Memory Leak in QTPlugin ? (QT7, and QT 6.5+)

Question

Trying to track this down, there is a problem with a memory leak when doing a endless loop quicktime sequence of images. To get the loop, I've created a SMIL file with the images, then have a HTML page that uses the EMBED tag to reference these SMIL files via QTNEXTxx, with a final GOTO0 to get back to the start.
It works, but if you watch the process with Activity Monitor (or top) you can see that memory consumption grows over time and will eventually crash whatever browser you are using. This happens if I open the HTML file with Safari, iCab, Opera, Firefox, RealPlayer, etc...
Very simple example with even one image will leak memory, albeit at a slower pace:
HTML: (replaced brackets with curly braces)
{html}
{head}
{title}radarLoops.html{/title}
{/head}
{body bgcolor="#000000"}
{center}
{embed src="file1.smil BGCOLOR="#000000" autoplay="true" controller="false" width="800" height="620" pluginspage="http://www.apple.com/quicktime/download/" QTNEXT1="GOTO0"}
{/center}
{/body}
{/html}
file1.smil:
SMILtext{smil xmlns:qt="http://www.apple.com/quicktime/resources/smilextensions" qt:autoplay="true" qt:time-slider="false"}
{head}
{layout}
{root-layout width="800" height="620" background-color="black" /}
{region id="region_1" left="0" top="0" width="800" height="620" fit="fill" /}
{/layout}
{/head}
{body}
{seq}
{img src="TEST.JPG" region="region_1" dur="1s" /}
{/seq}
{/body}
{/smil}
To workaround this issue, we had to revert to a 10.3.x system with QT6.4.x on it, reverting a 10.3.9 to QT6.5.x didn't work. A Tiger installation with 7.0.3 doesn't work either, it leaks like a sieve.
How can I debug this?

Answer 1

Write a main() that does the polling in a tight loop 1000 times. Then System.gc(); Thread.sleep(1000); System.exit(). Run the thing with -Xrunhprof. Observe the "live bytes" and "live objs" columns in the generated java.hprof.txt file. Anything that strikes as suspicious? If every polling round leaks one object, there's likely to be 1000 (or N*1000) of something live. Make sure the leak is in the polling routine by running it 1,000,000 rounds and getting an OutOfMemory.