thumb

The thumb command controls thumbnail generation on source devices, regardless of device type.

Thumbnail generation differs per device type

DN-200 Series devices use the SDVoE thumbnail stream; DN-300 devices use the integrated H.26x encoder. This affects how thumbnail state appears in notifications. See Notifications.

Command Type	DisplayNet
Minimum Version	3.x.x

Usage

thumb start <target>
thumb stop <target>

Arguments

Argument	Required	Description
target	Yes	Source device(s) to start or stop thumbnails on. See Targets.

Targets

Value	Applies to
<device>	A single device, by hostname or MAC address
<device>,<device>,...	Each listed device
ALL_TX	All transmitter devices

Examples

Start thumbnail generation on a source
thumb start bluray1

Stop thumbnails on every source
thumb stop ALL_TX

Fetching thumbnail images

Once thumbnails are enabled on a device, retrieve the image over HTTP via the server proxy:

http://<server_host>/thumbs/<device_mac>.<ext>?v=<cache_breaker>

Parameter	Description
server_host	Hostname or IP of the DisplayNet server
device_mac	MAC address of the transmitter (lowercase, no colons)
ext	png or jpg, matching the app.ThumbnailFormat setting. Changing the format deletes the images in the previous format
cache_breaker	Optional timestamp to bypass browser caching

Fetch the current thumbnail for device 6cdffb011b0f
http://displaynet.local/thumbs/6cdffb011b0f.png?v=1733012345678

Use the server proxy URL

DN-300 device notifications include a direct URL in Encoder.Thumbnail.Url (e.g. http://192.168.1.194/snap.jpg). That address is on the encoder's internal network and is typically not accessible from external clients, so always use the server proxy URL above.

Return value

thumb start bluray1
{
  "status": "SUCCESS",
  "request_id": null,
  "result": null,
  "error": null
}

Notifications

DN-200 Series

These devices report thumbnail state through device updates: the THUMBNAIL stream in the device object is STREAMING when enabled and STOPPED when disabled.

DN-300

These devices report it as the ThumbnailEnabled key in the stream list return and in DN_NOTIFICATION stream updates (excerpt):

thumb stop bluray1 (excerpt)
{
  "status": "DN_NOTIFICATION",
  "request_id": null,
  "result": {
    "streams_update": [
      {
        "device_id": "6cdffb00387f",
        "Encoder": {
          "Thumbnail": {
            "HDCPMode": "force",
            "Url": "http://192.168.1.194/snap.jpg"
          }
        },
        "ThumbnailEnabled": false
      }
    ]
  },
  "error": null
}

REST API

Endpoint type	DisplayNet API command
Address	POST /api/displaynet/<operation>, or name the operation in the body of a POST /api/displaynet. See Sending commands.
Role	User

Subcommand	Operation	Parameters
start	thumb_start	device
stop	thumb_stop	device

See also

• stream: configure the DN-300 H.26x encoder that generates thumbnails