Geek Answers Handbook

Videomixer does not work on sources, not Videotestsrc

I want to play two different local video files in one window at the same time. The code below without a demultiplexer and decoder works fine.

static void play_video(){ GMainLoop *loop; GstElement *pipeline,*videomixer; GstElement *src,*sink,*filter,*csp,*videobox; GstElement *src1,*filter1,*csp1,*videobox1; GstElement *srcb,*filterb,*cspb,*videoboxb; GstCaps *filtercaps,*filtercaps1,*filtercapsb; GstPad *pad,*pad1; const char pattern = "snow"; loop = g_main_loop_new(NULL, FALSE); pipeline = gst_pipeline_new("my-pipeline"); src = gst_element_factory_make ("videotestsrc","src"); src1 = gst_element_factory_make ("videotestsrc","src1"); g_object_set (G_OBJECT (src), "pattern", 10, NULL); filter = gst_element_factory_make("capsfilter","filter"); filter1 = gst_element_factory_make("capsfilter","filter1"); csp = gst_element_factory_make("ffmpegcolorspace","csp"); csp1 = gst_element_factory_make("ffmpegcolorspace","csp1"); /**/ videobox=gst_element_factory_make("videobox","videobox"); g_object_set(videobox,"top",0,"bottom",0,"left",0,"right",0,NULL); videobox1=gst_element_factory_make("videobox","videobox1"); g_object_set(videobox1,"top",-20,"bottom",0,"left",0,"right",0,NULL); videomixer=gst_element_factory_make("videomixer","videomixer"); /**/ sink = gst_element_factory_make("xvimagesink","sink"); if(sink == NULL) sink = gst_element_factory_make("ximagesink","sink"); if(sink == NULL) g_error("'ximagesink' yaratılamadı."); gst_bin_add_many(GST_BIN(pipeline),src,filter,videobox,videomixer,csp,sink, src1,filter1,videobox1,csp1,NULL); gst_element_link_many(src,filter,csp,videobox,videomixer,NULL); gst_element_link_many(src1,filter1,csp1,videobox1,videomixer,NULL); /* videotestsrc pattern="snow" ! video/x-raw-yuv, framerate=1/1, width=350, height=250 ! \ textoverlay font-desc="Sans 24" text="CAM2" valign=top halign=left shaded-background=true ! \ videobox border-alpha=0 top=-200 left=-450 ! mix. \ */ gst_element_link_many(videomixer,sink,NULL); filtercaps = gst_caps_new_simple ("video/x-raw-rgb", "width", G_TYPE_INT, 1024, "height", G_TYPE_INT, 768, "framerate", GST_TYPE_FRACTION, 25, 1, "bpp", G_TYPE_INT, 16, "depth", G_TYPE_INT, 16, "endianness", G_TYPE_INT, G_BYTE_ORDER, NULL); filtercaps1 = gst_caps_new_simple ("video/x-raw-rgb", "width", G_TYPE_INT, 200, "height", G_TYPE_INT, 500, "framerate", GST_TYPE_FRACTION, 25, 1, "bpp", G_TYPE_INT, 16, "depth", G_TYPE_INT, 16, "endianness", G_TYPE_INT, G_BYTE_ORDER, NULL); g_object_set (G_OBJECT (filter), "caps", filtercaps, NULL); gst_caps_unref (filtercaps); g_object_set (G_OBJECT (filter1), "caps", filtercaps1, NULL); gst_caps_unref (filtercaps1); /*pad = gst_element_get_pad (src, "src"); pad1 = gst_element_get_pad (src1, "src1"); //gst_pad_add_buffer_probe (pad, G_CALLBACK (cb_have_data), NULL); //gst_pad_add_buffer_probe (pad1, G_CALLBACK (cb_have_data), NULL); //gst_object_unref (pad); //gst_object_unref (pad1);*/ /* run */ gst_element_set_state (pipeline, GST_STATE_PLAYING); /* wait until it up and running or failed */ if (gst_element_get_state (pipeline, NULL, NULL, -1) == GST_STATE_CHANGE_FAILURE) { g_error ("Failed to go into PLAYING state"); } g_print ("Running ...\n"); g_main_loop_run (loop); /* exit */ gst_element_set_state (pipeline, GST_STATE_NULL); gst_object_unref (pipeline); }

The problem is that I replace videotestsrc with the files and it fails, and the only error message I get is "Could not find the NULL object by the destroy window signal of the object". I am not an expert gstreamer, and I believe that I could not install the demultiplexer and decoder.

 static void play_video5(){ GMainLoop *loop; GstElement *pipeline,*videomixer; GstElement *src,*sink,*filter,*csp,*videobox; GstElement *src1,*filter1,*csp1,*videobox1; GstElement *srcb,*filterb,*cspb,*videoboxb; GstCaps *filtercaps,*filtercaps1,*filtercapsb; GstPad *pad,*pad1; GstElement *demux,*decoder; const char pattern = "snow"; loop = g_main_loop_new(NULL, FALSE); pipeline = gst_pipeline_new("my-pipeline"); //Source src = gst_element_factory_make ("videotestsrc","src"); src1 = gst_element_factory_make ("filesrc","src1"); g_object_set (G_OBJECT (src1), "location", "file:///root/yu.mp4", NULL); //Demux demux = gst_element_factory_make ("mpegdemux", "demux"); //Decoder decoder = gst_element_factory_make ("decodebin", "decoder"); // decoder = gst_element_factory_make ("ffdec_mpeg4","mpeg4-decoder"); //Filter filter = gst_element_factory_make("capsfilter","filter"); filter1 = gst_element_factory_make("capsfilter","filter1"); //Colorspace csp = gst_element_factory_make("ffmpegcolorspace","csp"); csp1 = gst_element_factory_make("ffmpegcolorspace","csp1"); //Videobox videobox=gst_element_factory_make("videobox","videobox"); g_object_set(videobox,"top",0,"bottom",0,"left",0,"right",0,NULL); videobox1=gst_element_factory_make("videobox","videobox1"); g_object_set(videobox1,"top",-20,"bottom",0,"left",0,"right",0,NULL); //videomixer videomixer=gst_element_factory_make("videomixer","videomixer"); //Sink sink = gst_element_factory_make("xvimagesink","sink"); if(sink == NULL) sink = gst_element_factory_make("ximagesink","sink"); if(sink == NULL) g_error("'ximagesink' yaratılamadı."); //Add to Bin gst_bin_add_many(GST_BIN(pipeline),src,filter,videobox,videomixer,csp, src1,decoder,filter1,videobox1,csp1,sink,NULL); //Link Elements gst_element_link(src,filter); gst_element_link(filter,csp); gst_element_link(csp,videobox); gst_element_link(videobox, videomixer); gst_element_link(src1,decoder); gst_element_link(decoder,filter1); // gst_element_link(decoder,csp1); gst_element_link(filter1,csp1); gst_element_link(csp1,videobox1); gst_element_link(videobox1, videomixer); gst_element_link(videomixer,sink); //Cap definition filtercaps = gst_caps_new_simple ("video/x-raw-rgb", "width", G_TYPE_INT, 1024, "height", G_TYPE_INT, 768, "framerate", GST_TYPE_FRACTION, 25, 1, "bpp", G_TYPE_INT, 16, "depth", G_TYPE_INT, 16, "endianness", G_TYPE_INT, G_BYTE_ORDER, NULL); filtercaps1 = gst_caps_new_simple ("video/x-raw-yuv", "width", G_TYPE_INT, 640, "height", G_TYPE_INT, 480, "framerate", GST_TYPE_FRACTION, 25, 1, /*"bpp", G_TYPE_INT, 16, "depth", G_TYPE_INT, 16, "endianness", G_TYPE_INT, G_BYTE_ORDER,*/ NULL); //Cap to Filter g_object_set (G_OBJECT (filter), "caps", filtercaps, NULL); gst_caps_unref (filtercaps); g_object_set (G_OBJECT (filter1), "caps", filtercaps1, NULL); gst_caps_unref (filtercaps1); /* run */ gst_element_set_state (pipeline, GST_STATE_PLAYING); /* wait until it up and running or failed */ if (gst_element_get_state (pipeline, NULL, NULL, -1) == GST_STATE_CHANGE_FAILURE) { g_error ("Failed to go into PLAYING state"); } g_print ("Running ...\n"); g_main_loop_run (loop); /* exit */ gst_element_set_state (pipeline, GST_STATE_NULL); gst_object_unref (pipeline); }

Any ideas or corrections are welcome.

+3
source share
1 answer

A few questions:

  • filesrc does not take uris, but file path
  • / * wait until it works and does not work * / + the code below is not needed, it is better to listen to the bus for error messages and warnings
  • "Could not find NULL object when disconnecting signal in object window" has nothing to do with gstreamer
  • the entire business of video ads is not needed, as the video mixer pads have xpos, ypos and zorder.
+2
source

More articles:


All Articles