<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> <style type="text/css" style="display:none"></style> </head> <body dir="ltr" style="font-size:12pt;color:#000000;background-color:#FFFFFF;font-family:Calibri,Arial,Helvetica,sans-serif;"> <p>Hi all,<br> </p> <p><br> </p> <p>I have a rather general question about the refcounting within the<br> </p> <p>g_signal_emit_by_name()</p> <p>API.<br> </p> <p><br> </p> <p>I was examining some older gstreamer code of mine and found the following use<br> </p> <p><br> </p> <p><br> </p> <p> GstBuffer *gst_buff = gst_buffer_new_allocate(...);<br> </p> <p> // prepare a video/x-raw GstBuffer<br> </p> <div> g_signal_emit_by_name(VideoCamPipelineGst.src, "push-buffer", gst_buff, &ret);</div> <div> gst_buffer_unref(gst_buffer); // UNREF<br> </div> <p>}</p> <p><br> </p> <p>To clarify, the <span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 16px; background-color: rgb(255, 255, 255);">VideoCamPipelineGst.src</span> pointer is a pointer to a *appsrc* element.<br> </p> <div id="Signature"> <div name="divtagdefaultwrapper" style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:; margin:0"> <div name="divtagdefaultwrapper" style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:; margin:0"> <span style="font-size:16px">Now, the demonstrated code works (I've never seen it crash), but I have doubts as if it is stable or it might cause some unexpected seg fault.</span></div> <div name="divtagdefaultwrapper" style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:; margin:0"> <span style="font-size:16px">The problem I see is that right after I "emit" the "push-buffer" signal I unref the gst_buff (on the line with UNREF comment)</span></div> <div name="divtagdefaultwrapper" style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:; margin:0"> <span style="font-size:16px">which should be its only reference, unless the gst_buff's refcount is incremented within the <span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 16px; background-color: rgb(255, 255, 255);">g_signal_emit_by_name</span>.</span></div> <div name="divtagdefaultwrapper" style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:; margin:0"> <span style="font-size:16px"><br> </span></div> <div name="divtagdefaultwrapper" style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:; margin:0"> <span style="font-size:16px">The question is: is the above idiomatic use legit (i.e. is the <span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 16px; background-color: rgb(255, 255, 255);">g_signal_emit_by_name</span> increases the refcount of the buffer)</span></div> <div name="divtagdefaultwrapper" style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:; margin:0"> <span style="font-size:16px">or the above construction is illegal and I must switch to using</span></div> <div name="divtagdefaultwrapper" style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:; margin:0"> <span style="font-size:16px">gst_app_src_push_buffer()<br> </span></div> <div name="divtagdefaultwrapper" style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:; margin:0"> <span style="font-size:16px">instead?</span></div> <div name="divtagdefaultwrapper" style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:; margin:0"> <span style="font-size:16px"><br> </span></div> <div name="divtagdefaultwrapper" style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:; margin:0"> <span style="font-size:16px">Many thanks</span></div> <div name="divtagdefaultwrapper" style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:; margin:0"> <span style="font-size:16px">Martin</span></div> <div name="divtagdefaultwrapper" style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:; margin:0"> <span style="font-size:16px"><br> </span></div> </div> </div> </body> </html>