Roland SP-404SX sample file

Notes

Field types are marked using C-style notation:

• char[4] indicates a 4-byte fixed-width string
• uint[6] indicates a 6-byte sequence
• uint8, uint16, and uint32 are unsigned byte, short, and long integers
• int8, int16, and int32 are signed byte, short, and long integers
• long double is an 80-bit IEEE 754 floating-point number.

Fields that vary are marked in bold. All other fields should be constant across samples.

File name

• Sample files are stored in SP-404SX/ROLAND/SP-404SX/SMPL/
• Sample names are in the form A00000001.WAV, i.e. one letter for the bank followed by seven digits, padded with leading zeros, for the pad number.
• Samples can be either WAVE (.WAV) or AIFF (.AIF).

AIFF sample file format

This format is generated by the sampler when recording samples to the SD card.

Samples are 44.1 kHz 16-bit PCM files in AIFF format with an additional Roland-specific header. They can be either mono or stereo.

The sample is an AIFF file with the structure:

• AIFF chunk
  • COMM chunk
  • RLND chunk
  • SSND chunk

This is a big-endian format, i.e. the most significant byte comes first and bytes appear in the order written. For example, 176,400 is 2B110h and appears in the file as 00 02 B1 10.

AIFF chunk

Notes:

• ChunkSize is the length of the file remaining, i.e. the total file length in bytes minus eight.

COMM chunk

Notes:

• Chunk size is the number of bytes remaining in the chunk. It is always 18.
• NumChannels is 1 for mono, 2 for stereo.
• NumSamples is the number of samples in the audio data. For 16-bit stereo audio, this will be 1/4 of the length of the audio data in bytes.

APPL chunk

Notes:

• SampleIndex is always 4 for samples recorded on the device.
• This chunk is sized and padded with zeros to ensure that the the sample data starts exactly at offset 512.

SSND chunk

Notes:

• ChunkSize is equivalent to the number of samples ×
• Data always starts at offset 512 in the file.
• Data is a sequence of samples. Each sample is a pair of left and right values for a stereo file.
• ChunkSize is 8 + NumSampleFrames × NumChannels × BitsPerSample / 8

WAVE sample file format

This format is generated by the Roland Wave Converter application.

Samples are 44.1 kHz 16-bit PCM files in RIFF WAVE format with an additional Roland-specific header. They can be either mono or stereo.

The sample is a RIFF file with the structure:

• RIFF chunk
  • fmt chunk
  • RLND chunk
  • data chunk

This is a little-endian format, i.e. the least significant byte comes first and bytes appear in reverse order. For example, 176,400 is 2B110h and appears in the file as 10 B1 02 00.

RIFF chunk

Notes:

• ChunkSize is the length of the file remaining, i.e. the total file length in bytes minus eight.

fmt chunk

Notes:

• The chunk name is f m t space.
• Chunk size is the number of bytes remaining in the chunk. It is always 18.
• NumChannels is 1 for mono, 2 for stereo.
• ByteRate is computed as SampleRate × NumChannels × BitsPerSample / 8, or more simply as SampleRate × BlockAlign.
• BlockAlign is computed as NumChannels × BitsPerSample / 8, i.e. 2 for a mono sample and 4 for stereo.

RLND chunk

Notes:

• SampleIndex starts at zero for A1 and increases by 12 for each bank, i.e. A1 = 00h, A5 = 04h, B5 = 10h.
• This chunk is sized and padded with zeros to ensure that the the sample data starts exactly at offset 512.

data chunk

Notes:

• ChunkSize is equivalent to the number of samples × BlockAlign
• Data always starts at offset 512 in the file.

Pad info file

This is stored alongside the samples in PADINFO.BIN and contains 120 × 32-byte records, one for each pad from A1 to J12.

In this file, values are stored in big-endian order, i.e. an offset of 512 is 200h and stored as 00 00 02 00.

Notes:

• TempoMode is 0 = off, 1 = pattern, 2 = user.
• Format is 0 for an AIFF sample, and 1 for a WAVE sample. It is possible that this corresponds solely to the endianness of the data (0 = big endian, 1 = little endian).
• OrigTempo and UserTempo appear to be beats per minute mutiplied by 10, i.e. 4B0h = 1200 = 120 bpm. The Roland Wave Converter application computes the original tempo as 120 / sample length.
• Sample start and end offsets are relative to the original file: Wave Converter sets this to 512 because the length of the RIFF headers before the raw wave data is exactly 512 bytes.