**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?
/* 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);