Methodology, Formulas & Parameter Reference
Intra-frame cinema and mezzanine codecs such as Apple ProRes, Avid DNxHR, and Blackmagic RAW compress each video frame independently without referencing neighboring frames. Because there are no inter-frame P-frames or B-frames, the data rate scales linearly with both pixel count (resolution) and frame rate. If you double the frame rate from 24 fps to 48 fps at the same resolution, or quadruple the pixel count from 1920x1080 (\(2.07 \times 10^6\) pixels) to 3840x2160 (\(8.29 \times 10^6\) pixels), the sustained data rate and storage footprint scale in direct proportion.
Given a codec base data rate \(R_{\text{ref}}\) measured in megabits per second (Mbps) at a reference raster \(P_{\text{ref}}\) (\(1920 \times 1080\)) and reference frame rate \(F_{\text{ref}}\) (\(24\text{ fps}\)), the sustained write speed in megabytes per second (\(\text{MB/s}\)) for a target resolution \(W \times H\) and frame rate \(F\) is:
\[ \text{Write Speed (MB/s)} = \frac{R_{\text{ref}}}{8} \times \left(\frac{W \times H}{1920 \times 1080}\right) \times \left(\frac{F}{24}\right) \]
Multiplying the sustained write speed by \(3600\text{ seconds/hour}\), adding multi-channel uncompressed PCM audio (for example, 8 channels of 24-bit / 48 kHz audio adds \(1.15\text{ MB/s}\)), and multiplying by the camera count yields the hourly production footprint. Storage manufacturers label CFexpress, SDXC, and NVMe drives in decimal gigabytes (\(1\text{ GB} = 10^9\text{ bytes}\)), and camera operators should always reserve a 10% buffer on capture cards to prevent filesystem fragmentation and thermal write throttling near full capacity.
| Codec / Flavor | Bit Depth & Chroma | Sustained Data Rate | Hourly Footprint (1 Cam) |
|---|---|---|---|
Apple ProRes 422 Proxy |
10-bit 4:2:2 | 19.0 MB/s (152 Mbps) | 68.4 GB / hr |
Apple ProRes 422 LT |
10-bit 4:2:2 | 42.8 MB/s (342 Mbps) | 154.1 GB / hr |
Apple ProRes 422 Standard |
10-bit 4:2:2 | 61.8 MB/s (494 Mbps) | 222.5 GB / hr |
Apple ProRes 422 HQ |
10-bit 4:2:2 | 92.6 MB/s (741 Mbps) | 333.4 GB / hr |
Apple ProRes 4444 |
12-bit 4:4:4 + Alpha | 138.9 MB/s (1,111 Mbps) | 500.0 GB / hr |
Blackmagic RAW (BRAW 8:1) |
12-bit Bayer RAW | 53.0 MB/s (424 Mbps) | 190.8 GB / hr |
Blackmagic RAW (BRAW 3:1) |
12-bit Bayer RAW | 141.0 MB/s (1,128 Mbps) | 507.6 GB / hr |
Production Workflow Verification & Quality Control
Before committing a full batch transcode or publishing a final master, verify the generated parameters against a five-second test slice of your source timeline. In post-production pipelines, container metadata headers, variable frame rate (VFR) timebases from mobile or screen-capture recordings, and non-square pixel aspect ratios can alter how downstream players interpret stream flags. Running every calculation and file conversion locally in browser memory ensures your production assets remain private while providing deterministic numbers you can paste directly into terminal automation scripts, NLE export presets, or camera prep checklists.