<html> <head> <meta content="text/html; charset=utf-8" http-equiv="Content-Type"> </head> <body text="#000000" bgcolor="#FFFFFF"> GST_STATE_CHANGE_ASYNC is ok. it means that pipeline doesn't finished changing state before gst_element_set_state() return. whole pipeline run in separate thread. when you get state you practically wait until pipeline finish transition to desired state. so check in which state return gst_element_get_state() and does your callbacks end up called? <div class="moz-cite-prefix">Dňa 01.08.2014 o 14:37 Lasse Laursen napísal(a): </div> <blockquote cite="mid:53DB89F3.3080901@lasselaursen.com" type="cite"> <meta http-equiv="content-type" content="text/html; charset=utf-8"> Hey Dev's, I've been throwing myself at this problem for a few days without any significant progress. Hopefully someone can tell me what painfully obvious part I've overlooked. Essentially what I'm trying to do is just grab some frames of video during playback from an appsink, but it seems my simple pipeline is missing something vital, because when I get to changing the state to 'paused' or 'playing' the GstStateChangeReturn I recieve is 'GST_STATE_CHANGE_ASYNC (2)'. The debug log doesn't yield any error output, so I'm a bit unsure of what to look closer at? Have I perhaps not hooked something up correctly? What am I missing here? Below is my simple code for trying to hook up this simple pipeline and grab some frames. --------- std::string launchString = "uridecodebin uri=" + mVideoFileName + " ! appsink name=sink"; mGstPipeline = gst_parse_launch( launchString.c_str(), &pstGErr1 ); printErrorToConsole( pstGErr1 != nullptr, "GStreamer Error: Could not construct pipeline", pstGErr1 ); GstElement *mPipeline_AppSink; mPipeline_AppSink = gst_bin_get_by_name( GST_BIN( mGstPipeline ), "sink" ); ////////////////////////////////////////////////////////////////////////// VIDEO SINK // Config Video Sink gst_base_sink_set_sync( GST_BASE_SINK( mPipeline_AppSink ), true ); gst_app_sink_set_max_buffers( GST_APP_SINK( mPipeline_AppSink ), 8 ); gst_app_sink_set_drop( GST_APP_SINK( mPipeline_AppSink ), true ); gst_base_sink_set_max_lateness( GST_BASE_SINK( mPipeline_AppSink ), -1 ); // Set some fix caps for the video sink // It would seem that GStreamer then tries to transform any incoming video stream according to these caps GstCaps* caps = gst_caps_new_simple( "video/x-raw-rgb", "bpp", G_TYPE_INT, 24, "depth", G_TYPE_INT, 24, "endianness", G_TYPE_INT, 4321, "red_mask", G_TYPE_INT, 0xff0000, "green_mask", G_TYPE_INT, 0x00ff00, "blue_mask", G_TYPE_INT, 0x0000ff, "alpha_mask", G_TYPE_INT, 0x000000ff, NULL ); gst_app_sink_set_caps( GST_APP_SINK( mPipeline_AppSink ), caps ); gst_caps_unref( caps ); // Set the configured video appsink to the main pipeline //g_object_set( m_GstPipeline, "video-sink", m_GstVideoSink, (void*) NULL ); // Tell the video appsink that it should not emit signals as the buffer retrieving is handled via callback methods g_object_set( mPipeline_AppSink, "emit-signals", false, "sync", true, (void*) NULL ); GstAppSinkCallbacks cbs; // Does this need to be kept alive? // Set Video Sink callback methods cbs.eos = &GSCinderApp::onEosFromVideoSource; cbs.new_preroll = &GSCinderApp::onNewPrerollFromVideoSource; cbs.new_sample = &GSCinderApp::onNewBufferFromVideoSource; gst_app_sink_set_callbacks( GST_APP_SINK( mPipeline_AppSink ), &cbs, this, NULL ); ////////////////////////////////////////////////////////////////////////// BUS // Set GstBus //m_GstBus = gst_pipeline_get_bus( GST_PIPELINE( m_GstPipeline ) ); if ( mGstPipeline != NULL ) { // We need to stream the file a little bit in order to be able to retrieve information from it GstStateChangeReturn nStateChgRet; nStateChgRet = gst_element_set_state( mGstPipeline, GST_STATE_READY ); printErrorToConsole( nStateChgRet == GST_STATE_CHANGE_FAILURE, "GStreamer Error: State Change Failure 1" ); nStateChgRet = gst_element_set_state( mGstPipeline, GST_STATE_PAUSED ); printErrorToConsole( nStateChgRet == GST_STATE_CHANGE_FAILURE, "GStreamer Error: State Change Failure 1" ); // For some reason this is needed in order to gather video information such as size, framerate etc ... GstState state; gst_element_get_state( mGstPipeline, &state, NULL, 2 * GST_SECOND ); // Erm... Why get state? } else { printErrorToConsole( true, "GStreamer Error: Pipeline Empty?!" ); } // Retrieve and store all relevant Media Information //retrieveVideoInfo(); // Check if we actually end up playing? if ( mGstPipeline != NULL ) { GstStateChangeReturn nStateChgRet; nStateChgRet = gst_element_set_state( mGstPipeline, GST_STATE_PAUSED ); printErrorToConsole( nStateChgRet == GST_STATE_CHANGE_FAILURE, "GStreamer Error: State Change Failure 3" ); } else { printErrorToConsole( true, "GStreamer Error: Pipeline Empty?!" ); } ---------------- Regards, Lasse <div class="moz-signature">-- Lasse Farnung Laursen Post.doc at the University of Tokyo <a moz-do-not-send="true" href="http://www.lasselaursen.com">www.lasselaursen.com</a> FB: <a moz-do-not-send="true" href="https://www.facebook.com/lasse.laursen">lasse.laursen </a> Twitter: <a moz-do-not-send="true" href="https://twitter.com/PMP_J">@PMP_J</a></div> <fieldset class="mimeAttachmentHeader"></fieldset> <pre wrap="">_______________________________________________ gstreamer-devel mailing list <a class="moz-txt-link-abbreviated" href="mailto:gstreamer-devel@lists.freedesktop.org">gstreamer-devel@lists.freedesktop.org</a> <a class="moz-txt-link-freetext" href="http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel">http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel</a> </pre> </blockquote> </body> </html>