#include <string.h>

#include <gst/gst.h>

#include <gst/app/gstappsrc.h>
#include <gst/app/gstappbuffer.h>

/* these are the caps we are going to pass through the appsrc */
const gchar *video_caps =
    "video/x-raw-rgb,width=80,height=60,bpp=32,endianness=4321,depth=24,red_mask=65280,green_mask=16711680,blue_mask=-16777216,framerate=30/1";

typedef struct
{
  GMainLoop *loop;
  GstElement *sink;
} ProgramData;

/* used to inject a new buffer into the pipeline */
static void
inject_new_buffer_into_pipeline (ProgramData * data)
{
  guint size;
  gpointer raw_buffer;
  GstBuffer *app_buffer;
  GstElement *source;

  size = 80 * 60 * 4; // 80x60 pixels, 32 bpp.
  g_print ("Pushing a buffer of size %d\n", size);
  
  // Allocating the memory for the buffer.
  raw_buffer = g_malloc0 (size);
  
  app_buffer = gst_app_buffer_new (raw_buffer, size, g_free, raw_buffer);

  /* newer basesrc will set caps for use automatically but it does not really
   * hurt to set it on the buffer again */
  gst_buffer_set_caps (app_buffer, gst_caps_from_string (video_caps));

  /* get source an push new buffer */
  source = gst_bin_get_by_name (GST_BIN (data->sink), "testsource");
  gst_app_src_push_buffer (GST_APP_SRC (source), app_buffer);
}

/* called when we get a GstMessage from the sink pipeline when we get EOS, we
 * exit the mainloop and this testapp. */
static gboolean
on_sink_message (GstBus * bus, GstMessage * message, ProgramData * data)
{
  GstState state, pending;
  GstElement *source;

  switch (GST_MESSAGE_TYPE (message)) {
    case GST_MESSAGE_EOS:
      g_print ("Received End of Stream message\n");
      g_main_loop_quit (data->loop);
      break;
    case GST_MESSAGE_ERROR:
      g_print ("Received error\n");
      g_main_loop_quit (data->loop);
      break;
    case GST_MESSAGE_STATE_CHANGED:
      source = gst_bin_get_by_name (GST_BIN (data->sink), "testsource");
      gst_element_get_state(source, &state, &pending, GST_CLOCK_TIME_NONE);
      g_print ("State changed from %i to %i\n", state, pending);
      break;
	default:
      break;
  }
  return TRUE;
}

int
main (int argc, char *argv[])
{
  ProgramData *data = NULL;
  gchar *string = NULL;
  GstBus *bus = NULL;
  GstElement *testsource = NULL;
  int i;

  gst_init (&argc, &argv);

  data = g_new0 (ProgramData, 1);

  data->loop = g_main_loop_new (NULL, FALSE);

  /* setting up sink pipeline, we push video data into this pipeline that will
   * then be recorded to an avi file. */
  string =
      g_strdup_printf ("appsrc is-live=true name=testsource caps=\"%s\" ! ffmpegcolorspace ! video/x-raw-yuv,format=(fourcc)I420,width=80,height=60 ! queue ! videorate ! video/x-raw-yuv,framerate=30/1 ! xvidenc ! queue ! avimux ! queue ! filesink location=test.avi",
      video_caps);
  data->sink = gst_parse_launch (string, NULL);
  g_free (string);

  if (data->sink == NULL) {
    g_print ("Bad sink\n");
    return -1;
  }

  testsource = gst_bin_get_by_name (GST_BIN (data->sink), "testsource");
  /* configure for time-based format */
  g_object_set (testsource, "format", GST_FORMAT_TIME, NULL);
  /* uncomment the next line to block when appsrc has buffered enough */
  /* g_object_set (testsource, "block", TRUE, NULL); */

  bus = gst_element_get_bus (data->sink);
  gst_bus_add_watch (bus, (GstBusFunc) on_sink_message, data);
  gst_object_unref (bus);

  /* launching things */
  gst_element_set_state (data->sink, GST_STATE_PLAYING);

  /* Injecting 300 frames into the pipeline, which should generate a 1 second
   * avi file with the current framerate. */
  g_print ("Injecting buffers...\n");
  for (i = 0; i < 30; i++) inject_new_buffer_into_pipeline(data);
  gst_app_src_end_of_stream (GST_APP_SRC (testsource));
  g_print ("Done.\n");

  gst_element_set_state (data->sink, GST_STATE_PLAYING);

  g_print ("Creating movie...\n");
  g_main_loop_run (data->loop);
  g_print ("Done.\n");

  gst_element_set_state (data->sink, GST_STATE_NULL);

  gst_object_unref (testsource);
  gst_object_unref (data->sink);
  g_main_loop_unref (data->loop);
  g_free (data);

  return 0;
}