Description
Return required MIDI 1.0 channel-message byte counts from an explicit status, excluding running-status omission and system messages.
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
Return required MIDI 1.0 channel-message byte counts from an explicit status, excluding running-status omission and system messages.
When to use this tool
Use this tool to return required MIDI 1.0 channel-message byte counts from an explicit status, excluding running-status omission and system messages.
How to use the tool and how it works
- Enter status using the field definitions below.
- Run the operation. Correct input errors before interpreting an output.
- Read result.dataBytes, result.totalBytes. Use the ordering, boundary rules and absence conditions described below.
Validate a channel status byte. Return one data byte for program change or channel pressure, otherwise two, plus the status-inclusive total.2
| Input field | Meaning and units | Accepted input |
|---|---|---|
| status | MIDI 1.0 channel status byte, 128–239. | A finite safe integer within the operation’s stated bounds. |
| Output field | Interpretation |
|---|---|
| result | Object containing the named fields below. |
| result.dataBytes | Required data-byte count for the supplied channel status. |
| result.totalBytes | One status byte plus the required data bytes. |
{
"input": {
"status": 192
},
"output": {
"result": {
"dataBytes": 1,
"totalBytes": 2
}
}
}Limitations and assumptions
- System messages, timing bytes and transport overhead are excluded.
- 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 Channel Message Byte Count — tool.io
Similar or alternative tools
- MIDI Channel Message Channel Remapper
Remap all MIDI channel-message channels through an explicit sixteen-entry old-to-new channel table; preserve message type and data.
- MIDI Channel Message Controller Selector
Select explicit MIDI control-change records for a supplied seven-bit controller number, preserving channels and occurrence order.