Data loss of around 1.7 sec at start of every capture

[Ashish Kumar Mishra]

Dear Group Members ,

Our requirement is to create an 5min file for 8hours continuously.
So currently we are doing an pipeline start & stop after every 5min. 
Below is the details

  A) We have build an Gst application for :-
         Processor ( TI Netra DM8168)
         Audio ( Stereo 16bit 44.1KHZ)
         Video ( DVI 1080p @ 60hz using TFP401A-EP)
         MUX  (MATROSKA)
         Overlay ( Time )
         Filesink as ".avi"


B) We are loosing around 1.7sec at the start of every capture. Let me 
explain
      If we put the pipeline in PLAYING mode at t=0 for total duration 
of 100 sec , the recordded file has below mentioned status :-
         a) Video from t=0 to t=1.5 sec is not captured in the recorded 
file .
         b) The recorded file has first frame of video  from t=1.5 sec 
to t=101.5 sec


C)  This data loss of initial 1.5sec is observed every time i start & 
stop the engine.

D) The basic flow is :-
      a) Creating the pipeline with the elements and linking them in 
main thread .
            gst_bin_add_many(GST_BIN(pipeline), AVIMux, FileSink,NULL);
            gst_bin_add_many(GST_BIN(pipeline), omx_videosrc, 
clockoverlay, omx_videoEnc,NULL);
            gst_element_link_many(omx_videosrc, 
clockoverlay,omx_videoEnc, AVIMux, NULL);
            gst_bin_add(GST_BIN(pipeline), alsaAudSrc);
            gst_element_link(alsaAudSrc, AVIMux);
            gst_element_link(AVIMux, FileSink);

            if (TRUE != gst_pipeline_set_clock(pipeline, 
gst_system_clock_obtain())) {
                 printf("gst_pipeline_set_clock(GstSystemClock) did not 
work\n");
                 nRetVal = FAILURE;
                 goto labelExit;
            }



      b) Create an child thread and do the below mentioned activities ( 
rough flow ):-
              GSource *bus_source;
              GstBus *bus;
              main_loop_cntxt = g_main_context_new();
              g_main_context_push_thread_default(main_loop_cntxt);
              bus = gst_element_get_bus (pipeline); // Pipeline is 
created in parent thread
              bus_source = gst_bus_create_watch (bus);
              g_source_set_callback (bus_source, (GSourceFunc) 
gst_bus_async_signal_func, NULL, NULL);
              g_source_attach (bus_source, main_loop_cntxt);
              g_source_unref (bus_source);
              g_signal_connect (G_OBJECT (bus), "message::error", 
(GCallback)error_cb, NULL);
              g_signal_connect (G_OBJECT (bus), "message::eos", 
(GCallback)eos_cb, NULL);
              main_loop = g_main_loop_new(main_loop_cntxt, FALSE);
              gst_element_set_state (pipeline, GST_STATE_PLAYING);

              if (gst_element_get_state (pipeline, NULL, NULL, 
(GST_SECOND * 10)) == GST_STATE_CHANGE_FAILURE){
                         goto exit_label;
              }
              g_main_loop_run (main_loop);



So could team members please let me know where should we debug and 
probable point of problem.

Thanks ,
Ashish Kumar Mishra