How Much Bandwidth Do I Need For Security Cameras

Bitrates and resolitions

We get a lot of questions about how to find the optimal resolution to bitrate ratio. The truth is, there really is no right or wrong answer. Depending on your encoder, video content, audience, and streaming destination, your resolution and bitrate will likely exist unlike. That existence said, you tin optimize your resolution and bitrate to ensure consistent video quality and make your video viewable by the bulk of your audience.

What Are Resolutions? What Are Bitrates?

To best determine the optimal ratio for your stream, let's first ascertain what resolutions and bitrates are and how they bear upon video quality.

Different bitrates for different resolutions

Resolution is the number of pixels spread beyond a display and is usually written in the form of horizontal pixels x vertical pixels, such as 1920 10 1080. The resolution of your display affects the highest resolution of stream you can watch. Resolution is sometimes referred to in a shorthand format using just the vertical pixels, such as 720p instead of 1280x720.

For example, if you have a 720p monitor and are watching a 720p stream, that'due south perfect. Your monitor can display every pixel of the video. If the stream was broadcast in 1080p, however, your monitor will scale the paradigm into 720p. It won't inhibit the video quality, simply since the monitor can simply see 720 pixels, anything beyond that is wasted bandwidth.

Bitrates graph

Bitrate is the amount of data encoded for a unit of measurement of time, and for streaming is ordinarily referenced in megabits per 2nd (Mbps) for video, and in kilobits per second (kbps) for audio. From a streaming perspective, a college video bitrate means a higher quality video that requires more bandwidth. So why doesn't everyone just upload at the highest bitrate possible? Well, not every viewer tin download at the highest bitrate possible.

If you have a download speed of 5 Mbps and you are watching a stream at half dozen Mbps, the viewing experience will be choppy, and yous'll probably get stuck in buffering limbo because your connection tin can't go on upwards with the corporeality of information beingness sent on the stream.

Key Considerations for Choosing a Resolution and Bitrate

How much bandwidth practise I have to broadcast?

Yous must evaluate your network connection to determine whether it is stiff enough to support your stream at your desired resolution. Streaming at 1080p60 requires more bandwidth than streaming at 1080p30 or 720p60. Nosotros recommend only dedicating 50% of your upload speed to your stream in case your connection suddenly becomes unstable or you see unexpected interference from sending beyond the internet to the streaming platform.

If your available bandwidth isn't robust plenty to back up streaming at your desired resolution and bitrate, you tin can use network bonding to combine bandwidth from multiple internet sources into a single, stronger connectedness. By connecting your uniform encoder with Teradek's cloud stream direction platforms, Core or Sharelink, you can bond network connections from ethernet, wifi, cellular modems, and even mobile phones to overcome bandwidth restrictions on the encoder side.

Finally, if y'all have limited bandwidth at your broadcast site but your encoder is capable of streaming with a more efficient video codec similar HEVC / H.265 instead of just H.264, you tin can ship out a lower bitrate HEVC stream from your encoder and accept information technology transcoded to H.264 in the deject for terminal delivery to streaming destinations and viewers.

How is my audience watching? How much bandwidth do they take?

Consider where and how your audience volition be watching your video and what their bandwidth limitations may exist. Are they on computers or mobile phones? Using Ethernet or LTE? If the majority of your audience doesn't have enough bandwidth to watch your video in 1080p, then y'all shouldn't take to push button your bandwidth over the edge merely to upload a 1080p video.

Cloud transcoding can assistance those watching with slower connections or on mobile devices with data limits because it enables the unmarried stream sent out from your encoder to be converted into several lower resolution and lower bitrate streams that the viewers can choose instead of each viewer receiving the aforementioned higher resolution / higher bitrate stream. Platforms capable of deject transcoding include Facebook Live, YouTube Alive, Vimeo, and IBM Cloud Video.

What type of content am I sending? How much do I need to transport?

More than dynamic content requires higher bitrates to take good quality, and then you will demand a higher bitrate to stream sporting events or video game competitions as opposed to speakers giving presentations at a conference or commencement ceremonies.

The encoded frame charge per unit also affects the required bitrate. When streaming sports you could encode a 60 frames per 2d (fps) stream at 1080p60 or 720p60; for lower movement events like lectures or conferences, encoding and sending 60 fps may not provide a visible do good, but requires significantly more bandwidth than streaming at the more than common 30 fps. Not all online streaming platforms can have a 60 fps stream, and not all viewers tin can handle receiving 60 fps, and then exist sure to accept that into consideration.

Finally, in that location are 2 different methods of encoding the video: constant and variable. A abiding bitrate encodes at approximately the same charge per unit throughout the stream. While this can help maintain consequent quality, a constant bitrate isn't always ideal for streaming over the internet since the same amount of data is existence sent fifty-fifty when the content isn't very complex, incurring higher costs from mobile data plans.

Constant bitrate vs variable bitrate graph

Teradek encoders use a variable bitrate encoding to more efficiently encode. If there'south not a lot of motion - like a speaker at a podium - your encoder volition utilise a lower bitrate to save on outbound information but increment the encoding quality as needed, such every bit when you lot pan the camera or zoom for a wider shot.

To which CDN / OVP am I streaming?

If y'all're streaming to a unmarried destination - direct to Facebook Live or YouTube Alive, for instance - then your encoder's settings need to match that destination'southward requirements for bitrate and resolution on the incoming stream.

Some platforms similar YouTube Live or IBM Cloud Video need video bitrates to be within a sure range for the resolution, so if you don't have enough bandwidth at your site for a 1080 stream, you need to scale downward the streaming resolution and bitrate to autumn within their requirements.

If yous're using Core or Sharelink to stream to multiple destinations at the same time, then y'all demand to cull encoding settings that are compatible with every destination, since the encoder will only ship out a unmarried stream into Cadre or Sharelink, and that stream is then replicated to each destination.

Go along in mind that every streaming platform comes with different presets which may limit the video bitrate and resolution combinations they will take. Hither are some popular streaming destinations and their settings: