Video
What bitrate fits 2 hours on a 25 GB Blu-ray?
27.3Mbps of video
27.78 Mbps in total for 120 minutes in 25 GB, minus a 448 kbps audio track. In practice leave a few percent for the disc's file system.
A single-layer Blu-ray holds 25 GB, more than five times a DVD. That buys a much higher bitrate for the same running time.
The arithmetic
- 25 GB × 8 = 200,000,000,000 bits
- 120 minutes = 7,200 seconds
- 200,000,000,000 ÷ 7,200 = 27.78 Mbps for everything
- Less one Dolby Digital 5.1 audio track at 448 kbps (assumption): 27.33 Mbps for the video
| Running time | Total bitrate | Video bitrate |
|---|---|---|
| 60 min | 55.56 Mbps | 55.11 Mbps |
| 90 min | 37.04 Mbps | 36.59 Mbps |
| 120 min | 27.78 Mbps | 27.33 Mbps |
| 150 min | 22.22 Mbps | 21.77 Mbps |
| 180 min | 18.52 Mbps | 18.07 Mbps |