Video Bandwidth

How to use

1. Set the codec, headroom, and whether substreams are recorded. A site normally runs one codec. MJPEG uses JPEG quality and optional KB per frame on each group instead of smart codec.
2. List camera groups the way the job is bought: quantity, lenses per housing, resolution, frame rate, and scene activity. An override replaces the estimate for that group.
3. Add viewing clients separately. A video wall pulls streams off the recorder whether or not those cameras are recording. Mark each client local or remote.
4. Read the three segments. Cameras to recorder is recording traffic. Local and remote viewing are separate. The WAN total is the upload the internet connection has to carry.

Assumptions

• Bitrates are estimates. Every manufacturer’s encoder differs. The manufacturer bitrate calculator governs.
• Variable bitrate streams move with the scene. These figures are averages, not peaks.
• Audio, PTZ control, and metadata are not counted.
• Frame rate scaling is (frame rate ÷ 30) raised to 0.75 for inter-frame codecs. H.265 is 0.55 times the H.264 table. Smart codec is an additional 0.60 when enabled.
• MJPEG uses frame size in KB × frame rate × 8 ÷ 1,000. Medium-quality 1080p is 130 KB per frame. Activity still applies. MJPEG barely responds to motion because every frame is sent whole.
• Daily volume uses SI units: megabits per second × 3,600 × 24 ÷ 8 ÷ 1,000.
• The result is an estimate. Manufacturer data, the AHJ, and current applicable code govern material and whether a circuit is energized.

FAQ

Why is this number different from the camera’s configured maximum bitrate?

The configured maximum is a cap the encoder will not exceed. This page estimates an average for the selected resolution, frame rate, codec, and scene. A busy scene or a higher cap still sits under the manufacturer’s own calculator.

Why can a video wall swamp a recorder that handles recording fine?

Recording traffic is cameras to the recorder. Viewing traffic is a second set of streams leaving the recorder toward workstations. A wall showing 48 substreams at 1 Mbps is 48 Mbps of viewing, whether or not those cameras are being recorded a second time.

What does H.265 save on this page?

H.265 is 0.55 times the H.264 table. Twenty 1080p cameras at 30 fps and medium activity are 80 Mbps on H.264 and 44 Mbps on H.265. The camera has to actually encode H.265.

Why is the WAN segment the one that fails at a customer site?

Remote viewers pull streams across the site’s internet upload. A 100 Mbps handoff that is already carrying other traffic does not have 100 Mbps left for video. The WAN total is the number to compare to that upload.

Why can the cameras be Cat6 and the head end still need Cat6A?

A camera drop is normally well under 1 Gbps, and Cat6 carries 1 Gbps and 2.5 Gbps over a 100 m channel. The uplink that aggregates many cameras, or a workstation that pulls a large multi-view, is the link that can land at 10 Gbps. 10GBASE-T over a 100 m channel is Cat6A.

What does the Cat6 distance limit at 10 gig mean in an existing building?

Cat6 carries 10 Gbps only over a shortened channel, commonly cited as 37 to 55 m, depending on how much alien crosstalk the bundle sees. A longer existing Cat6 run at 10 gig is a distance question. Fiber with SFP+ or SFP28 optics is the other path when that channel is not enough.

Why is MJPEG usually run at a low frame rate?

MJPEG sends every frame as a complete JPEG, so bitrate scales linearly with frame rate. The same 1080p medium-quality stream is 10.4 Mbps at 10 fps and 31.2 Mbps at 30 fps.

Why can 1080p MJPEG at 30 fps cost more than seven times the same camera on H.264?

A medium-quality 1080p JPEG is 130 KB. At 30 fps that is 31.2 Mbps. The H.264 table value for the same camera is 4.0 Mbps. 31.2 divided by 4.0 is 7.8.