Edit a 4K film on the phone
Three 4K clips (479 MB) in one message. Keva pulls keyframes with the phone's hardware decoder to see the footage, adds slow motion, an original score and Japanese captions, then encodes a 30-second film with the phone's hardware encoder.
What happens in this video
- 0:00 Title card: "Make video creation a part of a better life." Keva v2026.41.6.
- 0:03 Three 4K clips (0:11, 0:31, 0:20) are picked from the gallery and previewed before sending (3840×2160).
- 0:10 The request: edit them into a 30-second Japanese-style healing video, with music and visuals carrying an emotional arc, slowing down or speeding up footage where it helps.
- 0:15 Sent to Claude Opus 5.5 with the three files attached (84.9 MB, 238.5 MB and 155.2 MB).
- 0:18 Keva inspects the clips (4K, 30 fps; 11 s, 32 s, 21 s) and pulls keyframe thumbnails to see what is in them.
- 0:20 It writes its editing script and asks for approval before running commands.
- 0:22 It tests motion-interpolated slow motion against frame blending, synthesizes the score, and picks NotoSerifCJK, a Mincho-style serif, for the Japanese captions.
- 0:23 All 900 frames go through the phone's hardware encoder (about 15 Mbps), then the music is muxed in. Done after about 20 minutes of work.
- 0:24 The finished film, hokkaido_winter_healing.mp4 (1920×1080, 0:30), plays in Keva: a snowy street, the winter sea and a wood stove, with Japanese captions and English subtitles.