tutorials: fix playback-speed example

Fixes gstreamer#425
Also avoids duplication

examples/tutorials/basic-tutorial-13.c

@@ -30,7 +30,7 @@ send_seek_event (CustomData * data)
     seek_event =
         gst_event_new_seek (data->rate, GST_FORMAT_TIME,
         GST_SEEK_FLAG_FLUSH | GST_SEEK_FLAG_ACCURATE, GST_SEEK_TYPE_SET,
-        position, GST_SEEK_TYPE_SET, -1);
+        position, GST_SEEK_TYPE_END, 0);
   } else {
     seek_event =
         gst_event_new_seek (data->rate, GST_FORMAT_TIME,

markdown/tutorials/basic/playback-speed.md

@@ -62,155 +62,7 @@ Copy this code into a text file named `basic-tutorial-13.c`.
 
 **basic-tutorial-13.c**
 
-``` c
-#include <string.h>
-#include <stdio.h>
-#include <gst/gst.h>
-
-typedef struct _CustomData {
-  GstElement *pipeline;
-  GstElement *video_sink;
-  GMainLoop *loop;
-
-  gboolean playing;  /* Playing or Paused */
-  gdouble rate;      /* Current playback rate (can be negative) */
-} CustomData;
-
-/* Send seek event to change rate */
-static void send_seek_event (CustomData *data) {
-  gint64 position;
-  GstEvent *seek_event;
-
-  /* Obtain the current position, needed for the seek event */
-  if (!gst_element_query_position (data->pipeline, GST_FORMAT_TIME, &position)) {
-    g_printerr ("Unable to retrieve current position.\n");
-    return;
-  }
-
-  /* Create the seek event */
-  if (data->rate > 0) {
-    seek_event = gst_event_new_seek (data->rate, GST_FORMAT_TIME, GST_SEEK_FLAG_FLUSH | GST_SEEK_FLAG_ACCURATE,
-        GST_SEEK_TYPE_SET, position, GST_SEEK_TYPE_NONE, 0);
-  } else {
-    seek_event = gst_event_new_seek (data->rate, GST_FORMAT_TIME, GST_SEEK_FLAG_FLUSH | GST_SEEK_FLAG_ACCURATE,
-        GST_SEEK_TYPE_SET, 0, GST_SEEK_TYPE_SET, position);
-  }
-
-  if (data->video_sink == NULL) {
-    /* If we have not done so, obtain the sink through which we will send the seek events */
-    g_object_get (data->pipeline, "video-sink", &data->video_sink, NULL);
-  }
-
-  /* Send the event */
-  gst_element_send_event (data->video_sink, seek_event);
-
-  g_print ("Current rate: %g\n", data->rate);
-}
-
-/* Process keyboard input */
-static gboolean handle_keyboard (GIOChannel *source, GIOCondition cond, CustomData *data) {
-  gchar *str = NULL;
-
-  if (g_io_channel_read_line (source, &str, NULL, NULL, NULL) != G_IO_STATUS_NORMAL) {
-    return TRUE;
-  }
-
-  switch (g_ascii_tolower (str[0])) {
-  case 'p':
-    data->playing = !data->playing;
-    gst_element_set_state (data->pipeline, data->playing ? GST_STATE_PLAYING : GST_STATE_PAUSED);
-    g_print ("Setting state to %s\n", data->playing ? "PLAYING" : "PAUSE");
-    break;
-  case 's':
-    if (g_ascii_isupper (str[0])) {
-      data->rate *= 2.0;
-    } else {
-      data->rate /= 2.0;
-    }
-    send_seek_event (data);
-    break;
-  case 'd':
-    data->rate *= -1.0;
-    send_seek_event (data);
-    break;
-  case 'n':
-    if (data->video_sink == NULL) {
-      /* If we have not done so, obtain the sink through which we will send the step events */
-      g_object_get (data->pipeline, "video-sink", &data->video_sink, NULL);
-    }
-
-    gst_element_send_event (data->video_sink,
-        gst_event_new_step (GST_FORMAT_BUFFERS, 1, ABS (data->rate), TRUE, FALSE));
-    g_print ("Stepping one frame\n");
-    break;
-  case 'q':
-    g_main_loop_quit (data->loop);
-    break;
-  default:
-    break;
-  }
-
-  g_free (str);
-
-  return TRUE;
-}
-
-int main(int argc, char *argv[]) {
-  CustomData data;
-  GstStateChangeReturn ret;
-  GIOChannel *io_stdin;
-
-  /* Initialize GStreamer */
-  gst_init (&argc, &argv);
-
-  /* Initialize our data structure */
-  memset (&data, 0, sizeof (data));
-
-  /* Print usage map */
-  g_print (
-    "USAGE: Choose one of the following options, then press enter:\n"
-    " 'P' to toggle between PAUSE and PLAY\n"
-    " 'S' to increase playback speed, 's' to decrease playback speed\n"
-    " 'D' to toggle playback direction\n"
-    " 'N' to move to next frame (in the current direction, better in PAUSE)\n"
-    " 'Q' to quit\n");
-
-  /* Build the pipeline */
-  data.pipeline = gst_parse_launch ("playbin uri=https://www.freedesktop.org/software/gstreamer-sdk/data/media/sintel_trailer-480p.webm", NULL);
-
-  /* Add a keyboard watch so we get notified of keystrokes */
-#ifdef G_OS_WIN32
-  io_stdin = g_io_channel_win32_new_fd (fileno (stdin));
-#else
-  io_stdin = g_io_channel_unix_new (fileno (stdin));
-#endif
-  g_io_add_watch (io_stdin, G_IO_IN, (GIOFunc)handle_keyboard, &data);
-
-  /* Start playing */
-  ret = gst_element_set_state (data.pipeline, GST_STATE_PLAYING);
-  if (ret == GST_STATE_CHANGE_FAILURE) {
-    g_printerr ("Unable to set the pipeline to the playing state.\n");
-    gst_object_unref (data.pipeline);
-    return -1;
-  }
-  data.playing = TRUE;
-  data.rate = 1.0;
-
-  /* Create a GLib Main Loop and set it to run */
-  data.loop = g_main_loop_new (NULL, FALSE);
-  g_main_loop_run (data.loop);
-
-  /* Free resources */
-  g_main_loop_unref (data.loop);
-  g_io_channel_unref (io_stdin);
-  gst_element_set_state (data.pipeline, GST_STATE_NULL);
-  if (data.video_sink != NULL)
-    gst_object_unref (data.video_sink);
-  gst_object_unref (data.pipeline);
-  return 0;
-}
-```
-
+{{ tutorials/basic-tutorial-13.c }}
 
 > ![Information](images/icons/emoticons/information.svg)
 > Need help?
@@ -298,7 +150,7 @@ explained in the Introduction.
 /* Create the seek event */
 if (data->rate > 0) {
   seek_event = gst_event_new_seek (data->rate, GST_FORMAT_TIME, GST_SEEK_FLAG_FLUSH | GST_SEEK_FLAG_ACCURATE,
-      GST_SEEK_TYPE_SET, position, GST_SEEK_TYPE_NONE, 0);
+      GST_SEEK_TYPE_SET, position, GST_SEEK_TYPE_END, 0);
 } else {
   seek_event = gst_event_new_seek (data->rate, GST_FORMAT_TIME, GST_SEEK_FLAG_FLUSH | GST_SEEK_FLAG_ACCURATE,
       GST_SEEK_TYPE_SET, 0, GST_SEEK_TYPE_SET, position);