start

The start command initiates one or more streams on one or more devices. In most cases you do not need to call it directly. connect starts the source stream automatically when routing.

Command Type	SDVoE
Minimum Version	2.x.x

Usage

start <target>:<stream_type>:<stream_index> [<dest_address>]

Arguments

Argument	Required	Description
target	Yes	Device ID of a single transmitter, or a device group. See Targets.
stream_type	Yes	The type of stream to start. See Stream types.
stream_index	Yes	The index of a stream of the specified type on the device.
dest_address	No	Destination IP address for the stream. See Destination address.

Targets

Value	Starts streams on
<device_id>	A single transmitter device
ALL	All devices
ALL_TX	All transmitter devices

Stream types

Value	Stream
HDMI	An HDMI video stream
HDMI_AUDIO	An HDMI audio stream
STEREO_AUDIO	A stereo (single I2S) audio stream
MULTICH_AUDIO	A multichannel (quad I2S) audio stream
THUMBNAIL	A video thumbnail stream

Destination address

If dest_address is omitted, the API server reuses the address already assigned to the stream by a previous start (if it has not been freed by stop), or otherwise allocates an unused multicast address.

If specified, dest_address must be an available, unused multicast IP address within the allocation range configured on the API server (default range: 224.1.1.1 to 224.1.3.255). For a THUMBNAIL stream, the destination can be either an available multicast address or a unicast IP address.

Examples

Start the primary HDMI stream on a transmitter
start 001ec0f04d9c:HDMI:0

Start a stream on a specific multicast address
start 001ec0f04d9c:HDMI:0 224.1.2.10

Return value

start is processed asynchronously. The immediate reply is PROCESSING with a request_id. Read the outcome with request.

start 001ec0f04d9c:HDMI:0
{
  "status": "PROCESSING",
  "request_id": 61,
  "result": null,
  "error": null
}

Errors

Request-level errors:

Error	Cause
ILLEGAL_ARGUMENT	The target is an invalid device ID or group name
ILLEGAL_ARGUMENT	A multicast address was specified with a group target, or without a stream type and index
ILLEGAL_ARGUMENT	The multicast address is outside the configured allocation range, or is reserved

The operation may also fail for individual devices:

Error	Cause
DEVICE_TYPE	The device does not have the specified stream type or index, or is a receiver
INVALID_STATE	The specified multicast address is already in use by another stream
INVALID_STATE	No more multicast addresses are available
INVALID_STATE	Starting the scaled stream (index 1) without a scaler resolution configured
INVALID_STATE	Starting a thumbnail stream while the thumbnail generator is not configured

REST API

Endpoint type	SDVoE API command, forwarded to the Control Server
Address	/api/device/{target}
Role	Governed by the device lock rather than by a DisplayNet role

POST /api/device/{target}

{
  "op": "start",
  "stream_type": "String",
  "stream_index": "Integer",
  "dest_address": "String (optional)"
}

Values labeled with a type name such as String or Integer are placeholders, not literal text. Replace them with actual values; fields marked (optional) can be omitted.

{target} takes a DisplayNet device name as readily as a device ID, and a locked device refuses a mutating operation. See SDVoE API operations for what DisplayNet adds to these calls.

See also

• stop: stop streams and free their multicast addresses
• connect: route a signal (starts the source stream automatically)