> As long as you cut a compressed audio / video file at the groups / jumps, you can cut it losslessly. If you had a video with keyframes 'd'K and delta frames

> As long as you cut a compressed audio / video file at the groups / jumps, you can cut it losslessly. If you had a video with keyframes 'd'K and delta frames 'd' like 0 1 |<-->| 2 KdddddddddddKdddddddddddKddddddddddd and you wanted to cut out the indicated frames, could you create a new keyframe from the keyframe marked '1' + the two following delta frames, and then another new keyframe from K{1}dddddddd? Something like 0 1 |<-->| 2 KdddddddddddKdddddddddddKddddddddddd Kdd = keyframe "L" Kdddddddd = keyframe "M" KdddddddddddKdLMddKddddddddddd Or I guess if you're creating new frames that weren't in the original, could you just rewrite all the deltas in between K1 and K2 such that those 5 frames aren't there? 0 1 |<-->| 2 KdddddddddddKdddddddddddKddddddddddd KdddddddddddKddeeeKddddddddddd (where 'e' marks recomputed deltas)