Prism encoders are flexible codecs capable of encoding H.264 and HEVC video up to 4K60, with configurable interlaced/progressive settings, 10 bit 4:2:2 support, and many other options. Multiple encoders can be configured as individual pipelines, and each pipeline contains its own independent encoder settings.
This section details all available settings on an encoder pipeline's page. To open it, select Pipelines > Encoder 1 (or another encoder pipeline) in the sidebar. For an introduction to pipelines and the web UI, see Web UI Overview.
Pipeline Header
The header strip at the top of the pipeline page shows the pipeline's state and its main routing (see image below).
- Back arrow - Returns to the Pipelines page.
- Name - The pipeline name. Click the pencil icon to rename the pipeline.
- State - The pipeline state (for example ENCODING) and how long it has been running. A warning such as No input signal appears when the input is lost.
- Live preview - Switches the preview between a periodic snapshot and a live WebRTC preview. The same switch is on the pipeline card and the Scopes tab.
- Pipeline options (three dots) - Deactivate, Restart, and Remove pipeline. These act on the device immediately.
- INPUT - The input the pipeline encodes and its signal status. Click it to choose a different input: a physical input (for example SDI 1 or HDMI) or a network input (for example Ingest 1). Without a Multi-Input Encode license, all encoder pipelines share one physical input, so changing the physical input on one pipeline changes it on every pipeline, and the web UI warns you before it applies the change. With the license, each pipeline can encode from its own physical input.
- ENCODER - The codec, resolution, and frame rate being encoded (for example H.264 - 3840x2160p30).
- OUTPUTS - The number of outputs. Click it to see each stream's state and uptime. Push streams that are ready but not sending (for example RTMP) show a Go Live button. Click Open Outputs to go to the Outputs tab.
- Recording status and Start Recording - The recorder's state (for example Invalid - Storage Media not selected) and the button to start recording this pipeline.
NOTE: Multi-Input Encode is an optional license for Prism Mobile, Prism Flex, Prism Flex MkII, Prism Jetpack, and Prism Rackmount encoders. To add a license, see System Settings.
Below the header, the pipeline's settings are split across tabs: Video & Audio, Metadata & OSD, Color Grading, Overlay Settings, Outputs, Recording, and Scopes.
Changes on the Video & Audio and Metadata & OSD tabs are staged before saving: an Unsaved badge appears and nothing reaches Prism until you click Apply. Click Discard to undo. Some controls on other tabs act immediately; these are noted below.
Video & Audio
Video Settings
Video Codec - Prism supports H.264 and HEVC (H.265).
- H.264 - (Default) More compatible with legacy and distribution workflows. Required for RTMP and WHIP streaming. Some third-party solutions require H.264 for ingest.
- HEVC - High Efficiency Video Coding gives the same quality as H.264 at about half the bitrate. Useful for low-bitrate bonding, video distribution links, and next-generation streaming protocols.
Interlacer - Sets whether Prism encodes interlaced or progressive video. Progressive video is required for RTMP and WHIP streaming. Interlaced video may be useful for 1080i50/59.94 contribution links.
- Match Input - Encodes interlaced or progressive to match the input.
- Interlaced
- Progressive - (Default) De-interlaces interlaced inputs.
Bitrate Selection - Sets how you choose the video bitrate. Lower bitrates require less bandwidth and can give a more stable stream. Higher bitrates give better video quality but need more network bandwidth.
- Auto - (Default) Prism sets the bitrate for you. Select the target quality in Auto Bitrate Quality.
- List - Select a bitrate from a list.
- Custom - Enter any bitrate.
Auto Bitrate Quality (Auto only) - The quality target Prism uses to set the bitrate: Best Quality, High, Medium, Low, or Minimum Bandwidth.
Bitrate (Kbps) (List or Custom) - The target video bitrate in kilobits per second (Default: 5000).
- List - 100, 200, 300, 500, 1000, 1500, 2000, 2500, 3000, 4000, 5000, 6000, 7000, 8000, 9000, 10000, 15000, 20000, 25000, 30000, 35000, 40000, 45000.
- Custom - Any value from 50 to 85000.
NOTE: For recording, set the bitrate to 45Mbps or less, and use an SD card that is speed class 10, UHS speed 1 or higher, or video speed V10 or higher.
Resolution - Sets the encoding resolution.
- Auto - (Default) Keeps the input's native resolution.
- Common - Select from a set of common resolutions (recommended): 360p, 540p, 720p, 864p, 1080p (default), 1296p, 1440p, 1728p, 1800p, 2160p.
- Custom - Enter a Width (240 to 4096) and Height (240 to 2160) in pixels. Defaults: 1920 x 1080.
Framerate Selection - Sets the encoding frame rate.
- Auto - (Default) Keeps the input frame rate (recommended).
- Common - Select from a set of common frame rates in Common Framerate: 23.976 p/psf, 24 p/psf, 25 p/psf, 29.97 p/psf, 30 p/psf (default), 50 p/i, 59.94 p/i, 60 p/i, 120 p.
- Exact - Enter any frame rate from 0 to 120 in Framerate Exact (Default: 30).
The image below shows Auto bitrate with Common resolution. The second image shows Custom bitrate, Custom resolution, and Exact frame rate.
Bit Depth - The number of bits used for each color component.
- 8-bit - (Default) Enough for most live-streaming applications.
- 10-bit - Required for HDR workflows, or wherever more color resolution is needed. Consider raising the bitrate when you use 10-bit.
Chroma Subsampling - Reduces color information in favor of luminance to save bandwidth.
- 4:2:0 - (Default) Suitable for most broadcast applications.
- 4:2:2 - For workflows that need higher color fidelity. Consider raising the bitrate when you use 4:2:2.
Advanced Settings
Click Advanced settings below Chroma Subsampling to show the advanced encoding settings. The number next to it shows how many settings are in the section (see image below).
Profile - The profile the bitstream conforms to.
- H.264: Baseline, High (Default), Main.
- Baseline - Basic profile for low-power devices and simple applications.
- Main - Standard profile for broadcast and streaming.
- High - Advanced profile for HD content and maximum quality.
- HEVC: Main only (shown, not selectable).
H265/HEVC Interlaced Field Coding (HEVC only) - When on, Prism codes interlaced video as separate fields instead of frames. This can improve compatibility with third-party decoders in interlaced workflows. It has no effect on progressive video (Default: Off).
Maximum Bitrate Ratio - Limits bitrate spikes to this ratio of the target bitrate, from 1 to 5 (Default: 1.5). Hidden when Bitrate Control Method is Constant Bitrate.
Bitrate Control Method - How the encoder manages the video bitrate to balance quality and data usage.
- Constant Bitrate - Tries to hold the target bitrate, filling unused bandwidth with null packets to keep the bitrate constant.
- Variable Bitrate - (Default) Tries to hold the target bitrate, but the bitrate may vary with picture complexity.
- Fast Adaptive Bitrate - Reacts faster to changes in picture complexity and has lower latency, at the expense of picture quality.
KFI Mode - Determines how often the whole picture (a key frame) is sent.
- Key Frame Interval - (Default) Set the interval in seconds in Key Frame Interval (0.1 to 10, Default: 2).
- Group of Pictures - Set the interval in frames in GOP Length (Frames), including the I picture (0 to 1000, Default: 30).
Scene Change Detection (Encoder 1 only) - Reduces artifacts after scene changes, and may insert extra I-frames (Default: On). Changing this setting restarts the encoder.
Entropy Mode - Selects the entropy coding mode.
- CABAC - (Default)
- CAVLC
Number of Slices - Divides each frame into sections (1 to 8) that are encoded independently, which reduces the impact of errors. Prism sets it to 8 automatically for 4K. Not all third-party decoders support slicing (Default: 8).
Skip Frame - Skips frames when needed to hold the target bitrate (Default: Off).
QP mode - How the encoder sets the Quantization Parameter (QP) for each coding unit.
- Auto - (Default) Adapts QP dynamically for better quality and compression.
- Uniform - Applies the same QP across all coding units for more predictable compression.
GDR Mode - Gradual Decoder Refresh refreshes the picture one horizontal band at a time instead of with full key frames. This reduces the bitrate spikes ("pulsing") from I-frames and helps low-latency workflows.
- Enabled
- Disabled - (Default)
Coded Picture Buffer Size - How much video, in seconds, a decoder must buffer before starting playback (0 to 10, Default: 1.5).
Minimum QP / Maximum QP - The range of QP values the encoder can use. A lower minimum allows higher quality with less compression; a higher maximum allows more compression at the cost of quality (0 to 51; Defaults: 10 and 51). A Minimum QP of 0 lets the encoder choose the minimum automatically.
Color Override - Lets you set the color range, colorimetry, and transfer function instead of following the input (Default: Off). When on (see image below):
- EOTF - The transfer function signaled in the stream: Default (Default, follows the source), SDR, SMPTE2084 (PQ), HLG.
- Colorimetry - The color space standard the encoder signals: Auto (Default), Rec.601, Rec.709, Rec.2020, Rec.2020-PQ, P3D65-PQ, Rec.2020-HLG, Unspecified.
- Range - Default (Default, follows the source), Legal (broadcast-safe values), Full (the entire code range).
Audio Settings
The AUDIO section sets where the pipeline's audio comes from and which audio tracks it encodes (see image below). Input settings (gain, Asynchronous Audio, Ignore SDI Phase), mixing, routing, and Analog Out are on the Audio page; see Audio. Audio track settings are shared: a change here also shows on the Audio page, and the reverse.
Audio Input Source - The audio source for this pipeline.
- Embedded - (Default) Audio embedded in the SDI or HDMI input.
- USB - A USB audio device.
- Analog - The 3.5mm analog input.
AUDIO TRACKS - A pipeline can encode up to 8 audio tracks. Each track row shows its codec, channel mode, and bitrate (for example AAC-LC - Stereo - 128) and a level meter. Click a track to show its settings.
- Add track - Opens a menu: Attach existing attaches a track that is already on the device, and Create new track creates a track with default settings and attaches it to the pipeline.
- Track options (three dots) - Detach from pipeline removes the track from this pipeline but keeps it on the device, so it can be attached again. Delete track permanently removes the track from the device after you confirm; any other pipeline or stream using the track loses it too.
Note: Adding, detaching, and deleting tracks act on the device immediately. They are not staged with Apply, and Discard does not undo them.
Audio Track Settings
Each track has these settings (see image above, Track 1 expanded):
Mute Track - Mutes the track but keeps encoding it as silent audio.
- Muted
- Unmuted - (Default)
Codec - The audio codec for this track. MPEG Layer II and OPUS are not supported in some stream modes.
- AAC-LC - (Default)
- MPEG Layer II (BETA)
- OPUS (BETA)
- AC3
NOTE: WHIP, WHEP, and similar WebRTC integrations always use the OPUS codec, regardless of this setting. MPEG Layer II and OPUS (outside of WebRTC workflows) are in Beta. Test your configuration for compatibility.
Afterburner (AAC-LC only) - Improves audio quality at the same bitrate, at the cost of a large increase in CPU load. Turning it off roughly halves the CPU used to encode the track, which is worth doing when you run several encoders at once.
- On (better quality) - (Default)
- Off (lower CPU)
Track Channel Mode - The channel layout of the track: Mono, Stereo (Default), 5.1, or 7.1.
Channel Layout Input (5.1 and 7.1 only) - How input channels are assigned to the surround channels: SMPTE, Film, HDMI, or Remap (Default). Remap uses the Channel Map below.
Bitrate (Kbps) - The audio bitrate for the track (Default: 128). The list depends on the codec:
- AAC-LC - 48, 64, 96, 128, 192, 256, 320, 512 (up to 320 at 32kHz).
- MPEG Layer II - up to 384.
- AC3 - up to 640.
- OPUS - up to 512 (stereo).
Samplerate Mode - Auto (Default) follows the input. Common shows Samplerate: 32000, 44100, or 48000 Hz. OPUS always encodes at 48000 Hz.
Input Delay (ms) - Delays or advances the track's audio to line it up with the video, from -1000 to 1000 (Default: 0).
Channel Map - Assigns an input channel to each channel of the track, for example Front Left and Front Right for a stereo track. Select Mute or an input channel from 1 to 16. SDI inputs carry up to 16 embedded channels; HDMI carries up to 8.
Generator Settings
The video generator replaces the picture when the input is lost, or all the time, so your outputs keep sending video (see image below).
Video Generator - When the generator is used.
- Failover - (Default) Switches to the generator pattern when there is no input video.
- Enabled - Always shows the generator pattern.
- Disabled - When the generator is disabled, nothing will be streamed unless there is an active video signal.
Generator Pattern - What the generator shows.
- With Failover
- Last Active Frame - (Default) Freezes the last frame from the input.
- Color Bars - SMPTE color bars test pattern.
- Custom Image - A still image you upload.
- Black Screen - Solid black.
- White Screen - Solid white.
Generator Delay (ms) (Failover only) - How long, in milliseconds, to wait after video loss before switching to the pattern, from 0 to 5000 (Default: 0). Until then, Prism encodes and streams the last frame, whatever pattern is selected.
Upload Image (Custom Image or Image) - Shows the current image file. Click Choose File to select an image on your computer, then click Upload.
Metadata & OSD
The Metadata & OSD tab holds the on-screen display (OSD) and the metadata Prism embeds in the stream (see image below).
OSD Mode - Burns timecode or the date and time into the picture.
- Disabled - (Default)
- SDI/HDMI Timecode
- Stream Timecode
- System Time
- System Date/Time
NOTE: The OSD may not work well with these video formats: 1080p60-B, 1080p59-B, 1080p50-B, 1080psf24, 1080psf23, 1080i60, 1080i59, 720p60, 720p59, 720p50, 576i.
When an OSD mode is selected, a PREVIEW with the OSD box and a POSITION control appear (see image below). Click one of the nine squares to place the OSD (top, middle, or bottom; left, center, or right), or click Manual and enter X and Y as a percentage of the frame (0 to 100). The default position is top left.
Timecode - Where the timecode embedded in the stream comes from.
- Disabled
- SDI/HDMI Timecode - (Default) Timecode from the input.
- Stream Timecode
- System Time
Closed Captions - Passes 608/708 closed captions from the input into the stream (Default: Off).
DPI (SCTE 104/35) - Requires a license, contact sales/support to purchase. When enabled, Prism converts SCTE 104 messages from the SDI input into SCTE 35 markers in the stream (Default: Off). You can also generate SCTE messages with the following configuration:
Color Grading
Prism can apply a color grade to the encoded picture using CDL and 3D LUT files stored on the unit, a grade you dial in with the color wheels, or a live grade from the Livegrade app on your network (see image below).
Source - Where the grade comes from.
- Files on this device - Applies the CDL and 3D LUT selected below, and lets you grade with the wheels (see image below).
- Livegrade app - The grade comes from the Livegrade app on your network. The controls on this tab are turned off.
- Off - (Default) No grade is applied. You can still edit files.
CDL - Applies a CDL file.
- On/off switch - Turns the CDL stage on or off.
- File - The CDL to apply. You create CDLs with Save as new below.
- CDL files (three dots) - Manage the stored CDL files.
- Split on the stream - Shows the original picture on the left half and the graded picture on the right half. Viewers of the stream see the split.
3D LUT - Applies a 3D LUT file.
- On/off switch - Turns the 3D LUT stage on or off.
- File - The 3D LUT to apply.
- Upload - Uploads a 3D LUT from your computer. Supported formats: .cube, .lut, .3dl, .m3d, .mga, .dat, .u16lergb, .cdl.
- From grade - Creates a 3D LUT from the grade on the wheels. Dial in a grade first.
- 3D LUT files (three dots) - Manage the stored 3D LUT files.
- Split on the stream - Shows the original picture on the left half and the graded picture on the right half.
New grade - Color wheels for building a CDL grade.
- Lift (Offset), Gamma (Power), Gain (Slope) - Drag the dot in each wheel, or enter a Master value and R, G, B values.
- Saturation - Default 1.00.
- Contrast - Default 1.00.
- Pivot - The contrast pivot point (Default: 0.435). Only applies when Contrast is not 1.00.
- Preview - Opens a larger preview of the grade. [CONFIRM]
- Reset - Returns the wheels to their defaults.
- Save as new - Stores the grade as a new CDL and selects it. The CDL stage must be on for the grade to be applied.
- Save - Saves changes to the selected CDL.
When Livegrade app is selected, a banner explains that the grade comes from Livegrade and the controls are off (see image below).
Overlay Settings
Overlays place graphics over your live stream (see image below).
Picture Overlay - Turns the overlay on or off (Default: Disabled).
NOTE: Overlays are not available for HEVC 4Kp59.94/60 or H.264 4Kp50/59.94/60.
OVERLAY IMAGE - The overlays you have designed. Click one to select it, or click Design overlay to create one.
PREVIEW - Shows the selected overlay over the picture. Turn on LIVE PREVIEW to use the live video instead of a snapshot.
POSITION - Click one of the nine squares to place the overlay, or enter X and Y in pixels (relative to a 3840 x 2160 frame).
Create an Overlay
- On the Overlay Settings tab, click Design overlay. The Design Overlay editor opens (see image below).
- Enter a name in the overlay name field.
- Click Text, Image, Rectangle, Circle, or Line to add a layer. Layers are listed under LAYERS on the right.
- Select a layer to edit it. Drag to move it; drag the corner handles to resize it. Shift-click or Ctrl-click, or drag on an empty area of the canvas, to select several layers.
- (Optional) Click Preview stream to see the overlay over the live picture.
- Click Save overlay. The overlay is added under OVERLAY IMAGE.
- Select the overlay, then turn on Picture Overlay and click Apply. The overlay appears on your live stream.
Outputs
The Outputs tab contains all the outputs streams configured for the current pipeline. The number next to the tab name is the number of outputs.
- Add output - Adds a stream to this pipeline: create a new stream or select an existing one.
- Stream cards - Each card shows the stream name (click the pencil icon to rename it), protocol, destination URL, and state. Click the arrow to show the stream's settings, including AUDIO ROUTING (which audio tracks the stream carries: All From Encoder or Custom Selection). The three-dots menu holds actions for the stream. Push streams show Go Live.
- LOCAL STREAM SETTINGS - Stream Airmix sends this pipeline to the Teradek TV or VUER app on the local network. When on, you can set Listen Port (Default: 2020), Auto Max Clients or Max Clients (1 to 20, Default: 10), and Encryption with an Encryption Passphrase.
The stream settings are the same as on the Streams page. For every stream mode and setting, see Streaming.
Recording
The Recording tab holds this pipeline's recorder: its state, Cloud upload, Storage, and Recording settings (see image below). These are the same settings as the pipeline's entry on the Recording > Recording Settings page. For details, see Recording.
Scopes
The Scopes tab shows video scopes for the encoded picture (see image below). Scopes analyze the pipeline's live preview (WHEP) in your browser using the GPU, so your browser must support WebGPU. A No WebGPU badge appears if it does not.
- TRANSFER - How the scopes interpret the picture: Auto (follows the stream, for example Auto - SDR), SDR, or HDR.
- LIVE PREVIEW - Turns on the live WebRTC feed for the scopes. The same switch is on the pipeline card and in the pipeline header.
- VIEW - The scope to show (for example Feed). Select a scope once the feed is up.
- PEAK NITS (HDR) - The peak brightness used for HDR scales (Default: 1000).
Differences Between Encoder Pipelines
All encoder pipelines share the same Video & Audio, Metadata & OSD, Outputs, Recording, and Scopes tabs, with these differences (Encoder 2 shown below):
- Color Grading and Overlay Settings tabs - Only on Encoder 1.
- Scene Change Detection - Only on Encoder 1. The scene change detection hardware serves the first encoder only.
- Audio Input Source - On Encoder 1 you can choose Embedded, USB, or Analog. On Encoder 2 the source is fixed to the embedded audio of the pipeline's input (for example HDMI - Embedded).
- Recording - A pipeline whose recorder is off shows Recording is off for this pipeline with a Turn on link in the header.