<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"> <head> <meta http-equiv="Content-Type" content="text/html; charset=us-ascii"> <meta name="Generator" content="Microsoft Word 15 (filtered medium)"> <style></style> </head> <body lang="DE" link="#0563C1" vlink="#954F72"> <style type="text/css" style="display:none;"></style> <div id="divtagdefaultwrapper" style="font-size:12pt;color:#000000;font-family:Calibri,Arial,Helvetica,sans-serif;" dir="ltr"> Hi! Thanks for your answer! And is there any way to check if the state change has hit an error? Maybe capturing the 'GST_MESSAGE_ERROR' event? I supposse I have to wait until the pipeline has change its state, isn't it? </div> <hr style="display:inline-block;width:98%" tabindex="-1"> <div id="divRplyFwdMsg" dir="ltr">De: gstreamer-devel <gstreamer-devel-bounces@lists.freedesktop.org> en nombre de Thornton, Keith <keith.thornton@zeiss.com> Enviado: martes, 4 de abril de 2017 14:30:31 Para: Discussion of the development of and with GStreamer Asunto: AW: gst_element_set_state question <div> </div> </div> <div> <div class="WordSection1"> Hi, you should create a listener for the message bus. Every element posts its state changed message on the bus. When complete, the pipeline also posts a state changed message on the bus. There are examples in the user manual<o:p></o:p> <o:p> </o:p> <div> <div style="border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0cm 0cm 0cm"> Von: gstreamer-devel [mailto:gstreamer-devel-bounces@lists.freedesktop.org] Im Auftrag von Jorge Fernandez Monteagudo Gesendet: Dienstag, 4. April 2017 12:59 An: gstreamer-devel@lists.freedesktop.org Betreff: gst_element_set_state question<o:p></o:p> </div> </div> <o:p> </o:p> <div id="divtagdefaultwrapper"> Hi all!<o:p></o:p> <o:p> </o:p> I would like to know what the correct way to wait for a state change in gstreamer.<o:p></o:p> I'm using a typical code doing a polling after the 'gst_element_set_state' call but<o:p></o:p> sometimes, with the machine under a heavy load, I get a timeout but gstreamer<o:p></o:p> is still working and finally changes the state.<o:p></o:p> <o:p> </o:p> Is there a better way? Is it possible to wait without timeout and look for some<o:p></o:p> error trying to change the state? What timeout is considered safe?<o:p></o:p> <o:p> </o:p> <o:p> </o:p> The code waiting for a state change with a 10 seconds timeout<o:p></o:p> <o:p> </o:p> <div> bool poll_for_state_change( GstState new_state ) { GTimeVal tfthen, tfnow; GstClockTimeDiff diff; GstStateChangeReturn result = GST_STATE_CHANGE_FAILURE; GstState current; gint32 timeescap = 0; gst_element_get_state( pipeline, &current, NULL, GST_SECOND ); printf( "%s - change state from %s to %s\n", __FUNCTION__, gst_element_state_get_name( current ), gst_element_state_get_name( new_state ) ); if( current == new_state ) return true; g_get_current_time( &tfthen ); result = gst_element_set_state( pipeline, new_state ); if( result == GST_STATE_CHANGE_FAILURE ) return false; while( 1 ) { gst_element_get_state( pipeline, &current, NULL, GST_SECOND ); g_get_current_time( &tfnow ); diff = GST_TIMEVAL_TO_TIME( tfnow ) - GST_TIMEVAL_TO_TIME( tfthen ); diff /= (1000 * 1000); timeescap = (unsigned int) diff; if( new_state == current ) break; if( timeescap > 10000 ) { printf( "%s - Time out in state transferring from %s to %s\n", __FUNCTION__, gst_element_state_get_name( current ), gst_element_state_get_name( new_state ) ); return false; } } return true; }<o:p></o:p> </div> <o:p> </o:p> Thanks!<o:p></o:p> Jorge<o:p></o:p> <o:p> </o:p> </div> </div> </div> </body> </html>