Media testing

Media testing asks a different question from checksum integrity: can the configured media tools successfully decode this supported file?

Archive Witness includes a matched FFmpeg/ffprobe pair for supported media validation. Advanced users may instead select a folder containing both tools; Archive Witness checks that they report matching versions and pass a compatibility test before using them. A media test does not require a saved checksum and does not start checksum work.

Result meanings

• Passed — the performed test completed without a finding that Archive Witness classifies as a failure or warning.
• Warning — decoding completed but a known diagnostic deserves review.
• Invalid media — the media content could not be successfully validated by the performed test.
• Unsupported — Archive Witness does not have an applicable test for the file.
• Timed out / Test failed / Incomplete — the test did not produce a normal completed conclusion.

Detailed results record the tool versions and technical evidence needed to understand the execution.

What a Passed result does not prove

A successful media test does not prove that the file matches an older version. It also does not prove that every aspect of the format or content is universally valid.

Use Integrity when byte identity matters. Use media testing as independent evidence about decode health.

Changed while testing

Archive Witness records stable file facts observed during the test. When suitable checksum evidence already matches those facts, it can retain a stronger link. Otherwise, the result is still useful media evidence, but size/date-only change detection has limits.