Rekordbox MIDI Learn CSV Protocol

Reverse-engineered from bundled controller CSVs and the official AlphaTheta MIDI Learn Operation Guide. The guide documents the UI workflow; this skill documents the CSV wire format that the UI reads and writes.

Ground truth: references/DDJ-FLX10.midi.csv (567 lines, 4-deck) and references/DDJ-GRV6.midi.csv (339 lines, 2-deck).

File Structure

Line 1:  @file,1,DDJ-FLX10                    ← file marker, format version (always 1), controller name
Line 2:  #name,function,type,input,deck1,deck2,deck3,deck4,output,deck1,deck2,deck3,deck4,option,comment
Line 3+: data rows, section headers, or empty separators

The CSV is also the EXPORT/IMPORT format — Rekordbox's MIDI setting window reads and writes this exact structure.

Column Definitions (15 columns, 0-indexed)

MIDI Hex Format

Codes are 4-digit hex: SSDD — status byte + data byte.

Status byte = upper nibble (message type) + lower nibble (channel 0-15)

  9x = Note On      Example: 900B = Note On, Ch 0, Note 0x0B
  8x = Note Off     Example: 800B = Note Off, Ch 0, Note 0x0B
  Bx = Control Change   Example: B640 = CC, Ch 6, CC 0x40

Channels are 0-indexed in the CSV (0-15) but conventionally displayed as 1-16.

Deck Assignment Patterns

Pattern 1: Base Code + Channel Offsets (most common)

PlayPause,PlayPause,Button,900B,0,1,2,3,900B,0,1,2,3,Fast;Priority=50;Dual,Play/Pause

Base 900B (Ch 0) + offsets 0,1,2,3 → Ch 0 (Deck 1), Ch 1 (Deck 2), Ch 2 (Deck 3), Ch 3 (Deck 4).

Pattern 2: Empty Base + Full MIDI in Deck Columns

Load,Load,Button,,9646,9647,9648,9649,,,,,,,Load to Deck

Input column empty; each deck column has a complete 4-digit MIDI code.

Pattern 3: Global (No Deck Assignment)

Browse,Browse,Rotary,B640,,,,,,,,,,,Browse

Channel 6 = global controls. All deck columns empty.

Pattern 4: Non-Sequential Channel Offsets

PAD1_PadMode1,PAD1_PadMode1,Pad,9000,7,9,11,13,...

Offsets 7, 9, 11, 13 → Channels 7, 9, 11, 13 for decks 1-4. Not always sequential.

Pattern 5: Multi-Row Per Function

FXPartSelectVocalOn,,Button,9714,,,,,9714,,,,,,FX PART SELECT VOCAL
FXPartSelectVocalOn,,Button,9914,,,,,9914,,,,,,FX PART SELECT VOCAL
FXPartSelectVocalOn,,Button,9B14,,,,,9B14,,,,,,FX PART SELECT VOCAL

Same function on separate rows with different MIDI codes (channels 7, 9, 11). Deck columns empty; channel is baked into the code.

Control Types

Verified in CSVs

Listed in Official Guide but NOT Found in CSVs

All faders in both CSVs use KnobSliderHiRes (14-bit). 7-bit knob types may exist in other controllers.

14-Bit Hi-Res Controls (MSB/LSB)

KnobSliderHiRes uses standard MIDI 14-bit CC encoding:

• •MSB: CC 0-31 (coarse value, appears in the CSV)
• •LSB: CC 32-63 (fine value, implicit — CC number = MSB CC + 32)
• •Combined value: MSB * 128 + LSB (range 0-16383)

Example: TempoSlider mapped to B000 (CC 0). The device also sends CC 32 as the LSB — this is NOT in the CSV but must be handled by any parser.

CSV entry:     B000 → CC 0 on base channel (MSB)
Implicit LSB:  B020 → CC 32 on same channel (LSB, not in CSV)

Parser must: recognize CC 32-63 as LSBs for CC 0-31 when the MSB maps to a KnobSliderHiRes function. The LSB shares the same function name and deck assignment.

Options Field

Semicolon-separated in column 13. Example: Fast;Priority=50;Dual

Row Types

#-Prefixed Rows

Column 0 starting with # marks controls not assignable through the MIDI Learn UI. Two subcategories observed:

1. •

   Hardwired + RO — Controller-reported state, firmware-fixed. All jog controls, deck select indicators. Always have RO option. (e.g., #JogScratch, #Deck3)

2. •

   Hardwired, not RO — Real input controls with fixed MIDI assignments that can't be remapped. No RO flag. (e.g., #CrossFader with Fast, #ChannelFader)

These rows have valid MIDI codes and produce real messages. A sniffer/parser should handle them.

Special Sections

# State — Status synchronization

VinylState,VinylState,Button,903A,0,1,2,3,,,,,,RO,LED State of Vinyl buttons
DeckState,DeckState,Button,903C,0,1,2,3,,,,,,RO,LED State of DECK

# illumination — LED control (Channel 15)

LoadedIndicator,LoadedIndicator,Indicator,,,,,,,9F00,9F01,9F02,9F03,RO;Priority=100,Load illumination
JogBrightnessSetting,JogBrightnessSetting,Value,BF46,,,,,BF46,,,,,RO;Priority=100,JOG RING brightness

Uses 9Fxx (Note On Ch 15) and BFxx (CC Ch 15).

# Parameter — Internal config

JogIndicatorInterval,JogIndicatorInterval,Parameter,FFF1,,,,,,,,,,Value=12,
MidiOutInterval,MidiOutInterval,Parameter,FFF3,,,,,,,,,,Value=2,

FFFx codes are outside standard MIDI range — internal to Rekordbox.

Channel Conventions (Hardware-Specific)

Some controls are NOT in the CSV — they're hardwired in controller firmware. These channel assignments are observed empirically:

Note: DDJ Ch 6 mappings confirmed on DDJ-GRV6 only. XDJ/DJM mappings are unverified — derived from community reports.

Lookup Algorithm

To find a Rekordbox function from a received MIDI message:

1. Parse message: type (note_on/note_off/cc), channel, data1
2. Build key: "{type}:{channel}:{data1}"
3. Search CSV rows:
   a. Pattern 1: base_code channel + deck_offset == message channel?
   b. Pattern 2: deck column contains full MIDI code matching message?
4. If CC 32-63 and no direct match:
   → Check CC (data1 - 32) as MSB for KnobSliderHiRes — this is the LSB
5. Return function from column 1, control type from column 2

Verification Status

Sources

• •Ground truth CSVs: references/DDJ-FLX10.midi.csv, references/DDJ-GRV6.midi.csv (bundled with this skill)
• •Official guide: AlphaTheta "MIDI LEARN Operation Guide" for rekordbox 7.0.5 (UI workflow, control type definitions)
• •CSV source: /Applications/rekordbox 7/rekordbox.app/Contents/Resources/MidiMappings/
• •MIDI spec: https://www.midi.org/specifications (14-bit CC, status bytes)