Generation loss, and why re-shared video looks bad
Video codecs are lossy: every encode discards detail to save space. Decoding and re-encoding a clip therefore loses a little more each time, and the losses compound. This is why a clip that has been downloaded, edited, uploaded, downloaded again and re-edited ends up soft and blocky while the original still looks fine.
The practical rule is to minimise the number of encodes between the source and the final upload. Edit once, from the highest-quality rendition you have, and export once.
Trimming without re-encoding
Cutting a clip at the start or end does not require re-encoding at all. Stream-copy trimming keeps the original compressed data and only changes where playback begins and ends, so the result is bit-for-bit as good as the source.
The catch is that cuts land on keyframes, so you cannot always cut at an exact arbitrary frame. For most social clips that imprecision is invisible and the quality saved is worth far more than frame-accuracy.
- 1
Start from the best source you have
Re-download at the highest rendition rather than editing a copy you already compressed.
- 2
Trim before anything else
Cutting first means every later operation processes less footage, which is faster and produces a smaller file.
- 3
Export once, at the target's native size
Exporting larger than the destination displays wastes bytes; the platform will re-encode it down anyway, costing you another generation.
Cropping and aspect ratio
Vertical feeds want tall video, and cropping a wide clip to a tall frame throws away most of the picture. When the subject is centred that is survivable; when it is not, you are better off framing the original inside the tall canvas and filling the space above and below than cutting the subject in half.
Never stretch to fit. Distorted faces read as careless immediately, and it is the one artefact viewers consistently notice.
Tools
For simple trims and crops, your phone's built-in photo editor is genuinely fine and does not re-encode more than necessary. For anything involving multiple clips, free desktop editors handle it well. Command-line tools give you exact control over whether a re-encode happens at all.
Editing tools built into Frenz are planned rather than available — until they ship, the techniques above apply to whatever editor you already use.
Common questions
- Why does my video look worse after uploading it?
- The platform re-encoded it. Every service re-compresses uploads to its own settings. Uploading a clean, correctly-sized file gives that encoder the best possible input to work from.
- Should I export at the highest possible bitrate?
- Up to a point. Beyond what the source actually contains, extra bitrate only makes the file larger and slower to upload without adding detail.