Recent advances in both wired and wireless networking technology have prompted the explosion of various networked video services, available to users through a diverse set of access links. To properly design and provide a video service, it is of paramount importance to accurately assess the transmitted video quality perceived by the end users.
As one of the significant quality-affecting factors, the impact of packet loss on perceptual video quality is received more and more attention recently. There are several attributes of packet losses that need to be taken into account when designing an effective and accurate perceptual quality metric, including packet loss position (with respect to both time and space), loss duration (i.e., the error propagation duration after a loss), loss severity(the level of perceptual distortion in recovering the loss-affected frames), loss rate, loss pattern (clustered or spreading). We have investigate the impacts of all the aforementioned factors both individually and jointly in our work , however, we do not have the copy right of the testing videos.
In addition, the saliency of packet losses is another non-neglectable quality-affecting element . For this purpose, we performed the following subjective test in our lab, but this subjective data can also be used as ground truth for other general loss-related quality evaluation problems.
DataSet : Packet_Loss Release I.
This subjective data consist two parts: one is for quality evaluation of individual loss-impaired frames, and the other is for quality evaluation of entire loss-impaired segments (due to error propagation). Totally 17 videos are selected from wide variety of standard test sequences,and rated by 32 viewers.
Here are some brief introductions to this subjective data:
- The subjective test is performed following the ACR-HR 5 scale standard.
- This subjective tests mainly target the low bitrate video application,
- The tes videos are encoded/decoded following H.264 standard. During each loss event, one entire frame is lost, and frame-copy error concealment is utilized.
(For more detailed information about this subjective dataset, please refer to Test_intro.pdf.
This dataset is packed in .rar file and is available for free for research use. For the password to unzip the file, or the futher information regarding this test, please contact Tao Liu at firstname.lastname@example.org.)
- T. Liu, Y. Wang, J. Boyce, H. Yang, and Z. Wu, "A Novel Video Quality Metric for Low Bit-rate Video Considering both Coding and Packet-loss Artifacts", Special Issue on Visual Media Quality Assessment, IEEE Journal of Selected Topics in Signal Processing, Vol.3 No. 2, pp.280~293, April 2009.
- Liu, Tao; Wang, Yao; Boyce, Jill M.; Wu, Zhenyu; Yang, Hua; “Subjective Quality Evaluation of Decoded Video in the Presence of Packet Losses,” IEEE Conf. Acoustics, Speech and Signal Processing, April 2007. (ICASSP 2007). Volume 1, Page(s):I-1125 - I-1128.
- Xin Feng, Tao Liu, Dan Yang, and Yao Wang, "Saliency Based Objective Quality Assessment of Decoded Video Affected by Packet Losses", in Proceedings of IEEE ICIP, San Diego, CA, October 2008.
- Tao Liu, Xin Feng, Amy Reibman, and Yao Wang, "Saliency Inspired Modeling of Packet-loss Visibility in Decoded Videos", Proceedings of Video Perceptual Quality Metric, 2009