HTML Standard Tracker

Filter

File a bug

SVNBugCommentTime (UTC)
3913Clarify that drawImage() and createPattern() aren't useless with anamorphic video.2009-09-19 22:22
@@ -27310,21 +27310,26 @@ idea from Mihai:
   <p>When the <code
   title="dom-context-2d-createPattern">createPattern()</code> method
   is passed an animated image as its <var title="">image</var>
   argument, the user agent must use the poster frame of the animation,
   or, if there is no poster frame, the first frame of the
   animation.</p>
   <!-- drawImage() has an equivalent paragraph -->
 
   <p>When the <var title="">image</var> argument is an
   <code>HTMLVideoElement</code>, then the frame at the <span>current
-  playback position</span> must be used as the source image.</p>
+  playback position</span> must be used as the source image, and the
+  source image's dimensions must be the <span
+  title="concept-video-intrinsic-width">intrinsic width</span> and
+  <span title="concept-video-intrinsic-height">intrinsic height</span>
+  of the <span>media resource</span> (i.e. after any aspect-ratio
+  correction has been applied).</p>
   <!-- drawImage() has an equivalent paragraph -->
 
   <!--
    Requests for v4 features:
     * apply transforms to patterns, so you don't have to create
       transformed patterns manually by rendering them to an off-screen
       canvas then using that canvas as the pattern.
   -->
 
   </div>
@@ -28935,21 +28940,26 @@ v4DVT (also check for '- -' bits in the part above) -->
   <p>When the <code
   title="dom-context-2d-drawImage">drawImage()</code> method
   is passed an animated image as its <var title="">image</var>
   argument, the user agent must use the poster frame of the animation,
   or, if there is no poster frame, the first frame of the
   animation.</p>
   <!-- createPattern() has an equivalent paragraph -->
 
   <p>When the <var title="">image</var> argument is an
   <code>HTMLVideoElement</code>, then the frame at the <span>current
-  playback position</span> must be used as the source image.</p>
+  playback position</span> must be used as the source image, and the
+  source image's dimensions must be the <span
+  title="concept-video-intrinsic-width">intrinsic width</span> and
+  <span title="concept-video-intrinsic-height">intrinsic height</span>
+  of the <span>media resource</span> (i.e. after any aspect-ratio
+  correction has been applied).</p>
   <!-- createPattern() has an equivalent paragraph -->
 
   <p>Images are painted without affecting the current path, and are
   subject to <span title="shadows">shadow effects</span>, <span
   title="dom-context-2d-globalAlpha">global alpha</span>, the <span
   title="clipping region">clipping region</span>, and <span
   title="dom-context-2d-globalCompositeOperation">global composition
   operators</span>.</p>
 
   </div>

|