Why a player screenshot loses quality
A screenshot records the player's displayed size, scaling and possibly its controls. This tool draws the decoded image at the video's display resolution. It cannot restore detail already lost in compression, and image export does not preserve HDR.
Why the final frame appears before the video ends
The total playing time marks the end of the video, not the start of a frame. With a fixed frame rate and equally long audio and video tracks, the final frame usually starts one frame interval before the end: total playing time minus 1 divided by frames per second. A changing frame rate or longer audio makes that shortcut unreliable. We measure the time of frames the browser actually shows; the picture still visible when playback finishes is the final decoded frame.
When to step back
In our sample of 179 public AI clips, 64.2% had a final-frame sharpness score below the best of the last 24 presented frames; the median cleanest position was 3 frames from the end. A high edge-sharpness score indicates strong local edges. A low score can reveal blur or a dark fade, but a sharp frame can still contain distorted hands or geometry. Choose the latest acceptable image and trim A there so the reference matches the actual cut.
How much the picture changes at the join
A change of 1× means the join's pixel change equals the median measured change inside the two clips. No change inside the clips makes the comparison undefined. Exposure, composition and motion can all change the value; inspect the side-by-side images, overlay and preview. Calibration is a comparison with our controls, not a pass/fail threshold.
Measured AI clip endings
| Measure | All clips | Seedance 2.0 |
|---|---|---|
| Clips measured | 179 | 178 |
| Final frame is not the sharpest of the last 24 | 64.2% | 64.0% |
| Sharpest frame: median distance from the end | 3 | 3 |
| Sharpest frame is the last frame | 33.0% | 33.1% |
| 1–3 frames before the end | 19.0% | 19.1% |
| 4–12 frames before the end | 15.6% | 15.7% |
| 13–23 frames before the end | 32.4% | 32.0% |
| Dark endings | 6.1% | 6.2% |
| Possible fade endings | 3.9% | 3.9% |
Questions about last-frame extraction
Does the video leave my device?
No. The browser reads the local file and exports the PNG locally. No video upload is required.
Is the final frame always the recommended one?
No. The recommendation picks the latest non-dark frame within 10% of the highest sharpness score in the captured tail. You can always select the final frame. In our sample of 179 public AI clips, 64.2% had a final-frame sharpness score below the best of the last 24 presented frames; the median cleanest position was 3 frames from the end.
Can I use iPhone MOV or HDR video?
Only if your browser decodes it. For unsupported HEVC or HDR, convert to H.264 MP4 in SDR. Portrait and rotation are drawn at the browser's display dimensions.
Does this export a trimmed video?
No. It exports a PNG and can count frames to prepare an ffmpeg trim command. The preview stops A at the selected frame before playing B.
Does a small change at the join prove continuity?
No. It compares brightness steps, not motion direction, identity or geometry. It is undefined when the baseline is zero. Watch the preview too.