Linked list test src

[iron_guitarist1987]

I'm trying to create a source element that outputs a linked list. I am getting the following error:

gst-launch vpeftestsrc ! filesink location=test.log
..
Pipeline is PREROLLING ...

(gst-launch-0.10:16208): GStreamer-CRITICAL **: gst_buffer_create_sub: assertion `buffer->mini_object.refcount > 0' failed
Caught SIGSEGV accessing address (nil)


Any suggestions? Thanks.

Code:

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <stdlib.h>
#include <gst/controller/gstcontroller.h>
#include <gst/gst.h>
#include "cgmtestsrc.h"

GST_DEBUG_CATEGORY_STATIC (cgm_test_src_debug);
#define GST_CAT_DEFAULT cgm_test_src_debug

enum
{
  PROP_0,
  PROP_LAST
};

static GstStaticPadTemplate gst_cgm_test_src_src_template =
    GST_STATIC_PAD_TEMPLATE ("src",
    GST_PAD_SRC,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS ("struct/cgm")
    );

GST_BOILERPLATE (GstCgmtestsrc, gst_cgm_test_src, GstBaseSrc,
    GST_TYPE_BASE_SRC);

static void gst_cgm_test_src_set_property (GObject * object,
    guint prop_id, const GValue * value, GParamSpec * pspec);
static void gst_cgm_test_src_get_property (GObject * object,
    guint prop_id, GValue * value, GParamSpec * pspec);
static GstFlowReturn gst_cgm_test_src_create (GstBaseSrc * basesrc,
    guint64 offset, guint length, GstBuffer ** buffer);

static void
gst_cgm_test_src_base_init (gpointer g_class)
{
  GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);

  gst_element_class_add_pad_template (element_class,
      gst_static_pad_template_get (&gst_cgm_test_src_src_template));
  gst_element_class_set_details_simple (element_class,
      "CGM test source", "struct/cgm",
      "Creates a linked list",
      "Jason Trinidad");
}

static void
gst_cgm_test_src_class_init (GstCgmtestsrcClass * klass)
{
  GObjectClass *gobject_class;
  GstBaseSrcClass *gstbasesrc_class;

  gobject_class = (GObjectClass *) klass;
  gstbasesrc_class = (GstBaseSrcClass *) klass;

  gobject_class->set_property = gst_cgm_test_src_set_property;
  gobject_class->get_property = gst_cgm_test_src_get_property;

  gstbasesrc_class->create = GST_DEBUG_FUNCPTR (gst_cgm_test_src_create);
}

static void
gst_cgm_test_src_init (GstCgmtestsrc * src, GstCgmtestsrcClass * g_class)
{
  GstPad *pad = GST_BASE_SRC_PAD (src);
 
  /* we operate in time */
  gst_base_src_set_format (GST_BASE_SRC (src), GST_FORMAT_TIME);
  gst_base_src_set_blocksize (GST_BASE_SRC (src), -1);
}


static GstFlowReturn
gst_cgm_test_src_create (GstBaseSrc * basesrc, guint64 offset,
    guint length, GstBuffer ** buffer)
{
  GstFlowReturn res;
  GstCgmtestsrc *src;
  src = GST_CGM_TEST_SRC (basesrc);
  GstBuffer *buf;
  CgmSet cgm;
 
  buf = gst_buffer_new_allocate(NULL, sizeof(cgm), NULL);
  buf = &cgm;
 
  *buffer = buf;

  return GST_FLOW_OK;
}

static void
gst_cgm_test_src_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec)
{
  GstCgmtestsrc *src = GST_CGM_TEST_SRC (object);

  switch (prop_id) {
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static void
gst_cgm_test_src_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec)
{
  GstCgmtestsrc *src = GST_CGM_TEST_SRC (object);

  switch (prop_id) {
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static gboolean
plugin_init (GstPlugin * plugin)
{
  /* initialize gst controller library */
  gst_controller_init (NULL, NULL);

  GST_DEBUG_CATEGORY_INIT (cgm_test_src_debug, "cgmtestsrc", 0,
      "Cgm Test Source");

  return gst_element_register (plugin, "cgmtestsrc",
      GST_RANK_NONE, GST_TYPE_CGM_TEST_SRC);
}

GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
    GST_VERSION_MINOR,
    "cgmtestsrc",
    "Creates test struct",
    plugin_init, VERSION, "LGPL", GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN);




This is what the struct looks like in the header file

typedef struct _CgmDetectedObjectSet CgmDetectedObjectSet;
struct _CgmDetectedObjectSet {

       
        gdouble sigma1;
        gdouble sigma2;
        gdouble rho12;
       
        CgmDetectedObjectSet * next;
};

[Mohammed Sameer]

On Mon, Jul 02, 2012 at 07:04:15AM -0700, iron_guitarist1987 wrote:

> I'm trying to create a source element that outputs a linked list. I am
> getting the following error:
>
> gst-launch vpeftestsrc ! filesink location=test.log
> ..
> Pipeline is PREROLLING ...
>
> (gst-launch-0.10:16208): GStreamer-CRITICAL **: gst_buffer_create_sub:
> assertion `buffer->mini_object.refcount > 0' failed
> Caught SIGSEGV accessing address (nil)

[...]
> static GstFlowReturn
> gst_cgm_test_src_create (GstBaseSrc * basesrc, guint64 offset,
>     guint length, GstBuffer ** buffer)
> {
>   GstFlowReturn res;
>   GstCgmtestsrc *src;
>   src = GST_CGM_TEST_SRC (basesrc);
>   GstBuffer *buf;
>   CgmSet cgm;

What is CgmSet ?

>   buf = gst_buffer_new_allocate(NULL, sizeof(cgm), NULL);
>   buf = &cgm;

Here you are overwriting the value returned by gst_buffer_new_allocate()
with CgmSet which is local to the function and will be destroyed when the function returns.


>  
>   *buffer = buf;
>
>   return GST_FLOW_OK;
> }

Cheers,

--
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[iron_guitarist1987]

Sorry, it's supposed to say typedef struct CgmDetectedObjectSet, instead of CgmSet.

It is defined in the header file as

typedef struct _CgmDetectedObjectSet CgmDetectedObjectSet;
struct _CgmDetectedObjectSet {

       
        gdouble sigma1;
        gdouble sigma2;
        gdouble rho12;
       
        CgmDetectedObjectSet * next;
};

[iron_guitarist1987]

Anyone have any recommendations? Thanks.

[Josh Doe]

On Tue, Jul 3, 2012 at 12:44 PM, iron_guitarist1987
<[hidden email]> wrote:
> Anyone have any recommendations? Thanks.

Several issues, the primary one being that you aren't treating the
GstBuffer as an object; data is but one property of a buffer, you must
also specify size, timestamp, etc. You need to malloc or new the
struct and set it using GST_BUFFER_DATA and GST_BUFFER_MALLOCDATA, or
preferably use gst_pad_alloc_buffer which does all of this and can be
more efficient.

-Josh
_______________________________________________
gstreamer-devel mailing list
[hidden email]
http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel

[iron_guitarist1987]

I'm sorry for being naive, but I'm still learning gstreamer. I changed my create function, but now I'm getting the following:

$ gst-launch cgmtestsrc ! fakesink
Setting pipeline to PAUSED ...
Pipeline is PREROLLING ...
Caught SIGSEGV accessing address 0xc5ae2e
Spinning.  Please run 'gdb gst-launch 5078' to continue debugging, Ctrl-C to quit, or Ctrl-\ to dump core.
^CCaught interrupt -- handling interrupt.
Interrupt: Stopping pipeline ...
ERROR: pipeline doesn't want to preroll.
Setting pipeline to NULL ...



static GstFlowReturn
gst_cgm_test_src_create (GstBaseSrc * basesrc, guint64 offset,
    guint length, GstBuffer ** buffer)
{
  GstFlowReturn res;
  GstCgmtestsrc *src;
  src = GST_CGM_TEST_SRC (basesrc);
  CgmDetectedObjectSet* cgm;
  static CgmDetectedObjectSet * prev;
  gint8 len;
 
  //Setting some default values for testing.
  cgm->boundingBoxHeight = 50;
  cgm->boundingBoxTopLeftCornerX=0;
  cgm->boundingBoxTopLeftCornerY=50;
  cgm->boundingBoxWidth=50;
 
  len = sizeof(cgm);
 
 
  GST_BUFFER_MALLOCDATA (buffer) = g_malloc (len);
  GST_BUFFER_DATA (buffer) = GST_BUFFER_MALLOCDATA (buf);
  GST_BUFFER_SIZE (buffer) = len;
 
  GST_BUFFER_DATA (buffer) = &cgm;

 
  return GST_FLOW_OK;
}