Description
Divide duration by speed; retain frequency when preservePitch or multiply it by speed otherwise.
Frequency ratios express pitch relationships, while cents express their logarithm relative to an octave. Playback speed and pitch-preserving time changes obey different models; the relevant reference and physical assumptions must be supplied.
Divide duration by speed; retain frequency when preservePitch or multiply it by speed otherwise.
When to use this tool
Use Ethnomusicological Audio Speed Time Factor when you need a stated pitch-ratio, reference or playback-speed term.
How to use the tool and how it works
- Enter sourceSeconds, speedFactor, sourceFrequency, preservePitch. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read outputSeconds, outputFrequency. Use the output convention below.
Require nonnegative source duration and positive speed factor/frequency. Divide duration by speed; retain frequency when preservePitch or multiply it by speed otherwise.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| sourceSeconds | Source Seconds | Required. Finite number; minimum 0. |
| speedFactor | Speed Factor | Required. Finite number; strictly above 0. |
| sourceFrequency | Source Frequency | Required. Finite number; strictly above 0. |
| preservePitch | Preserve Pitch | Required. Boolean. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| outputSeconds | Output Seconds | Required. Finite number. |
| outputFrequency | Output Frequency | Required. Finite number. |
{
"input": {
"sourceSeconds": 120,
"speedFactor": 0.8,
"sourceFrequency": 440,
"preservePitch": false
},
"output": {
"outputSeconds": 150,
"outputFrequency": 352
}
}Limitations and assumptions
- This is a predicted timing/pitch relationship, not actual audio processing or evidence that a particular pitch-preservation algorithm is available or artifact-free.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Use calibrated audio measurements and the appropriate processing method for actual recordings. Retain cultural tuning context and verify reference frequency, speed history and instrument assumptions separately.
References
Similar or alternative tools
- Archival Disc Speed Pitch Correction
Multiply frequency by target/source speed ratio, divide duration by it and express ratio as cents.
- Recording Pitch Reference Factor Tool
Compare supplied recorded and reference frequencies after an explicit octave adjustment without retuning audio.