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<p class="MsoPlainText">Hello,<o:p></o:p></p>
<p class="MsoPlainText"><span style="color:black"><o:p> </o:p></span></p>
<p class="MsoPlainText"><span style="color:black">I'm using GLES shader to run algorithms on image frames, I got very bad performance issue in GPU & CPU data sharing, especially retrieve data from GPU to CPU.<o:p></o:p></span></p>
<p class="MsoPlainText"><span style="color:black"><o:p> </o:p></span></p>
<p class="MsoPlainText"><span style="color:black">Basically, I use </span><b><i>glGenBuffers</i></b><span style="color:black">/</span><b><i>glBindBuffer</i></b><span style="color:black">/</span><b><i>glBufferData(target, size,
<span style="background:yellow;mso-highlight:yellow">data</span>, usage) </i></b><span style="color:black">to create GPU buffer object and initialize GPU data store with CPU data pointer. After GLES shader finished the processing, I use
</span><em><b><span style="font-family:"Calibri",sans-serif">glMapBufferRange</span></b></em><i><span style="color:black">
</span></i><span style="color:black">to retrieve processed image data back to CPU, and for some reason I have to do an extra data copy from the gl map pointer to another CPU buffer, this is super slow.<o:p></o:p></span></p>
<p class="MsoPlainText"><span style="color:black"><o:p> </o:p></span></p>
<p class="MsoPlainText"><span style="color:black">Here’s the code snippet <a href="https://github.com/intel/libxcam/blob/master/modules/gles/gl_buffer.cpp#L94">
https://github.com/intel/libxcam/blob/master/modules/gles/gl_buffer.cpp#L94</a></span><o:p></o:p></p>
<p class="MsoPlainText"><span style="color:black"><a href="https://github.com/intel/libxcam/blob/master/modules/gles/gl_buffer.cpp#L127">https://github.com/intel/libxcam/blob/master/modules/gles/gl_buffer.cpp#L127</a><o:p></o:p></span></p>
<p class="MsoPlainText"><span style="color:black"><o:p> </o:p></span></p>
<p class="MsoPlainText"><span style="color:black">I wonder If there has other efficient way to sharing data between CPU & GPU GLES shader?<o:p></o:p></span></p>
<p class="MsoPlainText"><span style="color:black"><o:p> </o:p></span></p>
<p class="MsoPlainText"><span style="color:black">Thanks,<o:p></o:p></span></p>
<p class="MsoPlainText"><span style="color:black">Zong Wei<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
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