Patryk GenschandClaude Opus 5
b99f239553
Whisper always encodes a full 30-second window, whatever the clip length, and the average line here is 4.4 seconds. Fed one at a time, 19.5 hours of speech costs what 135 hours of continuous audio would. Lines are now concatenated with a second of silence between them, filling a window with about five, and the result is cut back apart using the timestamps from whisper's JSON output. A segment goes to the line it overlaps most, so a line split across several segments is reassembled and a segment straying into the silence still lands correctly. Measured on 48 real lines, same set through both paths: speech (39) similarity 0.92, no text landed under the wrong file non-speech (9) similarity 0.54 — both modes invent music annotations Splicing turns out to be slightly *more* accurate on speech, because the model sees context: "Jeden raz czułem" becomes "Niejeden raz czułem", "muszę to pościć" becomes "puścić", "SOO?" becomes "Co?". On the whole collection this projects to 5.8 h → 3.5 h, a 1.7× gain rather than the 5× I claimed earlier from counting encoder windows alone. Encoding a window and decoding a line cost about the same, 0.65 s each, and decoding is per line no matter how the audio is packed — so only half the work can be folded away. Window size, gap and batch size are all settable, and catalog.whisper.concat=false restores the file-at-a-time path, which is how the two were compared. Output moved from -otxt to -oj because only the JSON carries the timestamps. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>