STANAG On Demand Server provides live HLS playback and recording functionality.
Session Types
STANAG On Demand Server supports two types of sessions:
- Events (live mission)
- Video on demand (VOD mission).
VOD Sessions
For VOD sessions, media files are available representing the entire duration of the mission. The manifest file is static and contains a complete list of all segments created since the beginning of the mission. This kind of session allows the client full access to the entire mission.
Live Sessions
Live sessions (events) can be presented as a complete record of an event, or as a sliding window with a limited time range the user can seek within. STANAG On Demand Server uses EVENT type session in order to record and ingest the mission. For live sessions, as new media files are created and made available, the manifest file is updated. When user stops a live mission, its session type is changed from EVENT to VOD and the mission is finalized (by adding #EXT-X-ENDLIST tag to the manifest).
Creating Live HLS mission.
In order to create Live HLS mission, add new mission, selecting Live mode and HLS mission format.
Next, configure the session.
In order to select the network interface (if you have more than one) add nic= argument to the url. For example:
- Note
- Network interface selection is different for Live Low Latency and Live HLS modes.
Another possibility is to change network interface priority in Windows or add IP route to the routing table.
- Configure telemetry related parameters, if needed.
By default, if no transcoding is activated, the stream will be presented and recorded at its original quality. If needed (for example for making it available over the Internet), you can transcode the stream, reducing required resolution and bandwidth.
To leave original resolution, set Width / Height values to -1.
Start the mission.
Now, if the stream is available, the mission's state should change to WaitingForData and a bit later, after the first segment is created, to Running. From this moment, your live mission is available for client access.
Note, the latency depends on the segment length and usually won't be less than 15 - 30 sec.
HLS CDN.
It is possible to configure Live HLS streaming in a way that the recorded segments are automatically uploaded to the CDN (content delivery network), for example AWS (Amazon Web Services) S3.
As depicted above, you can enable CDN Upload to AWS bucket.
The configuration parameters should be added to the file config.json that can be found in the data directory
Enabling CDN playback will automatically redirect client players to the AWS, which can handle high traffic without adding any load on the StServer.
- Note
- You must enable CORS to let the HLS players access to the video.
If you expect a higher traffic, want to have the video more locally to consumers, thus improving access speed for downloading the content, or need to take care of the secure access, take a look at the Amazon CloudFront.
Finalizing Live HLS mission.
When you stop a Live HLS mission, the server automatically finalizes the manifest and changes mission mode from Live to VOD.
Note, if during recording your server had experienced an unexpected shutdown, all active live HLS missions will be automatically finalized on the server's restart.
DVR Mode
In addition to providing a live video streaming, STANAG On Demand Server allows users to jump back in time and look at the recorded video content (at a specific moment). At any time it is possible to return to the live mode.
DVR Live steaming.
In live mode operation, a LIVE button (green color) appears on the control bar.
DVR Seek.
You can seek back in time using the slider. LIVE button will turn white in this mode. To return to the live stream just press the LIVE button.
Step Frame by Frame.
When in the Paused mode, you can step, frame by frame using < and > buttons.
