Polycom HDX 4500 Technical document

APPENDIX 11/04
TEST RESULTS FOR POLYCOM® HDX 4500
Manufacturer: Polycom®
Model: HDX 4500
Software Version: 3.0.3-14451
Optional Features and 1080p Resolution
Modifications:
Date of Test: 14th –18th November 2011
System front view

ii
HD Camera
Control Panel

iii
C O N T E N T S Page No.
A: INTRODUCTION ............................................................1
B: SETUP PROCEDURE ............................................................2
C: HARDWARE DESCRIPTION …................................................2
D: SYSTEM OPERATION ......................................................7
E: VIDEO TESTS SUMMARY ..................................................11
F: AUDIO TESTS SUMMARY ...................................................11
G: DATA TESTS .................................................................11
H: CONNECTIVITY .................................................................11
Appendix 1 Detailed Physical Information ......................................14
Appendix 2 Detailed Video Tests …………......................................15
Appendix 3 Detailed Audio Tests …………......................................20

1
A: INTRODUCTION
The Polycom® HDX 4500 is a self contained desktop High Definition (HD)
videoconferencing system with a maximum picture resolution of 1920 x 1080 pixels
(1080p) at 30fps. It is the highest specification model in Polycoms HDX 4000
series of conferencing solutions. The system comprises a 24‖ picture monitor,
CODEC, camera, microphones and loudspeakers integrated into a single desktop
unit. Compatibility with other H.323 and SIP CODECs is achieved across a range
of resolutions from SIF (352x240 pixels) up to 1920 x 1080 depending on the
capability of the remote CODEC and the connection bandwidth.
Available options include:
1080p resolution
4 Site Multipoint Conference unit (MCU)
The systems supplied for evaluation included the 1080p option only.
HDX 4500 Feature Summary:
A high definition videoconferencing system which supports variable resolutions
up to a maximum of 1920 x 1080 pixels (1080p) at 30fps or 1280 x 720 pixels
(720p) at 60fps.
A single integrated unit comprising: The 24‖ picture monitor, CODEC, camera,
dual microphones and loudspeakers.
An IP CODEC operating at connection speeds up to 4 Mbit/s over H.323
A fixed HD camera with 1920 x 1080 native resolution and a manual privacy
shutter feature.
Dual monitor support.
Supports H.261, H.263, H.263+, H.264 and H.264 High Profile video coding.
Supports G.711, G.722, G.722.1, G.728, G.729A, Siren 14 and Siren 22, audio
coding including Polycom® StereoSurround™.
External microphone input
Stereo headphone output
DVI PC data input
Stereo analogue audio input for connection of PC audio
Stereo-surround audio
Far-end camera control
H.239 second HD video connection with up to w1080p (1920 x 1080) resolution
Optional four site internal H.323 MCU with either continuous presence or voice
switched operation
AES Encryption

2
B: SETUP PROCEDURE
Installing the Polycom® HDX 4500 system was straight forward. The Quick Start
Guide clearly illustrated this simple procedure:
Connect the control panel to the unit.
Connect the RJ45-RJ45 cable to establish an Ethernet IP network connection
Connect mains power to the unit.
System set up was also convenient and trouble free. The IP address, IP Gateway,
Subnet mask and Gatekeeper address were all configured by the control panel
through the on screen menus.
Approximate set-up time: 15 minutes
Documentation quality: The documentation was concise and easy to follow
and included: Setup, Quick Start, User‘s and
Administrator guides.
C: HARDWARE DESCRIPTION
HDX 4500 System
The HDX 4500 systems supplied for evaluation had a maximum call bandwidth of
4 Mbit/s and included the 1080p (30fps) option.
The CODEC offers several video resolutions including:
SIF 352 x 240 pixels
CIF 352 x 288 pixels
2CIF 704 x 288 pixels
4CIF 704 x 576 pixels
High definition w720p i.e. 1280 x 720 @ 60 frames per second
High definition w1080p i.e. 1920 x 1080 @ 30 frames per second
The image resolution and frame rate are dependent on the call connection
bandwidth and the video mode (Motion or Sharpness), the default setting being
Sharpness:
Video Mode
Sharpness
Motion
Connection
Bandwidth
Resolution
Frame rate
Resolution
Frame rate
128 Kbit/s
704 x 576
25fps
352x288
50fps
384 Kbit/s
704 x 576
25fps
704x288
50fps
768 Kbit/s
1280 x720
25fps
704 x 576
50fps
1 Mbit/s
1920 x 1080
25fps
1280x720
50fps
2 Mbit/s
1920 x 1080
25fps
1280x720
50fps
4 Mbit/s
1920 x 1080
25fps
1280x720
50fps

3
To maintain picture sharpness (resolution) at the lower connection bandwidths the
frame rate was reduced as movement increased within the image
The HDX 4500 CODEC supports both single and dual monitor modes. When
multiple images are displayed on a single monitor only Picture outside Picture
(POP) is displayed, Picture in Picture (PIP) is not available. The second monitor
output may be configured as DVI, VGA or component video to cater for high
definition signals.
The Perspex screen across the front of the monitor was highly reflective and
degraded the image quality.
The aspect ratio and the video format of displayed images can be selected from the
comprehensive range of settings. This allows both transmitted and received images
to be optimised locally for both People and Content signals.
The options available are:
• None—Preserves the aspect ratio of the source video: The image is scaled (if
necessary) to the largest supported resolution that fits on the display without
cropping. Unused areas of the display are filled with black borders.
• Stretch—Aspect ratio not preserved: The image is scaled horizontally and
vertically to match exactly the resolution of the display.
• Zoom—Preserves the aspect ratio of the source video: The image is scaled to
exactly match one of the display dimensions while matching or exceeding the other
display dimension. The image is centred and cropped.
Only the ―None‖ setting was used during the evaluation.
In single monitor mode using the HDX4500 monitor only two images may be
displayed as a POP. Various layouts may be selected through the Layout button on
the remote control panel:
No Content being transmitted or received.
1. Near and far sites, same size, side by side
2. Far site big, near site small
3. Near site big, far site small
4. Near site, full screen
5. Far site, full screen

4
Point to Point Call, Picture outside Picture (POP) no content, near and far sites side
by side
This image clearly shows the screen reflections
Point to Point Call, Picture outside Picture (POP) no content, far site large, small
near site.

5
When Content is displayed, a small image of the far end conference participants
appears alongside the larger Content image, layouts may be altered using the
Layout button.
Content transmitted or received
1. Content big, far site small
2. Content big, near site small
3. Content and far site, same size, side by side
4. Content, full screen
Point to Point Call, Picture outside Picture (POP) with 16x9 Content
In dual monitor mode with no Content transmitted or received the main monitor
displays the far site image and system menus, the second monitor displays the near
site camera images.
When content is transmitted a number of layout options are available.
Main Monitor (includes Menus)
Second Monitor
Content and near site, same size,
side by side
Far site full screen
Content big, near site small
Far site full screen
Content big, far site small
Near site full screen
Content full screen
Near site full screen
Content full screen
Far site full screen

6
When Content is received a number of layout options are available.
Main Monitor (includes Menus)
Second Monitor
Far site big, near site small
Content full screen
Near site big, far site small
Content full screen
Near and far sites, same size, side
by side
Content full screen
Far site full screen
Content full screen
The Polycom® high definition camera has a native resolution of 1920 x 1080
(1080p) it has a fixed focus lens and tilts with the monitor adjustment. A 2x digital
zoom is available but unlike an optical zoom its use just degrades the image. A
manual privacy shutter control is provided above the camera.
A feature of the HDX system is People ‗on‘Content (conventionally called
―Chroma Key‖ or ―Colour Separation Overlay‖) to create an artificial background
behind a presenter. For example a weather presenter could be superimposed over a
map of the UK (derived from a PC image). This requires the presenter to be
positioned in front of a plain green background and viewed by the HD camera. The
green areas of the image (i.e. not the presenter bits) then cause an electronic switch
to select the appropriate parts of the map for superimposition. Unfortunately the
quality of these ―chroma-key‖ images is very variable and is critically dependant on
the quality of the lighting on the presenter. It can be very difficult to reduce the
‗shimmering‘ effect around the edge of the presenter image.
The optional high definition MCU provides four (host HDX CODEC plus three
remote sites). The speed of each connection is dependent on the total number of
sites in the MCU conference and the bandwidth capability of the CODEC. The
MCU option was not available on the evaluation systems.
During an H.323 call a second unidirectional video channel (Content) is provided
through H.239, ―People‖ being the normal conferencing channel. Thus video from
the camera and a second source e.g. a PC image could be transmitted
simultaneously and displayed on two monitors at the remote site. For People and
Content the bandwidth may be dynamically allocated between each channel or split
in the ratios, 50/50, 90/10 or 10/90 up to the limits of the maximum available
connection speed.
The HDX system is capable of transmitting and receiving two simultaneous high
resolution (1080p at 30fps) images. The high definition high frame rate Content
channel is a new development that enhances the overall conference experience.
Several audio formats are supported by the CODEC. Polycom has implemented the
Siren 22 audio protocol with 22KHz analogue audio bandwidth, including
StereoSurround™. The system captures stereo by using the two monitor
microphones to create a stereo image.
A separate stereo audio input using a 3.5mm mini jack connector allows for
straightforward interfacing to a PC or laptop. A useful feature mutes Content audio
on the local and remote loudspeakers until Content is selected for transmission.

7
Unfortunately not many other manufacturers provide this facility. Additionally
when the PC image is previewed its associated audio is only heard at the local site.
Echo cancellation is appropriately disabled on this input.
System control is normally through the wired remote but if preferred a Polycom
standard infra red control may be used. Remote configuration is another option via
a web browser from a network connected PC. This comprehensive web interface
provides control and configuration of the CODEC and displays diagnostic
information if required, together with web snapshots of near and far sites. For
added security this remote management system may be password protected. For
connection to a room control system etc. an RS232 serial control port is also
provided.
D: SYSTEM OPERATION
The remote control panel includes dedicated controls for Dial, Hang up, Directory,
Volume, Microphone mute, Zoom, Near/Far and Layout together with cursor
controls to navigate the on screen menus.
The Content (PC) input signal is controlled via two buttons. The monitor preview
button cycles between the PC input and the CODEC output, while the second
button transmits or stops transmission of the PC image over the conference link to
the remote site(s)
The ‗Info‘button has dual functions, providing context sensitive help when not in a
call and a shortcut to Call Status information during a call.
HDX 4500 Remote Control Panel

8
The PC input source to the HDX CODEC must be designated either ―People‖ or
―Content‖. People images are transmitted on the main video channel while Content
images are transmitted on the second H.239 video channel. When presentation
(Content) material is transmitted or received the system maintains the main (People)
channel resolution despite the reduction in bandwidth allocated to that channel. If it
is desired to allocate all the call bandwidth to the Content to maximise image
quality, then the Content (PC) signal may be connected to the main channel.
Network connection of a PC to the CODEC is also possible by loading the software
application ―People + Content™ IP‖ onto the PC or laptop, but this is limited to
visual material only as sound is not transmitted.
An H.239 (dual video) conference is initiated and terminated by pressing the ―Send
Computer‖button on the remote control panel. The camera occupies the first
channel and the PC image source the second channel. The two signals are then sent
to the remote site for simultaneous display on two picture monitors. Both channels
can deliver high resolution high frame rate images.
Successful H.239 conferences were established in both directions between HDX
systems and with other manufacturers‘CODECs for both high and ordinary
definition conferences. The HDX 4500 CODEC supports remote camera control.
The system takes just over two minutes to boot up from cold, when not in a call the
system automatically reverts to sleep mode after a user definable period. An
incoming call or remote control panel button press will return the system to active
mode.
Some problems were experienced after re-booting the system. Several user system
settings had returned to the default from their original user selection, these included:
Camera white balance and second monitor screen resolution. This could cause
problems for casual users as it occurred after a power off and/or a reboot.
At times some areas of the menu were ―greyed out‖ (i.e. could not be selected)
suggesting that the CODEC was in a call, when in fact it was not. The problem
could only be cleared by re-booting the system.

9
Web Interface Screen Shots:
Call Status
System Configuration
Screen shots of the transmitted and received images are also available from the web
interface using either ―Remote Monitoring‖which provides snapshots of the near
and far video images or ―Web Director‖which provides additional CODEC control
as well as participant screenshots.

10
Remote Monitoring
Web Director
Screenshots reproduced by permission of Polycom®

11
E: VIDEO TESTS SUMMARY
High Definition Image Quality
Unfortunately, during testing the cameras at both sites appeared to have faults that
limited the image quality. In calls between HDX 4500 systems one camera
produced soft focus images with a very limited depth of field. The other camera
produced more acceptable results but the edges of objects in the image appeared
artificially sharp whereas areas of fine detail, for example hair and skin texture
appeared blurred and with too much contrast (Posterised).
When Content material from a PC was transmitted on either channel the results
were good, suggesting that the problems experienced were camera related as
opposed to CODEC or picture monitor issues.
The ability to send and receive two high resolution, high frame rate images was
seen as a very positive feature.
F: AUDIO TESTS SUMMARY
Setup The echo canceller is fully automatic in operation. The quality of echo cancellation
and doubletalk from the system was excellent.
Audio levels adequate? (Yes/No)
Yes
Audio quality acceptable? (Yes/No)
Yes
Echo cancellation acceptable?
(Yes/No)
Yes
Quality of double talk
Excellent
When the frequency response was measured it was found to be quite uneven for all
audio protocols. The levels measured 0 dB at both 1KHz and 7 KHz but at mid-
band (i.e. 3.5 KHz) was -6dB indicating a notch in the frequency response between
these frequencies.
G: DATA TESTS
A PC may be directly connected to the CODEC via the DVI interface and may be
transmitted on either the main channel or the H.239 channel. Audio from a PC may
only be transmitted when the PC is selected on the main channel. People +
Content™ IP software may also be used to connect a PC to the CODEC across the
data network but with picture only
H: CONNECTIVITY
Connectivity between Like Machines
H.323
There were no problems in establishing connections between the HDX units over
IP.

12
During an H.323 call the network connection was removed and reconnected after a
specific time:
The normal 5 seconds test could not be checked as the calls dropped immediately,
this is very unusual after such a short period, as calls with other manufacturers‘
products typically reconnect after up to a 30 seconds network
disconnection/reconnection.
Time to Connect
H.323
All speeds
Approx. 3 seconds
Connectivity with Other Machines (models listed with comments)
H.323
Successful connections were made in each direction with the following CODECs,
where the systems supported H.239, presentation material was also shared.
C
o
n
n
e
c
t
C
L
P
o
H
In calls between the HDX4500 and Tandberg Edge 95 low resolution CIF was
transmitted by the Tandberg and SIF was transmitted by the HDX4500.
In calls between the HDX4500 and Tandberg 6000 MXP the HDX4500 transmitted
4CIF.
CODEC
Model and Software
Version
Call
Bandwidth
Resolution
Transmitted by
the HDX 4500
Resolution
Received by
the HDX 4500
Polycom PVX
S/W 8.0
1.5 Mbit/s
352 x 288
320 x 240
Polycom® VSX7000
S/W 9.0.5.1
2 Mbit/s
352 x 288
352 x 288
Tandberg Edge 95
S/W F9.0 PAL
2 Mbit/s
352 x 240
352 x 288
Tandberg 6000 MXP
S/W F9.0 PAL
2 Mbit/s
704 x 576
720p
Tandberg C40
S/W TC4.0.1
2 Mbit/s
1080p
720p
Tandberg C60
S/W TC3.1.1
2 Mbit/s
1080p
720p
Polycom HDX 9002
S/W 2.6.0
2 Mbit/s
720p
720p
Lifesize Team
S/W 4.7.10
2 Mbit/s
720p
720p
Lifesize Room 200
S/W 4.7.0
2 Mbit/s
720p
720p

13
Resolution in pixels and their common designation:
1920 x 1080 1080p
1280 x 720 720p
1024 x 576 W4CIF
704 x 576 4CIF
576 x 448 448p
512 x 288 WCIF
352 x 288 CIF
352 x 240 SIF
320 x 240 QVGA
Connectivity with Janet Videoconferencing Switching Service (JVCSS)
The HDX connected to the Codian MCU using H.264 Video and G.722.1 audio in
both directions. It interoperated successfully also negotiating 720p resolution on
the H.239 channel.
Received audio level was measured as peaking to -4dBm.
Procedure for making a call
1. Press the Call button on the remote control
2. Select connection speed
3. Input IP address or E.164 number
4. Press the Call button again.
Local Contacts Directory and Recent Call list are also available from the user
interface.

14
Appendix 1 Detailed Physical Information
Dimensions: (w x h x d) 75 x 53 x 21 cm
Video Inputs
Format
Connector
Main camera
Internal connection
PC input
VGA, DVI,
Component
DVI-I
Video Outputs
Format
Connector
Main monitor
Internal connection
Second monitor
VGA, DVI,
Component
DVI-I
Audio Inputs
Level
Connector
HDX microphones
Internal connection
3.5mm mini jack
PC audio input
Line
Audio Outputs
Level
Connector
Monitor
Loudspeakers
Internal connection
Both RCA Phono
Main audio output
Line
Data
1. 1 off LAN 10/100 Mbits/s Ethernet connection (RJ45)
2. 1 off 9 pin RS232 serial control
3. 1 off USB connector (to enable software updates)
Cables Supplied
1. 1 off 1.5 metre, VGA-DVI cable
2. 1 off 1.5 metre, DVI-DVI cable
3. 1 off 1.5 metre mini jack –mini jack
4. 1 off 3.6 metre RJ45-RJ45 network cable
5. 1 off IEC power cord
Mobility
The Polycom® HDX 4500 system can be moved easily. To establish a connection,
each new location will need the local area network information re-entered into the
configuration menu.

15
Appendix 2 Detailed Video Tests
The HDX system supports, H.261, H.263, H.263+ and H.264, but these protocols
are automatically selected. In calls between HDX units only the default protocol
H.264 could be tested as this was the one negotiated by the CODECs
For the following tests using the DVI input and with the PC input set to People and
Sharpness, the video resolution between HDX systems was 4SIF at 384Kbit/s rising
to 720p at all other connection speeds
Objective Video Tests: Signal measurements
1. 75% EBU bars
2. Grey scale
Subjective Video Impairments Tested:
Lip synchronisation
LS
Block distortion (tiling)
BLK
Blurring (reduced edge sharpness and spatial detail)
BLR
Colour errors
CLR
Jerkiness (distortion of smooth motion)
JRK
Object persistence
(lagging images from previous frames as faded or outline images)
OP
Scene cut response (i.e. time to build up the new image)
SCR
Scale of impairments:
Imperceptible 1
Perceptible 2
Slightly annoying 3
Annoying 4
Very annoying 5
MII Test Tape:
Signals recorded Time on tape
1. EBU colour bars 1min 30secs
2. Grey scale 1.40 - 2.40
3. Blue field 2.50 - 3.50
4. Medium close up female face, still 4.00 - 5.00
5. Medium close up female face, talking 5.10 - 6.10
6. Close up face, nodding 6.20 - 7.20
7. Close up face, shaking head side to side 7.30 - 8.30
8. Zoom out slowly to wide angle three people 8.40 - 9.40
9. Zoom in quickly to close up of centre person 9.50 - 10.50
10.Turntable speeds: 1,2,3 and 4 11.00 - 15.30
11.Football sequence 15.40 - 16.40
12.Zoom in and out of ―A to Z‖ map 16.50 - 17.50
13.Text legibility, font sizes 20 to 12 pt 20.30 - 20.50

16
14.Cut tests, scenes various with camera movements 21.00 - 22.00
15.Man teaching at whiteboard 22.10 - 23.23
(Insert 75% EBU bars at local site, measure at remote site)
Test 1 (H264): Colour bar test
(Insert 75% EBU bars at local site, measure at remote site)
Subjective Impairments H.323
384 kbit/s
768 kbit/s
2.0 Mbit/s
4.0 Mbit/s
BLK
1
1
1
1
BLR
1
1
1
1
CLR
1
1
1
1
Test 2 (H.264): Grey scale
(Insert grey scale at local site, measure at remote site)
Subjective Impairments H.323
384 kbit/s
768 kbit/s
2.0 Mbit/s
4.0 Mbit/s
BLK
1
1
1
1
BLR
1
1
1
1
CLR
1
1
1
1
Test 3 (H.264): Blue screen
(Insert blue screen at local site, measure at remote site)
Subjective Impairments H.323
384 kbit/s
768 kbit/s
2.0 Mbit/s
4.0 Mbit/s
BLK
1
1
1
1
CLR
1
1
1
1
Test 4 (H.264): Medium close up female (still)
Subjective Impairments H.323
384 kbit/s
768 kbit/s
2.0 Mbit/s
4.0 Mbit/s
BLK
2
1
1
1
BLR
2
2
1
1
CLR
1
1
1
1
Test 5 (H.264): Medium close up female (talking)
Subjective Impairments H.323
384 kbit/s
768 kbit/s
2.0 Mbit/s
4.0 Mbit/s
LS
2
1
1
1
BLK
3
2
1
1
BLR
3
2
1
1
CLR
1
1
1
1
JRK
2
1
1
1

17
Test 6 (H.264): Close up head (nodding)
Subjective Impairments H.323
384 kbit/s
768 kbit/s
2.0 Mbit/s
4.0 Mbit/s
BLK
3
1
1
1
BLR
3
2
2
1
CLR
1
1
1
1
JRK
1
1
1
1
Test 7 (H.264): Close up head (shaking side to side)
Subjective Impairments H.323
384 kbit/s
768 kbit/s
2.0 Mbit/s
4.0 Mbit/s
BLK
4
2
1
1
BLR
4
3
2
2
CLR
1
1
1
1
JRK
1
1
1
1
Test 8 (H.264): Medium close up, slow zoom out to three shot
Subjective Impairments H.323
384 kbit/s
768 kbit/s
2.0 Mbit/s
4.0 Mbit/s
BLK
3
1
1
1
BLR
3
2
1
1
CLR
1
1
1
1
JRK
2
1
1
1
Test 9 (H.264): Three shot, quick zoom in to medium close up centre person
Subjective Impairments H.323
384 kbit/s
768 kbit/s
2.0 Mbit/s
4.0 Mbit/s
BLK
3
1
1
1
BLR
3
2
1
1
CLR
1
1
1
1
JRK
2
1
1
1
Test 10a (H.264): Turntable speed 1
Subjective Impairments H.323
384 kbit/s
768 kbit/s
2.0 Mbit/s
4.0 Mbit/s
BLK
2
1
1
1
BLR
1
2
1
1
CLR
2
1
1
1
JRK
1
1
1
1
Test 10b (H.264): Turntable speed 2
Subjective Impairments H.323
384 kbit/s
768 kbit/s
2.0 Mbit/s
4.0 Mbit/s
BLK
2
1
1
1
BLR
2
2
2
1
CLR
2
2
1
1
JRK
2
2
1
1