gstoddsrc.c

/*
 * gcc gstoddsrc.c `pkg-config --cflags --libs gstreamer-1.0 gstreamer-base-1.0 gstreamer-video-1.0` -shared -o gstoddsrc.so
 *
 * GST_DEBUG=2 gst-launch-1.0 oddsrc ! video/x-raw,format=BGR,width=321,height=240 ! videoconvert ! autovideosink
 *
 *
 */
#include <gst/gst.h>
#include <gst/base/gstpushsrc.h>
#include <gst/video/video.h>

#define GST_TYPE_ODD_SRC   (gst_odd_src_get_type())
G_DECLARE_FINAL_TYPE (GstOddSrc, gst_odd_src, GST, ODD_SRC, GstPushSrc)

struct _GstOddSrc
{
  GstPushSrc base_odd_src;

};

GST_DEBUG_CATEGORY_STATIC (gst_odd_src_debug_category);
#define GST_CAT_DEFAULT gst_odd_src_debug_category

/* prototypes */

GType gst_odd_src_get_type (void);
static GstFlowReturn gst_odd_src_alloc(GstPushSrc *src, GstBuffer **buf);
static GstFlowReturn gst_odd_src_fill (GstPushSrc * src, GstBuffer * buf);

enum
{
  PROP_0
};

/* pad templates */

static GstStaticPadTemplate gst_odd_src_src_template =
GST_STATIC_PAD_TEMPLATE ("src",
    GST_PAD_SRC,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS ("video/x-raw,width=321,height=240,format=BGR,framerate=30/1")
    );


/* class initialization */

G_DEFINE_TYPE_WITH_CODE (GstOddSrc, gst_odd_src, GST_TYPE_PUSH_SRC,
    GST_DEBUG_CATEGORY_INIT (gst_odd_src_debug_category, "oddsrc", 0,
        "debug category for oddsrc element"));

static void
gst_odd_src_class_init (GstOddSrcClass * klass)
{
  GstPushSrcClass *push_src_class = GST_PUSH_SRC_CLASS (klass);

  /* Setting up pads and setting metadata should be moved to
     base_class_init if you intend to subclass this class. */
  gst_element_class_add_static_pad_template (GST_ELEMENT_CLASS (klass),
      &gst_odd_src_src_template);

  gst_element_class_set_static_metadata (GST_ELEMENT_CLASS (klass),
      "Odd Src", "Generic", "Send frames with odd widths and no stride",
      "Michael Gruner <michael.gruner@ridgerun.com>");

  push_src_class->alloc = GST_DEBUG_FUNCPTR (gst_odd_src_alloc);
  push_src_class->fill = GST_DEBUG_FUNCPTR (gst_odd_src_fill);

}

static void
gst_odd_src_init (GstOddSrc * oddsrc)
{
  gst_base_src_set_format (GST_BASE_SRC(oddsrc), GST_FORMAT_TIME);
  gst_base_src_set_live (GST_BASE_SRC(oddsrc), TRUE);
}

static GstFlowReturn
gst_odd_src_alloc (GstPushSrc * src, GstBuffer ** buf)
{
  GstOddSrc *self = GST_ODD_SRC (src);
  gint size = 321*240*3;

  *buf = gst_buffer_new_allocate (NULL, size, NULL);

  return GST_FLOW_OK;
}

static GstFlowReturn
gst_odd_src_fill (GstPushSrc * src, GstBuffer * buf)
{
  GstOddSrc *self = GST_ODD_SRC (src);
  gsize offset[GST_VIDEO_MAX_PLANES] = { 0 };
  gint stride[GST_VIDEO_MAX_PLANES] = { 321*3, 0, 0, 0 };
  GstMapInfo info = { 0 };
  GstVideoMeta *meta = NULL;

  meta =   gst_buffer_add_video_meta_full (buf, GST_VIDEO_FRAME_FLAG_NONE, GST_VIDEO_FORMAT_BGR,
					   321, 240, 1, offset, stride);


  gst_buffer_map (buf, &info, GST_MAP_WRITE);
  memset (info.data, 0, info.size);
  memset (info.data + 321*3*80, 255, 321*3*80);
  gst_buffer_unmap (buf, &info);

  return GST_FLOW_OK;
}

static gboolean
plugin_init (GstPlugin * plugin)
{

  /* FIXME Remember to set the rank if it's an element that is meant
     to be autoplugged by decodebin. */
  return gst_element_register (plugin, "oddsrc", GST_RANK_NONE,
      GST_TYPE_ODD_SRC);
}

/* FIXME: these are normally defined by the GStreamer build system.
   If you are creating an element to be included in gst-plugins-*,
   remove these, as they're always defined.  Otherwise, edit as
   appropriate for your external plugin package. */
#ifndef VERSION
#define VERSION "0.0.FIXME"
#endif
#ifndef PACKAGE
#define PACKAGE "FIXME_package"
#endif
#ifndef PACKAGE_NAME
#define PACKAGE_NAME "FIXME_package_name"
#endif
#ifndef GST_PACKAGE_ORIGIN
#define GST_PACKAGE_ORIGIN "http://FIXME.org/"
#endif

GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
    GST_VERSION_MINOR,
    oddsrc,
    "FIXME plugin description",
    plugin_init, VERSION, "LGPL", PACKAGE_NAME, GST_PACKAGE_ORIGIN)