HTTP Adaptive Streaming Standards

• MPEG DASH Standard [1]
• 3GP DASH Standard [2]
• HbbTV DASH Recommendation [3]

A comparison in terms of data description format, video codec, audio codec, format, and segment length can be found in TABLE II of [4].

References
[1] Information Technology—Dynamic Adaptive Streaming Over HTTP (DASH)—Part 1: Media Presentation Description and Segment Formats, ISO/IEC 23009-1:2012, 2012.
[2] European Telecommunications Standard Institute (ETSI). (2009). Universal Mobile Telecommunication System (UMTS); LTE; Transparent end-to-end Packet-Switched Streaming Service (PSS); Protocols and Codecs, Sophia-Antipolis Cedex, France, 3GPP TS 26.234 Version 9.1.0 Release 9.
[3] HbbTV Specification, HbbTV Association, Erlangen, Germany, 2012.
[4] Seufert, Michael, et al. "A survey on quality of experience of http adaptive streaming." IEEE Communications Surveys & Tutorials 17.1 (2015): 469-492.

Adaptive Video Streaming Products

• Adobe HTTP Dynamic Streaming (HDS) [1]
• Apple HTTP Live Streaming (HLS) [2]
• Microsoft Live Smooth Streaming [3]
• Adaptive Scalable Video Streaming over HTTP [4]

For an experimental evaluation of rate-adaptation algorithms in adaptive streaming over HTTP, refer to [5].

References

[1] Adobe Systems: HTTP Dynamic Streaming (HDS), February 2015, Available: http://tiny.cc/HDS.

[2] Apple: HTTP Live Streaming (HLS), February 2015, Available: http://tiny.cc/HLS2015.

[3] Microsoft: Live Smooth Streaming, February 2015, Available: http://tiny.cc/MSSmooth.
[4] S. Xiang. Scalable streaming. https://sites.google.com/site/svchttpstreaming/.
[5] S. Akhshabi, A. C. Begen, and C. Dovrolis. An experimental evaluation of rate-adaptation algorithms in adaptive streaming over HTTP. In ACM MMSys’11, pages 157–168, New York, NY, USA, 2011.

Encoding Settings For Streaming Vancouver Olympics

Level	Bitrate (kbps)	Resolution	Frame rate
1	400	312x176	15
2	600	400x224	15
3	900	512x288	15
4	950	544x304	15
5	1250	640x360	25
6	1600	736x416	25
7	1950	848x480	25
8	3450	1280x720	30

References
[1] Jan Ozer, “Adaptive Streaming in the Field”, in Streaming Media Magazine, 2011.
[2] Liu, Yao, et al. "User experience modeling for DASH video." 2013 20th International Packet Video Workshop. IEEE, 2013.

What affects the quality of adaptive video streams?

• Quality Switches
• Amplitude
• Frequency
• Stallings
• Duration 
• Frequency
• Initial Startup Delay

There are some surveys on the quality of experience for adaptive video streaming:

• Quality of Experience and HTTP adaptive streaming: A review of subjective studies [1]
• A Survey on Quality of Experience of HTTP Adaptive Streaming [2]
• User experience modeling for DASH video [3]

QoE is affected by spatial and temporal quality of the video stream. Initial delay, total stall duration, and number of stalls affect the temporal quality. Average video quality, number of switches, and average switch magnitude affect the spatial quality. In [3], the effect of each of these factors has been quantified.

Some important notes:

• Gradual multiple variations are preferred over abrupt variations.
• Constant quality is usually preferred to varying quality.
• In general, providing a bitrate as high as possible does not necessarily lead to the highest QoE.
• All is end that ends well: the end quality of the video has a definite impact on the perceived quality.
• The effect of spatial and temporal switching varies depending on the content type. 
• A single long stalling is preferred over multiple short freezes.
• Regular freezes are preferred over irregular freezes.
• Tolerable startup delay is dependent on the type of the application.
• Users prefer to wait longer if they can get less video stalling.       

Metrics

• Number of Quality Changes (NoC) [5]
• Number of Interruptions (NoI) [5]
• Percentage of Interruptions(PoI) [5]
• Impairment due to initial delay [3]
• Impairment due to stall [3]
• Impairment due to level fluctuations [3]
• Impairment due to low level video quality [3]
• Average playback Quality (APQ) [4]
• Playback Smoothness (PS) [6]
• Interruption Ratio [4]

References

[1] Garcia, M-N., et al. "Quality of experience and HTTP adaptive streaming: A review of subjective studies." Quality of Multimedia Experience (QoMEX), 2014 Sixth International Workshop on. IEEE, 2014.

[2] Seufert, Michael, et al. "A survey on quality of experience of http adaptive streaming." IEEE Communications Surveys & Tutorials 17.1 (2015): 469-492.
[3] Liu, Yao, et al. "User experience modeling for DASH video." 2013 20th International Packet Video Workshop. IEEE, 2013.
[4] S. Xiang, L. Cai, and J. Pan, “Adaptive scalable video streaming in wireless networks,” in Proc. of ACM MMSys, Feb. 2012, pp. 167–172.
[5] Yan, Zhisheng, Jingteng Xue, and Chang Wen Chen. "QoE continuum driven HTTP adaptive streaming over multi-client wireless networks." 2014 IEEE International Conference on Multimedia and Expo (ICME). IEEE, 2014.
[6] S. Nelakuditi, R. Harinath, E. Kusmierek, and Z. Zhang. Providing smoother quality layered video stream. In ACM NOSSDAV’00, June 2000.

What good does HTTP Adaptive Streaming (HAS) do?

HAS utilizes the HTTP protocol for streaming video content and inherits the advantages of HTTP such as transparent caching and network address translation (NAT) traversal, while the underlying transport control protocol (TCP) over which HTTP objects are transported offers congestion control functionality [1].

HAS is adaptive in the sense that the quality of the video is adjusted based on the bandwidth or data rate available between the server and the client. This is a particularly useful feature for a wireless environment since the data rate of the wireless link can vary substantially over time because of physical mobility or time-varying channel impairments such as shadowing or multipath fading, and variations in other traffic served by the same base station [1].


References
[1] D. De Vleeschauwer, H. Viswanathan, A. Beck, S. Benno, G. Li, and R. Miller, “Optimization of HTTP adaptive streaming over mobile cellular networks,” in Proc. IEEE INFOCOM, 2013, pp. 898–997.