Enhance the video/subtitle sync or quality at 02:01:36 in fjin046engsub.mp4.
ffmpeg -i fjin046engsub.mkv -map 0 -c:v libx265 -preset slow -crf 23 \
-x265-params "zones=7260k,7260k,b=1.2" \
-c:a libopus -b:a 96k -c:s copy output_fjin046_optimized.mkv
Breakdown:
Let鈥檚 compute: 02:01:36 in seconds = 2*60 + 1 + 36/100 = 121.36 seconds.
At 30 fps, that鈥檚 ~3640 frames. But if video is 23.976 fps, use frame number: 121.36 * 23.976 鈮� 2910.
Better to use time-based zones in newer FFmpeg: fjin046engsub convert020136 min better
- x265-params "zones=2910,2910,b=1.5"
This boosts bitrate around that scene by 50% to prevent artifacts. Enhance the video/subtitle sync or quality at 02:01:36
Total time for a 2.5h video: ~5 minutes (instead of 30+ minutes of CPU encoding). ffmpeg -i fjin046engsub
Here is the 3-minute process to make fjin046engsub truly better: