Interval logic and multiple begins with negative offset

Hi,

I am having trouble understanding the following SMIL 2.0 test case.

Could some one tell me why "video2" begins to be shown only at 9 sec
and not at 5 seconds?

"video1" begin is resolved to 10s document time, for (both intervals of  
par),
then "video2" begin is resolved to 5s document time. Then why is "video2"
shown only at 9 sec and not from 5 seconds as expected?

TIA,
John


<!--
             Copyright: Copyright 1998-2001 W3C (MIT, INRIA, Keio), All  
Rights Reserved.

See http://www.w3.org/Consortium/Legal/.

Author: Aaron Cohen (Intel), Jeff Boston (IBM)
            Version: May 1, 2001
             Module: Timing and Synchronization
            Feature: Interval logic and multiple begins with negative offset
          File Name: interval_logic_multiple_begins_negative_offset.smil
   Media Components: 2 QT, 1 JPG
  Expected Behavior: at t=9  video2 starts 4 seconds into the video.
                           at t=10 smile appears.
                           at t=10 video1 starts.
                         at t=15 video2 disappears.
                         at t=19 video1 disappears.
                         at t=20 smile disappears.
-->
<smil xmlns="http://www.w3.org/2001/SMIL20/Language">
<body>
         <par>
                 <img id="smile" begin="10s" dur="10s"  
src="../images/smile.jpg"/>
                 <par id="par1" begin="0s;10s" dur="9s">
                         <video id="video1" begin="smile.begin" dur="10s"  
src="../videos/nasa.qt"/>
                 </par>
                 <video id="video2" begin="video1.begin-5s" dur="10s"  
src="../videos/nasa.qt"/>
         </par>
</body>
</smil>

Received on Thursday, 12 August 2004 13:15:28 UTC