Pre-Upload Video Checklist: Verify Specs With a Detector
Upload rejected, playback blurry, sound missing — nine times out of ten the source file’s specs are the culprit. A ten-second parameter check before publishing beats an hour of debugging after rejection.
What the detector reads
One click pulls four groups from the container: codec and wrapper (H.264 or HEVC? MP4 or MKV?), resolution and frame rate, bitrate, and audio specs (codec, channels, sample rate).
These four groups explain most rejections: unsupported codec, oversized resolution, excessive bitrate, or an incompatible audio track.
Focus on codec first. H.264 + AAC is the universal dialect; HEVC works on some platforms with slow transcoding; VP9, AV1, and ProRes usually demand conversion first.
Four red lines before publishing
Codec: mainstream platforms treat H.264 + AAC as the lingua franca. If the detector says otherwise, transcode first — do not gamble on the platform’s server-side conversion.
Resolution: platforms cap dimensions and usually require even numbers. Odd sizes like 1919×1079 are the classic hidden trap some encoders refuse outright.
Bitrate: above the platform’s recommendation buys nothing — upload crawls and the platform recompresses anyway. Match the platform’s published bitrate table.
Audio: no track, multiple tracks, or non-AAC codecs cause “video plays, sound missing” and rejections. Multi-track files: extract the track you actually want.
Findings and their fixes
Wrong codec: convert to MP4 (H.264 + AAC). HEVC to H.264 is near-lossless; the larger file is expected.
Resolution or bitrate over limits: compress down to the platform’s spec — target-size mode takes platform caps directly.
Odd dimensions: one crop or resize step restores even numbers; do it while you are in there.
Broken audio: extract and inspect the track, or mute and re-dub. Confirm which track is the keeper before merging anything.
Make checking a habit
Keep a spec card per platform: target codec, resolution, bitrate cap, duration cap. Run the detector against the card after every export — ten seconds, every time.
Team and multi-account workflows benefit most: one person’s discovered pitfall, written onto the card, immunizes everyone.
A passing check does not tame the platform’s own recompression and review — but it locks down every variable you control.