Recasting

Recasting publishes the current media to another endpoint while STView is playing it. Use it to forward a stream to a UDP, SRT, or WHIP receiver without leaving the STView review workflow.

Configure recasting from the Recast tab in File > Open File or File > Open Stream. After the source is open and playback is running, use the Recast button in the transport controls to start or stop the output.

Basic workflow

1. Open File > Open File or File > Open Stream.
2. Select the source on the Source tab.
3. Open the Recast tab.
4. Enable Enable Recast.
5. Choose the Recast Source: Original or Flywheel.
6. Choose the target Protocol.
7. Enter the target address or WHIP endpoint.
8. Configure protocol-specific options if needed.
9. Open the source, start playback, then press Recast in the transport controls.

The Recast button is disabled until playback is active and Recast is configured.
Press the Recast button to start operation.

When recasting is active, the transport button shows the active state.

Target protocols

Protocol	Use when
UDP	You need MPEG-TS output to a unicast or multicast UDP address.
SRT	You need MPEG-TS output over SRT with caller, listener, or rendezvous connection setup.
WHIP	You need to publish to a WebRTC ingest endpoint such as a media server, SFU, or CDN.

For UDP, choose a Network Interface when the output must leave through a specific adapter, especially for multicast. Auto lets the operating system and SDK choose the route.

For SRT, configure:

• Connection Mode: Caller, Listener, or Rendezvous.
• Latency (ms) for SRT retransmission tolerance.
• Poll Timeout (ms) for socket state polling.
• Optional Stream ID.
• Optional Passphrase and Key Length when the receiver uses SRT encryption.

For WHIP, enter a full http:// or https:// endpoint. WHIP uses WebRTC signaling and has additional video and KLV options in Recast config.

Original source recasting

With Source set to Original, Recast publishes from the media source rather than from the composed viewer. This is the lowest-overhead path when you want to forward the input stream itself.

UDP and SRT recast targets are always MPEG-TS outputs. For WHIP targets, open Recast config to choose:

• Video mode: Transcode or Passthrough.
• WebRTC codec: H.264, VP8, or VP9.
• Video bitrate and Keyframe interval when transcoding.
• KLV data channels: Disabled, Raw, JSON, or Raw + JSON.

Use WHIP passthrough only when the source video is already compatible with the selected WebRTC codec and the receiver can accept it. Use transcode when the source codec or target codec requires re-encoding.

Using Recasting With Flywheel

Set Source to Flywheel when the recast target should receive the Flywheel program feed instead of the original source.

Flywheel affects recasting in these ways:

• Recast uses the Flywheel codec, CBR/VBR mode, target and maximum bitrate, keyframe interval, frame rate, width, and height settings from the Flywheel tab. CBR is the default; maximum bitrate is configurable for VBR.
• The output is re-encoded from the Flywheel path, so source video passthrough is not used.
• In the current STView recast path, Flywheel source recasting is started without overlay burn-in for the recast output.
• UDP and SRT targets always receive Flywheel MPEG-TS output. This output is not suitable for reopening in STView as an MPEG-TS source.
• WHIP targets receive a WebRTC output generated from the Flywheel path.
• Recast configuration for original-source WHIP video mode does not apply to Flywheel source recasting; the Flywheel path is always encoded.

Enable and configure Flywheel before selecting it as the Recast source. For more information about the Flywheel output path, see Flywheel.

Monitoring and stopping recast

Use the transport Recast button to stop an active recast before changing source, closing STView, or changing the Recast configuration.

An SRT recast remains active when its receiver is offline or the connection is interrupted. STView discards output packets while the target is unavailable and keeps trying to reconnect. Playback and the Recast controls remain responsive, and the main status plus the Recasting session show the connection error. The error clears automatically after the receiver connects again.

Stopping Recast successfully clears the connection error from the main status and the Recasting session. A stop failure remains visible so you can diagnose the output shutdown problem.

If Recast fails to start or stops unexpectedly, check the error message shown by STView and verify the target URI, network route, receiver state, license option, and protocol-specific settings. For SRT, verify that both sides use compatible connection modes and encryption settings. For WHIP, verify that the endpoint is reachable and accepts the selected codec and KLV data-channel mode.

Output status indicators

The status bar places Recast after playback Status, followed by Recorder. Indicators appear when an output starts and remain visible after an error until you stop it, retry, or close the source.

• Active: a green dot with measured bitrate for Recast or recorded size in MB for Recorder, using the same text color as Framerate and KLV Rate. Multiple active outputs show their combined bitrate or size; the tooltip lists each separately.
• Orange � Connecting / Starting: the initial operation is in progress. An SRT Listener can wait for its first peer without becoming an error.
• Orange � Waiting for data: the output is running without recent traffic.
• Red � Disconnected: an established SRT or WHIP connection was lost.
• Red � Error: starting, writing, sending, or stopping the output failed.

Hover or keyboard-focus an indicator for the destination, Original/Flywheel source, measured bitrate, current error, and timestamped last error. Recorder also shows recorded size, with separate details for each recording. Recovery clears the current error and restores green when traffic resumes; the previous error remains in the tooltip until restart or successful stop. Output errors do not replace the playback status message.

Rates refresh once per second over the latest three seconds. They measure transport output or recording file growth, not the configured encoder bitrate. No traffic for three seconds reports zero; unavailable or stale measurements show Bitrate unavailable. Buffered file writes may make recording rates arrive in bursts. UDP sending confirms local transmission, not receiver delivery. Successful stop hides the indicator and clears its error history.

For a running UDP or SRT MPEG-TS source, Original Recast uses the packets already received by playback. It does not open a competing receiver. UDP sends without a connection or acknowledgement: Waiting for data means no recent output bytes, not that STView is waiting for the target to connect.