Lab Case 04

VP9 WebM Import Test

A synthetic VP9-in-WebM file that tests a less universal editing path.

✓ Synthetic fixture✓ Browser-local test✓ Reproducible

Expected top-level behaviorTest Required

What this case is designed to prove

Verify that ClipCompat separates a readable media file from an editor compatibility guarantee when the codec/container combination is outside the strongest documented rules used by the checker.

Sample filevp9.webmabout 68 KB · synthetic test media

Download sample

Generated locally with FFmpeg/libvpx-vp9 and Opus audio from synthetic sources. It contains no user footage.

SHA-256f43c31eb02254fb46946c86794406bbe8d2166307ef4e4ae32de3406297f9378

VerificationFixture characteristics cross-checked with FFprobe 7.1.5 on September 30, 2026.

Sample input

Known media facts

These are the characteristics the fixture was generated to expose. MediaInfo may format some labels slightly differently across versions.

ContainerWebM

Video codecVP9

ProfileProfile 0

Resolution320 × 180

Frame rate30 fps

Frame-rate modeCFR

Bit depth8-bit

Chroma4:2:0

AudioOpus / 48 kHz

Expected behavior

What ClipCompat should report

Premiere should remain Test Required because VP9/WebM is intentionally not promoted to a universal support verdict without stronger version-specific evidence.
Resolve should remain Test Required for the WebM container even though the current rules can document VP9 in more common MOV/MP4/MKV workflows.
The user should see the actual codec and container so troubleshooting starts from facts rather than the extension alone.

Fixture context

What the fixture confirms

The fixture confirms that the media parser can read a VP9/WebM combination while leaving the editor rule engine free to make a cautious target-specific verdict.

Safe handling

Test the original in the installed editor first. If it fails, make an edit copy rather than replacing the source.

Observed analyzer evidence

From sample facts to a practical verdict

These synthetic files were analyzed on 2026-10-11 using MediaInfo WASM and the same normalization and compatibility rules used by the checker. This run used Node.js; it was not an import or playback test in Premiere or Resolve.

VP9 WebM Import Test

Detected media: WebM · VP9 · 0
Image and timing: 8-bit · 4:2:0 · CFR
Premiere / Windows: Test Required
Resolve Free / Windows: Test Required

Why Premiere / Windows received this result

VP9 requires a current Premiere test
VP9 behavior is more version- and container-dependent than the common H.264/MP4 path, so ClipCompat does not claim universal support without stronger version-specific evidence.
Evidence: heuristic

Next action: Test import first. If Premiere rejects the source, keep the original and create a separate edit-friendly copy.

Download the same sample

A readable codec is not a guarantee of editor support. Test Required records a limit of the current rules; Supported is not an editor benchmark. Download raw MediaInfo output, normalized facts, checksums and full findings (JSON). Read the methodology.

Run the test

Open a related checker.

The same sample can intentionally produce different guidance depending on the selected editor target.

ToolPremiere Pro CheckerOpen checker →ToolDaVinci Resolve CheckerOpen checker →ToolVideo Compatibility CheckerOpen checker →

Related troubleshooting guides

AV1 and VP9 in Premiere Pro →

More evidence

Compare all five Lab Cases.

Use the case index to move from a common H.264 baseline to VFR, HEVC 10-bit 4:2:2, VP9 and AV1 test media.

View all Lab Cases