Teradek User Guide


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In addition to configuring your stream type, Prism allows you to control various characteristics of the network video stream. The Encoder settings can be found by clicking Input/Encoding at the top of the web UI.


  • VIDEO INPUT - Prism 1RU/2RU: Displays the source of the video input.
    Prism Flex/Mobile: Select the source of the video input (SDI, HDMI, or Auto).
  • CODEC - Select either HEVC or H.264 compression formats.
  • DEINTERLACER (HEVC only) - The Deinterlacer converts interlaced video into progressive video before streaming, improving the appearance of video that has been scaled down from the original input resolution. In addition to supporting scaled down interlaced video, deinterlacing is also useful when streaming to the Internet or mobile devices instead of a decoder.
  • RESOLUTION  - Maintain the input’s native resolution (Auto), or manually enter a custom resolution (Custom).
  • BITRATE SELECTION - Select your stream’s target bitrate from a list of bitrate figures, or manually enter a custom bitrate. Lower bitrates require less bandwidth and may allow for a more stable stream while higher bitrates offer better video quality, but require more network bandwidth.
  • AUTO BITRATE QUALITY - Automatically adjusts the bitrate quality to achieve the desired resolution without having to indicate a specific bitrate value. NOTE: This setting is only available when the Bitrate Selection is set to Auto.
  • COLORIMETRY - Adjust your stream’s color parameters
  • BIT DEPTH  - The Bit Depth setting determines how many bits are used for each color component in a video stream. 8-bit color depth is sufficient for most live streaming applications, while 10-bit color depth is required for HDR workflows or other instances where higher color resolution is required.
  • CHROMA SUBSAMPLING  - Chroma Subsampling is a compression method that reduces the color information and file size in a signal in favor of luminance data and decreased bandwidth.
  • CLOSED CAPTIONS - Turn closed captions on and off


  • BITRATE CONTROL METHOD  - This option is used to define the quality and bitrate of the stream. Variable Bitrate allows the codec to modify the bitrate within a quality range according to the target bitrate. Constant Bitrate maintains the output data’s bitrate at a consistent level, regardless of the video complexity. Constant Quality maintains the quality of the video without limiting the maximum or minimum bitrates.
  •  KFI MODE  - Select either Key Frame Interval or Group of Pictures mode.
  • KEY FRAME INTERVAL/GOP LENGTH  - Adjust the amount of time between full picture refreshes (Key Frame Interval), or the number of frames (GOP Length).
  • FRAME RATE SELECTION  - Set the encoder frame rate to the exact figure or a fraction of the input frame rate.
  • NUMBER OF SLICES - Determine the number of slices in the video frame that enables efficient compression and processing. Dividing a frame into segments allows for more efficient compression and decompression of video, making it easier to transmit and store.
  • SKIP FRAME -  Helps maintain the target bitrate by skipping frames when necessary.


The Generator allows you to stream picture and sound for test purposes or when no source is present.

  • VIDEO GENERATOR - Enable or Disable the Video Generator, or select Failover to output a specific image in case your source goes offline.
  • VIDEO GENERATOR SOURCE - Select Black, Color Bars, or Image as the video test pattern source. 
  • UPLOAD IMAGE - Upload an image to use as your test pattern source. NOTE: Only PNG files are supported.
  • TEST TONE - Enable or Disable the Test Tone generator, or select On Video Generation to enable a Test Tone in case your source goes offline or is unavailable.
  • . Once enabled, you can adjust the Test Tone Frequency and Volume.


Prism's Color Management menu lets you manage and apply different looks to incoming video signals using 3D LUT and CDL files saved to your Prism from your computer. You can also link Prism to your LiveGrade account using the web UI.

  • MODE - Select either CDL + 3D LUT or LiveGrade for your color management mode.
    • CDL MODE - Enable or disable a CDL preset. Enabling CDL mode allows Prism to apply the preset to your preview.
    • CDL SPLIT - Enable the preview window to display a split screen; one side showing the CDL preset applied to the preview, and the other side without.
    • CDL FILE - Select a CDL file to apply to the video preview. CDL files must first be uploaded to Prism from your computer by clicking  Select file, then Upload CDL. To delete a file, click Delete CDL.
    • 3D LUT MODE - Enable or Disable a 3D LUT preset. Enabling 3D LUT mode allows Prism to apply the preset to your preview.
    • 3D LUT SPLIT - Enable the preview window to display a split screen; one side shows the 3D LUT preset applied to the preview, and the other does not.
    • 3D LUT FILE - Select a 3D LUT file to apply to the video preview. 3D LUT files must first be uploaded to Prism from your computer by clicking  Select file, then Upload 3D LUT. To delete a file, click Delete 3D LUT.


  • AUDIO INPUT - Configure the audio input source by selecting Embedded, Analog, or Mixed.
  • BITRATE SELECTION - Select from a list of bitrate figures, or manually enter a custom bitrate.
  • OSD SETTINGS - Configure how the time is displayed on your stream. Select either SDI, Stream, or UTC timecodes, or select disable.
  • OVERLAY SETTINGS - Select a file to overlay onto your video stream, then adjust the location of the image.


The Overlay settings allow you to place graphics and other media over your live stream. You can create several different overlays. 


1. To create an overlay, click the + Add Overlay tab.

2. From the Overlay editing screen, tap Image on the top right corner to select an image as your overlay, or use the tools to create an overlay.

3. To preview how your Overlay will appear on the live stream, click Preview stream. To return to a transparent background, click Transparent.

4. Elements used to create an overlay are listed on the right. To modify an element, click any of the elements listed to open the editing panel. Click Save when you're done to return to the web UI.

5. From the Overlay settings, click Enabled, then select the overlay you want displayed on your live stream. Click Save when you're done. NOTE: Overlays will not appear unless you click Enabled.

The Overlay is now visible on your live stream

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