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