Python scripts for processing GoPro karting session videos - split into individual lap clips and create side-by-side lap comparisons.

• Python 3.12+
• FFmpeg (for video processing)

Splits a GoPro session video into individual lap clips with timing overlays.

Usage with inline lap times:

./kart_splitter.py \ --video session.mp4 \ --first-lap 00:12.500 \ --laps "43.605,44.120,44.001,44.389,43.881" \ --outdir laps_out

Usage with CSV file:

./kart_splitter.py \ --video GOPR2000.MP4 \ --first-lap 2:05.000 \ --laps-csv laps_1.csv \ --outdir laps_out

CSV Format (laps_1.csv):

lap,time 1,00:48.561 2,00:49.107 3,00:46.274 4,00:46.559 5,00:46.238 6,00:45.876 7,00:45.119 8,00:46.362 9,00:45.736 10,00:44.936 11,00:44.945 12,00:46.318 

Creates side-by-side comparison videos of selected laps from the same session.

Usage:

python3 lap_compare.py \ --video GOPR2000.MP4 \ --first-lap 2:05.000 \ --laps-csv laps_1.csv \ --select 10,11 \ --out compare_10_vs_11.mp4 \ --audio left

Audio Options:

• --audio left: Use only the first lap's audio
• --audio mix: Mix both laps' audio together
• --audio none: No audio output

Other Options:

• --select 2,5,7,9: Compare 2-4 laps (grid layout)
• --width 1920 --height 1080: Output resolution
• --crf 20: Video quality (lower = better quality)
• --preset veryfast: Encoding speed vs quality tradeoff
• --fontfile /path/to/font.ttf: Custom font for overlays (optional)

Both scripts support flexible timestamp formats:

• Seconds: 43.605
• MM:SS: 01:23.456
• HH:MM:SS: 01:02:34.567

• ✅ Fixed FFmpeg drawtext filter escaping issues
• ✅ Fixed audio stream processing logic preventing "unconnected output" errors
• ✅ Improved error handling with detailed FFmpeg output
• ✅ All audio modes now working correctly (left/mix/none)