Video QC (quality control) is the check a finished video goes through before anyone outside the edit suite sees it. Someone watches the exported file, or runs it through a tool, looking for errors that have nothing to do with taste.
Think of a black frame at a cut, audio that peaks into distortion, a surname spelled wrong in a lower third or a file exported at the wrong frame rate. When QC works, the client never finds any of them.
In short
- QC checks the exported file for technical and editorial errors, not whether the edit works.
- It covers the picture, the sound, the text on screen and the file itself.
- Run a short QC before every cut goes to the client and a full one before final delivery.
- A machine measures loudness, peaks, silence and short black or frozen stretches well; sync, color between shots and names still need a person.
- When a broadcaster or a platform sends a spec sheet, the spec decides what passes.
What video QC checks
QC looks at four areas: picture, sound, text on screen and the file. Each has its own usual suspects.
- Picture. Black and flash frames left at cuts, freezes from a stalled render, dropped frames, compression blocks in dark scenes and gradients, black bars that shouldn’t be there.
- Sound. Peaks that clip, loudness far from the target, silence where there should be sound, a missing or swapped channel, pops at edits, sync that drifts.
- Text on screen. Typos and wrong names in titles and lower thirds, text outside title safe, subtitles made from an earlier cut, an end card with last year’s website.
- The file. Resolution, frame rate, aspect ratio, codec, audio channel layout, duration, and the first and last frames, all against what the delivery asked for.
The item-by-item version, in the order that saves time, is the final QC checklist.
QC is not the same as review
Review asks whether the video is right. QC asks whether the file is correct. In a review, the director or the client judges the story, the pacing and the music. In QC, nobody reopens the edit.
That’s why QC runs on the exported file, not on the timeline. A frame that stalled in the render, an encoder setting that crushed the shadows or an export range one frame past the last clip only exist in the file.
It’s also why the editor shouldn’t be the only one doing the final pass. They know what is supposed to be on screen and tend to see it even when it isn’t there.
When to run QC
The cheapest error is the one caught before it gets copied into the next version. QC isn’t a single step at the end, and most teams check at three moments:
- When footage comes in. A quick look at the dailies catches soft focus, a camera on the wrong frame rate or a lav that cut out, while there’s still time to reshoot.
- Before every cut goes to the client. A short pass on the export: one watch start to finish, every piece of text read, headphones on. That way the client’s notes are about the edit and not about a typo.
- Before final delivery. The full pass, against the spec, on every file you hand over. A vertical version or a smaller web file went through its own export and can break where the master didn’t.
What a machine can check, and what it can’t
Anything that can be measured, a tool checks faster and more consistently than a person. Loudness, true peak, silence, short black gaps and frozen frames are numbers, and a tool doesn’t get tired on the fourth version at 11 p.m.
Anything that depends on intent or context still needs a person. A tool can measure that the picture went black for two seconds, but not whether the director wanted that pause before the logo.
It can read a lower third, too, without knowing that the client’s head of marketing changed her surname last spring. What stays with a person:
- Sync, especially near the end of long takes, where drift builds up.
- Color between shots, since a shot swapped in after the grade can look fine on its own. See how to review video color.
- Names, titles and the end card, checked against the list the client confirmed.
- Whether a black, a freeze or a silence was meant to be there.
The sensible split is machine first, person second. Let the tool flag the measurable problems on every upload, fix those, and spend the human watch on what only a human can judge.
When the delivery comes with a spec sheet
For broadcast and streaming, the spec sheet decides what passes, and the receiving side runs its own QC against it. Ask for the spec before the edit starts, not on delivery day.
Loudness is where a lot of rejections start. EBU R 128, the European broadcast standard, sets an integrated loudness of -23 LUFS with true peaks no higher than -1 dBTP. In the US, ATSC A/85 sets -24 LKFS. The targets and how to measure them are in audio level standards.
Broadcast specs also cover things a web video never worries about. In the UK, Ofcom’s guidance on flashing images limits flashes to three per second, and many specs ask for black, bars and tone or a slate before the programme starts.
Web and social jobs rarely come with a spec. Write a short one yourself with resolution, frame rate, aspect ratio and loudness target, and agree it with the client before the first cut. Export settings are in video encoding best practices.
Who does QC, and how to write it down
The final pass is best done by someone who didn’t cut the video. On a small team that’s often the producer; on a larger one, an assistant editor with a checklist and headphones.
Write each problem down at its timecode, with what’s wrong. “00:01:12:08, one black frame at the cut” goes straight to a fix, while “something flickers near the end” sends the editor through the whole video again. The timecode guide covers how to write it.
Keep the notes after delivery. If something was left as is on purpose, write down who on the client side agreed to it.
How this works in RecReview
In RecReview, AI Review runs on a version when you ask for it, or on every upload if automatic AI Review is on for the workspace. It covers the part of QC that can be measured.
On the sound, it measures the whole export: peaks above a safe limit, loudness far above or below what web playback expects, long silences mid-video, dropouts, clipping and isolated clicks. The reference is web playback, so a mix made at a broadcast level shows up as quiet.
On the picture, it looks for a stray frame inside a shot, a short black gap with a hard edge and a brief freeze between moving shots. It reads the text on screen for clear spelling mistakes and text cut off at the edge, and when the task has a script, it compares what’s said with what was written.
Each finding has a timecode and shows up as a marker on the player bar and in the comment list. A second check looks at the frames around a picture finding, and if it looks deliberate, like a fade, the finding moves to a collapsed list of low-confidence checks instead of disappearing.
AI Review doesn’t check a file against a broadcaster’s spec sheet, and it doesn’t judge sync or color between shots. That part of QC stays with a person, in the same player, with each note pinned to the frame for the editor.
