Differences

This shows you the differences between two versions of the page.

--- wiki:statmux_priorities [2016/12/09 09:13] – [3Priorities design] walkeradmin
+++ wiki:statmux_priorities [2023/03/09 22:35] (current) – external edit 127.0.0.1
@@ Line 8: / Line 8: @@
 \\
 \\
+----
 ==== Context ====
 \\
@@ Line 16: / Line 18: @@
 \\
 \\
+----
 ==== Specifications ====
-\\
 \\
 In this first version, the priority will be set only by mpeg4.cfg by specifying for each channel the prioritized level (1 or 0), using  the following line:
@@ Line 40: / Line 43: @@
 \\
 \\
-The expected behavior is that a prioritized channel will have a better average objective video quality than without being prioritized. It could be checked by comparing in the same pool the same channel with and without priority.
+The expected behaviour is that a prioritized channel will have a better average objective video quality than without being prioritized. It could be checked by comparing in the same pool the same channel with and without priority.
 \\
 \\
@@ Line 55: / Line 58: @@
 \\
 \\
+----
 ==== 3	Priorities design ====
 \\
@@ Line 76: / Line 81: @@
 \\
+----
+==== 4	Priorities and distortion control ====
+\\
+The distortion control aims at weighting channel’s complexity according to their MSE. Bigger the channel’s MSE, bigger the distortion factor is. Factors are computed every four statmux iterations (around twice a second). Factors are clipped between 0.5 and 2.
+\\
+\\
+However, when priorities are enabled, the distortion control could in some cases nullify the priority.  Indeed, as distortion factors can inferior to 1, it could nullify the impact of prioritizing a channel.
+To avoid such cases, factors are clipped according to the channel’s complexity:
+\\
+  * 	1.00 < F < 2.0 with a very high priority
+  * 	0.75 < F < 2.0 with a high complexity
+  * 	0.50 < F < 2.0 with a normal priority
+  * 	0.50 < F < 1.5 with a low priority
+  * 	0.50 < F < 1.0 with a very low complexity.
+\\
+\\