gstreamer/sys/dshowsrcwrapper/gstdshowvideosrc.cpp

/* GStreamer
 * Copyright (C)  2007 Sebastien Moutte <sebastien@moutte.net>
 * Copyright (C)  2009 Julien Isorce <julien.isorce@gmail.com>
 *
 * gstdshowvideosrc.c:
 *
 * 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.
 */

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

#include "gstdshowvideosrc.h"

#include <gst/video/video.h>

GST_DEBUG_CATEGORY_STATIC (dshowvideosrc_debug);
#define GST_CAT_DEFAULT dshowvideosrc_debug

static GstStaticPadTemplate src_template = GST_STATIC_PAD_TEMPLATE ("src",
    GST_PAD_SRC,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS (GST_VIDEO_CAPS_BGR ";"
        GST_VIDEO_CAPS_YUV ("{ I420 }") ";"
        GST_VIDEO_CAPS_YUV ("{ YUY2 }") ";"
        "video/x-dv,"
        "systemstream = (boolean) FALSE,"
        "width = (int) [ 1, MAX ],"
        "height = (int) [ 1, MAX ],"
        "framerate = (fraction) [ 0, MAX ],"
        "format = (fourcc) dvsd;" "video/x-dv," "systemstream = (boolean) TRUE")
    );

static void gst_dshowvideosrc_init_interfaces (GType type);

GST_BOILERPLATE_FULL (GstDshowVideoSrc, gst_dshowvideosrc, GstPushSrc,
    GST_TYPE_PUSH_SRC, gst_dshowvideosrc_init_interfaces);

enum
{
  PROP_0,
  PROP_DEVICE,
  PROP_DEVICE_NAME
};

static void gst_dshowvideosrc_probe_interface_init (GstPropertyProbeInterface *
    iface);
static const GList *gst_dshowvideosrc_probe_get_properties (GstPropertyProbe *
    probe);
static GValueArray *gst_dshowvideosrc_probe_get_values (GstPropertyProbe *
    probe, guint prop_id, const GParamSpec * pspec);
static GValueArray *gst_dshowvideosrc_get_device_name_values (GstDshowVideoSrc *
    src);
static gboolean gst_dshowvideosrc_probe_needs_probe (GstPropertyProbe * probe,
    guint prop_id, const GParamSpec * pspec);
static void gst_dshowvideosrc_probe_probe_property (GstPropertyProbe * probe,
    guint prop_id, const GParamSpec * pspec);


static void gst_dshowvideosrc_dispose (GObject * gobject);
static void gst_dshowvideosrc_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec);
static void gst_dshowvideosrc_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec);
static GstCaps *gst_dshowvideosrc_get_caps (GstBaseSrc * src);
static GstStateChangeReturn gst_dshowvideosrc_change_state (GstElement *
    element, GstStateChange transition);


static gboolean gst_dshowvideosrc_start (GstBaseSrc * bsrc);
static gboolean gst_dshowvideosrc_stop (GstBaseSrc * bsrc);
static gboolean gst_dshowvideosrc_unlock (GstBaseSrc * bsrc);
static gboolean gst_dshowvideosrc_unlock_stop (GstBaseSrc * bsrc);
static gboolean gst_dshowvideosrc_set_caps (GstBaseSrc * bsrc, GstCaps * caps);
static GstCaps *gst_dshowvideosrc_get_caps (GstBaseSrc * bsrc);
static void gst_dshowvideosrc_src_fixate (GstBaseSrc * bsrc, GstCaps * caps);
static GstFlowReturn gst_dshowvideosrc_create (GstPushSrc * psrc,
    GstBuffer ** buf);

/*utils*/
static GstCaps *gst_dshowvideosrc_getcaps_from_streamcaps (GstDshowVideoSrc *
    src, IPin * pin);
static GstCaps *gst_dshowvideosrc_getcaps_from_enum_mediatypes (GstDshowVideoSrc *
    src, IPin * pin);
static gboolean gst_dshowvideosrc_push_buffer (guint8 * buffer, guint size,
    gpointer src_object, GstClockTime duration);

static void
gst_dshowvideosrc_init_interfaces (GType type)
{
  static const GInterfaceInfo dshowvideosrc_info = {
    (GInterfaceInitFunc) gst_dshowvideosrc_probe_interface_init,
    NULL,
    NULL,
  };

  g_type_add_interface_static (type,
      GST_TYPE_PROPERTY_PROBE, &dshowvideosrc_info);
}

static void
gst_dshowvideosrc_probe_interface_init (GstPropertyProbeInterface * iface)
{
  iface->get_properties = gst_dshowvideosrc_probe_get_properties;
  iface->needs_probe = gst_dshowvideosrc_probe_needs_probe;
  iface->probe_property = gst_dshowvideosrc_probe_probe_property;
  iface->get_values = gst_dshowvideosrc_probe_get_values;
}

static void
gst_dshowvideosrc_base_init (gpointer klass)
{
  GstElementClass *element_class = GST_ELEMENT_CLASS (klass);

  gst_element_class_add_pad_template (element_class,
      gst_static_pad_template_get (&src_template));

  gst_element_class_set_details_simple (element_class,
      "DirectShow video capture source", "Source/Video",
      "Receive data from a directshow video capture graph",
      "Sebastien Moutte <sebastien@moutte.net>");
}

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

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

  gobject_class->dispose = GST_DEBUG_FUNCPTR (gst_dshowvideosrc_dispose);
  gobject_class->set_property =
      GST_DEBUG_FUNCPTR (gst_dshowvideosrc_set_property);
  gobject_class->get_property =
      GST_DEBUG_FUNCPTR (gst_dshowvideosrc_get_property);

  gstelement_class->change_state =
      GST_DEBUG_FUNCPTR (gst_dshowvideosrc_change_state);

  gstbasesrc_class->get_caps = GST_DEBUG_FUNCPTR (gst_dshowvideosrc_get_caps);
  gstbasesrc_class->set_caps = GST_DEBUG_FUNCPTR (gst_dshowvideosrc_set_caps);
  gstbasesrc_class->fixate = GST_DEBUG_FUNCPTR (gst_dshowvideosrc_src_fixate);
  gstbasesrc_class->start = GST_DEBUG_FUNCPTR (gst_dshowvideosrc_start);
  gstbasesrc_class->stop = GST_DEBUG_FUNCPTR (gst_dshowvideosrc_stop);
  gstbasesrc_class->unlock = GST_DEBUG_FUNCPTR (gst_dshowvideosrc_unlock);
  gstbasesrc_class->unlock_stop =
      GST_DEBUG_FUNCPTR (gst_dshowvideosrc_unlock_stop);

  gstpushsrc_class->create = GST_DEBUG_FUNCPTR (gst_dshowvideosrc_create);

  g_object_class_install_property
      (gobject_class, PROP_DEVICE,
      g_param_spec_string ("device", "Device",
          "Directshow device path (@..classID/name)", NULL,
          static_cast < GParamFlags > (G_PARAM_READWRITE)));

  g_object_class_install_property
      (gobject_class, PROP_DEVICE_NAME,
      g_param_spec_string ("device-name", "Device name",
          "Human-readable name of the sound device", NULL,
          static_cast < GParamFlags > (G_PARAM_READWRITE)));

  GST_DEBUG_CATEGORY_INIT (dshowvideosrc_debug, "dshowvideosrc", 0,
      "Directshow video source");

}

static void
gst_dshowvideosrc_init (GstDshowVideoSrc * src, GstDshowVideoSrcClass * klass)
{
  src->device = NULL;
  src->device_name = NULL;
  src->video_cap_filter = NULL;
  src->dshow_fakesink = NULL;
  src->media_filter = NULL;
  src->filter_graph = NULL;
  src->caps = NULL;
  src->pins_mediatypes = NULL;
  src->is_rgb = FALSE;

  src->buffer_cond = g_cond_new ();
  src->buffer_mutex = g_mutex_new ();
  src->buffer = NULL;
  src->stop_requested = FALSE;

  CoInitializeEx (NULL, COINIT_MULTITHREADED);

  gst_base_src_set_live (GST_BASE_SRC (src), TRUE);
}

static void
gst_dshowvideosrc_src_fixate (GstBaseSrc * bsrc, GstCaps * caps)
{
  /* If there is no desired video size, set default video size to device preffered video size */

  GstDshowVideoSrc *src = GST_DSHOWVIDEOSRC (bsrc);
  GstStructure *structure = gst_caps_get_structure (caps, 0);
  guint i = 0;
  gint res = -1;

  for (; i < gst_caps_get_size (src->caps) && res == -1; i++) {
    GstCaps *capstmp = gst_caps_copy_nth (src->caps, i);

    if (gst_caps_is_subset (caps, capstmp)) {
      res = i;
    }
    gst_caps_unref (capstmp);
  }

  if (res != -1) {
    GList *type_pin_mediatype = g_list_nth (src->pins_mediatypes, res);
    if (type_pin_mediatype) {
      GstCapturePinMediaType *pin_mediatype =
          (GstCapturePinMediaType *) type_pin_mediatype->data;
      gst_structure_fixate_field_nearest_int (structure, "width",
          pin_mediatype->defaultWidth);
      gst_structure_fixate_field_nearest_int (structure, "height",
          pin_mediatype->defaultHeight);
      gst_structure_fixate_field_nearest_fraction (structure, "framerate",
          pin_mediatype->defaultFPS, 1);
    }
  }
}

static void
gst_dshowvideosrc_dispose (GObject * gobject)
{
  GstDshowVideoSrc *src = GST_DSHOWVIDEOSRC (gobject);

  if (src->device) {
    g_free (src->device);
    src->device = NULL;
  }

  if (src->device_name) {
    g_free (src->device_name);
    src->device_name = NULL;
  }

  if (src->caps) {
    gst_caps_unref (src->caps);
    src->caps = NULL;
  }

  if (src->pins_mediatypes) {
    gst_dshow_free_pins_mediatypes (src->pins_mediatypes);
    src->pins_mediatypes = NULL;
  }

  /* clean dshow */
  if (src->video_cap_filter) {
    src->video_cap_filter->Release ();
    src->video_cap_filter = NULL;
  }

  if (src->buffer_mutex) {
    g_mutex_free (src->buffer_mutex);
    src->buffer_mutex = NULL;
  }

  if (src->buffer_cond) {
    g_cond_free (src->buffer_cond);
    src->buffer_cond = NULL;
  }

  if (src->buffer) {
    gst_buffer_unref (src->buffer);
    src->buffer = NULL;
  }

  CoUninitialize ();

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

static gboolean
gst_dshowvideosrc_probe_needs_probe (GstPropertyProbe * probe,
    guint prop_id, const GParamSpec * pspec)
{
  static gboolean init = FALSE;
  gboolean ret = FALSE;

  if (!init) {
    ret = TRUE;
    init = TRUE;
  }

  return ret;
}

static void
gst_dshowvideosrc_probe_probe_property (GstPropertyProbe * probe,
    guint prop_id, const GParamSpec * pspec)
{
  GObjectClass *klass = G_OBJECT_GET_CLASS (probe);

  switch (prop_id) {
    case PROP_DEVICE_NAME:
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (probe, prop_id, pspec);
      break;
  }
}

static const GList *
gst_dshowvideosrc_probe_get_properties (GstPropertyProbe * probe)
{
  GObjectClass *klass = G_OBJECT_GET_CLASS (probe);
  static GList *props = NULL;

  if (!props) {
    GParamSpec *pspec;

    pspec = g_object_class_find_property (klass, "device-name");
    props = g_list_append (props, pspec);
  }

  return props;
}

static GValueArray *
gst_dshowvideosrc_get_device_name_values (GstDshowVideoSrc * src)
{
  GValueArray *array = g_value_array_new (0);
  ICreateDevEnum *devices_enum = NULL;
  IEnumMoniker *moniker_enum = NULL;
  IMoniker *moniker = NULL;
  HRESULT hres = S_FALSE;
  ULONG fetched;

  hres = CoCreateInstance (CLSID_SystemDeviceEnum, NULL, CLSCTX_INPROC_SERVER,
      IID_ICreateDevEnum, (LPVOID *) & devices_enum);
  if (hres != S_OK) {
    GST_ERROR ("Can't create system device enumerator (error=0x%x)", hres);
    array = NULL;
    goto clean;
  }

  hres = devices_enum->CreateClassEnumerator (CLSID_VideoInputDeviceCategory,
      &moniker_enum, 0);
  if (hres != S_OK || !moniker_enum) {
    GST_ERROR ("Can't get enumeration of video devices (error=0x%x)", hres);
    array = NULL;
    goto clean;
  }

  moniker_enum->Reset ();

  while (hres = moniker_enum->Next (1, &moniker, &fetched), hres == S_OK) {
    IPropertyBag *property_bag = NULL;

    hres =
        moniker->BindToStorage (NULL, NULL, IID_IPropertyBag,
        (LPVOID *) & property_bag);
    if (SUCCEEDED (hres) && property_bag) {
      VARIANT varFriendlyName;

      VariantInit (&varFriendlyName);
      hres = property_bag->Read (L"FriendlyName", &varFriendlyName, NULL);
      if (hres == S_OK && varFriendlyName.bstrVal) {
        gchar *friendly_name =
            g_utf16_to_utf8 ((const gunichar2 *) varFriendlyName.bstrVal,
            wcslen (varFriendlyName.bstrVal), NULL, NULL, NULL);

        GValue value = { 0 };
        g_value_init (&value, G_TYPE_STRING);
        g_value_set_string (&value, friendly_name);
        g_value_array_append (array, &value);
        g_value_unset (&value);
        g_free (friendly_name);
        SysFreeString (varFriendlyName.bstrVal);
      }
      property_bag->Release ();
    }
    moniker->Release ();
  }

clean:
  if (moniker_enum)
    moniker_enum->Release ();

  if (devices_enum)
    devices_enum->Release ();

  return array;
}

static GValueArray *
gst_dshowvideosrc_probe_get_values (GstPropertyProbe * probe,
    guint prop_id, const GParamSpec * pspec)
{
  GstDshowVideoSrc *src = GST_DSHOWVIDEOSRC (probe);
  GValueArray *array = NULL;

  switch (prop_id) {
    case PROP_DEVICE_NAME:
      array = gst_dshowvideosrc_get_device_name_values (src);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (probe, prop_id, pspec);
      break;
  }

  return array;
}

static void
gst_dshowvideosrc_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec)
{
  GstDshowVideoSrc *src = GST_DSHOWVIDEOSRC (object);

  switch (prop_id) {
    case PROP_DEVICE:
    {
      if (src->device) {
        g_free (src->device);
        src->device = NULL;
      }
      if (g_value_get_string (value)) {
        src->device = g_strdup (g_value_get_string (value));
      }
      break;
    }
    case PROP_DEVICE_NAME:
    {
      if (src->device_name) {
        g_free (src->device_name);
        src->device_name = NULL;
      }
      if (g_value_get_string (value)) {
        src->device_name = g_strdup (g_value_get_string (value));
      }
      break;
    }
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static void
gst_dshowvideosrc_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec)
{

}

static GstCaps *
gst_dshowvideosrc_get_caps (GstBaseSrc * basesrc)
{
  HRESULT hres = S_OK;
  IBindCtx *lpbc = NULL;
  IMoniker *videom;
  DWORD dwEaten;
  GstDshowVideoSrc *src = GST_DSHOWVIDEOSRC (basesrc);
  gunichar2 *unidevice = NULL;

  if (src->caps) {
    return gst_caps_ref (src->caps);
  }

  if (!src->device) {
    src->device =
        gst_dshow_getdevice_from_devicename (&CLSID_VideoInputDeviceCategory,
        &src->device_name);
    if (!src->device) {
      GST_ERROR ("No video device found.");
      return NULL;
    }
  }

  unidevice =
      g_utf8_to_utf16 (src->device, strlen (src->device), NULL, NULL, NULL);

  if (!src->video_cap_filter) {
    hres = CreateBindCtx (0, &lpbc);
    if (SUCCEEDED (hres)) {
      hres =
          MkParseDisplayName (lpbc, (LPCOLESTR) unidevice, &dwEaten, &videom);
      if (SUCCEEDED (hres)) {
        hres = videom->BindToObject (lpbc, NULL, IID_IBaseFilter,
            (LPVOID *) & src->video_cap_filter);
        videom->Release ();
      }
      lpbc->Release ();
    }
  }

  if (!src->caps) {
    src->caps = gst_caps_new_empty ();
  }

  if (src->video_cap_filter && gst_caps_is_empty (src->caps)) {
    /* get the capture pins supported types */
    IPin *capture_pin = NULL;
    IEnumPins *enumpins = NULL;
    HRESULT hres;

    hres = src->video_cap_filter->EnumPins (&enumpins);
    if (SUCCEEDED (hres)) {
      while (enumpins->Next (1, &capture_pin, NULL) == S_OK) {
        IKsPropertySet *pKs = NULL;
        hres =
            capture_pin->QueryInterface (IID_IKsPropertySet, (LPVOID *) & pKs);
        if (SUCCEEDED (hres) && pKs) {
          DWORD cbReturned;
          GUID pin_category;
          RPC_STATUS rpcstatus;

          hres =
              pKs->Get (AMPROPSETID_Pin,
              AMPROPERTY_PIN_CATEGORY, NULL, 0, &pin_category, sizeof (GUID),
              &cbReturned);

          /* we only want capture pins */
          if (UuidCompare (&pin_category, (UUID *) & PIN_CATEGORY_CAPTURE,
                  &rpcstatus) == 0) {
            {
              GstCaps *caps =
                  gst_dshowvideosrc_getcaps_from_streamcaps (src, capture_pin);
              if (caps) {
                gst_caps_append (src->caps, caps);
              } else {
                caps = gst_dshowvideosrc_getcaps_from_enum_mediatypes (src, capture_pin);
                if (caps)
                  gst_caps_append (src->caps, caps);
              }
            }
          }
          pKs->Release ();
        }
        capture_pin->Release ();
      }
      enumpins->Release ();
    }
  }

  if (unidevice) {
    g_free (unidevice);
  }

  if (src->caps) {
    return gst_caps_ref (src->caps);
  }

  return NULL;
}

static GstStateChangeReturn
gst_dshowvideosrc_change_state (GstElement * element, GstStateChange transition)
{
  HRESULT hres = S_FALSE;
  GstDshowVideoSrc *src = GST_DSHOWVIDEOSRC (element);

  switch (transition) {
    case GST_STATE_CHANGE_NULL_TO_READY:
      break;
    case GST_STATE_CHANGE_READY_TO_PAUSED:
      break;
    case GST_STATE_CHANGE_PAUSED_TO_PLAYING:
      if (src->media_filter)
        hres = src->media_filter->Run (0);
      if (hres != S_OK) {
        GST_ERROR ("Can't RUN the directshow capture graph (error=0x%x)", hres);
        return GST_STATE_CHANGE_FAILURE;
      }
      break;
    case GST_STATE_CHANGE_PLAYING_TO_PAUSED:
      if (src->media_filter)
        hres = src->media_filter->Stop ();
      if (hres != S_OK) {
        GST_ERROR ("Can't STOP the directshow capture graph (error=%d)", hres);
        return GST_STATE_CHANGE_FAILURE;
      }
      break;
    case GST_STATE_CHANGE_PAUSED_TO_READY:
      break;
    case GST_STATE_CHANGE_READY_TO_NULL:
      break;
  }

  return GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
}

static gboolean
gst_dshowvideosrc_start (GstBaseSrc * bsrc)
{
  HRESULT hres = S_FALSE;
  GstDshowVideoSrc *src = GST_DSHOWVIDEOSRC (bsrc);

  hres = CoCreateInstance (CLSID_FilterGraph, NULL, CLSCTX_INPROC,
      IID_IFilterGraph, (LPVOID *) & src->filter_graph);
  if (hres != S_OK || !src->filter_graph) {
    GST_ERROR
        ("Can't create an instance of the dshow graph manager (error=0x%x)",
        hres);
    goto error;
  }

  hres = src->filter_graph->QueryInterface (IID_IMediaFilter,
      (LPVOID *) & src->media_filter);
  if (hres != S_OK || !src->media_filter) {
    GST_ERROR
        ("Can't get IMediacontrol interface from the graph manager (error=0x%x)",
        hres);
    goto error;
  }

  src->dshow_fakesink = new CDshowFakeSink;
  src->dshow_fakesink->AddRef ();

  hres = src->filter_graph->AddFilter (src->video_cap_filter, L"capture");
  if (hres != S_OK) {
    GST_ERROR ("Can't add video capture filter to the graph (error=0x%x)",
        hres);
    goto error;
  }

  hres = src->filter_graph->AddFilter (src->dshow_fakesink, L"sink");
  if (hres != S_OK) {
    GST_ERROR ("Can't add our fakesink filter to the graph (error=0x%x)", hres);
    goto error;
  }

  return TRUE;

error:
  if (src->dshow_fakesink) {
    src->dshow_fakesink->Release ();
    src->dshow_fakesink = NULL;
  }

  if (src->media_filter) {
    src->media_filter->Release ();
    src->media_filter = NULL;
  }
  if (src->filter_graph) {
    src->filter_graph->Release ();
    src->filter_graph = NULL;
  }

  return FALSE;
}

static gboolean
gst_dshowvideosrc_set_caps (GstBaseSrc * bsrc, GstCaps * caps)
{
  HRESULT hres;
  IPin *input_pin = NULL;
  GstDshowVideoSrc *src = GST_DSHOWVIDEOSRC (bsrc);
  GstStructure *s = gst_caps_get_structure (caps, 0);

  /* search the negociated caps in our caps list to get its index and the corresponding mediatype */
  if (gst_caps_is_subset (caps, src->caps)) {
    guint i = 0;
    gint res = -1;

    for (; i < gst_caps_get_size (src->caps) && res == -1; i++) {
      GstCaps *capstmp = gst_caps_copy_nth (src->caps, i);

      if (gst_caps_is_subset (caps, capstmp)) {
        res = i;
      }
      gst_caps_unref (capstmp);
    }

    if (res != -1 && src->pins_mediatypes) {
      /* get the corresponding media type and build the dshow graph */
      GList *type_pin_mediatype = g_list_nth (src->pins_mediatypes, res);

      if (type_pin_mediatype) {
        GstCapturePinMediaType *pin_mediatype =
            (GstCapturePinMediaType *) type_pin_mediatype->data;
        gchar *caps_string = NULL;
        gchar *src_caps_string = NULL;

        /* retrieve the desired video size */
        VIDEOINFOHEADER *video_info = NULL;
        gint width = 0;
        gint height = 0;
        gint numerator = 0;
        gint denominator = 0;
        gst_structure_get_int (s, "width", &width);
        gst_structure_get_int (s, "height", &height);
        gst_structure_get_fraction (s, "framerate", &numerator, &denominator);

        /* check if the desired video size is valid about granularity  */
        /* This check will be removed when GST_TYPE_INT_RANGE_STEP exits */
        /* See remarks in gst_dshow_new_video_caps function */
        if (pin_mediatype->granularityWidth != 0
            && width % pin_mediatype->granularityWidth != 0)
          g_warning ("your desired video size is not valid : %d mod %d !=0\n",
              width, pin_mediatype->granularityWidth);
        if (pin_mediatype->granularityHeight != 0
            && height % pin_mediatype->granularityHeight != 0)
          g_warning ("your desired video size is not valid : %d mod %d !=0\n",
              height, pin_mediatype->granularityHeight);

        /* update mediatype */
        video_info = (VIDEOINFOHEADER *) pin_mediatype->mediatype->pbFormat;
        video_info->bmiHeader.biWidth = width;
        video_info->bmiHeader.biHeight = height;
        video_info->AvgTimePerFrame =
            (LONGLONG) (10000000 * denominator / (double) numerator);
        video_info->bmiHeader.biSizeImage = DIBSIZE (video_info->bmiHeader);
        pin_mediatype->mediatype->lSampleSize = DIBSIZE (video_info->bmiHeader);

        src->dshow_fakesink->gst_set_media_type (pin_mediatype->mediatype);
        src->dshow_fakesink->gst_set_buffer_callback (
            (push_buffer_func) gst_dshowvideosrc_push_buffer, src);

        gst_dshow_get_pin_from_filter (src->dshow_fakesink, PINDIR_INPUT,
            &input_pin);
        if (!input_pin) {
          GST_ERROR ("Can't get input pin from our dshow fakesink");
          goto error;
        }

        hres = src->filter_graph->ConnectDirect (pin_mediatype->capture_pin,
            input_pin, pin_mediatype->mediatype);
        input_pin->Release ();

        if (hres != S_OK) {
          GST_ERROR
              ("Can't connect capture filter with fakesink filter (error=0x%x)",
              hres);
          goto error;
        }

        /* save width and height negociated */
        gst_structure_get_int (s, "width", &src->width);
        gst_structure_get_int (s, "height", &src->height);

        src->is_rgb = FALSE;
        caps_string = gst_caps_to_string (caps);
        if (caps_string) {
          if (strstr (caps_string, "video/x-raw-rgb")) {
            src->is_rgb = TRUE;
          } else {
            src->is_rgb = FALSE;
          }
          g_free (caps_string);
        }
      }
    }
  }

  return TRUE;

error:
  return FALSE;
}

static gboolean
gst_dshowvideosrc_stop (GstBaseSrc * bsrc)
{
  IPin *input_pin = NULL, *output_pin = NULL;
  HRESULT hres = S_FALSE;
  GstDshowVideoSrc *src = GST_DSHOWVIDEOSRC (bsrc);

  if (!src->filter_graph)
    return TRUE;

  /* disconnect filters */
  gst_dshow_get_pin_from_filter (src->video_cap_filter, PINDIR_OUTPUT,
      &output_pin);
  if (output_pin) {
    hres = src->filter_graph->Disconnect (output_pin);
    output_pin->Release ();
  }

  gst_dshow_get_pin_from_filter (src->dshow_fakesink, PINDIR_INPUT, &input_pin);
  if (input_pin) {
    hres = src->filter_graph->Disconnect (input_pin);
    input_pin->Release ();
  }

  /* remove filters from the graph */
  src->filter_graph->RemoveFilter (src->video_cap_filter);
  src->filter_graph->RemoveFilter (src->dshow_fakesink);

  /* release our gstreamer dshow sink */
  src->dshow_fakesink->Release ();
  src->dshow_fakesink = NULL;

  /* release media filter interface */
  src->media_filter->Release ();
  src->media_filter = NULL;

  /* release the filter graph manager */
  src->filter_graph->Release ();
  src->filter_graph = NULL;

  /* reset caps */
  if (src->caps) {
    gst_caps_unref (src->caps);
    src->caps = NULL;
  }

  /* reset device id */
  if (src->device) {
    g_free (src->device);
    src->device = NULL;
  }
  
  return TRUE;
}

static gboolean
gst_dshowvideosrc_unlock (GstBaseSrc * bsrc)
{
  GstDshowVideoSrc *src = GST_DSHOWVIDEOSRC (bsrc);

  g_mutex_lock (src->buffer_mutex);
  src->stop_requested = TRUE;
  g_cond_signal (src->buffer_cond);
  g_mutex_unlock (src->buffer_mutex);

  return TRUE;
}

static gboolean
gst_dshowvideosrc_unlock_stop (GstBaseSrc * bsrc)
{
  GstDshowVideoSrc *src = GST_DSHOWVIDEOSRC (bsrc);

  src->stop_requested = FALSE;

  return TRUE;
}

static GstFlowReturn
gst_dshowvideosrc_create (GstPushSrc * psrc, GstBuffer ** buf)
{
  GstDshowVideoSrc *src = GST_DSHOWVIDEOSRC (psrc);

  g_mutex_lock (src->buffer_mutex);
  while (src->buffer == NULL && !src->stop_requested)
    g_cond_wait (src->buffer_cond, src->buffer_mutex);
  *buf = src->buffer;
  src->buffer = NULL;
  g_mutex_unlock (src->buffer_mutex);

  if (src->stop_requested) {
    if (*buf != NULL) {
      gst_buffer_unref (*buf);
      *buf = NULL;
    }
    return GST_FLOW_FLUSHING;
  }

  GST_DEBUG ("dshowvideosrc_create => pts %" GST_TIME_FORMAT " duration %"
      GST_TIME_FORMAT, GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (*buf)),
      GST_TIME_ARGS (GST_BUFFER_DURATION (*buf)));

  return GST_FLOW_OK;
}

static GstCaps *
gst_dshowvideosrc_getcaps_from_streamcaps (GstDshowVideoSrc * src, IPin * pin)
{
  GstCaps *caps = NULL;
  HRESULT hres = S_OK;
  int icount = 0;
  int isize = 0;
  VIDEO_STREAM_CONFIG_CAPS vscc;
  int i = 0;
  IAMStreamConfig *streamcaps = NULL;

  hres = pin->QueryInterface (IID_IAMStreamConfig, (LPVOID *) & streamcaps);
  if (FAILED (hres)) {
    GST_ERROR ("Failed to retrieve IAMStreamConfig (error=0x%x)", hres);
    return NULL;
  }

  streamcaps->GetNumberOfCapabilities (&icount, &isize);

  if (isize != sizeof (vscc)) {
    streamcaps->Release ();
    return NULL;
  }

  caps = gst_caps_new_empty ();

  for (i = 0; i < icount; i++) {

    GstCapturePinMediaType *pin_mediatype =
      gst_dshow_new_pin_mediatype_from_streamcaps (pin, i, streamcaps);

    if (pin_mediatype) {

      GstCaps *mediacaps = NULL;
      GstVideoFormat video_format = 
        gst_dshow_guid_to_gst_video_format (pin_mediatype->mediatype);

      if (video_format != GST_VIDEO_FORMAT_UNKNOWN) {
        mediacaps = gst_dshow_new_video_caps (video_format, NULL,
            pin_mediatype);

      } else if (gst_dshow_check_mediatype (pin_mediatype->mediatype,
              MEDIASUBTYPE_dvsd, FORMAT_VideoInfo)) {
        mediacaps =
            gst_dshow_new_video_caps (GST_VIDEO_FORMAT_UNKNOWN,
            "video/x-dv, systemstream=FALSE", pin_mediatype);

      } else if (gst_dshow_check_mediatype (pin_mediatype->mediatype,
              MEDIASUBTYPE_dvsd, FORMAT_DvInfo)) {
        mediacaps =
            gst_dshow_new_video_caps (GST_VIDEO_FORMAT_UNKNOWN,
            "video/x-dv, systemstream=TRUE", pin_mediatype);

        pin_mediatype->granularityWidth = 0;
        pin_mediatype->granularityHeight = 0;
      }

      if (mediacaps) {
        src->pins_mediatypes =
            g_list_append (src->pins_mediatypes, pin_mediatype);
        gst_caps_append (caps, mediacaps);
      } else {
        /* failed to convert dshow caps */
        gst_dshow_free_pin_mediatype (pin_mediatype);
      }
    }
  }

  streamcaps->Release ();

  if (caps && gst_caps_is_empty (caps)) {
    gst_caps_unref (caps);
    caps = NULL;
  }

  return caps;
}

static GstCaps *
gst_dshowvideosrc_getcaps_from_enum_mediatypes (GstDshowVideoSrc * src, IPin * pin)
{
  GstCaps *caps = NULL;
  IEnumMediaTypes *enum_mediatypes = NULL;
  HRESULT hres = S_OK;
  GstCapturePinMediaType *pin_mediatype = NULL;

  hres = pin->EnumMediaTypes (&enum_mediatypes);
  if (FAILED (hres)) {
    GST_ERROR ("Failed to retrieve IEnumMediaTypes (error=0x%x)", hres);
    return NULL;
  }

  caps = gst_caps_new_empty ();

  while ((pin_mediatype = gst_dshow_new_pin_mediatype_from_enum_mediatypes (pin, enum_mediatypes)) != NULL) {

    GstCaps *mediacaps = NULL;
    GstVideoFormat video_format = gst_dshow_guid_to_gst_video_format (pin_mediatype->mediatype);

    if (video_format != GST_VIDEO_FORMAT_UNKNOWN)
      mediacaps = gst_video_format_new_caps (video_format, 
          pin_mediatype->defaultWidth, pin_mediatype->defaultHeight,
          pin_mediatype->defaultFPS, 1, 1, 1);

    if (mediacaps) {
      src->pins_mediatypes =
          g_list_append (src->pins_mediatypes, pin_mediatype);
      gst_caps_append (caps, mediacaps);
    } else {
      /* failed to convert dshow caps */
      gst_dshow_free_pin_mediatype (pin_mediatype);
    }
  }

  enum_mediatypes->Release ();

  if (caps && gst_caps_is_empty (caps)) {
    gst_caps_unref (caps);
    caps = NULL;
  }

  return caps;
}

static gboolean
gst_dshowvideosrc_push_buffer (guint8 * buffer, guint size, gpointer src_object,
    GstClockTime duration)
{
  GstDshowVideoSrc *src = GST_DSHOWVIDEOSRC (src_object);
  GstBuffer *buf = NULL;
  IPin *pPin = NULL;
  HRESULT hres = S_FALSE;
  AM_MEDIA_TYPE *pMediaType = NULL;

  if (!buffer || size == 0 || !src) {
    return FALSE;
  }

  /* create a new buffer assign to it the clock time as timestamp */
  buf = gst_buffer_new_and_alloc (size);

  GST_BUFFER_SIZE (buf) = size;

  GstClock *clock = gst_element_get_clock (GST_ELEMENT (src));
  GST_BUFFER_TIMESTAMP (buf) =
    GST_CLOCK_DIFF (gst_element_get_base_time (GST_ELEMENT (src)), gst_clock_get_time (clock));
  gst_object_unref (clock);

  GST_BUFFER_DURATION (buf) = duration;

  if (src->is_rgb) {
    /* FOR RGB directshow decoder will return bottom-up BITMAP
     * There is probably a way to get top-bottom video frames from
     * the decoder...
     */
    gint line = 0;
    gint stride = size / src->height;

    for (; line < src->height; line++) {
      memcpy (GST_BUFFER_DATA (buf) + (line * stride),
          buffer + (size - ((line + 1) * (stride))), stride);
    }
  } else {
    memcpy (GST_BUFFER_DATA (buf), buffer, size);
  }

  GST_DEBUG ("push_buffer => pts %" GST_TIME_FORMAT "duration %"
      GST_TIME_FORMAT, GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (buf)),
      GST_TIME_ARGS (duration));

  /* the negotiate() method already set caps on the source pad */
  gst_buffer_set_caps (buf, GST_PAD_CAPS (GST_BASE_SRC_PAD (src)));

  g_mutex_lock (src->buffer_mutex);
  if (src->buffer != NULL)
    gst_buffer_unref (src->buffer);
  src->buffer = buf;
  g_cond_signal (src->buffer_cond);
  g_mutex_unlock (src->buffer_mutex);

  return TRUE;
}