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<!DOCTYPE bugzilla SYSTEM "https://bugs.webkit.org/page.cgi?id=bugzilla.dtd">

<bugzilla version="5.0.4.1"
          urlbase="https://bugs.webkit.org/"
          
          maintainer="admin@webkit.org"
>

    <bug>
          <bug_id>102439</bug_id>
          
          <creation_ts>2012-11-15 15:15:11 -0800</creation_ts>
          <short_desc>Audio graph nodes stuck in &quot;scheduled&quot; state</short_desc>
          <delta_ts>2012-11-16 13:13:06 -0800</delta_ts>
          <reporter_accessible>1</reporter_accessible>
          <cclist_accessible>1</cclist_accessible>
          <classification_id>1</classification_id>
          <classification>Unclassified</classification>
          <product>WebKit</product>
          <component>Web Audio</component>
          <version>528+ (Nightly build)</version>
          <rep_platform>Mac (Intel)</rep_platform>
          <op_sys>OS X 10.8</op_sys>
          <bug_status>RESOLVED</bug_status>
          <resolution>DUPLICATE</resolution>
          <dup_id>97369</dup_id>
          
          <bug_file_loc>http://jsfiddle.net/alnitak/pUBLm/13/</bug_file_loc>
          <status_whiteboard></status_whiteboard>
          <keywords></keywords>
          <priority>P2</priority>
          <bug_severity>Normal</bug_severity>
          <target_milestone>---</target_milestone>
          
          
          <everconfirmed>0</everconfirmed>
          <reporter name="Ray Bellis">ray</reporter>
          <assigned_to name="Chris Rogers">crogers</assigned_to>
          <cc>crogers</cc>
          

      

      

      

          <comment_sort_order>oldest_to_newest</comment_sort_order>  
          <long_desc isprivate="0" >
    <commentid>768553</commentid>
    <comment_count>0</comment_count>
    <who name="Ray Bellis">ray</who>
    <bug_when>2012-11-15 15:15:11 -0800</bug_when>
    <thetext>In the linked code, an Oscillator used as a source in a side chain used to control a filter&apos;s cutoff frequency remains stuck in the &quot;scheduled&quot; state.

The code works correctly in Chrome 25, but doesn&apos;t work in Chrome 23 or Safari 6.0.2.

This second oscillator (running as an LFO in this demo) is connected to a GainNode so that the amplitude of the change to the filter cutoff can be controlled.  I&apos;ve verified that the problem persists if I remove that GainNode, although at that point the +/- 1 output from the LFO is insufficient to make the cutoff modulation audible.

If the LFO is also connected to the primary oscillator&apos;s frequency AudioParam then it correctly starts up.</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>768555</commentid>
    <comment_count>1</comment_count>
    <who name="Ray Bellis">ray</who>
    <bug_when>2012-11-15 15:18:00 -0800</bug_when>
    <thetext>NB: this code is cut down as much as I could to still demonstrate the problem.  The real use case in my own code is that I&apos;m trying to use that side chain to emulate a VCF envelope generator, but in the earlier WebKit builds that are in the released versions it appears to be impossible to use an AudioNode to modulate a BiquadFilterNode&apos;s cutoff frequency.</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>769588</commentid>
    <comment_count>2</comment_count>
    <who name="Chris Rogers">crogers</who>
    <bug_when>2012-11-16 12:48:54 -0800</bug_when>
    <thetext>Ray, thanks for the example.  I can&apos;t see from your code how the test is &quot;passing&quot; or &quot;failing&quot;.  In other words how are checking that it&apos;s &quot;stuck&quot; or &quot;unstuck&quot;.  Can you please update your test to explain more fully the problem you&apos;re seeing.</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>769591</commentid>
    <comment_count>3</comment_count>
    <who name="Ray Bellis">ray</who>
    <bug_when>2012-11-16 12:51:29 -0800</bug_when>
    <thetext>Look in the console - the value of 1 being printed in the setTimeout callback on Chrome 23 indicates &quot;scheduled&quot; (i.e. it never ran) whereas Chrome 25 shows 2 (&quot;running&quot;).</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>769594</commentid>
    <comment_count>4</comment_count>
    <who name="Ray Bellis">ray</who>
    <bug_when>2012-11-16 12:52:47 -0800</bug_when>
    <thetext>jsfiddle updated</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>769606</commentid>
    <comment_count>5</comment_count>
    <who name="Chris Rogers">crogers</who>
    <bug_when>2012-11-16 13:06:42 -0800</bug_when>
    <thetext>Ray, thanks for updating the test.  It looks like it&apos;s simply this bug which was fixed here:
https://bugs.webkit.org/show_bug.cgi?id=97369

Chrome 23 and Safari 6 have not yet picked up this change.  But Chrome Canary and WebKit nightly builds will have the fix.

*** This bug has been marked as a duplicate of bug 97369 ***</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>769611</commentid>
    <comment_count>6</comment_count>
    <who name="Ray Bellis">ray</who>
    <bug_when>2012-11-16 13:11:04 -0800</bug_when>
    <thetext>Is there any known workaround?</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>769614</commentid>
    <comment_count>7</comment_count>
    <who name="Chris Rogers">crogers</who>
    <bug_when>2012-11-16 13:13:06 -0800</bug_when>
    <thetext>(In reply to comment #6)
&gt; Is there any known workaround?

I don&apos;t think so, we just have to wait for the fix to percolate into the stable shipping browsers.  Chrome 24 may get this fix.</thetext>
  </long_desc>
      
      

    </bug>

</bugzilla>