Presentation AES X-170 at IEEE 1722.1 Face to Face Robby Gurdan and Richard Foss [email protected]...

Presentation AES X-170at

IEEE 1722.1 Face to Face

Robby Gurdan and Richard Foss [email protected] [email protected]

10.04.23

5th April 2010

mailto:[email protected]

mailto:[email protected]

XFN Overview

• IP-based peer to peer protocol

• Addressing of parameters is hierarchical

– Hierarchy reflects structure of device

– Levels in hierarchy are fixed

• Parameters can also be addressed by ID’s

• Parameters can be joined into groups

• ‘Modifiers’ can modify addresses/ values

• Desk Items – graphic display info in device

10.04.23 AES X-170 Presentation

XFN Message Structure1

IP header including source and destination IP address

UDP header including source and destination port

XFN header and XFN address block


Target IP Address (32 bit)

Target XFN Node ID (8 bit)

Sender IP Address (32 bit)

Sender IP address(continued)

Sender XFN Node ID (8 bit)

Sender Parameter ID (32 bit)

Sender Parameter ID (continued)

User Level (8 bit)

Message Type (8 bit)

Sequence ID (32 bit)

Command Executive (8 bit)

Command Qualifier (8 bit)

Address Block (104 bit)

Address Block (continued)


XFN Message Structure 2


Target XFN Node ID(8 bit)






User Level (8 bit)
















User Level (8 bit)
















User Level (8 bit)



Command Executive(8 bit)













User Level (8 bit)










Command Executive, Command Qualifier

• Command Executive – indicates fundamental nature of command• Examples – GET, SET, ACT, JOIN/UNJOIN, CREATE

• Command Qualifier – refines the command executive• Examples – VAL, VTBL, FLAG, SEC, PUSH, DATA_BLOCK, PTP, MSTSLV, USG

• Example commands:• SET VAL <address of parameter> <Value>

• GET FLAG <address of parameter> - gets the flag field of a parameter

• JOIN PTP <address of parameter1> <Value-address of parameter 2,abs/rel>

• CREATE USG <address of parameter> <Value - address1, address2, …>


2. Input matrix

3/4. Input channels

5/6. Bus matrix

7. Outputchannels

1. Digital/Analogueinput

8. OutputMatrix

9. Digital/Analogueoutput

The Origins of the Address Block

The 7 levels of the Address Block

Most parameters conform to similar functional groupings:

• 1; Section Block – eg. Input section, Output section

• 2 ; Section Type – eg. Mic input, Line Input, ADAT input

• 3 ; Section Number – eg. Channel number

• 4 ; Parameter Block – eg. Equalizer block

• 5; Parameter Block Index – eg. Equalization sub-grouping (Q, freq)

• 6; Parameter Type – eg. Low frequency, gain, threshold

• 7; Parameter Index – eg. To identify gain parameter number



Command Executive

(8 bit)


Section Block(8 bit)

Section Type(8 bit)

Section Number(24 bit)

Parameter Block(8 bit)

Parameter Block Index(24 bit)

Parameter Type(16 bit)

Parameter Type(continued)

Parameter Index(16 bit)

Value Format(8 bit)



Command Executive

(8 bit)

Command Qualifier (8 bit) SCT_BLOCK_INPUT

ID – 0x01SCT_TYPE_AUDIO

ID – 0xD1

CHANNEL_NUMBERID – 0x100001

PRM_BLK_DIG_AMP ID – 0x11

PRM_BLK_INDEXID – 0x00001

GAINID – 0x201

GAIN(continued)

PRM_INDEXID – 0x0001

8 bit integerID – 0x00


Motivations for fixed 7 level structure

• Can control any device without discovery

Example – – Small controller in large network of complex pro-audio devices– Address of gain parameter is known for:

• Channel 1• On any device

• Wildcard (all 1’s) can be inserted at any level• Provides single message control over many parameters• Allows for partial discovery


Creating a parameter on a device


X170 Device Applicat

ion

X170 Stack

Callback

Hierarchical tree

Parameter entry structures

Level structures

1. Create level and parameter structures

2. Add to tree

Points to

Parameter Access


X170 Device

0x00020xD1010x100007

X170 Stack

Stored Parameter Values

Callback

Hierarchical tree

Application

.

.

Parameter entry structures

1 – X170 message

2 - Traverse tree

3 – call callback

4 – Access parameter

X-170 Connection Management Concepts

• Ethernet AVB -Multiple channels of audio in ‘streams’• X-170 - view as being clustered into multicore cables, or ‘multicores’

Audio device Audio device

Network cable

Multicore Audio channel

MulticoreOut socket

MulticoreIn socket


Devices View

This is where you choose the 2 devices that you want to connect with a multicore

Multicore View

This is where you choose the transmitting devices output multicore socket and the receiving device’s input multicore socket

Transmitter View

This is where you indicate how audio inputs to the transmitting device are routed to multicore audio channels

Receiver View

This is where you indicate how multicore channels coming into the receiving device are routed to audio outputs from the device

Control and Monitoring

This is where manufacturer-specific desk items can be displayed

User-tailored Control and Monitoring

This is where the user can construct a tailored control and monitoring surface using controls from more than one device.

The User view of the multicore concept


GUI Display of X170 Connection Management

1 Devices

2 Multicores

3 Talker

4 Listener

5 Deskitem

6 User


1 2

3 4

5

6

X-170 parameters for AVB connection management

Each Ethernet AVB device will have:

– Talker Streams – Listener Streams

These Streams can be viewed as multicores

via XFN, it is possible to determine:

– types of Streams an Ethernet AVB device has– properties associated with each stream


SECBLK XFN_SCT_BLOCK_OUTPUT


SECTYPE XFN_SCT_TYPE_STREAM

SECNR Interface No

PBLK XFN_PRM_BLOCK_AVB_MULTICORE

PBLIX Multicore number

PARTP XFN_PTYPE_STREAM_ID

PARIX 1

‘Talker’ parameters

• Multicore number – X-170 identifier for a particular stream• ‘Wildcard’ this level to determine no of talker streams




SECNR Interface No



PARTP XFN_PTYPE_STREAM_ID

PARIX 1

Stream ID parameter

• Each Talker Stream has a 64-bit Stream ID associated with it.


Talker Advertise parameter

When doing an XFN GET VALUE on this parameter:

0: The Stream has not been advertised to the Ethernet AVB network1: The Stream has been advertised to the Ethernet AVB network

When doing an XFN SET VALUE on this parameter:

0: If the associated Stream is being advertised, the Talker Advertise will be withdrawn. This will also have the effect of stopping this Stream, if it is currently streaming.

1: If the associated Stream is not being advertised, this will have the effect of advertising the Stream to the network.

PBLIX Multicore numberPARTP XFN_PTYPE_ADVERTISEPARIX 1


‘Listener’ parameters

• Multicore number – X-170 identifier for a particular stream• ‘Wildcard’ this level to determine no of listener streams

SECBLK XFN_SCT_BLOCK_INPUT


SECNR Interface No



PARTP Specific parameter type value

PARIX Specific parameter type index


When doing an XFN GET VALUE request on this parameter:

0: The associated Listener Stream is not receiving stream data from any Talker1: The associated Listener Stream has requested that a Talker stream data towards it

When doing an XFN SET VALUE on this parameter:

0: If the associated Listener Stream has requested attachment to a Talker Stream, the request will be withdrawn. If the Talker has no other Listeners receiving the Stream, it will stop sending out its Stream

1: If there is not currently a request to receive a Stream, a Listener Ready request will be sent out onto the AVB network. The Listener Ready request will contain the Stream ID that is associated with the Listener Stream.

Listener ‘Listen’ parameter

PBLIX Multicore numberPARP XFN_PTYPE_LISTENPARIX 1


Internal Routings

Level Name Audio input to audio output cross point enable

Section Block XFN_SCT_BLK_INPUT

Section Type XFN_SCT_TYPE_AUDIO

Section Number Integer – audio in number

Parameter Block XFN_PRM_BLOCK_OUTPUT

Param Block Index Integer – audio out number

Parameter Type XFN_CROSSPOINT_ENABLE

Parameter Index 1


Encapsulation – some of the outputs will be channels within multicores

Establishing and Tearing Down Streams

To establish a Stream connection between an AVB Talker and Listener device, the XFN device making the connection needs to:• Obtain the Stream ID of the required Stream associated with the AVB Talker device

– XFN GET VALUE request on the Stream ID parameter of the Talker’s Stream.

• Set the Stream ID of the required Stream that is associated with the AVB Listener device. – XFN SET VALUE request on the Stream ID parameter of the Listener’s Stream.

• Set the appropriate Talker’s XFN Advertise parameter to a value of 1.• Set the appropriate Listener’s XFN Listen parameter to a value of 1.

To tear-down a stream between an AVB Talker and an AVB Listener device, the device tearing down the stream needs to:• Set the appropriate Listener’s XFN Listen parameter to a value of 0.



A typical AVB test configuration

The concept of ‘Pushing’

• Often not efficient to GET values: – Multiple meter displays for target device– Repeated updates, short intervals

• ‘PUSH’ mechanism created:– Control application sends SET PUSH to target– Gives full address of parameter to push to

• Target adds control app parameter to its metering parameter Push list

• Target continuously:– Scans Push list of parameter– Sends meter block to each member of Push list



Pushing a Data block

Control application XFN

Stack

Parameter

Entry 1

Entry 2

Entry n

Push List

PeriodicProcess

Data to be pushed

Target Device

1.Read

2.Read3.Send data

4.SET DATABLOCK

Grouping Parameters

• Alter one parameter -> alter other parameters

• 2 types of groups:– Master/Slave - Change master, slaves change – change slave, no change of

master– Peer to peer – change any group member, others also change

• 2 types of relationship:– Absolute - take on same value– Relative – offset is maintained


• Master/Slave, relative, A is master:

Grouping examples


A

12

B

5

C

17

A

14

B

7

C

19

A

12

B

5

C

17

A

12

B

1

C

17

Peer to Peer relative:

Grouping examples


A

12

B

5

C

17

A

14

B

7

C

19

A

12

B

5

C

17

A

8

B

1

C

13

Each parameter will contain 3 lists:

• A list of peer parameters• A list of parameters that are its master• A list of parameters that are its slaves

Master/Slave: - make parameter A the master of parameter B

JOIN MSTSLV <address: XFN address of parameter A> <XFN address of parameter B> <abs/rel> Peer to peer: - join parameter A parameter B as peers: JOIN PTP <address: XFN address of parameter A> <XFN address of parameter B> <abs/rel>

Grouping Mechanisms


The Modifier Concept

• Can create ‘Modifier Blocks’ with variables• Variables modify value or level addresses

– Input Value Parameter (IVP)– Output Value Parameter (OVP)– Value script variable parameter (VVP)– Address block level 1 script variable parameter (L1VP)– Address block level 2 script variable parameter (L2VP)– Address block level 3 script variable parameter (L3VP)– Address block level 4 script variable parameter (L4VP)– Address block level 5 script variable parameter (L5VP)– Address block level 6 script variable parameter (L6VP)– Address block level 7 script variable parameter (L7VP)



Joining to and from Modifier parameters

FaderParameter

Input ValueParameter

ModifierParameterBlock

FaderParameter

Output ValueParameter

Value Change ScriptJoin

XFN msg

Join

XFN msg

•Graphical control items on desk top, examples:– slider, – pan pot.

•Information about desk items is in device:– Nature of desk item– Position of desk item– Graphical images for desk item– Associated device parameter

•Information allows a controller to:– Extract desk item information from device– Display in desired layout– Allow for user control of device parameter

Desk Items


The Desk Item mechanism


Desk item info

Device A

Desk item info

Device B

Desk item info

Device C

Device display

Control deviceDesk item info request

A Desk Item Editor

The Desk Item Displayed

A different desk item

•Enables fast discovery of a defined group of parameters–Controller indicates a defined set of parameters (IP address, name, etc)

–Broadcasts the following:Create USG <fragment size><no of address entries> <full address1, full address2, … fulladdressN>

–Controller directs the following message to each device:Get USG List <List N>

–Device provides parameter ID’s and values for these addressesListData<full address1, xfnID1, Value format1, Value1, full address1,

xfnID2, Value2, … full addressN, xfnIDN, Value formatN, ValueN>

•Two other contexts for using this:–Retrieval of parameter values from a device for later restoration (snapshots)

Set USG<No of entries> <xfnID1, Value format1, Value1, xfnID2, Value format2, Value2, … xfnIDN, Value formatN, ValueN>

–Regular bulk parameter updates from device to controller (eg for metering)

Device Discovery



Display of discovered devices

A possible scenario:Multiple devices on network, all able to generate and receive 1722 streamsDevices implement varying connection management and control protocolsDevices can’t stream to each other

Possible solutionsController that can speak multiple protocolsA proxy that can translate protocol messages

Either wayDetermine the protocol spoken by devicesUse Zeroconf to do this

Zeroconf and protocol Interoperability


- Created OSC device on Linux PC

- Creates OSC address space with stream parameters

- Create _osc._udp service type

- Register the service to be published using avahi to:Create an entry group Add service to entry group (specify name, service type, port n0, DNS TXT rec)Commit the entry group

- A proxy then:Browses for the _osc._udp service (callback called when service is available)Resolves the service within callback (obtains IP address, port number)

X170 and OSC Interoperability


April 2010

Thank You!


Presentation AES X-170 at IEEE 1722.1 Face to Face Robby Gurdan and Richard Foss [email protected]...

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Transcript of Presentation AES X-170 at IEEE 1722.1 Face to Face Robby Gurdan and Richard Foss [email protected]...