EnergYT: Energy Efficient YouTube Player
- 1. EnergYT: Energy Efficient YouTube Player Khaled Ziyaeen Michail Giannakopoulos Miroslav Cupak
- 2. Outline • Problem • Motivation • Approach • Architecture • Implementation • Future Work • Related Work • Conclusion
- 3. Problem • Energy is scarce on mobile phones. • One of the most energy consuming tasks on a mobile phone is streaming and playing video content – GSM (WiFi) and backlight are two highest energy consumers
- 5. Network Data Download Consumption
- 6. Signal Strength vs. Energy Use • Higher Signal Strength results in lower energy consumption – Energy Consumption increased by 30% when signal strength lowered by 10dBm over 3G data download • 3G data download suffers more severely than WiFi data download when signal strength is lowered
- 7. Motivation • Opportunity to save energy during YouTube video streaming – Particularly, backlight and data download • Backlight energy consumption is set by the user • Data Download energy consumption can be controlled by app developer
- 8. Approach • Save energy during video streaming without interrupting user experience in any way • Schedule data downloads during periods of high signal strength • Implement this energy-aware feature into a new Android YouTube media player – Download a YouTube video from a YouTube link
- 9. Http Request TCP Socket Connectionwith YoutubeServer MobileStorage Source File Media Player Connection Component Media Component Append Server Component Localhost Connection Process Request Stream Content EnergYT Architecture
- 10. Implementation • Connection Component • Server Component • Media Component
- 11. Http Request TCP Socket Connectionwith YoutubeServer MobileStorage Source File Media Player Connection Component Media Component Append Server Component Localhost Connection Process Request Stream Content EnergYT Architecture
- 12. Connection Component • Determines actual video URL from YouTube link • Downloads video data in chunks • Stores video data into local file • Signal strength is monitored – Connection closed when 1. Signal strength drops below threshold 2. Remaining buffer allows delaying next chunk download – Connection reopened when signal is strong again
- 13. Energy-Aware Algorithm while (video file is being downloaded) { if (bufferSize > DISCONNECT_THRESHOLD && currSignal < prevSignal && connection is on) disconnect(); if ((bufferSize > CONNECT_THRESHOLD && connection is off) || (currSignal > prevSignal)) { prevSignal <- getSignal(); connect(); downloadVideoChunk(); } }
- 14. Http Request TCP Socket Connectionwith YoutubeServer MobileStorage Source File Media Player Connection Component Media Component Append Server Component Localhost Connection Process Request Stream Content EnergYT Architecture
- 15. Server Component • Listens for local client connection • Streams video content to Media Component – Reads and transmits local file created by Connection Component • Reads file while video content is being downloaded by Connection Component
- 16. Http Request TCP Socket Connectionwith YoutubeServer MobileStorage Source File Media Player Connection Component Media Component Append Server Component Localhost Connection Process Request Stream Content EnergYT Architecture
- 17. Media Component • Connects to Server Component – setVideoURI(“127.0.0.1:8893/file”); • Plays video as soon as it receives content from Server Component • Performs local buffering – Allows video playback even when connection is closed by Connection Component – Waits for video content if none available • Enables user to control playback
- 18. Major Issues • Reverse engineering approach to retrieve the actual Youtube streaming URL • Reconnecting to continue download from a specific point • Getting video in an encoding supported by Android’s VideoView widget • Enabling playback of incomplete files • Turning off radio from the application (Fast Dormancy)
- 19. Future Work • Evaluation process: – Energy consumption comparing simple version of our media player versus energy-aware one – Use AIRPLANE_MODE to simulate radio shutdown • Cannot be enabled from the application layer • Develop a more sophisticated method for predicting the threshold values
- 20. Related Work • “Envi: Energy Efficient Video Player for Mobiles”, S.Suneja, V.Navda, R.Ramjee, E.DeLara • “Bartendr: a practical approach to energy-aware cellular data scheduling”, A.Schulman, V.Navda, R.Ramjee, N.Spring, P.Deshpande, C.Grunewald, K.Jain, V.N.Padmanabhan – MobiCom, 2010 • “Energy Consumption in Mobile Phones: A Measurement Study and Implementations for Network Applications”, N.Balasubramanian, A.Balasubramanian, A.Venkataramani – ICM, 2009 • “Energy Consumption of Mobile YouTube: Quantitative Measurement and Analysis”, Y.Xiao, R.S.Kalyanaraman, A.Yla-Jaaski – NGMAST, 2008 • “An analysis of Power Consumption in a Smartphone”, A.Carroll, G.Heiser – USENIX, 2010
- 21. Conclusion • We developed the infrastructure for an energy aware YouTube player on the Android Platform • We developed an energy aware algorithm for streaming YouTube videos.