HTTP-based Video Delivery

Students: Kevin J. Ma and Swapnil Bhatia
Collaborators: Man Li, Alan Huang, Raj Nair, and Mikhail Mikhailov (Azuki Systems)
Faculty: Radim Bartoš

Project outline:

This project is an ongoing investigation of the evolution of HTTP-based video delivery. Traditional streaming approaches have been optimized for just-in-time delivery, taking into account the unique rendering characteristics of video files, i.e., that video is rendered at a relatively constant rate. For well provisioned networks, the use of unreliable UDP-based transport reduces the protocol overhead of video delivery and allows for multicast delivery and "graceful degradation" of video quality, i.e., dropped packets are ignored. For closed networks, like those used by mobile network operators (MNOs) and multiple service operators (MSOs), i.e., cable operators, the optimized delivery of streaming video reduces costs, while video quality is enforced through strict network provisioning. In recent years, however, a dramatic shift in viewing habits has elevated over-the-top (OTT) video delivery, i.e., video delivered through the public internet using a standard data connection, to be one of the primary methods of video delivery used today.

HTTP is the preferred delivery protocol for OTT content delivery. TCP-based HTTP provides quality guarantees required for public Internet delivery. HTTP does not require specialized servers and can take advantage of existing optimized content delivery network (CDN) infrastructures. HTTP is also firewall friendly and doesnt require dynamic firewall "fixups" as are necessary with RTSP/RTP. Our work has progressed through a phased effort following the evolution of OTT video delivery to mobile devices:

Phase 1: Server-side pacing for HTTP progressive download.
We demonstrate the server scalability advantages of our Zippy HTTP streaming server architecture, compared with the existing de facto standard Apache HTTP server and the Darwin RTSP streaming server, for single bitrate files.
Phase 2: Client-side pacing with stitched file-based rate adaptation.
We demonstrate the viability of seek-based rate adaptation using stitched media files in legacy devices that only support monolithic video file playback, compared to multi-player-based segmented and non-segmented rate adaptation. We also investigate the encryption requirements for DRM enforcement when using stitched media files.
Phase 3: Client-side pacing with segment-based rate adaptation.
We investigate different segment-based rate adaptation schemes, e.g., Apple HTTP Live Streaming (HLS), Microsoft Silverlight Smooth Streaming, Adobe HTTP Dynamic, MPEG Dynamic Adaptive Streaming over HTTP (DASH), as well as our own HTTP Adaptive RTP Tunneling (HART) protocol. We also examine DRM schemes for segment-based delivery protocols.

The long term goal of this project is to understand the different traffic patterns and network requirements of these new OTT HTTP-based video delivery protocols so that, as they become an ever more prominent portion of MNO and MSO network traffic, network optimization techniques may be adapted to address performance issues while still ensuring video quality and DRM security.


  1. K. J. Ma, R. Nair, and R. Bartoš “DRM Workflow Analysis for Over-the-Top HTTP Segmented Delivery,” to appear in Proc. of The IEEE International Conference on Multimedia & Expo - ICME 2011, Barcelona, Spain, July, 2011.
  2. K. J. Ma, M. Mikhailov, and R. Bartoš “DRM Optimization for Stitched Media File Rate Adaptation,” to appear in Proc. of The IEEE International Conference on Multimedia & Expo - ICME 2011, Barcelona, Spain, July, 2011.
  3. K. J. Ma, R. Bartoš, S. Bhatia, and R. Nair, “Mobile Video Delivery with HTTP,” IEEE Communications Magazine. vol.49, no.4, pp.166-175, April 2011. [doi: 10.1109/MCOM.2011.5741161, pdf at IEEE Xplore]
  4. K. J. Ma, M. Li, A. Huang, and R. Bartoš, “Video Rate Adaptation in Mobile Devices via HTTP Progressive Download of Stitched Media Files,” IEEE Communications Letters, vol. 15, no. 3, pp. 320-322, March 2011. [doi: 10.1109/LCOMM.2011.012511.102044, pdf at IEEE Xplore]
  5. K. J. Ma, R. Bartoš, and S. Bhatia, “A Survey of Schemes for Internet-based Video Delivery,” Elsevier Journal of Network and Computer Applications, 15 p., Corrected Proof, Available online 19 February 2011. [doi: 10.1016/j.jnca.2011.02.001, pdf at ScienceDirect]
  6. K. J. Ma, R. Bartoš, and S. Bhatia, “Scalability of HTTP Pacing with Intelligent Bursting,” in Proc. of The IEEE International Conference on Multimedia & Expo - ICME 2009, New York, NY, June-July, 2009. [PDF 316K]