Bitrate (Quality vs. File Size)

If you export a video using the H.264 codec, you must tell the encoder how much data it is allowed to use per second. This is called the Bitrate, usually measured in Kilobits per second (Kb/s) or Megabits per second (Mb/s).

Bitrate is the single most important factor determining the final visual quality of a web video.

Automatic vs. Restricted

In Oraphim's Render Settings, under the Quality section, you have two options:

Automatic

• Oraphim analyzes the motion in your video and assigns whatever bitrate it thinks is best.
• "Best" will create a massive, pristine file. "Medium" will create a smaller file with some compression artifacts.

Restrict To

• This forces a strict data limit. This is crucial when delivering to clients with strict IT requirements or uploading to sites with file size limits.

How to Choose a Bitrate

A higher resolution and a higher frame rate require a higher bitrate. (A 4K 60fps video has 8 times more data per second than a 1080p 24fps video).

Standard Bitrate Recommendations (H.264)

• 1080p (24-30fps): 10,000 to 15,000 Kb/s (10-15 Mbps). Good for standard YouTube uploads.
• 1080p (60fps): 15,000 to 22,000 Kb/s.
• 4K (24-30fps): 45,000 to 60,000 Kb/s. If you upload 4K video at 10 Mbps, it will look like blocky, pixelated garbage.
• 4K (60fps): 60,000 to 80,000 Kb/s.

Note: If you are using the H.265 codec, you can safely cut these numbers in half and achieve the exact same visual quality.

Variable Bitrate (VBR) vs. Constant Bitrate (CBR)

Some advanced codecs allow you to choose the encoding strategy:

• CBR (Constant): The encoder uses exactly 15,000 Kb/s every single second, whether it is an action scene or a completely black screen. This guarantees exact file sizes, but wastes data.
• VBR (Variable): You set an average target (e.g., 15,000) and a maximum peak (e.g., 20,000). The encoder intelligently lowers the bitrate to 2,000 Kb/s during a slow, static interview (saving space), and spikes it to 20,000 Kb/s during a massive explosion with flying debris (preventing pixelation). VBR is almost always the preferred choice.

Calculating File Size

You can mathematically calculate your final file size before you even hit render. Bitrate (in Megabytes per second) x Duration of video (in seconds) = Total File Size.

(Remember to divide Megabits by 8 to get Megabytes).

• A 10-minute video (600 seconds) at 16 Mbps (2 MB/s).
• 600 x 2 = 1,200 MB (or 1.2 Gigabytes).