gst-plugin-linescan/sys/gstniimaq.c

/* GStreamer
 * Copyright (C) <2006> Eric Jonas <jonas@mit.edu>
 * Copyright (C) <2006> Antoine Tremblay <hexa00@gmail.com>
 * Copyright (C) 2010 United States Government, Joshua M. Doe <oss@nvl.army.mil>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

/**
 * SECTION:element-niimaqsrc
 *
 * Source for National Instruments IMAQ frame grabber (Camera Link and analog cameras)
 * 
 * <refsect2>
 * <title>Example launch line</title>
 * |[
 * gst-launch -v niimaqsrc ! ffmpegcolorspace ! autovideosink
 * ]|
 * </refsect2>
 */

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

#include "gst/interfaces/propertyprobe.h"

#include "gstniimaq.h"

#include <time.h>
#include <string.h>

GST_DEBUG_CATEGORY (niimaq_debug);
#define GST_CAT_DEFAULT niimaq_debug

static GstElementDetails niimaq_details =
GST_ELEMENT_DETAILS ("NI-IMAQ Video Source",
    "Source/Video",
    "National Instruments based source, supports Camera Link and analog cameras",
    "Joshua Doe <oss@nvl.army.mil>");

enum
{
  PROP_0,
  PROP_INTERFACE,
  PROP_TIMESTAMP_OFFSET,
  PROP_BUFSIZE
      /* FILL ME */
};

#define DEFAULT_PROP_INTERFACE "img0"
#define DEFAULT_PROP_TIMESTAMP_OFFSET  0
#define DEFAULT_PROP_BUFSIZE  10

static void gst_niimaq_init_interfaces (GType type);

GST_BOILERPLATE_FULL (GstNiImaq, gst_niimaq, GstPushSrc,
    GST_TYPE_PUSH_SRC, gst_niimaq_init_interfaces);

/* GObject virtual methods */
static void gst_niimaq_dispose (GObject * object);
static void gst_niimaq_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec);
static void gst_niimaq_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec);

/* GstBaseSrc virtual methods */
static GstCaps *gst_niimaq_get_caps (GstBaseSrc * bsrc);
static gboolean gst_niimaq_set_caps (GstBaseSrc * bsrc, GstCaps * caps);
static void gst_niimaq_src_fixate (GstPad * pad, GstCaps * caps);
static void gst_niimaq_get_times (GstBaseSrc * basesrc,
    GstBuffer * buffer, GstClockTime * start, GstClockTime * end);
static gboolean gst_niimaq_start (GstBaseSrc * src);
static gboolean gst_niimaq_stop (GstBaseSrc * src);

/* GstPushSrc virtual methods */
static GstFlowReturn gst_niimaq_create (GstPushSrc * psrc, GstBuffer ** buffer);

/* GstNiImaq methods */
static gboolean gst_niimaq_parse_caps (const GstCaps * caps,
    gint * width,
    gint * height,
    gint * rate_numerator, gint * rate_denominator, gint * depth, gint * bpp);

static gboolean gst_niimaq_set_caps_color (GstStructure * gs, int bpp, int depth);
static gboolean gst_niimaq_set_caps_framesize (GstStructure * gs, gint width,
    gint height);

static GstCaps *gst_niimaq_get_all_niimaq_caps ();
static GstCaps *gst_niimaq_get_cam_caps (GstNiImaq * src);

static void _____BEGIN_FUNCTIONS_____();

/**
* gst_niimaq_probe_get_properties:
* @probe: #GstPropertyProbe
*
* Gets list of properties that can be probed
*
* Returns: #GList of properties that can be probed
*/
static const GList *
gst_niimaq_probe_get_properties (GstPropertyProbe * probe)
{
  GObjectClass *klass = G_OBJECT_GET_CLASS (probe);
  static GList *list = NULL;

  if (!list) {
    list = g_list_append (NULL, g_object_class_find_property (klass, "interface"));
  }

  return list;
}

static gboolean init = FALSE;
static GList *interfaces = NULL;

/**
* gst_niimaq_class_probe_interfaces:
* @klass: #GstNiImaqClass
* @check: whether to enumerate interfaces
*
* Probes NI-IMAQ driver for available interfaces
*
* Returns: TRUE always
*/
static gboolean
gst_niimaq_class_probe_interfaces (GstNiImaqClass * klass, gboolean check)
{
  if (!check) {
    guint32 n;
    gchar name[256];

    /* clear interface list */
    while (interfaces) {
      gchar *iface = interfaces->data;
      interfaces = g_list_remove (interfaces, iface);
      g_free (iface);
    }

    GST_DEBUG_OBJECT (klass, "About to probe for IMAQ interfaces");

    /* enumerate interfaces, limiting ourselves to the first 64 */
    for (n = 0; n < 64; n++) {
      guint32 iid;
      guint32 nports;
      guint32 port;
      gchar * iname;

      /* get interface names until there are no more */
      if (imgInterfaceQueryNames (n, name) != 0)
        break;

      /* ignore NICFGen */
      if (g_strcmp0 (name, "NICFGen.iid") == 0)
        continue;

      /* try and open the interface */
      if (imgInterfaceOpen (name, &iid) != 0)
        continue;

      /* find how many ports the interface provides */
      imgGetAttribute (iid, IMG_ATTR_NUM_PORTS, &nports);
      imgClose (iid, TRUE);

      /* iterate over all the available ports */
      for (port=0; port < nports; port++) {
        /* if the there are multiple ports append the port number */
        if (nports > 1)
          iname = g_strdup_printf ("%s::%d", name, port);
        else
          iname = g_strdup (name);

        /* TODO: should check to see if a camera is actually attached */
        interfaces = g_list_append (interfaces, iname);

        GST_DEBUG_OBJECT (klass, "Adding interface '%s' to list", iname);
      }
    }

    init = TRUE;
  }

  klass->interfaces = interfaces;

  return init;
}

/**
* gst_niimaq_probe_probe_property:
* @probe: #GstPropertyProbe
* @prop_id: Property id
* @pspec: #GParamSpec
*
* GstPropertyProbe _probe_proprty vmethod implementation that probes a
*   property for possible values
*/
static void
gst_niimaq_probe_probe_property (GstPropertyProbe * probe,
    guint prop_id, const GParamSpec * pspec)
{
  GstNiImaqClass *klass = GST_NIIMAQ_GET_CLASS (probe);

  switch (prop_id) {
    case PROP_INTERFACE:
      gst_niimaq_class_probe_interfaces (klass, FALSE);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (probe, prop_id, pspec);
      break;
  }
}

/**
* gst_niimaq_probe_needs_probe:
* @probe: #GstPropertyProbe
* @prop_id: Property id
* @pspec: #GParamSpec
*
* GstPropertyProbe _needs_probe vmethod implementation that indicates if
*   a property needs to be updated
*
* Returns: TRUE if a property needs to be updated
*/
static gboolean
gst_niimaq_probe_needs_probe (GstPropertyProbe * probe,
                           guint prop_id, const GParamSpec * pspec)
{
  GstNiImaqClass *klass = GST_NIIMAQ_GET_CLASS (probe);
  gboolean ret = FALSE;

  switch (prop_id) {
    case PROP_INTERFACE:
      ret = !gst_niimaq_class_probe_interfaces (klass, TRUE);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (probe, prop_id, pspec);
      break;
  }

  return ret;
}

/**
* gst_niimaq_class_list_interfaces:
* @klass: #GstNiImaqClass
*
* Returns: #GValueArray of interface names
*/
static GValueArray *
gst_niimaq_class_list_interfaces (GstNiImaqClass * klass)
{
  GValueArray *array;
  GValue value = { 0 };
  GList *item;

  if (!klass->interfaces)
    return NULL;

  array = g_value_array_new (g_list_length (klass->interfaces));
  item = klass->interfaces;
  g_value_init (&value, G_TYPE_STRING);
  while (item) {
    gchar *iface = item->data;

    g_value_set_string (&value, iface);
    g_value_array_append (array, &value);

    item = item->next;
  }
  g_value_unset (&value);

  return array;
}

/**
* gst_niimaq_probe_get_values:
* @probe: #GstPropertyProbe
* @prop_id: Property id
* @pspec: #GParamSpec
*
* GstPropertyProbe _get_values vmethod implementation that gets possible
*   values for a property
*
* Returns: #GValueArray containing possible values for requested property
*/
static GValueArray *
gst_niimaq_probe_get_values (GstPropertyProbe * probe,
                          guint prop_id, const GParamSpec * pspec)
{
  GstNiImaqClass *klass = GST_NIIMAQ_GET_CLASS (probe);
  GValueArray *array = NULL;

  switch (prop_id) {
    case PROP_INTERFACE:
      array = gst_niimaq_class_list_interfaces (klass);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (probe, prop_id, pspec);
      break;
  }

  return array;
}

/**
* gst_v4l_property_probe_interface_init:
* @iface: #GstPropertyProbeInterface
*
* Install property probe interfaces functions
*/
static void
gst_niimaq_property_probe_interface_init (GstPropertyProbeInterface * iface)
{
  iface->get_properties = gst_niimaq_probe_get_properties;
  iface->probe_property = gst_niimaq_probe_probe_property;
  iface->needs_probe = gst_niimaq_probe_needs_probe;
  iface->get_values = gst_niimaq_probe_get_values;
}

/**
* gst_niimaq_init_interfaces:
* @type: #GType
*
* Initialize all interfaces
*/
static void
gst_niimaq_init_interfaces (GType type)
{
  static const GInterfaceInfo niimaq_propertyprobe_info = {
    (GInterfaceInitFunc) gst_niimaq_property_probe_interface_init,
    NULL,
    NULL,
  };

  g_type_add_interface_static (type,
    GST_TYPE_PROPERTY_PROBE, &niimaq_propertyprobe_info);
}

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

  gst_element_class_set_details (element_class, &niimaq_details);

  gst_element_class_add_pad_template (element_class,
      gst_pad_template_new ("src", GST_PAD_SRC, GST_PAD_ALWAYS,
          gst_niimaq_get_all_niimaq_caps ()));

}

static void
gst_niimaq_class_init (GstNiImaqClass * klass)
{
  GObjectClass *gobject_class;
  GstBaseSrcClass *gstbasesrc_class;
  GstPushSrcClass *gstpushsrc_class;
  GstElementClass *gstelement_class;

  gobject_class = (GObjectClass *) klass;
  gstbasesrc_class = (GstBaseSrcClass *) klass;
  gstpushsrc_class = (GstPushSrcClass *) klass;
  gstelement_class = (GstElementClass *) klass;

  gobject_class->dispose = gst_niimaq_dispose;
  gobject_class->set_property = gst_niimaq_set_property;
  gobject_class->get_property = gst_niimaq_get_property;

  g_object_class_install_property (G_OBJECT_CLASS (klass),
      PROP_INTERFACE, g_param_spec_string ("interface",
        "Interface",
        "NI-IMAQ interface to open", DEFAULT_PROP_INTERFACE, G_PARAM_READWRITE));

  g_object_class_install_property (G_OBJECT_CLASS (klass),
      PROP_TIMESTAMP_OFFSET, g_param_spec_int64 ("timestamp-offset",
          "Timestamp offset",
          "An offset added to timestamps set on buffers (in ns)", G_MININT64,
          G_MAXINT64, DEFAULT_PROP_TIMESTAMP_OFFSET, G_PARAM_READWRITE));

  g_object_class_install_property (G_OBJECT_CLASS (klass),
      PROP_BUFSIZE, g_param_spec_int ("buffer-size",
          "The number of frames in the dma ringbuffer",
          "The number of frames in the dma ringbuffer", 1,
          G_MAXINT, DEFAULT_PROP_BUFSIZE, G_PARAM_READWRITE));

  gstbasesrc_class->get_caps = gst_niimaq_get_caps;
  gstbasesrc_class->set_caps = gst_niimaq_set_caps;

  gstbasesrc_class->get_times = gst_niimaq_get_times;
  gstpushsrc_class->create = gst_niimaq_create;
  gstbasesrc_class->start = gst_niimaq_start;
  gstbasesrc_class->stop = gst_niimaq_stop;
}

static void
gst_niimaq_init (GstNiImaq * src, GstNiImaqClass * g_class)
{
  GstPad *srcpad = GST_BASE_SRC_PAD (src);

  gst_base_src_set_live (GST_BASE_SRC (src), TRUE);
  gst_pad_use_fixed_caps (srcpad);

  src->timestamp_offset = 0;
  src->caps = gst_niimaq_get_all_niimaq_caps ();
  src->bufsize = 10;
  src->n_frames = 0;
  src->cumbufnum = 0;
  src->n_dropped_frames = 0;
  src->buflist = 0;
  src->sid = 0;
  src->iid = 0;
  src->camera_name = g_strdup (DEFAULT_PROP_INTERFACE);
  src->interface_name = g_strdup (DEFAULT_PROP_INTERFACE);

}

static void
gst_niimaq_dispose (GObject * object)
{
  GstNiImaq *src = GST_NIIMAQ (object);

  g_free (src->camera_name);
  src->camera_name = NULL;

  g_free (src->interface_name);
  src->interface_name = NULL;

  G_OBJECT_CLASS (parent_class)->dispose (object);
}

static void
gst_niimaq_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec)
{
  GstNiImaq *src = GST_NIIMAQ (object);

  switch (prop_id) {
    case PROP_INTERFACE:
      if (src->interface_name)
        g_free (src->interface_name);
      src->interface_name = g_strdup (g_value_get_string (value));

      if (src->camera_name)
        g_free (src->camera_name);
      src->camera_name = g_strdup (g_value_get_string (value));
      break;
    case PROP_TIMESTAMP_OFFSET:
      src->timestamp_offset = g_value_get_int64 (value);
      break;
    case PROP_BUFSIZE:
      src->bufsize = g_value_get_int (value);
    default:
      break;
  }
}

static void
gst_niimaq_get_property (GObject * object, guint prop_id, GValue * value,
    GParamSpec * pspec)
{
  GstNiImaq *src = GST_NIIMAQ (object);

  switch (prop_id) {
    case PROP_INTERFACE:
      g_value_set_string (value, src->interface_name);
      break;
    case PROP_TIMESTAMP_OFFSET:
      g_value_set_int64 (value, src->timestamp_offset);
      break;
    case PROP_BUFSIZE:
      g_value_set_int (value, src->bufsize);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static GstCaps *
gst_niimaq_get_caps (GstBaseSrc * bsrc)
{
  GstNiImaq *gsrc;

  gsrc = GST_NIIMAQ (bsrc);

  g_return_val_if_fail (gsrc->caps, NULL);

  return gst_caps_copy (gsrc->caps);
}


static gboolean
gst_niimaq_set_caps (GstBaseSrc * bsrc, GstCaps * caps)
{

  gboolean res = TRUE;
  GstNiImaq *niimaq;
  gint width, height, rate_denominator, rate_numerator;
  gint bpp, depth;

  niimaq = GST_NIIMAQ (bsrc);

  if (niimaq->caps) {
    gst_caps_unref (niimaq->caps);
  }

  niimaq->caps = gst_niimaq_get_cam_caps(niimaq);

  res = gst_niimaq_parse_caps (niimaq->caps, &width, &height,
      &rate_numerator, &rate_denominator, &depth, &bpp);

  if (res) {
    /* looks ok here */
    niimaq->width = width;
    niimaq->height = height;
    niimaq->rate_numerator = rate_numerator;
    niimaq->rate_denominator = rate_denominator;
    niimaq->depth = depth;
    niimaq->bpp = bpp;
    niimaq->framesize = width * height * (depth/8);
  }

  return res;
}

static void
gst_niimaq_get_times (GstBaseSrc * basesrc, GstBuffer * buffer,
    GstClockTime * start, GstClockTime * end)
{
  /* for live sources, sync on the timestamp of the buffer */
  if (gst_base_src_is_live (basesrc)) {
    GstClockTime timestamp = GST_BUFFER_TIMESTAMP (buffer);

    if (GST_CLOCK_TIME_IS_VALID (timestamp)) {
      /* get duration to calculate end time */
      GstClockTime duration = GST_BUFFER_DURATION (buffer);

      if (GST_CLOCK_TIME_IS_VALID (duration)) {
        *end = timestamp + duration;
      }
      *start = timestamp;
    }
  } else {
    *start = -1;
    *end = -1;
  }
}

static GstFlowReturn
gst_niimaq_create (GstPushSrc * psrc, GstBuffer ** buffer)
{
  GstNiImaq *src;
  gpointer data;
  GstCaps *caps;
  GstFlowReturn res = GST_FLOW_OK;
  uInt32 newval, *bufaddr;
  Int32 rval;
  uInt32 dropped;

  src = GST_NIIMAQ (psrc);

  data = g_malloc(src->framesize);

  GST_INFO_OBJECT(src, "Examining buffer %d", src->cumbufnum);
  rval=imgSessionExamineBuffer2(src->sid, src->cumbufnum, &newval, &bufaddr);
  if (rval) {
    GST_ELEMENT_ERROR (src, RESOURCE, FAILED,
      ("failed to examine buffer %d", src->cumbufnum), ("failed to examine buffer %d", src->cumbufnum));
    goto error;
  }

  memcpy (data, (guchar *) bufaddr,
      src->framesize);

  imgSessionReleaseBuffer(src->sid);
  GST_INFO_OBJECT(src, "Releasing buffer %d", newval);

  *buffer = gst_buffer_new ();
  GST_BUFFER_DATA (*buffer) = data;
  GST_BUFFER_MALLOCDATA (*buffer) = data;
  GST_BUFFER_SIZE (*buffer) = src->framesize;

  caps = gst_pad_get_caps (GST_BASE_SRC_PAD (psrc));
  gst_buffer_set_caps (*buffer, caps);
  gst_caps_unref (caps);

  //GST_BUFFER_TIMESTAMP (outbuf) = src->timestamp_offset + src->running_time;
  //if (src->rate_numerator != 0) {
  //  GST_BUFFER_DURATION (outbuf) = gst_util_uint64_scale_int (GST_SECOND,
  //      src->rate_denominator, src->rate_numerator);
  //}

  dropped = newval - src->cumbufnum;
  if(dropped) {
    src->n_dropped_frames += dropped;
    GST_WARNING_OBJECT(src, "Dropped %d frames (%d total)",dropped,src->n_dropped_frames);
  }

  src->cumbufnum = newval + 1;
  src->n_frames++;
  //if (src->rate_numerator != 0) {
  //  src->running_time = gst_util_uint64_scale_int (src->n_frames * GST_SECOND,
  //      src->rate_denominator, src->rate_numerator);
  //}

  return res;

error:
  {
    return GST_FLOW_ERROR;
  }
}


static gboolean
gst_niimaq_parse_caps (const GstCaps * caps,
    gint * width,
    gint * height,
    gint * rate_numerator, gint * rate_denominator, gint * depth, gint * bpp)
{
  const GstStructure *structure;
  GstPadLinkReturn ret;
  const GValue *framerate;

  if (gst_caps_get_size (caps) < 1)
    return FALSE;

  structure = gst_caps_get_structure (caps, 0);

  ret = gst_structure_get_int (structure, "width", width);
  ret &= gst_structure_get_int (structure, "height", height);

  framerate = gst_structure_get_value (structure, "framerate");

  ret &= gst_structure_get_int (structure, "depth", depth);

  ret &= gst_structure_get_int (structure, "bpp", bpp);


  if (framerate) {
    *rate_numerator = gst_value_get_fraction_numerator (framerate);
    *rate_denominator = gst_value_get_fraction_denominator (framerate);
  } else {
    ret = FALSE;
  }

  return ret;
}

/* Set color on caps */
static gboolean
gst_niimaq_set_caps_color (GstStructure * gs, int bpp, int depth)
{
  gboolean ret = TRUE;

  gst_structure_set_name (gs, "video/x-raw-gray");
  gst_structure_set (gs,
      "bpp", G_TYPE_INT, bpp,
      "depth", G_TYPE_INT, depth, NULL);
  if(depth>8)
    gst_structure_set(gs, "endianness", G_TYPE_INT, G_LITTLE_ENDIAN,NULL);

  return ret;
}


static gboolean
gst_niimaq_set_caps_framesize (GstStructure * gs, gint width, gint height)
{
  gst_structure_set (gs,
      "width", G_TYPE_INT, width, "height", G_TYPE_INT, height, NULL);
  return TRUE;
}

GstCaps *
gst_niimaq_get_all_niimaq_caps ()
{
  /* 
     generate all possible caps

   */

  GstCaps *gcaps;
  GstStructure *gs;
  gint i = 0;

  gcaps = gst_caps_new_empty ();

  gs = gst_structure_empty_new ("video");
  gst_structure_set_name (gs, "video/x-raw-gray");
  gst_structure_set (gs,
      "width", GST_TYPE_INT_RANGE, 1, G_MAXINT,
      "height", GST_TYPE_INT_RANGE, 1, G_MAXINT,
      "bpp", GST_TYPE_INT_RANGE, 10, 16,
      "depth", G_TYPE_INT, 16,
      "endianness", G_TYPE_INT, G_LITTLE_ENDIAN,
      "framerate", GST_TYPE_FRACTION_RANGE, 0, 1, G_MAXINT, 1, NULL);
  gst_caps_append_structure (gcaps, gs);

  gs = gst_structure_empty_new ("video");
  gst_structure_set_name (gs, "video/x-raw-gray");
  gst_structure_set (gs,
      "width", GST_TYPE_INT_RANGE, 1, G_MAXINT,
      "height", GST_TYPE_INT_RANGE, 1, G_MAXINT,
      "bpp", G_TYPE_INT, 8,
      "depth", G_TYPE_INT, 8,
      "framerate", GST_TYPE_FRACTION_RANGE, 0, 1, G_MAXINT, 1, NULL);
  gst_caps_append_structure (gcaps, gs);

  return gcaps;
}

GstCaps *
gst_niimaq_get_cam_caps (GstNiImaq * src)
{
  GstCaps *gcaps = NULL;
  Int32 rval;
  uInt32 val;
  int width, height, depth, bpp;
  GstStructure *gs;

  gcaps = gst_caps_new_empty ();

  if (!src->iid) {
    GST_ELEMENT_ERROR (src, RESOURCE, FAILED, ("Camera interface not open"),
        ("Camera interface not open"));
    goto error;
  }

  rval &= imgGetAttribute(src->iid, IMG_ATTR_BITSPERPIXEL, &val);
  bpp = val;
  rval &= imgGetAttribute(src->iid, IMG_ATTR_BYTESPERPIXEL, &val);
  depth = val*8;
  rval &= imgGetAttribute(src->iid, IMG_ATTR_ROI_WIDTH, &val);
  width = val;
  rval &= imgGetAttribute(src->iid, IMG_ATTR_ROI_HEIGHT, &val);
  height = val;

  if (rval) {
    GST_ELEMENT_ERROR (src, STREAM, FAILED,
        ("attempt to read attributes failed"),
        ("attempt to read attributes failed"));
    goto error;
  }

  gs = gst_structure_empty_new ("video");
  if (!gst_niimaq_set_caps_color(gs, bpp, depth) ||
      !gst_niimaq_set_caps_framesize(gs, width, height)) {
    GST_ELEMENT_ERROR (src, STREAM, FAILED,
        ("attempt to set caps %dx%dx%d (%d) failed", width,height,depth, bpp),
        ("attempt to set caps %dx%dx%d (%d) failed", width,height,depth, bpp));
    goto error;
  }

  gst_structure_set(gs, "framerate", GST_TYPE_FRACTION_RANGE, 0, 1, G_MAXINT, 1, NULL);

  gst_caps_append_structure (gcaps, gs);

  return gcaps;

error:

  if (gcaps) {
    gst_caps_unref (gcaps);
  }

  return NULL;
}

static gboolean
gst_niimaq_start (GstBaseSrc * src)
{
  GstNiImaq* filter = GST_NIIMAQ(src);
  Int32 rval;
  int i;

  GST_LOG_OBJECT (filter, "Opening camera interface: %s", filter->interface_name);

  filter->iid = 0;
  filter->sid = 0;

  rval=imgInterfaceOpen(filter->interface_name,&(filter->iid));

  if (rval) {
    GST_ELEMENT_ERROR (filter, RESOURCE, FAILED, ("Failed to open camera interface"),
        ("Failed to open camera interface %s", filter->interface_name));
    goto error;
  }

  GST_LOG_OBJECT (filter, "Opening camera session: %s", filter->interface_name);

  rval=imgSessionOpen(filter->iid, &(filter->sid));
  if (rval) {
    GST_ELEMENT_ERROR (filter, RESOURCE, FAILED, ("Failed to open camera session"),
        ("Failed to open camera session %d", filter->sid));
    goto error;
  }

  GST_LOG_OBJECT (filter, "Creating ring with %d buffers", filter->bufsize);

  filter->buflist = g_new(guint32*, filter->bufsize);
  for(i=0;i<filter->bufsize;i++) {
    filter->buflist[i] = 0;
  }
  rval=imgRingSetup(filter->sid, filter->bufsize, (void**)(filter->buflist), 0, FALSE);
  if(rval) {
    GST_ELEMENT_ERROR (filter, RESOURCE, FAILED, ("Failed to create ring buffer"),
        ("Failed to create ring buffer with %d buffers", filter->bufsize));
    goto error;
  }

  //GST_LOG_OBJECT (filter, "Registering callback functions");
  //rval=imgSessionWaitSignalAsync2(filter->sid, IMG_SIGNAL_STATUS, IMG_BUF_COMPLETE, IMG_SIGNAL_STATE_RISING, Imaq_BUF_COMPLETE, filter);
  //if(rval) {
   // GST_ELEMENT_ERROR (filter, RESOURCE, FAILED, ("Failed to register BUF_COMPLETE callback"),
      //  ("Failed to register BUF_COMPLETE callback"));
   // goto error;
  //}

  GST_LOG_OBJECT (filter, "Starting acquisition");

  rval=imgSessionStartAcquisition(filter->sid);

  i = 0;
  while (rval != 0 && i++ < 5) {
    g_usleep (50000);
    if (rval=imgSessionStartAcquisition(filter->sid)) {
      if (rval != 0) {
        GST_LOG_OBJECT (src, "camera is still off , retrying");
      }
    }
  }

  if (i >= 5) {
    GST_ELEMENT_ERROR (filter, RESOURCE, FAILED,
        ("Camera doesn't seem to want to turn on!"),
        ("Camera doesn't seem to want to turn on!"));
    goto error;
  }

  GST_LOG_OBJECT (src, "got transmision status ON");

  return TRUE;

error:

  if(filter->sid)
    imgClose(filter->sid,TRUE);
  filter->sid = 0;
  if(filter->iid)
    imgClose(filter->iid,TRUE);
  filter->iid = 0;

  return FALSE;;

}


gboolean gst_niimaq_stop( GstBaseSrc * src )
{
  GstNiImaq* filter = GST_NIIMAQ(src);
  Int32 rval;

  rval=imgSessionStopAcquisition(filter->sid);
  if (rval) {
    GST_ELEMENT_ERROR (filter, RESOURCE, FAILED, ("Unable to stop transmision"),
        ("Unable to stop transmision"));
  }

  if(filter->sid)
    imgClose(filter->sid,TRUE);
  filter->sid = 0;
  if(filter->iid)
    imgClose(filter->iid,TRUE);
  filter->iid = 0;

  GST_DEBUG_OBJECT (filter, "Capture stoped");

  return TRUE;
}

static gboolean
plugin_init (GstPlugin * plugin)
{
  GST_DEBUG_CATEGORY_INIT (niimaq_debug, "niimaqsrc", 0, "NI-IMAQ interface");

  return gst_element_register (plugin, "niimaqsrc", GST_RANK_NONE,
      GST_TYPE_NIIMAQ);

}

GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
GST_VERSION_MINOR,
           "niimaq",
           "NI-IMAQ Video Source",
           plugin_init, VERSION, GST_LICENSE, GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN)