Posted by Demoscene Passivist on Jul 14, 2010; 12:44pm
URL: https://forum.jogamp.org/Texture-rendering-performance-problems-tp966089p966328.html

A common slowdown reason is mismatched glTexImage2D parameters that would force format conversions to occur on the CPU side. Most video streams are in GL_RGB format and not GL_RGBA wich is to my experience the most widely accelerated texture format.

To test if the problem lies in a wrong texture format simply change the glTexImage2D to use GL_RGBA. The video will be fucked up but performance should  greatly increase. If so u know thats most likely the problem.