Cakewalk Work Normal

Cakewalk Work Normal (.wrk) is the file format used to store sequenced projects by the original Cakewalk sequencer. A .wrk file contains sequenced track data and references to external audio.

Cakewalk Bundle (.bun) is the file format used by Cakewalk to bundle audio along with sequenced track data.

Cakewalk was a sequencer developed by Twelve Tone Systems. Cakewalk was superceded by Cakewalk SONAR, which used .cwp for sequenced projects and .cwb for bundles instead.

Note

An existing alternative implementation of .wrk parser, Drumstick, was discovered through wrk2mid. For the following reasons, we've decided to not get involved with Drumstick in any form, including interacting with its source code.

  • During our testing, .wrk files even remotely new (produced at least later than 1997) all fail the conversion proces of wrk2mid. It does not mean you will have the broken experience like us. This includes...
    • Official demo songs distributed by Cakewalk (Twelve Tone Systems).
    • Any .wrk file produced by our own validation target, Cakewalk Home Studio 2002.
  • Drumstick is licensed under GNU GPL v3, which conflicts with GNU LGPL v3, the license Octavia and its MICC subsystem distribute under. We do not want to impose additional restrictions GNU GPL v3 may impose on our downstream consumers that aren't already present in GNU LGPL v3.

Format categorisation

BUN

  • MICC group: 12tone.cakewalk.bundle
  • Schema: RIFF, chunked TLV
  • Header size: 12 (RIFF)
  • Chunk type: FourCC
  • Chunk size: u32le
  • Padding: Even
  • Validation targets: Cakewalk Home Studio 2002

WRK

  • MICC group: 12tone.cakewalk
  • Schema: Chunked TLV
  • Header size: 11
  • Chunk type: u8
  • Chunk size: u32le
  • Padding: None
  • Validation targets: Cakewalk Home Studio 2002

Canonical order

BUN

RIFFHEAD
fmt 
PAD 
<[data ...]>
wrk4

WRK

Chunks

BUN

RIFF header

  • Type: N/A
  • MICC group: N/A
HEAD

Standard RIFF header typed the same as .wav files, likely used to prevent causing problems to programs not supporting the wrk4 chunk.

52 49 46 46 ss ss ss ss 57 41 56 45
  • ss (u32le): File size, excluding both 52 49 46 46 ss ss ss ss and the entire wrk4 chunk.

Wave format

  • Type: fmt
  • MICC group: microsoft.wave.format (unused)

Standard .wav sample format description.

File padding

  • Type: PAD
  • MICC group: ltgc.micc.junk (unused)

File-level padding. Its whole existence is to make the PCM sample data start at 0x1000 offset.

PADZ

Only a single element.

PADZ
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ...

Padded zero. All bytes are 00.

Wave data

  • Type: data
  • MICC group: microsoft.wave.data (unused)

Standard .wav sample data.

Sequence data

  • Type: wrk4
  • MICC group: 12tone.cakewalk.wrk (unused)

Actual sequencer data. Exact same content as .wrk files.

WRK