Performance Analysis of Home Streaming Video Using Orb

Rabin Karki, Thangam Seenivasan, Mark Claypool and Robert Kinicki

Worcester Polytechnic Institute

Presented By:Rabin Karki27 May, 2010

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Introduction

• Video streaming largest fraction of Web-based traffic to homes [cite]

• New trend - users streaming video from home to Internet

• Needs:

–Understand how available bandwidth determined

–Measure bandwidth use of new systems

–Ascertain video quality

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Introduction

• Orb – free video streaming system from home to the Internet

• Features– MyCast service– Instant access to photos, music, videos,

television, and other digital content on PC– Access anytime and from any Internet-

connected device

• Launched in 2005, now 7+ million users

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Overview

• Introduction• Goals• Experiments• Results• Conclusions

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Goals

• Ascertain how Orb determines bandwidth available for streaming

• Measure Orb network traffic under different bandwidth constraints

• Investigate video performance at streaming client

• Understand resource usage at streaming host

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Overview

• Introduction• Goals• Experiments• Results• Conclusions

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Orb – Streaming Modes

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Experiments – Setup

Orb Server

WPI LAN

Host PC Router Client PC

Internet

Direct streaming

Uplink Bandwidth estimation

Downlink Bandwidth estimation

Direct streaming

Host and Client PC• Windows XP running Orb

Router • Linux with Netem

Network• Direct streaming

Tools• Wireshark and MediaTracker

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Experiments – Videos Used

Encode:• Windows Streaming Media, low quality

320x240, 768 kbps, 25 fps• Windows Streaming Media, high quality

1280x720, 1546 kbps, 25 fps• Flash Video

320x214, 320 kbps

Source:• Documentary, High def,

.mov video, 150 seconds

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Overview

• Introduction• Goals• Experiments• Results• Conclusions

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Low Quality Video: Frame Rate

• Lower frame rate suggests coarse scaling

• 250 ends later

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Low Quality Video: Bit rate

• Different encoding levels suggest quality scaling.

• Extremely low bitrate at 250 kbps

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Low Quality Video: Bandwidth

• Video streamed just below available b/w (except 250 kbps)

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High Quality Video: Frame rate

• Frame rates similar to low quality video.

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High Quality Video: Bit rate

• Bitrates different than low quality

• When buffer progress is 100% for some time, bit rate is doubled.

• If buffer progress doesn’t improve, bit rate is reduced.

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High Quality Video: Bandwidth

•Bandwidth used more closely follows the bandwidth settings than do the encoded bitrates.

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Host Load

To FLV To WMV0

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40

60

80

100

120

140

160

180

FLVWMVWMV (HQ)

CP

U L

oad

(%

) Source Format

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Overview

• Introduction• Goals• Experiments• Results• Conclusions

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Conclusions

• Bit rate adapts to capacity constraints using TCP

• Temporal and quality scaling

– Temporal scaling coarse

– Quality scaling smoother for low-quality video

• Transcoding in real-time

– Resource intensive for streaming host

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Future work

• Other devices• Indirect streaming• Other network settings

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Thank you!

Questions?