Merge pull request #861 from AOMediaCodec/sunghee-hwang-patch-1

Fix #860, num_layers -> num_layouts

index.bs

@@ -3258,7 +3258,7 @@ The [=Mix Presentation OBU=] for one single channel-based [=Audio Element=] is s
 - [=loudness_layout=]: set to L(1), L(2), ..., L(N), where L(i) is the measured layout for the i-th layer and i = 1, 2, ..., N.
 	- [=LoudnessInfo()=] for L(1), [=LoudnessInfo()=] for L(2), ..., [=LoudnessInfo()=] for L(N): loudness information of the audio rendered to to the measured layout L(i).
 
-NOTE: If the input channel layouts do not include Stereo, then [=num_layers=] is set to N + 1 and the [=loudness_layout=]s includes Stereo.
+NOTE: If the input channel layouts do not include Stereo, then [=num_layouts=] is set to N + 1 and the [=loudness_layout=]s includes Stereo.
 
 
 The [=Mix Presentation OBU=] for one single scene-based [=Audio Element=] is set as follows: