Byte Range Bit Offset

Map a nonnegative half-open byte range to bit offsets; empty ranges stay empty.

Description

Map a nonnegative half-open byte range to bit offsets; empty ranges stay empty.

A half-open whole-byte range maps to a bit offset by multiplying every boundary by eight.

When to use this tool

Map a nonnegative half-open byte range to bit offsets; empty ranges stay empty.

Prepare the supplied startByte, byteLength fields for this operation.
Compare the complete example with the representation used by your own input before carrying the result into another step.

How to use the tool and how it works

Enter startByte, byteLength. Use the exact text syntax, units and index conventions explained below.
Run the tool. If input validation fails, correct the supplied fields before interpreting any result.
Read result.startBit, result.endBit. Interpret false, null and empty lists using the distinctions below; they can be valid outputs.

Require nonnegative integer startByte and byteLength. Return startBit=startByte*8 and endBit=(startByte+byteLength)*8.^[1]

Input field	Meaning and representation	Accepted input
startByte	start byte.	Integer from 0 to 1e9 inclusive
byteLength	byte length.	Integer from 0 to 1e9 inclusive

Output field	Interpretation
result	Object containing the named outputs below.
result.startBit	The start bit value under the stated formula or text convention.
result.endBit	The end bit value under the stated formula or text convention.

json

{
  "input": {
    "startByte": 3,
    "byteLength": 2
  },
  "output": {
    "result": {
      "startBit": 24,
      "endBit": 40
    }
  }
}

Limitations and assumptions

No data is read and no within-byte bit order is chosen. These are boundaries rather than inclusive final-bit indexes.
Every declared top-level field is required and unexpected fields are rejected. Numeric inputs must be finite; ordinary text fields are bounded to 8,192 UTF-16 code units, with tighter operation-specific limits where stated.
Lists are limited to 128 entries. JSON text must meet bounded size and depth checks, and numeric outputs beyond the safe finite magnitude are rejected. Exact large integers use decimal strings.
Indexes are zero-based and spans have an exclusive end unless explicitly stated otherwise. A valid false, null or empty-list result is distinct from malformed input.

Alternative or Complementary methods

Retain the field-width, bit-index and byte-order conventions when combining operations. Slicing, escaping, permutation and alignment are separate transforms; none supplies a complete framing or cryptographic protocol.

References

Tool behavior and example: Byte Range Bit Offset — tool.io

Similar or alternative tools

Bit Range Byte Envelope
Find the smallest half-open byte envelope of a bit range; empty bit ranges return an empty envelope.
Bit String Byte Grouping
Group a complete MSB-first binary string into eight-bit bytes; partial final bytes are rejected.