Batch-correct slow video. Leave audio timing alone.
Choose video and audio groups in matching filename order. Inspect every pair, then run the real FFmpeg queue locally.
Source groups
ENGINE IDLEVIDEO FILTER setpts=0.125*PTS
AUDIO TIMING unchanged
PAIR RULE sorted video[i] + audio[i]
AUDIO TIMING unchanged
PAIR RULE sorted video[i] + audio[i]
Pairing queue0 MATCHED / 0 BLOCKED
Select equal video and audio groups. Files are sorted by name and paired by position; review names before conversion.
VIDEO FRAMES / TIMESTAMPS COMPRESSEDAUDIO / NO ATEMPO FILTER
Ready. Use the bundled sample or choose equal groups of paired media.
Exact operation, assumptions, and limits
ffmpeg -i [slow-video] -i [normal-audio] -filter:v setpts=0.125*PTS -map 0:v:0 -map 1:a:0 -shortest -c:v libx264 -preset ultrafast -c:a aac [corrected.mp4]
The selected audio is re-encoded for MP4 compatibility but receives no speed filter. Each pair must depict the same action. The shorter transformed stream determines output length. Long 4K batches may exceed browser memory; process smaller groups or use the displayed desktop command.