HowCurio original keyframe cutting exercise — 14 October 2026
trim-source.mp4:8seconds,640x36030fps, visible frame numbers; keyframe times0,2,4,6seconds. No audio by design.
keep-segment.csv: one no-header row:4,6,Practice keep segment. LosslessCut documents three CSV columns: start seconds,end seconds,label. The row describes what to KEEP. Its import was not independently tested in LosslessCut.

The following two supplied outputs were made by FFmpeg stream copy, not the LosslessCut interface.
trim-aligned.mp4: requested start4seconds,requested duration2seconds; first copied packet came from source PTS4.0;62packets; actualcontainerduration2.066667seconds.
trim-before-keyframe.mp4: requested start3.2seconds,requested duration2seconds; firstcopiedpacket came from sourcePTS2.0;98packets; actualcontainerduration3.266667seconds.
Each copied video packet's SHA256 matched a packet in the source. ContainerfileSHA differs. Timing behavior depends on stream structure and options; these examples are not predictions for every LosslessCut export. Inspect first/last frames in your actual output before sharing.

Source and outputs use only original test graphics and are free to use/adapt.