

Reference Types[edit]

ID TYPE
0x0300 DSP ADPCM Info
0x0301 IMA ADPCM Info
0x1F00 Sample Data
0x7000 Info Block
0x7001 Data Block
0x7100 Channel Info