AES67 subscribe (SDP)

Subscribe a channel input patch to an AES67 RTP stream by PUTting SDP text (or structured rtp_flow) on the Maxx Control REST API.

When to use

Use this when a third-party sender (PipeWire, another AES67 device, etc.) publishes an SDP session and you want a MAXX channel to receive that multicast/unicast RTP stream as its input source AES67 STREAM (source_id 25).

Do not confuse this with:

API concept	`source_id`	Typical fields
AES67 STREAM	`25`	`sdp_text` (PUT) or `rtp_flow`
DANTE STREAM	`23`	`label` / `channel_name` / `device_name`
Device Dante AES67 mode	n/a	`PUT /settings/device/dante/aes67` with `{"value": true\|false}`

Dante AES67 enable is a separate device setting (Brooklyn AES67 mode). AES67 STREAM patches use the channel patch API below.

Prerequisites

Amplifier reachable at http://${IP}/rest-api/… (see REST API overview).
Firmware that exposes AES67 STREAM as an input source. Confirm with:
```
curl -X OPTIONS "http://${IP}/rest-api/settings/channel/1/dsp/patch"
```
Look for source_id: 25 / "AES67 STREAM" in the source list.
A complete SDP the device can parse (see SDP requirements below).
Write calls need the API key header token (default documented in the overview).

API path and method

Item	Value
Method	PUT (writes require `token`)
Path	`/settings/channel/{channel_id}/dsp/patch`
Body	JSON array of patch objects (`SettingsPatches`)
Read back	GET same path (or `…/patch/{patch_id}`)
Constraints	OPTIONS on the same path

There is no PUT on /settings/channel/{channel_id}/dsp/patch/{patch_id} — only GET for a single patch. Writes always go to the collection path with one or more objects in the array.

Payload fields (AES67 STREAM)

Field	Role
`patch_id`	Required. Patch slot on the channel (`1`…`16`).
`source_id`	`25` for AES67 STREAM.
`channel`	Slot within the RTP stream (`1`…`N` from SDP `a=rtpmap` channel count), not the Brooklyn RX channel.
`sdp_text`	PUT-only, at patch root. Full SDP string; server parses into flow params. Max length 512. Not returned on GET.
`rtp_flow`	Alternative to `sdp_text`: structured fields (`connection_ip`, `rtp_port`, `sample_rate`, `encoding`, `channels`, `session_name`, `clock_offset`, `session_id`, `source_address`). Returned on GET after a successful subscribe.
`gain`	Optional patch gain (dB).
`mute`	Optional patch mute.
`stream_channel`	GET-only Brooklyn RX channel assigned after placement (`0` until placed). Do not send on PUT.

Rules from firmware / OpenAPI:

Put sdp_text on the patch object root. Nested rtp_flow.sdp_text is rejected.
Do not send sdp_text and structured rtp_flow params together.
Prefer one approach: paste SDP or fill rtp_flow.

SDP requirements

Server-side parse (same as Maxx Control paste) requires a parseable AES67 SDP with:

PCM encoding L16 or L24 (encoding 16 or 24)
o= session id and origin IPv4 (source address)
a=mediaclk:direct=… (or equivalent) so clock offset is present

OpenAPI maxLength for sdp_text is 512 characters. Trim optional SDP lines if you hit the limit.

Step-by-step: PUT with `sdp_text`

Choose amp channel (channel_id) and patch (patch_id, often 1).
Choose stream slot (channel: 1 = first channel in the SDP, 2 = second, …).
PUT an array with one AES67 patch object including sdp_text.
GET the patch back — expect source_id 25 and populated rtp_flow (not sdp_text).
Optionally check patch status and persist with /settings/save.

Example SDP

v=0
o=root 1 3991817848 IN IP4 172.149.4.123
s=stream1
c=IN IP4 239.192.150.1/32
t=3991817848 0
m=audio 5004 RTP/AVP 127
i=2 channels: L, R
a=recvonly
a=rtpmap:127 L24/48000/2
a=source-filter: incl IN IP4 239.192.150.1 172.149.4.123
a=ssrc:2393712005
a=ptime:1.000000
a=framecount:48
a=ts-refclk:ptp=IEEE1588-2008:00-1D-C1-FF-FE-29-1C-8A:0
a=mediaclk:direct=2626298912
a=tool:PipeWire 1.6.7
a=type:broadcast

This session is 2 channels at 48 kHz / L24. Use "channel": 1 for L and "channel": 2 for R on two amp channels (or two patches) if needed.

JSON shape

[
  {
    "patch_id": 1,
    "source_id": 25,
    "channel": 1,
    "gain": 0.0,
    "sdp_text": "v=0\no=root 1 3991817848 IN IP4 172.149.4.123\ns=stream1\n…"
  }
]

Newlines in SDP must be encoded inside the JSON string (\n). Do not put raw multi-line SDP inside a single-quoted -d '…' shell string unless you build JSON with a tool.

curl (recommended: build JSON with Python)

export IP=10.77.150.42
export TOKEN=f4005bf8507999192162d989d5a60823

BODY=$(python3 - <<'PY'
import json
sdp = """v=0
o=root 1 3991817848 IN IP4 172.149.4.123
s=stream1
c=IN IP4 239.192.150.1/32
t=3991817848 0
m=audio 5004 RTP/AVP 127
i=2 channels: L, R
a=recvonly
a=rtpmap:127 L24/48000/2
a=source-filter: incl IN IP4 239.192.150.1 172.149.4.123
a=ssrc:2393712005
a=ptime:1.000000
a=framecount:48
a=ts-refclk:ptp=IEEE1588-2008:00-1D-C1-FF-FE-29-1C-8A:0
a=mediaclk:direct=2626298912
a=tool:PipeWire 1.6.7
a=type:broadcast"""
print(json.dumps([{
    "patch_id": 1,
    "source_id": 25,
    "channel": 1,
    "gain": 0.0,
    "sdp_text": sdp,
}]))
PY
)

curl -X PUT "http://${IP}/rest-api/settings/channel/1/dsp/patch" \
  -H "token: ${TOKEN}" \
  -H "Content-Type: application/json" \
  -d "${BODY}"

curl (inline `\n` escapes)

curl -X PUT "http://${IP}/rest-api/settings/channel/1/dsp/patch" \
  -H "token: ${TOKEN}" \
  -H "Content-Type: application/json" \
  -d '[{"patch_id":1,"source_id":25,"channel":1,"gain":0.0,"sdp_text":"v=0\no=root 1 3991817848 IN IP4 172.149.4.123\ns=stream1\nc=IN IP4 239.192.150.1/32\nt=3991817848 0\nm=audio 5004 RTP/AVP 127\ni=2 channels: L, R\na=recvonly\na=rtpmap:127 L24/48000/2\na=source-filter: incl IN IP4 239.192.150.1 172.149.4.123\na=ssrc:2393712005\na=ptime:1.000000\na=framecount:48\na=ts-refclk:ptp=IEEE1588-2008:00-1D-C1-FF-FE-29-1C-8A:0\na=mediaclk:direct=2626298912\na=tool:PipeWire 1.6.7\na=type:broadcast"}]'

Structured `rtp_flow` alternative

If you already know the RTP parameters (or you copied them from a GET after an SDP PUT):

curl -X PUT "http://${IP}/rest-api/settings/channel/1/dsp/patch" \
  -H "token: ${TOKEN}" \
  -H "Content-Type: application/json" \
  -d '[{
    "patch_id": 1,
    "source_id": 25,
    "channel": 1,
    "gain": 0.0,
    "rtp_flow": {
      "connection_ip": "239.192.150.1",
      "rtp_port": 5004,
      "sample_rate": 48000,
      "encoding": 24,
      "channels": 2,
      "session_name": "stream1",
      "clock_offset": 2626298912,
      "session_id": "3991817848",
      "source_address": "172.149.4.123"
    }
  }]'

Exact field meaning matches OpenAPI schema SettingsPatch / rtp_flow.

Verify

# Settings: parsed flow (sdp_text is write-only — not echoed)
curl "http://${IP}/rest-api/settings/channel/1/dsp/patch/1"

# Patch health
curl "http://${IP}/rest-api/status/channel/1/dsp/patch/1"

# Optional: SAP-discovered sessions (cache; may include sdp_text)
curl "http://${IP}/rest-api/info/aes67"

# Optional: Dante interface flows (interface_id from GET /status/interface/interfaces)
curl "http://${IP}/rest-api/status/interface/interfaces/4"

Persist runtime settings if needed:

curl -X PUT "http://${IP}/rest-api/settings/save" \
  -H "token: ${TOKEN}"

Path	Method	Purpose
`/info/aes67`	GET	SAP-discovered AES67 flows (cache)
`/info/aes67/refresh`	PUT	Clear SAP cache (listening continues)
`/settings/device/dante/aes67`	GET/PUT	Device Dante AES67 enable (`{"value": bool}`)

Source of truth

Path lists and schemas follow the on-device OpenAPI (Maxx Control → OVERVIEW → REST API DOC). Firmware versions can add fields; always confirm SettingsPatch on the live device. See also the REST API overview and input patch recipes.

AES67 subscribe (SDP)

Tags:

Categories:

When to use

Prerequisites

API path and method

Payload fields (AES67 STREAM)

SDP requirements

Step-by-step: PUT with `sdp_text`

Example SDP

JSON shape

curl (recommended: build JSON with Python)

curl (inline `\n` escapes)

Structured `rtp_flow` alternative

Verify

Source of truth

AES67 subscribe (SDP)

When to use

Prerequisites

API path and method

Payload fields (AES67 STREAM)

SDP requirements

Step-by-step: PUT with sdp_text

Example SDP

JSON shape

curl (recommended: build JSON with Python)

curl (inline \n escapes)

Structured rtp_flow alternative

Verify

Related discovery endpoints

Source of truth

Step-by-step: PUT with `sdp_text`

curl (inline `\n` escapes)

Structured `rtp_flow` alternative