Packet Video & Audio Tools on PC’s (A Cookbook)

1. Packet Video & Audio Tools on PC’s (A Cookbook) February 7-11, 2000 H.A. “Kipp” Kippenhan, Jr. [kippenhan@fnal.gov] CHEP 2000

2. Outline • Classification of systems • Packet Tools - Background • ITU Standards • Applications • Audio considerations • Video considerations • Additional suggestions • Summary • Questions CHEP 2000

3. Classification of Systems – Pre H.323 CHEP 2000

4. Classification of Systems – Post H.323 CHEP 2000

5. Packet Tools - Background • Genus of the tools was research at Xerox PARC and Lawrence Berkeley Laboratory • Tools generally needed to participate • sdr (session directory) • vic (video conferencing tool) • rat (robust audio tool) • vat (visual audio tool) • wbd (white board) • Targeted for IP multicast (interactive use is more demanding) • What works well on Unix workstations may work differently (?not so well?) on PC’s CHEP 2000

6. ITU Standards • H.320 umbrella standard Video & audio over public switched telephone network (e.g. - ISDN) • H.323 umbrella standard Video & audio over networks with no Quality of Service guarantee (i.e. – TCP/IP) • Video encoding • H.261 encoding (part of H.320) • Discrete cosine transform encoding • Maximum of 352x288 pixel resolution • Subset of MPEG encoding (optimized for symmetric transmission/reception) CHEP 2000

7. ITU Standards • Video encoding • H.263 encoding (part of H.323) • Improved motion compensation (a factor of 5) • Maximum of 352x288 pixel resolution • Provision for 704x576 and 1408x1152 resolution (no products presently available) • Audio encoding (H.320 & H.323) • G.711 encoding – 3 KHz audio (uses 48, 56 or 64 Kbps of bandwidth) • G.722 encoding – 7 KHz audio (uses 48, 56, or 64 Kbps of bandwidth) • G.728 encoding – 3KHz audio (uses 16 Kbps of bandwidth) CHEP 2000

8. ITU Standards • Audio encoding (H.323 unique) • G.723 – 3 KHz audio (uses 6.4 or 5.3 Kbps of bandwidth) • G.729 – 3 KHz audio (uses 8 Kbps of bandwidth) • What’s important • Only G.711 must be supported (even in H.323 products) • G.723 encoding is shipping in commercial products (e.g. – Cisco) • H.323 encoding only supports 352x288 pixels (in products shipping today) • Voice over IP products are classed as H.323 compliant CHEP 2000

9. The Applications • Audio Tools Provide for the transmission/reception of audio information via packet networks • Vat (4.0b2) • Provides echo cancellation • PC version not full duplex audio • No recent development work • Rat (v 3.0.35) • No echo cancellation • Supports full-duplex audio • Supported by UCL (MECCANO project) CHEP 2000

10. The Applications • Video tools Provide for the transmission/reception of video information via packet networks • Nv • Doesn’t support H.261 encoding • Supports 640x480 resolution • No recent development • Vic (2.8ucl-1.0) • Support H.261 and H.263 encoding • 352x288 (FCIF) resolution (640x480 – nv encoding) • Supported by UCL (MECCANO project) CHEP 2000

11. The Applications • Other tools There are a variety of other tools (e.g. – HEPNRC multi-session bridge, VRVS) available for various special needs. They won’t be discussed here • Sdr (ver. 2.9) • Supports the announcement of or joining of IP multicast sessions on the Mbone • If announcing a session, the sdr process must not be stopped (announcement will disappear) • Automatically launches other tools (vic, rat, wbd, …) • Supported by UCL (MECCANO project) CHEP 2000

12. The Applications • Wbd (ver. 1.0ucl4) • A conferencing tool – not a drawing tool • Import previously prepared drawings (postscript format) • Supports shared text (like ‘chat’) • Supported by UCL (MECCANO project) CHEP 2000

13. Audio Considerations • Only important if you want to present (i.e. – source audio) • Echo cancellation • Not supported by rat • For groups, use hardware that supports it (e.g. – Polycom SoundPoint (speaker / microphone) • Audio level control Too many level controls to tweak (especially with Windows) • On speaker • Sound card (software – in systray) • Application (slider bar in rat) CHEP 2000

14. Audio Considerations • Karaoke effect • Disable feature when using rat or vat • PC sound system usable as a Public Address (PA) system • Full-duplex problem • PC hardware • Chipset on motherboard (not full-duplex until recently) • Discrete sound card (may not be full-duplex) • Driver • May not support full-duplex operation • Verification • Must do a point-to-point connection using rat CHEP 2000

15. Audio Considerations • Windows 2000 now shipping • Don’t assume anything • Compatibility issues • Users must perform tests CHEP 2000

16. Video Considerations • Only important if you want to present (i.e. – source video) • Video capture card unnecessary if PC operating system supports USB devices - use a USB camera (e.g - 3Com #3718) • Drivers are always a problem (get latest from vendor web site) • HEPNRC has had success with the Hauppauge Win-TV (model 401) • Windows 2000 now shipping • Compatibility issues • Users must perform tests CHEP 2000

17. Additional Suggestions • For a single user, get a headset (e.g. – LabTec C-324) • Disable ‘suppress silence’ option in audio tool (not doing so produces unacceptable audio performance on PC’s) • Adopt push-to-talk model (use mouse to enable microphone) • Accept variability of audio level between systems • Test your system before the day of an important meeting • Currently no bridge between H.323 / H.323 end points and packet tools (e.g. – Polycom to VRVS) CHEP 2000

18. Summary • H.323 (connection based) devices are appearing at HEP research sites • There’s still life in your H.320 (ISDN based) codec • New codec purchases should support both standards – H.320 & H.323 (e.g. - Polycom Viewstation) • MCU’s (e.g. – Accord MGC-100) will support hybrid meetings (mixture of H.320 & H.323 devices) • IP firewalls and H.323 devices don’t interoperate well (it takes some tuning) CHEP 2000

19. Summary • Vic (H.263) and rat (G.728) support necessary standards – why don’t H.323 systems interoperate with VRVS? • No way to do call-setup • Many H.323 systems don’t support rtp protocol • Suggestion – consult the following web page: http://www.hep.net/hepnrc/video/video.html CHEP 2000

20. Questions • ??? CHEP 2000