<?xml version="1.0" encoding="UTF-8"?><rss xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:content="http://purl.org/rss/1.0/modules/content/" xmlns:atom="http://www.w3.org/2005/Atom" version="2.0"><channel><title><![CDATA[Performance issues with detached QProcess]]></title><description><![CDATA[<p dir="auto">Hi everyone,</p>
<p dir="auto">I've built an interface in Qt which interacts with a camera and a projector for synchronized image capture. I am using a button linked to a QProcess command on the interface to launch an external process which sends images to the projector to trigger image capture.</p>
<p dir="auto">The issue is that, when I launch the process from this interface, the OpenGL instance created by the external process suffers greatly in performance, resulting in botched image captures. Such a performance drop is not experienced when running the process by itself. The only thing that I think might affect the new process is the 2 OpenGL instances running in the interface, but the external process itself does not do much processing at all: it just draws a square, binds a PNG image onto the surface, and refreshes at 60 Hz  for all images.</p>
<p dir="auto">I was wondering if this is an issue with the way I have launched the program, or if its due to hardware limitations (the workstation does not have the highest specs. Thanks in advance! My launching code is included below:</p>
<p dir="auto">@            bool bStartSuccess;<br />
QString sProgram = CASIO_EXE_PATH;<br />
QString sProgramDir = CASIO_EXE_DIR;<br />
QStringList arguments;<br />
arguments &lt;&lt; QString("%1").arg(pattern_list.count());<br />
QString sOldPath = QDir::currentPath();<br />
QDir::setCurrent( sProgramDir );<br />
QProcess *process = new QProcess(this);<br />
bStartSuccess = process-&gt;startDetached(sProgram, arguments);<br />
QDir::setCurrent(sOldPath);<br />
@</p>
]]></description><link>https://forum.qt.io/topic/36616/performance-issues-with-detached-qprocess</link><generator>RSS for Node</generator><lastBuildDate>Thu, 30 Jul 2026 19:10:20 GMT</lastBuildDate><atom:link href="https://forum.qt.io/topic/36616.rss" rel="self" type="application/rss+xml"/><pubDate>Tue, 14 Jan 2014 22:51:51 GMT</pubDate><ttl>60</ttl><item><title><![CDATA[Reply to Performance issues with detached QProcess on Wed, 15 Jan 2014 03:18:32 GMT]]></title><description><![CDATA[<p dir="auto">I don't suspect issue with process creation. Can you try with process-&gt;start API and QProcess::exec methods as well. Is it on Linux or Windows ?</p>
]]></description><link>https://forum.qt.io/post/210857</link><guid isPermaLink="true">https://forum.qt.io/post/210857</guid><dc:creator><![CDATA[dheerendra]]></dc:creator><pubDate>Wed, 15 Jan 2014 03:18:32 GMT</pubDate></item></channel></rss>