Teradek User Guide

Encoder Configuration

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Prism Encoders are extremely flexible codecs capable of encoding up to 4KP60 in H.264 or H.265 with many resolutions in between.
Prism supports native interlaced encoding 1080i50/59 in both h.264 (beta) and h.265 as well as 1080p120 over HDMI inputs.

ENCODER MODE

Prism Devices have two modes as of 2.22

  • Next-Gen - Supports a more robust and lower latency workflow
  • Standard - Supports legacy workflows (deprecated as of 2.23)

NOTE: This section only applies to Next Gen Mode

VIDEO SETTINGS

VIDEO INPUT 

  • Prism 853/877: Displays the video input source as SDI or HDMI
  • Prism Flex/Mobile - (Default: Auto) Select the source of the video input (SDI, HDMI, or Auto). Auto will attempt to select the active video source.  If two video sources are present, the first connected video source will be activated.

CODEC - Prism Supports either H.264 or HEVC (H.265) codecs (Default: H.264).

  • H.264 Compression is more compatible with legacy and distribution workflows and is currently required for RTMP and WHIP streaming.  Some 3rd party solutions might require H.264 for ingest.
  • HEVC (H.265) compression allows for the same quality as H. 264 but half the bitrate. This is useful for low-bitrate bonding, video distribution links, and next-generation streaming protocols.

INTERLACER - The Interlacer allows the Prism to either stream in Interlaced mode or Progressive (de-interlaced) mode.  Progressive Video is required for RTMP and WHIP streaming, while interlaced video may be desirable 1080i50/59 contribution links. (Default: Progressive) 

RESOLUTION  - Sets the encoding resolution (Default Auto).

  • Auto: Maintains the input’s native resolution
  • Common: Select from a common set of resolutions for encoding (recommended)
  • Custom: Manually enter a custom resolution with Width and Height declarations

FRAMERATE SELECTION - Sets the encoding framerate (Default Auto).

  • Auto: Maintains the framerate from input (recommended)
  • Fraction: Sets a fraction of the input framerate, ie. 1/2 of a 60fps would be 30fps
  • Common: Select from a common set of framerates for encoding.
  • Custom: Manually enter a custom framerate

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 (Default Auto).

  • Auto - Automatically adjusts the bitrate quality to achieve the desired resolution without indicating a specific bitrate value.
  • List - Lists Bitrate in pre-defined increments in kilobytes per second
  • Custom - Allows a custom bitrate in kilobytes per second

NOTE: For recording, we recommend setting the bitrate at 45Mbps or less.

BIT DEPTH - The Bit Depth setting determines how many bits are used for each color component in a video stream (Default 8-bit).  

  • 8-bit color depth is sufficient for most live-streaming applications,
  • 10-bit color depth is required for HDR workflows or other instances where higher color resolution is desired. It may be important to increase bitrate when using 10-bit color

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 (Default 4:2:0). 

  • 4:2:0 is acceptable for most broadcast applications and is typically used.
  • 4:2:2 may be required where higher color fidelity is required.  It is important to increase bitrate when using 4:2:2

Advanced Settings

PROFILE -  H.264 Profile (Default: High).

  • Baseline
  • Main
  • High

BITRATE CONTROL METHOD - Specifies how the encoder manages video bitrate to balance quality and data usage (Default: Fast Adaptive Bitrate).

  • Fast Adaptive Bitrate - reacts more quickly to changing video complexity allowing to maintain target bitrate more accurately than in variable bitrate mode at the expense of the picture quality
  • Constant Bitrate  - tries to maintain target bitrate, but will fill bitrate with null packet values to maintain a constant bitrate
  • Variable Bitrate - tries to maintain target bitrate, but may vary depending on the specified quality range and picture complexity

COLOR OVERRIDE  - Color Override allows the manual selection of color range and colorimetry settings (Default: Disabled)

  • Range:
    • Default - Adheres to the source input
    • Legal - Outputs to standard broadcast-safe values
    • Full - Expands to the entire color range for enhanced detail
  • Colorimetry: Overrides the color space standard used by the encoder to interpret color values
    • Auto, Rec.601, Rec.709, Rec.2020, Rec.2020-PQ, P3D65-PQ, Rec.2020-HLG

KFI MODE  - Determines how often the whole picture is transmitted (Default: Key Frame Interval - 2).

  • Key Frame Interval (seconds) and set the KEY FRAME INTERVAL below
  • Group of Pictures(frames) and set the GOP LENGTH (Frames) below

NUMBER OF SLICES - Automatically set to 8 if using 4K. Slicing divides a video frame into smaller, independently encoded sections, which helps reduce the impact of errors. Not all 3rd party decoding applications support slicing (Default: 8).

SKIP FRAME: Allows the codec to skip frames to enhance picture quality.

QP MODE - Specifies how to generate Quantization Parameter (QP) values per Coding Unit (CU) in H.264/H.265 encoding (Default: Auto).

  • Auto - allows the encoder to adapt QP dynamically for optimized quality and compression,
  • Uniform - applies a consistent QP across all CUs for more predictable compression behavior.

GDR MODE - Gradual Decoder Refresh, a method that refreshes parts of the frame independently without requiring a full key frame (I-frame). Improves bandwidth utilization and eliminates I-frame "pulsing".  When to use: when low latency is required and to eliminate pulsing (Default: Disabled

CODED PICTURE BUFFER SIZE - Specifies how much video the decoder would need to buffer before starting playback (Default: 1.5s)

QP MINIMUM and MAXIMUM - Specifies the range of Quantization Parameter (QP) settings that the encoder can use during compression, where the minimum value allows for the highest possible quality with less compression, and the maximum value enables greater compression at the expense of video quality (Default 10/51).

AUDIO SETTINGS

MULTI-TRACK - Enables or disables the multi-track audio configuration (default: disabled). See the section below for multi-track setup.

  • Prism supports up to 8 audio tracks, each configurable as Mono, Stereo, 5.1, or 7.1.
  • Prism can detect 16 audio channels from SDI and 8 channels from HDMI, and it allows remapping of these channels.

Single Track Mode Settings (Multi-Track Disabled)

  • AUDIO INPUT - Select which audio source to use.
    • Embedded - up to the first 8 channels in mono, stereo, 5.1, or 7.1 configuration HDMI or SDI digital audio input.  
    • Analog - Mono or Stereo
  • INPUT GAIN - Allows adjustment of input gain for analog or embedded modes. Applies to all input channels in the track.
  • ANALOG OUT - Adjusts the Analog output (3.5mm) gain.
  • CHANNEL MODE - Sets track encoding to mono, stereo, 5.1, or 7.1
  • BITRATE SELECTION - Select from a list of bitrate figures, or manually enter a custom bitrate.

Advanced Settings

  • ASYNCHRONOUS AUDIO - Enable this option if embedded audio is asynchronous (out of sync with video). This setting corrects issues with certain embedding devices.
  • IGNORE SDI PHASE - Ignores SDI Phase sync information.  Helpful for situations where the timing between audio and video might not be precise.
  • ENCODE AUDIO - Enable/Disable audio encoding.
  • AUDIO CODEC - Allows selection of Audio Codec between AAC, OPUS (BETA), and MPEG II (BETA).

NOTE: WHIP, WHEP, and similar integrations always use the OPUS codec, regardless of other codec selections. MPEG II and OPUS codecs (outside of WebRTC-based workflows) are considered in Beta. Please test your configuration for compatibility.

  • SAMPLERATE MODE - Allows selection of Sample Rate:  32000,  44100, 48000 kHz (Default: Auto)
  • INPUT DELAY - Adds audio delay to align video.  Useful for aligning audio with video

Multi-Track Mode Settings (Multi-Track Enabled)

Multitrack mode is an incredibly flexible mode that allows any audio input to be assigned to any audio track (up to 8) in any audio encoding.

  • AUDIO PRESETS - Select a preset to automatically assign the appropriate channels for stereo use and populate up to 8 audio tracks in sequence. For example, the "2 Tracks" preset assigns two stereo tracks using inputs 1-4 as follows: Left 1, Right 2, Left 3, Right 4
  • ADD TRACK - Adds a default audio track for configuration.

Advanced Settings

  • ASYNCHRONOUS AUDIO - Enable this option if embedded audio is asynchronous (out of sync with video). This setting corrects issues with certain embedding devices.
  • IGNORE SDI PHASE - Ignores SDI Phase sync information.  Helpful for situations where the timing between audio and video might not be precise

Configuring Tracks

  • MUTE TRACK (Default: Unmuted) - Mutes the configured audio track while continuing to encode blank audio
  • AUDIO CODEC - Allows selection of Audio Codec between AAC, OPUS (BETA) and MPEG II (BETA).
  • TRACK CHANNEL MODE - Sets track encoding to mono, stereo, 5.1, or 7.1
  • SAMPLE RATE MODE (Default: Auto) - Allows selection of Sample Rate:  32000,  44100, 48000bps
  • INPUT DELAY - adds audio delay for the purposes of aligning video.  Useful for aligning audio with video
  • CHANNEL SELECTOR - Allows remapping of channels onto the track depending on TRACK CHANNEL MODE mode selection.

METADATA SETTINGS

Prism's Metadata Settings allow you to embed Timecode and Closed Captioning data from your camera onto your video footage.

  • TIMECODE (Default Disabled)- Select where the timecode metadata is extracted from.
    • Disabled
    • SDI/HDMI Timecode
    • Stream Timecode
    • System Timecode
  • CLOSED CAPTIONS - Enables / Disables  608/708 Closed Captioning

OSD SETTINGS

On Screen Display allows moving overlay with Timecode or Date / Time

  • OSD MODE (default disabled)
    • Disabled
    • SDI/HDMI Timecode
    • Stream Timecode
    • System Timecode
    • System Time
    • System Date/Time

LOCATION  - Define the location of the OSD with a preset location or manual location.

 

OVERLAY SETTINGS

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

  • OVERLAY
    • Enable - Enables overlay as active
    • Disable - Removes overlays

CREATE AN OVERLAY

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

COLOR MANAGEMENT

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.
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