CBR vs VBR

What is it?

Two philosophies for spending your bitrate budget:

• CBR (Constant Bitrate): the video uses the same amount of data every second, no matter what's on screen. Predictable, steady, network-friendly.
• VBR (Variable Bitrate): the video spends more data on busy, fast-moving scenes and less on still ones. Efficient, but the data flow spikes up and down.

Like a salary (CBR — same amount every month, easy to plan around) versus freelance income (VBR — efficient overall, but unpredictable spikes).

Practical example

A streamer uses VBR. During a calm talking segment everything is fine, but when they play a fast-action clip the bitrate suddenly spikes above what their internet can upload — the stream stutters at exactly the most exciting moment. Switching to CBR caps the flow at a steady rate the connection can always handle, and the stutters disappear. This is why live streaming platforms recommend CBR, while VBR rules in offline video files (like uploads to YouTube), where there's no real-time pipe to overflow.

Key things to know (non-technical)

• Live = CBR (stability beats efficiency when a network is involved in real time).
• Recorded files = VBR (efficiency wins when nothing has to survive a live connection).
• VBR's danger in live: spikes during action scenes are what break streams.
• Most streaming apps default to CBR for broadcast — a default worth never changing.

In Tupic Live

Tupic Live's broadcaster should lock CBR for the live feed (stability first), while VBR can be used when processing recordings and clips afterward — smaller VOD files, same quality.