Quote:
Originally Posted by Ryan711 
Just curious as to if that, assuming all other things being equal, would provide a noticeably better picture quality over a standard bluray due to what I assume is a less compressed copy than what would be found on bluray.
Just curious as to if that, assuming all other things being equal, would provide a noticeably better picture quality over a standard bluray due to what I assume is a less compressed copy than what would be found on bluray.
it`s a matter of digital processing & storing video files.
DCI files have a lot more video information than BDs.
Its not only the higher frame rates & resolutions that
increase the file size, its also the video information.
The .pdf that 707 posted writes
that dci movies store 12 bit color information per pixel (native deep color )
when bds store 4:2:0 8bit. This is a lot more GBs
(The color gamut is also wider.)
at last, there is no audio codec.
The audio files are uncompressed lossless PCM tracks.
all these facts increase the video file size.
i will copy paste it directly from the .pdf (p.69)
Quote:
Capacity
Excluding storage necessary for redundancy, the storage system is required to provide
for, at a minimum, the storage of three features (including pre-show content) per screen
(one feature currently showing and a second or upcoming feature). Shown in Table 9
below, are some example storage requirements. The numbers are based on:
One three-hour feature
Table 9: Example of Storage Capacity for one 3-Hour Feature (12 bits @ 24 FPS)
Capacity
Excluding storage necessary for redundancy, the storage system is required to provide
for, at a minimum, the storage of three features (including pre-show content) per screen
(one feature currently showing and a second or upcoming feature). Shown in Table 9
below, are some example storage requirements. The numbers are based on:
One three-hour feature
- 20 minutes of pre-show material at the same resolution
- 16 channels of uncompressed audio at 48 kHz at 24 (AES3) bits
- 3,000 sub pictures in PNG file format
- 3,000 Timed Text lines
| Average Bit Rate (Mbits/sec) | 3 Hour Image (GBytes) | 3 Hour Audio (Gbytes) | 20min pre-show (Gbytes) | Sub Picture(Gbytes) | Timed Text (Gbytes) | 3 HOur (Gbytes) |
| 250 | 337.500 | 2.074 | 37.500 | 0.300 | 0.001 | 377.374 |
| 200 | 270.000 | 2.074 | 30.000 | 0.300 | 0.001 | 302.374 |
| 125 | 168.750 | 2.074 | 18.750 | 0.400 | 0.001 | 189.974 |
| 100 | 135.000 | 2.074 | 15.000 | 0.600 | 0.001 | 152.674 |
| 80 | 108.000 | 2.074 | 12.000 | 0.800 | 0.001 | 122.874 |
Table 9: Example of Storage Capacity for one 3-Hour Feature (12 bits @ 24 FPS)
- Image size: Calculated by: {Average or max bit rate (Mbits/sec) * hours * 60 min/hour * 60 sec/min} / {8 bits/byte *1000} the results is in GBytes
- Audio size: Calculated by: {32 (AES bits) * 48,000 samples/sec *16 (channels) * hours * 60 min/hour * 60 sec/min / 8 (bits/byte) = size or
Calculated by: {32 (AES bits) * 96,000 samples/sec *16 DCI Digital Cinema System Specification v.1.2 Page 70 (channels) * hours * 60 min/hour * 60 sec/min / 8 (bits/byte) = size - Sub Picture size: Calculated by: 100,000 (bytes/png file @ level 1) * 3,000 (subtitles/feature) = size
- Timed Text size: Calculated by estimate of 1 MBytes per feature
more bits always mean more information
more digital often means better quality
