Video Bitrate / File Size Calculator implementation

Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

Record owner

Guth Instruments

Lifecycle

verified-clean

Evidence ID

t4-263

Effect

Computation or source lookup only

Input and validation requirements

A zero-duration inverse calculation produces an undefined result and must be rejected. The specification also leaves audio-bitrate inclusion and decimal-versus-binary size units ambiguous, which can produce materially different displayed results.

Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

{
  "inputs": {
    "duration_s": 600,
    "bitrate_mbps": 8
  },
  "expected_outputs": {
    "file_size_MB": 600
  },
  "working": "size = bitrate × duration ÷ 8\n= 8 Mbps × 600 s ÷ 8\n= 4,800 ÷ 8\n= 600 MB"
}

Other records

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json
• evidence-tranche4/tranche4-results.json