Loss Rate (LR)

The effect of LR on video quality was the main goal of several previous studies as it is an important parameter [23,53,58]. As shown in Figure 7.5, the quality drastically decreases when the LR increases from 0 up to 10 %. But the absolute decrease of the quality depends on the other parameters' values: about 1.3 for BR=0.15, while 5.0 for BR=0.8. As depicted in Figure 7.8, the absolute deterioration is about 3.8 for 6 fps, but 4.6 for 30 fps. The variation of the quality is about 4.4 for RA=0.5 and 3.8 for RA=0.05, when BR=0.35, FR=30 fps and CLP=2, as shown in Figure 7.12. Again, the fact that for LR set to zero there is no change on quality when CLP varies (Figs. 7.6, 7.9 and 7.11), shows that our RNN captures with great precision and reliability the characteristics of the quality as a function of the parameters. It may be thought that this is due to large values of BR and FR, but we varied all these parameters and we got the same behavior. In the case of using ANN, it is not easy to get this result (see Figure 4.9(b)).

Figure 7.8: The impact of FR and LR on video quality.

  

Figure 7.9: The impact of FR and CLP on video quality.