An empirical study of realvideo performance across the internet

Wang, Yubing; Claypool, Mark; Zuo, Zheng

doi:10.1145/505202.505239

Cited by 72 publications

(51 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The video data itself is sent using either TCP or UDP. By default, the actual choice of transport protocol used is determined automatically by the RealPlayer and RealServer, resulting in UDP about 1/2 the time and TCP the other half [34]. The decision making process RealPlayer uses to choose either UDP or TCP is not publicly documented, and may be interesting future work.…”

Section: Realvideo Backgroundmentioning

confidence: 99%

“…To study media scaling in RealPlayer we used RealTracer, 10 developed for a previous study [34], which plays RealVideo streams and records application level statistics, including encoding rate. One of the client machines was 9 Recent work measuring broadband access links suggest some ISP providers similarly use TBFs to limit capacities [15].…”

Section: Media Scaling Measurement Environmentmentioning

confidence: 99%

“…Communication with commercial streaming media product developers has been ineffective in providing adequate, scientific information on the congestion responsiveness, leaving measurement as the next viable option. While there have been some studies characterizing streaming traffic [20], [31], [6], [16], [34], as well as some measurements of commercial streaming media on private testbeds [14], [22], there are few empirical studies that analyze the responsiveness, or lack of it, of current streaming media products over the Internet.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Empirical evaluation of the congestion responsiveness of RealPlayer video streams

Chung

Claypool

2006

Multimed Tools Appl

Self Cite

View full text Add to dashboard Cite

Abstract-Increasingly popular commercial streaming media applications over the Internet often use UDP as the underlying transmission protocol for performance reasons. Hand-in-hand with the increase in streaming media comes the impending threat of unresponsive UDP traffic, often cited as the major threat to the stability of the Internet. Unfortunately, there are few empirical studies that analyze the responsiveness, or lack of it, of commercial streaming media applications. In this work, we evaluate the responsiveness of RealNetworks' RealVideo over UDP by measuring the performance of numerous streaming video clips selected from a variety of RealServers on the Internet, analyze the TCPFriendliness of the UDP streams and correlate the results with network and application layer statistics. We find that most RealVideo UDP streams respond to Internet congestion by reducing the application layer encoding rate, and streams with a minimum encoding rate less than the fair share of the capacity often achieve a TCP-Friendly rate. In addition, our results suggest that a reason streaming applications choose not to use TCP is that the TCP API hides network information, such as loss rate and round-trip time, making it difficult to estimate the available capacity for effective media scaling.

show abstract

Section: Realvideo Backgroundmentioning

confidence: 99%

Section: Media Scaling Measurement Environmentmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Empirical evaluation of the congestion responsiveness of RealPlayer video streams

Chung

Claypool

2006

Multimed Tools Appl

Self Cite

View full text Add to dashboard Cite

show abstract

“…On the average, Dynamic provides the most power saving (80% improvement) but it is only slightly better than Direct (77%). Figure 10 shows the accuracy of the four DVS approaches in terms of error, defined as the ratio of standard deviation of inter-frame playout times [28] to playout interval. This parameter basically defines how well a DVS method was able to meet frame deadlines, as also how smooth a video clip played with the given method.…”

Section: Effect Of Prediction Accuracy On Dvs Performancementioning

confidence: 99%

Dynamic voltage scaling techniques for power efficient video decoding

Liu

Nurvitadhi

Dixit

et al. 2005

Journal of Systems Architecture

View full text Add to dashboard Cite

This paper presents a comparison of power-aware video decoding techniques that utilize Dynamic Voltage Scaling (DVS) capability. These techniques reduce the power consumption of a processor by exploiting high frame variability within a video stream. This is done through scaling of the voltage and frequency of the processor during the video decoding process. However, DVS causes frame deadline misses due to inaccuracies in decoding time predictions and granularity of processor settings used. Four techniques were simulated and compared in terms of power consumption, accuracy, and deadline misses. We propose the Frame-data Computation Aware (FDCA) technique, which is a useful power-saving technique not only for stored video but also for real-time video applications. We compare this technique with the GOP, Direct, and Dynamic methods, which tend to be more suited for stored video applications. The simulation results indicated that the Dynamic per-frame technique, where the decoding time prediction adapts to the particular video being decoded, provides the most power saving with a performance comparable to the ideal case. On the other hand, the FDCA method consumes more power than the Dynamic method but can be used for stored video and real-time time video scenarios without the need for any preprocessing. Our findings also indicate that in general power savings increase, but the number of deadline misses also increase as the number of processor settings used in a DVS algorithm are increased. More importantly, most of these deadline misses are within 10%-20% of the playout interval and thus insignificant. However, video clips with high variability in frame complexities combined with inaccurate decoding time predictions may degrade the video quality. Finally, our results show that a processor with 13 voltage/frequency settings should be sufficient to achieve near maximum performance with the experimental environment and the video workloads we have used.

show abstract

“…These applications typically require that the user explicitly select the desired streaming rate from the corresponding web page and are frequently used by end-users for constant bitrate (CBR) streaming. The exact streaming protocols and system-level bitstreams used in both applications [7], [12] remain proprietary, which explains why only a few research studies focused on this type of Internet traffic (e.g., [4], [11]). Furthermore, the absence of prior active measurement studies (as opposed to passive studies [4]) of real-time streaming in the Internet is another reason that prompted us to conduct a large-scale real-time streaming experiment to study the end-to-end dynamics of video streaming in the best-effort Internet, investigate the effect of large end-to-end delays on the video quality (i.e., the frequency of underflow events), and analyze the overall effectiveness of real-time retransmission.…”

Section: Introductionmentioning

confidence: 99%

Effects of channel delays on underflow events of compressed video over the Internet

Loguinov

Radha

Proceedings. International Conference on Image Processing

View full text Add to dashboard Cite

This paper presents an extensive statistical study and analysis of the effects of channel delays in the current (best-effort) Internet on underflow events in MPEG-4 video streaming. Two types of network delays are considered: end-to-end round-trip delays and delay jitter. Our data were collected in a seven-month real-time streaming experiment, which was conducted between a number of unicast dialup clients in more than 600 major U.S. cities and a backbone video server. Among other findings, our analysis shows that startup delays approximately 15-20 times the average roundtrip time (RTT) are required for the client to avoid 90% of late packets caused by delay jitter. Meanwhile, startup delays of only 3-4 times the average RTT are needed to achieve lost-packet recovery rates of 90% or more. Hence, a key finding of our study is that delay jitter represents a more challenging problem for video streaming applications than round-trip delays. We also show that the probability density function (PDF) of RTT samples, which are associated with retransmitted video packets, can be modeled using a Pareto distribution. This observation indicates that the upper tail of the RTT PDF decays slower than reported in earlier studies.

show abstract

An empirical study of realvideo performance across the internet

Cited by 72 publications

References 18 publications

Empirical evaluation of the congestion responsiveness of RealPlayer video streams

Empirical evaluation of the congestion responsiveness of RealPlayer video streams

Dynamic voltage scaling techniques for power efficient video decoding

Effects of channel delays on underflow events of compressed video over the Internet

Contact Info

Product

Resources

About