Merge pull request #1072 from w3c/issue-1070-sRGB-gamma-value

Correct the sRGB EOTF gamma in the HDR compositing example (Annex Q.1)

spec/ttml2.xml

@@ -28967,6 +28967,10 @@ application based on <bibref ref="html52"/>), rather than of the Document Instan
 The following illustrates the use of <loc href="#style-attribute-luminanceGain"><att>tts:luminanceGain</att></loc> to composite <bibref ref="srgb"/> pixels onto HDR pixels
 that conform to the system colorimetry specified in <bibref ref="bt2100_1"/> using perceptual quantizer (PQ) EOTF and full-range quantization.
 </p>
+<note role="elaboration">
+<p>The following example is not intended to provide generic color management and be applicable to all situations, e.g. it assumes the target compositing 
+surface is 10-bit and uses full-range quantization.</p>
+</note>
 <olist>
 <item>
 <p>
@@ -28987,9 +28991,9 @@ Invert the 8-bit full-range quantization:
 </item>
 <item>
 <p>
-Linearize using the <bibref ref="srgb"/> EOTF:
+Linearize using the <bibref ref="srgb"/> reference display EOTF:
 </p><p>
-<code>(r<sup>2.4</sup>, g<sup>2.4</sup>, b<sup>2.4</sup>) → (r, g, b)</code>
+<code>(r<sup>2.2</sup>, g<sup>2.2</sup>, b<sup>2.2</sup>) → (r, g, b)</code>
 </p>
 </item>
 <item>