Snapshot Target

Introduction

The Snapshot Target periodically saves a still image of the composed scene to disk as PNG or JPEG. It runs in the background on its own save thread, so writing a frame to disk never stalls the render pipeline. It's a deliberately simple companion to the streaming targets — no encoder, no network, no muxing — just "every N seconds, drop a picture on the filesystem".

Snapshots are written to a Snapshots folder next to the application, named <ProjectName>-snapshot-<timestamp>.<ext>. The project-name prefix is also used by the automatic clean-up — only files matching the current project's prefix are eligible for deletion, so snapshots from other projects sharing the same folder are left alone.

Configuration

Snapshot interval — eight presets from every 10 seconds to once a day. Pick the longest interval that still gives the coverage you need; every snapshot is a file on disk.
Delete snapshots older than — six retention buckets (1 minute, 10 minutes, 1 day, 1 week, 1 month, 1 year). Combined with a tight interval, long retention can build a large archive fast — size accordingly.
Image format — JPEG (small files, configurable quality, the right pick for thumbnails and web dashboards) or PNG (lossless, the right pick for pixel-accurate captures or downstream image processing).
JPEG quality — 1–100, defaulting to 85. 80–90 is the sweet spot for thumbnails; ignored when the format is PNG.
Autostart when application starts — for unattended installations that should begin capturing the moment Composer loads, with no operator action.

Common use cases

Unattended-stream monitoring — a web dashboard shows the latest snapshot so an operator can confirm at a glance that the stream is on-air without bringing up a full preview client.
Thumbnail archive of a long broadcast — capture every minute through a multi-hour event for a scrubable timeline of what the program looked like at each point.
Editor preview thumbnails — feed the snapshot folder to a downstream editor or asset manager so editors can locate specific moments before pulling the full recording.
Compliance / evidencing — fixed-interval stills of on-air content for log-keeping that an audit chain can rely on.
Social-media still generation — auto-publish the latest snapshot to a social channel during a live event for a steady drip of in-broadcast stills.

Driving from outside

The standard set: Start, Stop, plus Open snapshots folder (opens the destination directory in Windows Explorer). All invokable from the property panel, the HTTP API (/api/invokecommand?targetname=Snapshot+Target&command=StartCommand), a Connector, or the Script Engine via ExecuteCommand / ExecuteCommandById. Live status — capture state, last snapshot saved (timestamp + filename), running count, save-queue depth, and a countdown to the next capture — is surfaced as readable properties for dashboards and scripts.

Snapshot Target - Settings

Property	Description
`Autostart when application starts`	When true, snapshot capture begins automatically as soon as the application starts. Useful for unattended installations where you want continuous capture without manual intervention.

Configuration

Configuration section — how often snapshots are taken, how long they are kept, and the image format.

Property	Description
`Snapshot interval`	How often a new snapshot is captured — every 10 seconds up to once a day. Pick the longest interval that still gives you the coverage you need, since each snapshot writes a file to disk and contributes to the on-disk archive size.
`Delete snapshots older than`	Maximum age of stored snapshots before they are deleted automatically. Only files whose name starts with the current project name are eligible for clean-up, so snapshots from other projects in the same folder are kept. Set this with disk capacity in mind — frequent intervals plus long retention can build up a large archive quickly.
`Image format`	File format for saved snapshots. `JPEG` produces small files at adjustable quality and is the usual choice for thumbnails and dashboards. `PNG` is lossless — pick it when image quality matters more than file size, such as when the snapshot will be used as artwork or analysed pixel-by-pixel.
`JPEG quality`	JPEG compression quality. [min=1, max=100, default=85]. Higher values give better-looking images and larger files; 80–90 is a good balance for thumbnails. Ignored when `ImageFormat` is `PNG`.

Commands

Commands section — start and stop capture.

Property	Description
`Start capturing snapshots`	Start the periodic snapshot capture using the current interval and image-format settings.
`Stop capturing snapshots`	Stop the periodic snapshot capture. Any image already queued is finished writing before the worker thread exits.

Misc

Misc section — convenience commands and live status read-outs.

Property	Description
`Open snapshots folder`	Opens the `Snapshots` folder in Windows Explorer so you can review or move the captured images.
`Capture state`	Current capture state: `Stopped`, `Starting`, `Running` or `Stopping` (read-only). Useful from scripts to confirm capture started successfully before issuing further commands.

Performance & properties

Performance & properties section — counters and timing read-outs for the current capture session.

Property	Description
`Last snapshot saved`	Date and time the most recent snapshot was written, formatted as `yyyy-MM-dd HH:mm:ss` (read-only). Reads `Never` until the first snapshot is saved.
`Last snapshot filename`	File name of the most recent snapshot written to disk (read-only). Useful in scripts that want to push the latest snapshot to a thumbnail service or web dashboard.
`Snapshots saved`	Total number of snapshots saved since capture was last started (read-only). Resets to zero each time `StartCommand` is called.
`Save queue size`	(advanced) Number of snapshots currently waiting to be written to disk (read-only, debug). A value that keeps growing means the disk cannot keep up with the chosen interval and image size.
`Next snapshot in`	Countdown to the next snapshot capture, formatted as `Xs`, `Xm Ys` or `Xh Ym` (read-only). Useful for live dashboards that show when the next image will appear.

Inherits from: AbstractTarget.