Optimizing x264 settings and per-title ladders
3 days ago
- Optimizing x264 can reduce bandwidth by 33% (from 4.9 Mbps to 3.27 Mbps) and boost VMAF by 0.66 points, but encoding time triples.
- The breakeven point where bandwidth savings cover extra encoding costs is 186 hours of viewing per hour of content.
- Per-title encoding is the most effective optimization, delivering substantial bitrate savings for easy content and better quality for hard content.
- After H.264 optimization, fair comparisons with new codecs like HEVC or AV1 require optimizing them as well.
- Tests used 13 clips in two stages: first tuning 1080p parameters (presets, GOP, passes, reference frames), then building full encoding ladders.