Capture Sources
WATCHOUT 7 supports four capture technologies for bringing live video into your show: NDI, Spout, Deltacast, and MediaFoundation. NDI capture is covered in its own article — see NDI Video Sources. This article covers the remaining three technologies: Spout, Deltacast, and MediaFoundation.
Each capture technology serves a different use case, but they all follow the same workflow inside WATCHOUT: you create a capture device, add one or more capture streams to it, and then place the device on a timeline as a cue.
Supported Capture Technologies
| Technology | Use Case | Requirements |
|---|---|---|
| Spout | Real-time video sharing between Windows applications on the same machine. Low-latency, lossless capture supporting up to 32-bit float RGBA. | Spout sender and WATCHOUT Runner must run on the same machine. |
| Deltacast | Professional video capture cards for broadcast and live production workflows. Supports HDMI 2.1. | Deltacast capture card installed. NVIDIA GPU required for GPU-direct capture. |
| MediaFoundation | Any Windows MediaFoundation-compatible capture device — USB webcams, USB capture cards, internal capture devices. | Device drivers installed and device recognized by Windows. |
Setup Workflow
The setup workflow is the same regardless of which capture technology you are using:
- Open the Devices window (Window > Devices).
- Click Add and choose Capture Device to create a new capture device.
- In the device properties, click Add Capture Source to add a stream.
- Configure the source properties in the dialog (see below).
- Drag the capture device onto a Timeline to create a cue referring to the captured stream.
Capture Source Properties
When you click Add Capture Source, a dialog appears with the following properties:
| Property | Description |
|---|---|
| Host | The node (machine) where the capture source is available. For Spout sources, this must be the same machine running the Spout sender. For Deltacast, this is the machine with the capture card installed. For MediaFoundation, this is the machine with the capture device connected. |
| Refresh | Updates the stream list for this source. Click this if you have connected a new device or started a new Spout sender since opening the dialog. |
| Stream | Lists all available capture streams on the selected host. Depending on the technology, this shows Spout senders, Deltacast inputs, or MediaFoundation devices. |
| Format | Pixel format for the captured stream: YUV or RGB. Available for hardware capture only (Deltacast, MediaFoundation). |
| Range | Signal range override. Available for hardware capture only. |
| Color Space | Override the color space interpretation of the incoming signal. |
| Sync Mode | Controls how captured frames are synchronized with WATCHOUT playback. |
Range Options
| Option | Description |
|---|---|
| Auto | Uses whatever signal range the device provides. |
| Limited | Overrides to limited range (16–235 for 8-bit signals). |
| Full | Overrides to full range (0–255 for 8-bit signals). |
Color Space Options
| Option | Description |
|---|---|
| Auto | WATCHOUT selects the color space automatically based on the stream. |
| Rec. 601 | Standard-definition color space. |
| Rec. 709 | HD color space (most common for 1080p content). |
| Rec. 2020 | Wide-gamut UHD color space. |
| Rec. 2100 HLG | HDR color space using Hybrid Log-Gamma transfer function. |
| Rec. 2100 PQ | HDR color space using Perceptual Quantizer transfer function. |
| scRGB | Extended linear RGB color space. |
| sRGB | Standard RGB color space. |
| sRGB (gamma 2.2) | sRGB color space with a simple 2.2 gamma curve. |
Sync Mode
| Option | Description |
|---|---|
| Off | No synchronization. Frames are used as they arrive. This minimizes latency but may result in occasional frame skips or repeats if the source frame rate does not match the output. |
| Maintain | Preserves the original frame timing of the captured stream. This adds latency but ensures smoother playback. |
Source Prioritization
Each capture device supports a prioritized list of sources. WATCHOUT uses the first valid stream starting from the top of the list. If the topmost stream becomes unavailable — for example, if a Spout sender is closed or a USB device is disconnected — WATCHOUT automatically falls back to the next available stream in the list.
You can rearrange the priority order using the up and down arrow buttons in the capture device properties. This is useful for building redundancy into your capture setup: add a primary source at the top and a backup source below it.
Use source prioritization to create automatic failover between capture sources. For example, you could list a Deltacast input as the primary source and a MediaFoundation USB capture card as the fallback.
General Device Properties
Each capture device has the following general properties:
| Property | Description |
|---|---|
| Name | A user-defined name for the capture device. This name appears in the Devices window and is used when placing the device on timelines. |
| Width | The horizontal resolution of the cue associated with the captured stream. |
| Height | The vertical resolution of the cue associated with the captured stream. |
Spout
Spout is a real-time video sharing framework for Windows. It allows applications running on the same machine to share video frames through shared GPU textures, providing very low latency and lossless quality at up to 32-bit float RGBA precision.
The Spout sender application and the WATCHOUT Runner must be running on the same machine. Spout does not transmit video over the network — it uses shared GPU memory for frame transfer.
Compatible Applications
The following applications can send video to WATCHOUT via Spout (this is not an exhaustive list):
- Resolume Arena / Avenue
- TouchDesigner
- Notch
- Unity (with Spout plugin)
- Unreal Engine (with Spout plugin)
- OBS Studio (with Spout plugin)
Any application that implements the Spout sender API will appear in the Stream dropdown when adding a capture source on the same machine.
Deltacast
Deltacast capture cards are professional video I/O devices used in broadcast and live production environments. WATCHOUT supports Deltacast cards for low-latency, high-quality video capture, including HDMI 2.1 sources.
GPU-direct capture with Deltacast requires an NVIDIA GPU. This allows captured frames to be transferred directly from the capture card to GPU memory without passing through system RAM, reducing latency and CPU overhead.
Deltacast inputs appear in the Stream dropdown when a supported Deltacast card is installed on the selected host machine and the appropriate drivers are loaded.
MediaFoundation
MediaFoundation is the standard media framework in Windows. Any capture device that exposes itself as a MediaFoundation-compatible source is supported by WATCHOUT. This includes:
- USB webcams
- USB capture cards (e.g. Magewell, Datapath)
- Internal capture devices
MediaFoundation devices appear in the Stream dropdown when connected to the selected host machine and recognized by Windows.
Monitoring Capture During Playback
During playback, you can monitor the actual capture status and stream information in the Node Info window. This shows real-time data about each active capture source, including the current resolution, frame rate, and whether frames are being received successfully. Use this to verify that your capture sources are operating as expected during rehearsals and performances.
Relationship to Other Articles
- NDI Video Sources — NDI capture and output configuration
- Connecting Devices — assigning capture sources and displays to nodes
- Firewall Configuration — network ports and firewall rules