https://community.intel.com/t5/Intel-Integrated-Performance/MPEG-4-OpenMP-threads/m-p/892445#M11673 <P>I am using IPP 5.1 media sample to decode MPEG-4 streams. I am linking to the umc libraries statically in my Visual Studio 2005 dll. I noticed on an XP SP2 dual core machine that the threads are not cleaned up right. After further investgation, I concluded that the thread leak is related to OpenMP. Every time I instantiate an MPEG-4 decoder, an extra thread starts and does not get cleaned up after I destroy the decoder. In our application, I can open a multiplexer window that shows MPEG-4 images from up to 64 streams. On closing the window, I notice that the number of leaked theads is exactly equal to the number of decoder instances. I stopped at a break point and noticed the call stack for each of the extra thread is stopped at the call _vcomp NullAPCFunc.</P> <P>I tried to use ippSetNumThreads(1) right after ippStaticInit when loading the dll to disable IPP internal threading and observe the difference but it made no difference. Any ideas?</P> Tue, 06 May 2008 19:20:30 GMT mmoussa 2008-05-06T19:20:30Z https://community.intel.com/t5/Intel-Integrated-Performance/MPEG-4-OpenMP-threads/m-p/892445#M11673 <P>I am using IPP 5.1 media sample to decode MPEG-4 streams. I am linking to the umc libraries statically in my Visual Studio 2005 dll. I noticed on an XP SP2 dual core machine that the threads are not cleaned up right. After further investgation, I concluded that the thread leak is related to OpenMP. Every time I instantiate an MPEG-4 decoder, an extra thread starts and does not get cleaned up after I destroy the decoder. In our application, I can open a multiplexer window that shows MPEG-4 images from up to 64 streams. On closing the window, I notice that the number of leaked theads is exactly equal to the number of decoder instances. I stopped at a break point and noticed the call stack for each of the extra thread is stopped at the call _vcomp NullAPCFunc.</P> <P>I tried to use ippSetNumThreads(1) right after ippStaticInit when loading the dll to disable IPP internal threading and observe the difference but it made no difference. Any ideas?</P> Tue, 06 May 2008 19:20:30 GMT https://community.intel.com/t5/Intel-Integrated-Performance/MPEG-4-OpenMP-threads/m-p/892445#M11673 mmoussa 2008-05-06T19:20:30Z https://community.intel.com/t5/Intel-Integrated-Performance/MPEG-4-OpenMP-threads/m-p/892446#M11674 <P>Could you please check this on the latest version, which is IPP 6.0 beta?</P> <P>Regards,<BR /> Vladimir</P> Tue, 06 May 2008 19:38:43 GMT https://community.intel.com/t5/Intel-Integrated-Performance/MPEG-4-OpenMP-threads/m-p/892446#M11674 Vladimir_Dudnik 2008-05-06T19:38:43Z https://community.intel.com/t5/Intel-Integrated-Performance/MPEG-4-OpenMP-threads/m-p/892447#M11675 <P>I removed the OpenMP support from the media sample version 5.1 and recompiled. It works fine now with no thread leak and without affecting the performance on the dual core machine.</P> <P>Thanks a lot for your help.</P> Wed, 07 May 2008 19:10:02 GMT https://community.intel.com/t5/Intel-Integrated-Performance/MPEG-4-OpenMP-threads/m-p/892447#M11675 mmoussa 2008-05-07T19:10:02Z