Playback
The Playback page provides timeline-based review of recorded footage with high-performance delivery. The interface features a Milestone-style centered playhead with zoom control, event markers, and multi-camera synchronized playback.
Playback Architecture
Section titled “Playback Architecture”High-Performance Media Delivery
Section titled “High-Performance Media Delivery”Meridian VMS uses an optimised media serving layer for recorded segments. Segment files are read directly from disk and served with minimal overhead, enabling high-throughput playback across many concurrent viewers.
The management server handles API requests and authentication, while the media serving layer delivers video segments efficiently.
Segment Delivery
Section titled “Segment Delivery”When the browser requests playback:
- The management server queries the segment index for the requested camera and time range.
- A dynamic HLS
.m3u8playlist is generated referencing segments on the appropriate recording server. - The management server routes segment requests to the appropriate recording server.
- The recording server reads the segment file and serves the requested data efficiently.
- The browser’s video player plays the stream seamlessly.
Operators only need connectivity to the management server. Direct access to recording servers is not required.
Timeline
Section titled “Timeline”Centered Playhead Design
Section titled “Centered Playhead Design”The timeline uses a Milestone-style centered playhead:
- The playhead stays fixed in the center of the timeline bar.
- The timeline scrolls beneath the playhead as footage plays.
- Click and drag the timeline to scrub through footage.
- The current timestamp is always displayed at the playhead position.
This design keeps the operator’s focus point consistent and makes it easy to see context before and after the current position.
Recording Coverage Bars
Section titled “Recording Coverage Bars”The timeline displays colored bars indicating segment coverage:
- Solid blue bars — continuous recorded coverage
- Gaps — periods with no recording (camera offline, server down, maintenance)
- Red markers — detection events (person, vehicle, etc.)
- Orange markers — alarm events
Click any position on the timeline to jump to that timestamp. Click an event marker to jump directly to that event.
Zoom Slider
Section titled “Zoom Slider”The zoom slider controls the visible time range on the timeline:
| Zoom Level | Visible Range | Use Case |
|---|---|---|
| Maximum out | 24 hours | Full day overview |
| Medium | 4 hours | Shift review |
| Close | 1 hour | Incident investigation |
| Maximum in | 5 minutes | Frame-level detail |
Use the mouse scroll wheel over the timeline to zoom in and out. The zoom centers on the current playhead position.
Event Markers
Section titled “Event Markers”Detection and alarm events are displayed as colored markers on the timeline:
| Marker | Color | Source |
|---|---|---|
| Person detected | Blue | AI detection |
| Vehicle detected | Green | AI detection |
| License plate read | Purple | LPR |
| Alarm triggered | Red | Alarm system |
| Motion detected | Yellow | Motion detection |
Hover over a marker to see event details (class, confidence, zone). Click to jump to that timestamp and see the detection thumbnail.
Playback Grid
Section titled “Playback Grid”Layouts
Section titled “Layouts”| Layout | Tiles | Use Case |
|---|---|---|
| 1x1 | 1 | Focused single-camera investigation |
| 2x2 | 4 | Side-by-side comparison or multi-angle review |
| 3x3 | 9 | Multi-camera incident review |
Synchronized Playback
Section titled “Synchronized Playback”When multiple cameras are in the grid, all tiles play in sync at the same timestamp. Scrubbing the timeline moves all cameras simultaneously. This allows reviewing an incident from multiple angles at once.
Each tile can also be independently controlled by unlocking it from sync mode.
Adding Cameras
Section titled “Adding Cameras”Drag cameras from the location tree onto grid tiles, the same as in Live View.
Playback Controls
Section titled “Playback Controls”Speed Control
Section titled “Speed Control”| Speed | Use Case |
|---|---|
| 0.25x | Frame-by-frame analysis |
| 0.5x | Slow-motion review |
| 1x | Normal speed (default) |
| 2x | Fast review |
| 4x | Rapid scanning |
| 8x | Quick overview of long periods |
| 16x | Maximum speed scan |
Frame Step
Section titled “Frame Step”Use the frame-step buttons or keyboard shortcuts to advance one frame at a time:
| Key | Action |
|---|---|
| . (period) | Step forward one frame |
| , (comma) | Step backward one frame |
| Space | Play / pause |
| Left arrow | Skip backward 10 seconds |
| Right arrow | Skip forward 10 seconds |
Toggle audio per tile using the mute/unmute button. Audio is muted by default.
Clip Export
Section titled “Clip Export”Export a portion of recorded footage as a standalone MP4 file:
- Position the playhead at the start of the desired clip.
- Click Mark In or press I.
- Move to the end of the clip.
- Click Mark Out or press O.
- The selected range is highlighted on the timeline.
- Click Export Clip to start the export.
The server extracts the selected range, packages it as an MP4 (stream-copy, no re-encoding), and provides a download link. Export progress is shown in a notification.
For multi-camera exports, each camera in the grid is exported as a separate file in a ZIP archive.
Digital Evidence Export
Section titled “Digital Evidence Export”For evidentiary use, exported clips include:
| Metadata | Description |
|---|---|
| Camera name | Source camera identifier |
| Time range | Start and end timestamps (UTC) |
| Server ID | Recording server that captured the footage |
| Checksum | SHA-256 hash of the exported file for integrity verification |
| Export timestamp | When the export was created |
| Export user | Which operator performed the export |
RBAC and Visibility
Section titled “RBAC and Visibility”Playback respects role-based access control. Operators can only play back recordings from cameras within their permitted locations. The location tree filters automatically based on the current user’s role.