Pikmin Technical Knowledge Base - User contributions [en]

AST file

2026-04-24T08:48:14Z

Xayrga: Header

AST files contain streamed audio data, and are used in Pikmin 2.
To simply play audio files, you can use [https://vgmstream.org/ vgmstream], an audio playback library for multiple video game specific audio formats.

To convert .wav to .ast, you can use [https://github.com/XAYRGA/jatast/releases/download/stable/publish_win64.zip JATAST]. This defaults to ADPCM encoding, as the GameCube's disc reading (whether on real hardware or emulated with dolphin) will not be able to keep up with large streamed music otherwise.

= File Format =
== Header ==
The file starts with a 0x40 bytes long header as follows:
{| class="wikitable"
|-
! Offset !! Type !! Name !! Description
|-
| 0x00 || int32 || magic || 'STRM' 0x5354524D
|-
| 0x04 || int32 || size || (File Size - 0x40)
|-
| 0x08 || u16 || Format || 0 = ADPCM, 1 = PCM16.
|-
| 0x0A || u16 || BitsPerFrame || Usually 16.
|-
| 0x0C || u16 || channelCount || Number of channels.
|-
| 0x0E || bool (u16) || loop || 0xFFFF = true, 0x0000 = false
|-
| 0x10 || int32 || sampleRate || Sample Rate.
|-
| 0x14 || int32 || sampleCount || Sample Count
|-
| 0x18 || int32 || loopStart || Start of loop in samples (Aligned to nearest 16 samples)
|-
| 0x1C || int32 || loopEnd || End of loop, aligned to nearest 16 samples. SampleCount if no loop.
|-
| 0x20 || int32 || blockSize || Block size. Generally 0x00002760.
NOTE: This is the size of ONE CHANNEL. If you have 2 channels, the block will be 4EC0 in length, but this should still say 0x2760
|-
| 0x24 || int32 || unknown || 0
|-
| 0x28 || u8 || volume || Volume modifier, byte. 0x7F = 100%
|-
| 0x29 || Byte[0x17] || padding ||Padding to align header to 0x40
|-
| 0x40 || BLCK[] || ... || ...

|}

== Block / BLCK ==

{| class="wikitable"
|-
! Offset !! Type !! Name !! Description
|-
| +0x00 || int32 || magic || 'BLCK' 0x424C434B
|-
| +0x04 || int32 || size || Block size, 0x2760 if full block.
NOTE: See the above comment regarding block size. This will be the length of one channel. The last BLCK's size might differ, but the rest will generally remain 0x2760
|-
| +0x08 || u16[2][6] || sampleHist || Historical samples for ADPCM4 only.
|-
| +0x20 || u8[size][channelCount] || sampleData || Sample data. Each channel will be packed directly following the previous channel.
|-
| +(size + 0x20) || Next BLCK
|}

=== Trivia ===
When encoding the sampleHist part of the block in ADPCM, this will be the historical values (last = l, p = penultimate)

Each set of two u16's represents one channel in the AST. If there aren't that many channels, the value will be set to 0.

[[File:ASTHistorySamples.png|thumb]]

The value of these will be the last evaluated (decoded) samples from the previous block (matching channel). Without these, the predictor for the current block will overscale, resulting in "crunchy" Audio.

[[Category:File formats]]
[[Category:Pikmin 2]]

AST file

2026-04-24T08:46:58Z

Xayrga: format documentation

AST files contain streamed audio data, and are used in Pikmin 2.
To simply play audio files, you can use [https://vgmstream.org/ vgmstream], an audio playback library for multiple video game specific audio formats.

To convert .wav to .ast, you can use [https://github.com/XAYRGA/jatast/releases/download/stable/publish_win64.zip JATAST]. This defaults to ADPCM encoding, as the GameCube's disc reading (whether on real hardware or emulated with dolphin) will not be able to keep up with large streamed music otherwise.

= File Format =
== Header ==
The file starts with a 0x40 bytes long header as follows:
{| class="wikitable"
|-
! Offset !! Type !! Name !! Description
|-
| 0x00 || int32 || magic || 'STRM' 0x5354524D
|-
| 0x04 || int32 || size || (File Size - 0x40)
|-
| 0x08 || u16 || Format || 0 = ADPCM, 1 = PCM16.
|-
| 0x0A || u16 || BitsPerFrame || Usually 16.
|-
| 0x0C || u16 || channelCount || Number of channels.
|-
| 0x0E || bool (u16) || loop || 0xFFFF = true, 0x0000 = false
|-
| 0x10 || int32 || sampleRate || Sample Rate.
|-
| 0x14 || int32 || sampleCount || Sample Count
|-
| 0x18 || int32 || loopStart || Start of loop in samples (Aligned to nearest 16 samples)
|-
| 0x1C || int32 || loopEnd || End of loop, aligned to nearest 16 samples. SampleCount if no loop.
|-
| 0x20 || int32 || blockSize || Block size. Generally 0x00002760.
NOTE: This is the size of ONE CHANNEL. If you have 2 channels, the block will be 4EC0 in length, but this should still say 0x2760
|-
| 0x24 || int32 || unknown || 0
|-
| 0x28 || u8 || volume || Volume modifier, byte. 0x7F = 100%
|-
| 0x29 || Byte[0x17] || padding ||Padding to align header to 0x48
|-
| 0x40 || BLCK[] || ... || ...

|}

== Block / BLCK ==

{| class="wikitable"
|-
! Offset !! Type !! Name !! Description
|-
| +0x00 || int32 || magic || 'BLCK' 0x424C434B
|-
| +0x04 || int32 || size || Block size, 0x2760 if full block.
NOTE: See the above comment regarding block size. This will be the length of one channel. The last BLCK's size might differ, but the rest will generally remain 0x2760
|-
| +0x08 || u16[2][6] || sampleHist || Historical samples for ADPCM4 only.
|-
| +0x20 || u8[size][channelCount] || sampleData || Sample data. Each channel will be packed directly following the previous channel.
|-
| +(size + 0x20) || Next BLCK
|}

=== Trivia ===
When encoding the sampleHist part of the block in ADPCM, this will be the historical values (last = l, p = penultimate)

Each set of two u16's represents one channel in the AST. If there aren't that many channels, the value will be set to 0.

[[File:ASTHistorySamples.png|thumb]]

The value of these will be the last evaluated (decoded) samples from the previous block (matching channel). Without these, the predictor for the current block will overscale, resulting in "crunchy" Audio.

[[Category:File formats]]
[[Category:Pikmin 2]]

File:ASTHistorySamples.png

2026-04-24T08:42:53Z

Xayrga:

AST Historical samples shown in HxD

BMS file

2025-05-31T10:52:23Z

Xayrga: siis

A <code>.bms</code> file holds data for sequenced music in ''Pikmin 2''. BMS files are similar to [[wikipedia:MIDI|MIDI files]], but have many more advanced features. Custom BMS files can be made with Flaaffy by Arookas (which can be found [https://github.com/arookas/flaaffy/releases here]), however Yoshi2's fork of Flaaffy is better suited to making BMS files for ''Pikmin 2''. You can find that [https://github.com/RenolY2/flaaffy/releases here]. You can also use [https://xayr.gay/tools/jaimaker1/JAIMaker+JAISeqX1.5.9.zip JAIMaker] for a GUI based converter.

== Documentation ==
{{todo|Actually document every byte of a bms header and music data and what it all means.}}

A BMS file is made up of a sequence of commands which are a single byte, and can include a range of arguments. Each command has a fixed number of arguments. Values are read as big endian.

{| class="wikitable"
! Instruction || Mnemonic || Type || Additional Arguments
|-
| 0x00 - 0x80 || NOTE_ON || NoteOn || Variable
|-
| 0x80 || CMD_WAIT8 || Wait || int8 LEN,
|-
| 0x81 || NOTE_OFF || NoteOff || None
|-
| 0x88 || CMD_WAIT16 || Wait || int16 LEN
|-
| 0x90 || SETPARAM_90 || Param || byte Destination Register, byte Value
|-
| 0x91 || SETPARAM_91 || Param || byte Destination Register, byte Value
|-
| 0x92 || SETPARAM_92 || Param || byte Destination Register, byte Value
|-
| 0x94 || PERF_U8_NODUR || Perf || byte PERFValue, byte value
|-
| 0x96 || PERF_U8_DUR_U8 || Perf || byte PERFValue, byte value, byte duration
|-
| 0x97 || PERF_U8_DUR_U16 || Perf || byte PERFValue, byte value, short duration
|-
| 0x98 || PERF_S8_NODUR || Perf || byte PERFValue, sbyte value
|-
| 0x9A || PERF_S8_DUR_U8 || Perf || byte PERFValue, sbyte value, byte duration
|-
| 0x9B || PERF_S8_DUR_U16 || Perf || byte PERFValue, sbyte value, short duration
|-
| 0x9C || PERF_S16_NODUR || Perf || byte PERFValue, short value
|-
| 0x9D || PERF_S16_DUR_U8 || Perf || byte PERFValue, short value, byte duration
|-
| 0x9E || PERF_S16_DUR_U8_9E || Perf || byte PERFValue, short value, byte duration
|-
| 0x9F || PERF_S16_DUR_U16 || Perf || byte PERFValue, short value, short duration
|-
| 0xA0 || PARAM_SET_R || Param || byte dest_register, byte src_register
|-
| 0xA1 || PARAM_ADD_R || Param || byte dest_register, byte src_register
|-
| 0xA2 || PARAM_MUL_R || Param || byte dest_register, byte src_register
|-
| 0xA3 || PARAM_CMP_R || Param || byte dest_register, byte src_register
|-
| 0xA4 || PARAM_SET_8 || Param || byte register, byte value
|-
| 0xA5 || PARAM_ADD_8 || Param || byte register, byte value
|-
| 0xA6 || PARAM_MUL_8 || Param || byte register, byte value
|-
| 0xA7 || PARAM_CMP_8 || Param || byte register, byte value
|-
| 0xA8 || PARAM_LOAD_UNK || ? || ?
|-
| 0xA9 || PARAM_BITWISE || Param ||
|-
| 0xAA || PARAM_LOADTBL || Param ||
|-
| 0xAB || PARAM_SUBTRACT || Param ||
|-
| 0xAC || PARAM_SET_16 || Param || byte register, short value
|-
| 0xAD || PARAM_ADD_16 || Param || byte register, short value
|-
| 0xAE || PARAM_MUL_16 || Param || byte register, short value
|-
| 0xAF || PARAM_CMP_16 || Param || byte register, short value
|-
| 0xB0 || OPOVERRIDE_1 || Override || It's complicated.
|-
| 0xB1 || OPOVERRIDE_2 || Override ||
|-
| 0xB4 || OPOVERRIDE_4 || Override ||
|-
| 0xB8 || OPOVERRIDE_R || Override ||
|-
| 0xC1 || OPENTRACK || Track || byte trackID <= 0xF, int24 trackID
|-
| 0xC2 || OPENTRACKBROS || Track ||
|-
| 0xC4 || CALL || Flow || byte condition, int24 address
|-
| 0xC5 || RETURN_NOARG || Flow ||
|-
| 0xC6 || RETURN || Flow || byte condition
|-
| 0xC8 || JMP || Flow || int24 address
|-
| 0xC9 || LOOP_S || Flow || byte count
|-
| 0xCA || LOOP_E || Flow ||
|-
| 0xCB || READPORT || Port || byte srcPort, byte dstRegister
|-
| 0xCC || WRITEPORT || Port || byte srcPort, byte dstRegister
|-
| 0xCD || CHECKPORTIMPORT || Port || byte srcPort
|-
| 0xCE || CHECKPORTEXPORT || Port || byte srcPort
|-
| 0xCF || CMD_WAITR || Wait || byte register
|-
| 0xD1 || PARENTWRITEPORT || Port ||
|-
| 0xD2 || CHILDWRITEPORT || Port ||
|-
| 0xD4 || SETLASTNOTE || || byte lastNoteValue
|-
| 0xD5 || TIMERELATE || ||
|-
| 0xD6 || SIMPLEOSC || Oscillator ||
|-
| 0xD7 || SIMPLEENV || Envelope ||
|-
| 0xD8 || SIMPLEADSR || ||
|-
| 0xD9 || TRANSPOSE || ||
|-
| 0xDA || CLOSETRACK || Track || byte trackID
|-
| 0xDB || OUTSWITCH || ||
|-
| 0xDC || UPDATESYNC || ||
|-
| 0xDD || BUSCONNECT || Port ||
|-
| 0xDE || PAUSESTATUS || Flow ||
|-
| 0xDF || SETINTERRUPT || Interrupt || byte InterruptID, int24 Callback_Address
|-
| 0xE0 || DISINTERRUPT || Interrupt ||
|-
| 0xE1 || CLRI || Interrupt ||
|-
| 0xE2 || SETI || Interrupt ||
|-
| 0xE3 || RETI || Interrupt ||
|-
| 0xE4 || INTTIMER || Interrupt ||
|-
| 0xE5 || VIBDEPTH || ||
|-
| 0xE6 || VIBDEPTHMIDI || ||
|-
| 0xE7 || SYNCCPU || Flow || short syncdata?
|-
| 0xE8 || FLUSHALL || ||
|-
| 0xE9 || FLUSHRELEASE || ||
|-
| 0xEA || WAIT_VLQ || Wait || VLC delay
|-
| 0xEB || PANPOWSET || ||
|-
| 0xEC || IIRSET || ||
|-
| 0xED || FIRSET || ||
|-
| 0xEE || EXTSET || ||
|-
| 0xEF || PANSWSET || ||
|-
| 0xF0 || OSCROUTE || ||
|-
| 0xF1 || IIRCUTOFF || ||
|-
| 0xF2 || OSCFULL || ||
|-
| 0xF3 || VOLUMEMODE || ||
|-
| 0xF4 || VIBPITCH || ||
|-
| 0xFA || CHECKWAVE || ||
|-
| 0xFB || PRINTF || PrintF || Variable
|-
| 0xFC || NOP || Misc || Skips this opcode, can be used for patching things out
|-
| 0xFD || TEMPO || Flow || int16 Tempo
|-
| 0xFE || TIMEBASE || Flow || int16 Timebase
|-
| 0xFF || FINISH || Track ||
|}

== List of BMS files ==
A full list of all the BMS files in ''Pikmin 2'' can be found [[Pikmin 2 BMS file list|here]].

== Interactive music ==
A lot of BMS music in ''Pikmin 2'' is interactive, meaning that parts of it change depending on what you do in the game. A tutorial to do this can be found [[Creating Interactive BMS Files|here]]. Cave music is a different process, and can be found [[Creating cave music|here]].

[[Category:File formats]]
[[Category:Pikmin 2]]