midi-rekordbox

name	midi-rekordbox
description	Use when parsing or generating Rekordbox MIDI Learn CSV mapping files, implementing MIDI-to-function lookup, working with deck channel offsets, hi-res 14-bit CC controls, or understanding DDJ/XDJ/DJM controller MIDI conventions.

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)

Col	Header	Purpose	Notes
0	#name	Internal identifier	Often matches col 1; # prefix = not user-assignable in MIDI Learn UI
1	function	Rekordbox function (key column)	Supports modifiers: +Shift, +LongPress, +Press
2	type	Control type	See Control Types below
3	input	Base MIDI IN code (4-digit hex)	Empty when deck columns have full codes
4-7	deck1-deck4	Input deck assignments	Channel offsets OR full MIDI codes
8	output	Base MIDI OUT code (LED feedback)	Often mirrors input
9-12	deck1-deck4	Output deck assignments	Mirrors input pattern
13	option	Flags (semicolon-separated)	See Options below
14	comment	Human description

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

CSV Name	MIDI Message	Resolution	Description
Button	Note On/Off	—	Momentary button
Pad	Note On (velocity)	—	Velocity-sensitive pad
KnobSliderHiRes	CC (14-bit)	0-16383	High-resolution fader (MSB+LSB)
Rotary	CC (relative)	—	Rotary encoder (64=center, >64=CW, <64=CCW)
JogRotate	CC	—	Jog wheel rotation
JogTouch	Note On/Off	—	Jog wheel touch detect
JogIndicator	—	—	Jog display feedback (output only)
Difference	CC	—	Position difference (search/seek)
Indicator	—	—	Output-only LED feedback
Value	CC	—	Special: Needle Search or Velocity Sampler
Parameter	—	—	Internal config, uses FFFx codes (outside standard MIDI)

Listed in Official Guide but NOT Found in CSVs

UI Name	Expected CSV Name	Status
Knob/Slider (0h-7Fh)	Knob or KnobSlider	Not observed in DDJ-FLX10 or DDJ-GRV6 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

Option	Format	Description
Fast	flag	Priority processing for time-critical controls
Priority=N	key=value	Priority level 0-100
Dual	flag	4-deck mode support (DDJ-FLX10)
Blink=N	key=value	LED blink rate in milliseconds
RO	flag	Read-only: controller reports state, not user-assignable
Value=N	key=value	Config value (used with Parameter type)
Min=N	key=value	Minimum value
Max=N	key=value	Maximum value

Row Types

Type	Column 0	Column 1	Example
Functional	name	function	PlayPause,PlayPause,Button,900B,...
Section header	# Name	empty	# Browser,,,,,,,,,,,,,,
Separator	empty	empty	,,,,,,,,,,,,,,
#-prefixed functional	#Name	function	#JogScratch,JogScratch,JogRotate,...
# placeholder	#	function	#,Browse+Press+Shift,Button,...

#-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:

Controller Family	Channel	Known Controls
DDJ controllers	Ch 6	MicLevel (CC 5), MasterLevel (CC 8), BoothLevel (CC 9), CueMasterMix (CC 12), HeadphonesLevel (CC 13)
XDJ all-in-ones	Ch 4	MasterLevel (CC 24), BoothLevel (CC 25)
DJM mixers	Ch 0	MasterLevel (CC 24), BoothLevel (CC 25)
All (illumination)	Ch 15	LED feedback (9Fxx, BFxx)

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

Claim	Evidence	Confidence
CSV structure (15 cols, @file header)	2 CSVs + official IMPORT/EXPORT	High
Deck offset patterns 1-4	Verified in both CSVs	High
Pattern 5 (multi-row)	DDJ-GRV6 lines 223-226	High
Control types (verified list)	Exhaustive grep of both CSVs	High
Knob/KnobSlider types	NOT found in either CSV	Unverified
14-bit MSB/LSB	Working parser + MIDI spec	High
# prefix = not UI-assignable	Observed behavior, not confirmed	Medium
DDJ Ch 6 built-in controls	Confirmed on DDJ-GRV6 hardware	Medium
XDJ/DJM channel conventions	Community reports, no hardware test	Low

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)