Description
Compact consecutive equal explicit MIDI channel statuses into running-status byte tokens; no system or realtime record support.
MIDI 1.0 channel messages use a status byte identifying a message type and a channel, followed by one or two seven-bit data bytes. This family uses channel indexes 0–15 and raw program values 0–127. Raw message bytes do not include musical timing, instrument state or a MIDI file container.1
Compact consecutive equal explicit MIDI channel statuses into running-status byte tokens; no system or realtime record support.
When to use this tool
Use this tool to compact consecutive equal explicit MIDI channel statuses into running-status byte tokens; no system or realtime record support.
How to use the tool and how it works
- Enter messagesJson using the field definitions below. For JSON text, serialize the explicit records in the shown shape.
- Run the operation. Correct input errors before interpreting an output.
- Read result.bytes. Use the ordering, boundary rules and absence conditions described below.
Validate explicit channel-message records and omit a status byte only when it repeats the previous record’s status, preserving every data byte.2
| Input field | Meaning and units | Accepted input |
|---|---|---|
| messagesJson | JSON text encoding array of {status: number, data: array of number}. Keep the record keys and value types shown in the decoded example below. | Text, at most 8,192 UTF-16 code units; the operation’s grammar also applies. |
These are the decoded structures used in the example’s JSON text fields. Supply the corresponding serialized JSON strings as input.
{
"messagesJson": [
{
"status": 144,
"data": [
60,
100
]
},
{
"status": 144,
"data": [
62,
0
]
}
]
}| Output field | Interpretation |
|---|---|
| result | Object containing the named fields below. |
| result.bytes | Raw integer message bytes in serialization order. |
{
"input": {
"messagesJson": "[{\"status\":144,\"data\":[60,100]},{\"status\":144,\"data\":[62,0]}]"
},
"output": {
"result": {
"bytes": [
144,
60,
100,
62,
0
]
}
}
}Limitations and assumptions
- No real-time interleaving, MIDI file timing or device transport is handled.
- Message data bytes must be integers 0–127 and channel statuses 128–239. Channels are zero-based; this family does not implement MIDI 2.0 UMP, audio synthesis or a complete timed MIDI file.
- Every declared top-level input field is required and unexpected fields are rejected. Ordinary strings are limited to 8,192 UTF-16 code units and lists to 128 entries, with tighter operation-specific bounds where stated. JSON text has bounded nesting and node counts.
- Numeric outputs must be finite and no larger in absolute magnitude than the safe-integer limit; operations returning exact large integers use decimal text. Positions are zero-based and spans end exclusively unless the operation explicitly states a different convention.
Alternative or Complementary methods
Separate channel-message encoding from timing, running status and device interpretation. Use a MIDI sequencer or full file/stream parser when those additional layers matter.
References
-
Summary of MIDI 1.0 Messages — The MIDI Association
-
Tool behavior and example: MIDI Running Status Token Compactor — tool.io
Similar or alternative tools
- MIDI Running Status Token Expander
Expand channel-only MIDI running status into complete message records; incomplete data, system messages and realtime interleaving are rejected.
- MIDI Status Byte Channel Join
Join MIDI 1.0 channel-message type 8–14 with zero-based channel 0–15; system message types are rejected.