spectrum while playing a file

[victor]

Hello to all

I'd like to implement a spectrum measurment on a file that i'm playing; i'm aware of the exeamples at http://http://cgit.freedesktop.org/gstreamer/gst-plugins-good/tree/tests/examples/spectrum/ but the exeamples are with either "alsasrc" or "audiotestsrc"; nothing with a file that is played.

When i type in a terminal :
filesrc location="/home/victor/Music/my_file.wav" ! decodebin2 ! spectrum bands=100 threshold=-80 message=TRUE message-phase=TRUE interval=1000000 ! alsasink

it works (i don't have the display of the spectrum but i have the sound file playing).

When i try it in a C program, i always have the 'complain' that elemets cannot be linked...

Please, is there a think t forgot....?

Here is my "int main" function:

int
main (int argc, char *argv[])
{
  GstElement *bin;
  GstElement *src, *audioconvert, *decodebin, *spectrum, *sink;
  GstBus *bus;
  GstCaps *caps;
  GMainLoop *loop;

  gst_init (&argc, &argv);

  bin = gst_pipeline_new ("bin");

  src = gst_element_factory_make ("filesrc", "src");
  g_object_set (G_OBJECT (src), "location", "file:///home/victor/Music/Gurdieff-Elena/gymnastique_medicale.wav", NULL);
  decodebin = gst_element_factory_make ("decodebin2", "decodebin2");
  g_signal_connect (decodebin, "new-decoded-pad", G_CALLBACK (cb_newpad), NULL);
  spectrum = gst_element_factory_make ("spectrum", "spectrum");
  g_object_set (G_OBJECT (spectrum), "bands", spect_bands, "threshold", -80,
      "message", TRUE, "message-phase", TRUE, NULL);
  sink = gst_element_factory_make ("alsasink", "sink");
  g_object_set (G_OBJECT (sink), "sync", TRUE, NULL);
  gst_bin_add_many (GST_BIN (bin), src, decodebin, spectrum, sink, NULL);

  caps = gst_caps_new_simple ("audio/x-raw-int",
      "rate", G_TYPE_INT, AUDIOFREQ, NULL);

  if (!gst_element_link (src, decodebin))
{ fprintf (stderr, "can't link elements 1\n");
    exit (1);
  }
  if (!gst_element_link_filtered (decodebin, spectrum, caps))
        { fprintf (stderr, "can't link elements 2\n");
    exit (1);
  }
  if  (!gst_element_link (spectrum, sink)) {
    fprintf (stderr, "can't link elements 3\n");
    exit (1);
  }
  gst_caps_unref (caps);

  bus = gst_element_get_bus (bin);
  gst_bus_add_watch (bus, message_handler, NULL);
  gst_object_unref (bus);

  gst_element_set_state (bin, GST_STATE_PLAYING);

  /* we need to run a GLib main loop to get the messages */
  loop = g_main_loop_new (NULL, FALSE);
  g_main_loop_run (loop);

  gst_element_set_state (bin, GST_STATE_NULL);

  gst_object_unref (bin);

  return 0;
}

Thank you

 Victor

[Jan Schmidt-6]

Hi Victor,

As always when dealing with decodebin, or any element that has dynamic
pads, you need to trigger on new-pad creation and link decodebin
downstream then.

Here is an example in python:

http://www.jonobacon.org/2006/11/03/gstreamer-dynamic-pads-explained/

- Jan.

On Mon, 2010-11-15 at 17:45 -0800, victor wrote:

> Hello to all
>
> I'd like to implement a spectrum measurment on a file that i'm playing; i'm
> aware of the exeamples at
> http://http://cgit.freedesktop.org/gstreamer/gst-plugins-good/tree/tests/examples/spectrum/
> http://http://cgit.freedesktop.org/gstreamer/gst-plugins-good/tree/tests/examples/spectrum/ 
> but the exeamples are with either "alsasrc" or "audiotestsrc"; nothing with
> a file that is played.
>
> When i type in a terminal :
> filesrc location="/home/victor/Music/my_file.wav" ! decodebin2 ! spectrum
> bands=100 threshold=-80 message=TRUE message-phase=TRUE interval=1000000 !
> alsasink
>
> it works (i don't have the display of the spectrum but i have the sound file
> playing).
>
> When i try it in a C program, i always have the 'complain' that elemets
> cannot be linked...
>
> Please, is there a think t forgot....?
>
> Here is my "int main" function:
>
> int
> main (int argc, char *argv[])
> {
>   GstElement *bin;
>   GstElement *src, *audioconvert, *decodebin, *spectrum, *sink;
>   GstBus *bus;
>   GstCaps *caps;
>   GMainLoop *loop;
>
>   gst_init (&argc, &argv);
>
>   bin = gst_pipeline_new ("bin");
>
>   src = gst_element_factory_make ("filesrc", "src");
>   g_object_set (G_OBJECT (src), "location",
> "file:///home/victor/Music/Gurdieff-Elena/gymnastique_medicale.wav", NULL);
>   decodebin = gst_element_factory_make ("decodebin2", "decodebin2");
>   g_signal_connect (decodebin, "new-decoded-pad", G_CALLBACK (cb_newpad),
> NULL);
>   spectrum = gst_element_factory_make ("spectrum", "spectrum");
>   g_object_set (G_OBJECT (spectrum), "bands", spect_bands, "threshold", -80,
>       "message", TRUE, "message-phase", TRUE, NULL);
>   sink = gst_element_factory_make ("alsasink", "sink");
>   g_object_set (G_OBJECT (sink), "sync", TRUE, NULL);
>   gst_bin_add_many (GST_BIN (bin), src, decodebin, spectrum, sink, NULL);
>
>   caps = gst_caps_new_simple ("audio/x-raw-int",
>       "rate", G_TYPE_INT, AUDIOFREQ, NULL);
>
>   if (!gst_element_link (src, decodebin))
> { fprintf (stderr, "can't link elements 1\n");
>     exit (1);
>   }
>   if (!gst_element_link_filtered (decodebin, spectrum, caps))
>     { fprintf (stderr, "can't link elements 2\n");
>     exit (1);
>   }
>   if  (!gst_element_link (spectrum, sink)) {
>     fprintf (stderr, "can't link elements 3\n");
>     exit (1);
>   }
>   gst_caps_unref (caps);
>
>   bus = gst_element_get_bus (bin);
>   gst_bus_add_watch (bus, message_handler, NULL);
>   gst_object_unref (bus);
>
>   gst_element_set_state (bin, GST_STATE_PLAYING);
>
>   /* we need to run a GLib main loop to get the messages */
>   loop = g_main_loop_new (NULL, FALSE);
>   g_main_loop_run (loop);
>
>   gst_element_set_state (bin, GST_STATE_NULL);
>
>   gst_object_unref (bin);
>
>   return 0;
> }
>
> Thank you
>
>  Victor
>
>
>

--
Jan Schmidt <[hidden email]>


------------------------------------------------------------------------------
Beautiful is writing same markup. Internet Explorer 9 supports
standards for HTML5, CSS3, SVG 1.1,  ECMAScript5, and DOM L2 & L3.
Spend less time writing and  rewriting code and more time creating great
experiences on the web. Be a part of the beta today
http://p.sf.net/sfu/msIE9-sfdev2dev
_______________________________________________
gstreamer-devel mailing list
[hidden email]
https://lists.sourceforge.net/lists/listinfo/gstreamer-devel