gstreamer/tools/gst-launch.c

/* GStreamer
 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
 *               2000 Wim Taymans <wtay@chello.be>
 *               2004 Thomas Vander Stichele <thomas@apestaart.org>
 *
 * gst-launch.c: tool to launch GStreamer pipelines from the command line
 *
 * 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

/* FIXME: hack alert */
#ifdef HAVE_WIN32
#define DISABLE_FAULT_HANDLER
#endif

#include <stdio.h>
#include <string.h>
#include <signal.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifndef DISABLE_FAULT_HANDLER
#include <sys/wait.h>
#endif
#include <locale.h>             /* for LC_ALL */
#include "tools.h"

/* FIXME: This is just a temporary hack.  We should have a better
 * check for siginfo handling. */
#ifdef SA_SIGINFO
#define USE_SIGINFO
#endif

extern volatile gboolean glib_on_error_halt;

#ifndef DISABLE_FAULT_HANDLER
static void fault_restore (void);
static void fault_spin (void);
static void sigint_restore (void);
static gboolean caught_intr = FALSE;
#endif

/* event_loop return codes */
typedef enum _EventLoopResult
{
  ELR_NO_ERROR = 0,
  ELR_ERROR,
  ELR_INTERRUPT
} EventLoopResult;

static GstElement *pipeline;
static EventLoopResult caught_error = ELR_NO_ERROR;
static gboolean quiet = FALSE;
static gboolean tags = FALSE;
static gboolean messages = FALSE;
static gboolean is_live = FALSE;
static gboolean waiting_eos = FALSE;

/* convenience macro so we don't have to litter the code with if(!quiet) */
#define PRINT if(!quiet)g_print

#ifndef DISABLE_FAULT_HANDLER
#ifndef USE_SIGINFO
static void
fault_handler_sighandler (int signum)
{
  fault_restore ();

  /* printf is used instead of g_print(), since it's less likely to
   * deadlock */
  switch (signum) {
    case SIGSEGV:
      fprintf (stderr, "Caught SIGSEGV\n");
      break;
    case SIGQUIT:
      if (!quiet)
        printf ("Caught SIGQUIT\n");
      break;
    default:
      fprintf (stderr, "signo:  %d\n", signum);
      break;
  }

  fault_spin ();
}

#else /* USE_SIGINFO */

static void
fault_handler_sigaction (int signum, siginfo_t * si, void *misc)
{
  fault_restore ();

  /* printf is used instead of g_print(), since it's less likely to
   * deadlock */
  switch (si->si_signo) {
    case SIGSEGV:
      fprintf (stderr, "Caught SIGSEGV accessing address %p\n", si->si_addr);
      break;
    case SIGQUIT:
      if (!quiet)
        printf ("Caught SIGQUIT\n");
      break;
    default:
      fprintf (stderr, "signo:  %d\n", si->si_signo);
      fprintf (stderr, "errno:  %d\n", si->si_errno);
      fprintf (stderr, "code:   %d\n", si->si_code);
      break;
  }

  fault_spin ();
}
#endif /* USE_SIGINFO */

static void
fault_spin (void)
{
  int spinning = TRUE;

  glib_on_error_halt = FALSE;
  g_on_error_stack_trace ("gst-launch");

  wait (NULL);

  /* FIXME how do we know if we were run by libtool? */
  fprintf (stderr,
      "Spinning.  Please run 'gdb gst-launch %d' to continue debugging, "
      "Ctrl-C to quit, or Ctrl-\\ to dump core.\n", (gint) getpid ());
  while (spinning)
    g_usleep (1000000);
}

static void
fault_restore (void)
{
  struct sigaction action;

  memset (&action, 0, sizeof (action));
  action.sa_handler = SIG_DFL;

  sigaction (SIGSEGV, &action, NULL);
  sigaction (SIGQUIT, &action, NULL);
}

static void
fault_setup (void)
{
  struct sigaction action;

  memset (&action, 0, sizeof (action));
#ifdef USE_SIGINFO
  action.sa_sigaction = fault_handler_sigaction;
  action.sa_flags = SA_SIGINFO;
#else
  action.sa_handler = fault_handler_sighandler;
#endif

  sigaction (SIGSEGV, &action, NULL);
  sigaction (SIGQUIT, &action, NULL);
}
#endif /* DISABLE_FAULT_HANDLER */

static void
print_error_message (GstMessage * msg)
{
  GError *err = NULL;
  gchar *name, *debug = NULL;

  name = gst_object_get_path_string (msg->src);
  gst_message_parse_error (msg, &err, &debug);

  g_printerr (_("ERROR: from element %s: %s\n"), name, err->message);
  if (debug != NULL)
    g_printerr (_("Additional debug info:\n%s\n"), debug);

  g_error_free (err);
  g_free (debug);
  g_free (name);
}

static void
print_tag (const GstTagList * list, const gchar * tag, gpointer unused)
{
  gint i, count;

  count = gst_tag_list_get_tag_size (list, tag);

  for (i = 0; i < count; i++) {
    gchar *str;

    if (gst_tag_get_type (tag) == G_TYPE_STRING) {
      if (!gst_tag_list_get_string_index (list, tag, i, &str))
        g_assert_not_reached ();
    } else if (gst_tag_get_type (tag) == GST_TYPE_BUFFER) {
      GstBuffer *img;

      img = gst_value_get_buffer (gst_tag_list_get_value_index (list, tag, i));
      if (img) {
        gchar *caps_str;

        caps_str = GST_BUFFER_CAPS (img) ?
            gst_caps_to_string (GST_BUFFER_CAPS (img)) : g_strdup ("unknown");
        str = g_strdup_printf ("buffer of %u bytes, type: %s",
            GST_BUFFER_SIZE (img), caps_str);
        g_free (caps_str);
      } else {
        str = g_strdup ("NULL buffer");
      }
    } else {
      str =
          g_strdup_value_contents (gst_tag_list_get_value_index (list, tag, i));
    }

    if (i == 0) {
      PRINT ("%16s: %s\n", gst_tag_get_nick (tag), str);
    } else {
      PRINT ("%16s: %s\n", "", str);
    }

    g_free (str);
  }
}

#ifndef DISABLE_FAULT_HANDLER
/* we only use sighandler here because the registers are not important */
static void
sigint_handler_sighandler (int signum)
{
  PRINT ("Caught interrupt -- ");

  /* If we were waiting for an EOS, we still want to catch
   * the next signal to shutdown properly (and the following one
   * will quit the program). */
  if (waiting_eos) {
    waiting_eos = FALSE;
  } else {
    sigint_restore ();
  }
  /* we set a flag that is checked by the mainloop, we cannot do much in the
   * interrupt handler (no mutex or other blocking stuff) */
  caught_intr = TRUE;
}

/* is called every 250 milliseconds (4 times a second), the interrupt handler
 * will set a flag for us. We react to this by posting a message. */
static gboolean
check_intr (GstElement * pipeline)
{
  if (!caught_intr) {
    return TRUE;
  } else {
    caught_intr = FALSE;
    PRINT ("handling interrupt.\n");

    /* post an application specific message */
    gst_element_post_message (GST_ELEMENT (pipeline),
        gst_message_new_application (GST_OBJECT (pipeline),
            gst_structure_new ("GstLaunchInterrupt",
                "message", G_TYPE_STRING, "Pipeline interrupted", NULL)));

    /* remove timeout handler */
    return FALSE;
  }
}

static void
sigint_setup (void)
{
  struct sigaction action;

  memset (&action, 0, sizeof (action));
  action.sa_handler = sigint_handler_sighandler;

  sigaction (SIGINT, &action, NULL);
}

static void
sigint_restore (void)
{
  struct sigaction action;

  memset (&action, 0, sizeof (action));
  action.sa_handler = SIG_DFL;

  sigaction (SIGINT, &action, NULL);
}

/* FIXME 0.11: remove SIGUSR handling (also from man page) */
static void
play_handler (int signum)
{
  switch (signum) {
    case SIGUSR1:
      PRINT ("Caught SIGUSR1 - Play request.\n");
      gst_element_set_state (pipeline, GST_STATE_PLAYING);
      break;
    case SIGUSR2:
      PRINT ("Caught SIGUSR2 - Stop request.\n");
      gst_element_set_state (pipeline, GST_STATE_NULL);
      break;
  }
}

static void
play_signal_setup (void)
{
  struct sigaction action;

  memset (&action, 0, sizeof (action));
  action.sa_handler = play_handler;
  sigaction (SIGUSR1, &action, NULL);
  sigaction (SIGUSR2, &action, NULL);
}
#endif /* DISABLE_FAULT_HANDLER */

/* returns ELR_ERROR if there was an error
 * or ELR_INTERRUPT if we caught a keyboard interrupt
 * or ELR_NO_ERROR otherwise. */
static EventLoopResult
event_loop (GstElement * pipeline, gboolean blocking, GstState target_state)
{
#ifndef DISABLE_FAULT_HANDLER
  gulong timeout_id;
#endif
  GstBus *bus;
  GstMessage *message = NULL;
  EventLoopResult res = ELR_NO_ERROR;
  gboolean buffering = FALSE;

  bus = gst_element_get_bus (GST_ELEMENT (pipeline));

#ifndef DISABLE_FAULT_HANDLER
  timeout_id = g_timeout_add (250, (GSourceFunc) check_intr, pipeline);
#endif

  while (TRUE) {
    message = gst_bus_poll (bus, GST_MESSAGE_ANY, blocking ? -1 : 0);

    /* if the poll timed out, only when !blocking */
    if (message == NULL)
      goto exit;

    /* check if we need to dump messages to the console */
    if (messages) {
      GstObject *src_obj;
      const GstStructure *s;
      guint32 seqnum;

      seqnum = gst_message_get_seqnum (message);

      s = gst_message_get_structure (message);

      src_obj = GST_MESSAGE_SRC (message);

      if (GST_IS_ELEMENT (src_obj)) {
        PRINT (_("Got message #%u from element \"%s\" (%s): "),
            (guint) seqnum, GST_ELEMENT_NAME (src_obj),
            GST_MESSAGE_TYPE_NAME (message));
      } else if (GST_IS_PAD (src_obj)) {
        PRINT (_("Got message #%u from pad \"%s:%s\" (%s): "),
            (guint) seqnum, GST_DEBUG_PAD_NAME (src_obj),
            GST_MESSAGE_TYPE_NAME (message));
      } else if (GST_IS_OBJECT (src_obj)) {
        PRINT (_("Got message #%u from object \"%s\" (%s): "),
            (guint) seqnum, GST_OBJECT_NAME (src_obj),
            GST_MESSAGE_TYPE_NAME (message));
      } else {
        PRINT (_("Got message #%u (%s): "), (guint) seqnum,
            GST_MESSAGE_TYPE_NAME (message));
      }

      if (s) {
        gchar *sstr;

        sstr = gst_structure_to_string (s);
        PRINT ("%s\n", sstr);
        g_free (sstr);
      } else {
        PRINT ("no message details\n");
      }
    }

    switch (GST_MESSAGE_TYPE (message)) {
      case GST_MESSAGE_NEW_CLOCK:
      {
        GstClock *clock;

        gst_message_parse_new_clock (message, &clock);

        PRINT ("New clock: %s\n", (clock ? GST_OBJECT_NAME (clock) : "NULL"));
        break;
      }
      case GST_MESSAGE_CLOCK_LOST:
        PRINT ("Clock lost, selecting a new one\n");
        gst_element_set_state (pipeline, GST_STATE_PAUSED);
        gst_element_set_state (pipeline, GST_STATE_PLAYING);
        break;
      case GST_MESSAGE_EOS:{
        waiting_eos = FALSE;
        PRINT (_("Got EOS from element \"%s\".\n"),
            GST_MESSAGE_SRC_NAME (message));
        goto exit;
      }
      case GST_MESSAGE_TAG:
        if (tags) {
          GstTagList *tags;

          if (GST_IS_ELEMENT (GST_MESSAGE_SRC (message))) {
            PRINT (_("FOUND TAG      : found by element \"%s\".\n"),
                GST_MESSAGE_SRC_NAME (message));
          } else if (GST_IS_PAD (GST_MESSAGE_SRC (message))) {
            PRINT (_("FOUND TAG      : found by pad \"%s:%s\".\n"),
                GST_DEBUG_PAD_NAME (GST_MESSAGE_SRC (message)));
          } else if (GST_IS_OBJECT (GST_MESSAGE_SRC (message))) {
            PRINT (_("FOUND TAG      : found by object \"%s\".\n"),
                GST_MESSAGE_SRC_NAME (message));
          } else {
            PRINT (_("FOUND TAG\n"));
          }

          gst_message_parse_tag (message, &tags);
          gst_tag_list_foreach (tags, print_tag, NULL);
          gst_tag_list_free (tags);
        }
        break;
      case GST_MESSAGE_INFO:{
        GError *gerror;
        gchar *debug;
        gchar *name = gst_object_get_path_string (GST_MESSAGE_SRC (message));

        gst_message_parse_info (message, &gerror, &debug);
        if (debug) {
          PRINT (_("INFO:\n%s\n"), debug);
        }
        g_error_free (gerror);
        g_free (debug);
        g_free (name);
        break;
      }
      case GST_MESSAGE_WARNING:{
        GError *gerror;
        gchar *debug;
        gchar *name = gst_object_get_path_string (GST_MESSAGE_SRC (message));

        /* dump graph on warning */
        GST_DEBUG_BIN_TO_DOT_FILE_WITH_TS (GST_BIN (pipeline),
            GST_DEBUG_GRAPH_SHOW_ALL, "gst-launch.warning");

        gst_message_parse_warning (message, &gerror, &debug);
        PRINT (_("WARNING: from element %s: %s\n"), name, gerror->message);
        if (debug) {
          PRINT (_("Additional debug info:\n%s\n"), debug);
        }
        g_error_free (gerror);
        g_free (debug);
        g_free (name);
        break;
      }
      case GST_MESSAGE_ERROR:{
        /* dump graph on error */
        GST_DEBUG_BIN_TO_DOT_FILE_WITH_TS (GST_BIN (pipeline),
            GST_DEBUG_GRAPH_SHOW_ALL, "gst-launch.error");

        print_error_message (message);

        /* we have an error */
        res = ELR_ERROR;
        goto exit;
      }
      case GST_MESSAGE_STATE_CHANGED:{
        GstState old, new, pending;

        /* we only care about pipeline state change messages */
        if (GST_MESSAGE_SRC (message) != GST_OBJECT_CAST (pipeline))
          break;

        /* ignore when we are buffering since then we mess with the states
         * ourselves. */
        if (buffering) {
          PRINT (_("Prerolled, waiting for buffering to finish...\n"));
          break;
        }

        gst_message_parse_state_changed (message, &old, &new, &pending);

        /* if we reached the final target state, exit */
        if (target_state == GST_STATE_PAUSED && new == target_state)
          goto exit;

        /* else not an interesting message */
        break;
      }
      case GST_MESSAGE_BUFFERING:{
        gint percent;

        gst_message_parse_buffering (message, &percent);
        PRINT ("%s %d%%  \r", _("buffering..."), percent);

        /* no state management needed for live pipelines */
        if (is_live)
          break;

        if (percent == 100) {
          /* a 100% message means buffering is done */
          buffering = FALSE;
          /* if the desired state is playing, go back */
          if (target_state == GST_STATE_PLAYING) {
            PRINT (_("Done buffering, setting pipeline to PLAYING ...\n"));
            gst_element_set_state (pipeline, GST_STATE_PLAYING);
          } else
            goto exit;
        } else {
          /* buffering busy */
          if (buffering == FALSE && target_state == GST_STATE_PLAYING) {
            /* we were not buffering but PLAYING, PAUSE  the pipeline. */
            PRINT (_("Buffering, setting pipeline to PAUSED ...\n"));
            gst_element_set_state (pipeline, GST_STATE_PAUSED);
          }
          buffering = TRUE;
        }
        break;
      }
      case GST_MESSAGE_LATENCY:
      {
        PRINT (_("Redistribute latency...\n"));
        gst_bin_recalculate_latency (GST_BIN (pipeline));
        break;
      }
      case GST_MESSAGE_REQUEST_STATE:
      {
        GstState state;
        gchar *name = gst_object_get_path_string (GST_MESSAGE_SRC (message));

        gst_message_parse_request_state (message, &state);

        PRINT (_("Setting state to %s as requested by %s...\n"),
            gst_element_state_get_name (state), name);

        gst_element_set_state (pipeline, state);

        g_free (name);
        break;
      }
      case GST_MESSAGE_APPLICATION:{
        const GstStructure *s;

        s = gst_message_get_structure (message);

        if (gst_structure_has_name (s, "GstLaunchInterrupt")) {
          /* this application message is posted when we caught an interrupt and
           * we need to stop the pipeline. */
          PRINT (_("Interrupt: Stopping pipeline ...\n"));
          res = ELR_INTERRUPT;
          goto exit;
        }
      }
      default:
        /* just be quiet by default */
        break;
    }
    if (message)
      gst_message_unref (message);
  }
  g_assert_not_reached ();

exit:
  {
    if (message)
      gst_message_unref (message);
    gst_object_unref (bus);
#ifndef DISABLE_FAULT_HANDLER
    g_source_remove (timeout_id);
#endif
    return res;
  }
}

static GstBusSyncReply
bus_sync_handler (GstBus * bus, GstMessage * message, gpointer data)
{
  GstElement *pipeline = (GstElement *) data;

  switch (GST_MESSAGE_TYPE (message)) {
    case GST_MESSAGE_STATE_CHANGED:
      /* we only care about pipeline state change messages */
      if (GST_MESSAGE_SRC (message) == GST_OBJECT_CAST (pipeline)) {
        GstState old, new, pending;
        gchar *state_transition_name;

        gst_message_parse_state_changed (message, &old, &new, &pending);

        state_transition_name = g_strdup_printf ("%s_%s",
            gst_element_state_get_name (old), gst_element_state_get_name (new));

        /* dump graph for (some) pipeline state changes */
        {
          gchar *dump_name = g_strconcat ("gst-launch.", state_transition_name,
              NULL);
          GST_DEBUG_BIN_TO_DOT_FILE_WITH_TS (GST_BIN (pipeline),
              GST_DEBUG_GRAPH_SHOW_ALL, dump_name);
          g_free (dump_name);
        }

        /* place a marker into e.g. strace logs */
        {
          gchar *access_name = g_strconcat (g_get_tmp_dir (), G_DIR_SEPARATOR_S,
              "gst-launch", G_DIR_SEPARATOR_S, state_transition_name, NULL);
          g_file_test (access_name, G_FILE_TEST_EXISTS);
          g_free (access_name);
        }

        g_free (state_transition_name);
      }
    default:
      break;
  }
  return GST_BUS_PASS;
}

int
main (int argc, char *argv[])
{
  /* options */
  gboolean verbose = FALSE;
  gboolean no_fault = FALSE;
  gboolean no_sigusr_handler = FALSE;
  gboolean trace = FALSE;
  gboolean eos_on_shutdown = FALSE;
  gchar *savefile = NULL;
  gchar *exclude_args = NULL;
#ifndef GST_DISABLE_OPTION_PARSING
  GOptionEntry options[] = {
    {"tags", 't', 0, G_OPTION_ARG_NONE, &tags,
        N_("Output tags (also known as metadata)"), NULL},
    {"verbose", 'v', 0, G_OPTION_ARG_NONE, &verbose,
        N_("Output status information and property notifications"), NULL},
    {"quiet", 'q', 0, G_OPTION_ARG_NONE, &quiet,
        N_("Do not print any progress information"), NULL},
    {"messages", 'm', 0, G_OPTION_ARG_NONE, &messages,
        N_("Output messages"), NULL},
    {"exclude", 'X', 0, G_OPTION_ARG_NONE, &exclude_args,
        N_("Do not output status information of TYPE"), N_("TYPE1,TYPE2,...")},
    {"no-fault", 'f', 0, G_OPTION_ARG_NONE, &no_fault,
        N_("Do not install a fault handler"), NULL},
    {"no-sigusr-handler", '\0', 0, G_OPTION_ARG_NONE, &no_sigusr_handler,
        N_("Do not install signal handlers for SIGUSR1 and SIGUSR2"), NULL},
    {"trace", 'T', 0, G_OPTION_ARG_NONE, &trace,
        N_("Print alloc trace (if enabled at compile time)"), NULL},
    {"eos-on-shutdown", 'e', 0, G_OPTION_ARG_NONE, &eos_on_shutdown,
        N_("Force EOS on sources before shutting the pipeline down"), NULL},
    GST_TOOLS_GOPTION_VERSION,
    {NULL}
  };
  GOptionContext *ctx;
  GError *err = NULL;
#endif
  gchar **argvn;
  GError *error = NULL;
  gint res = 0;

  free (malloc (8));            /* -lefence */

#ifdef ENABLE_NLS
  bindtextdomain (GETTEXT_PACKAGE, LOCALEDIR);
  bind_textdomain_codeset (GETTEXT_PACKAGE, "UTF-8");
  textdomain (GETTEXT_PACKAGE);
#endif

  g_thread_init (NULL);

  gst_tools_set_prgname ("gst-launch");

#ifndef GST_DISABLE_OPTION_PARSING
  ctx = g_option_context_new ("PIPELINE-DESCRIPTION");
  g_option_context_add_main_entries (ctx, options, GETTEXT_PACKAGE);
  g_option_context_add_group (ctx, gst_init_get_option_group ());
  if (!g_option_context_parse (ctx, &argc, &argv, &err)) {
    if (err)
      g_printerr ("Error initializing: %s\n", GST_STR_NULL (err->message));
    else
      g_printerr ("Error initializing: Unknown error!\n");
    exit (1);
  }
  g_option_context_free (ctx);
#else
  gst_init (&argc, &argv);
#endif

  gst_tools_print_version ("gst-launch");

#ifndef DISABLE_FAULT_HANDLER
  if (!no_fault)
    fault_setup ();

  sigint_setup ();

  if (!no_sigusr_handler)
    play_signal_setup ();
#endif

  if (trace) {
    if (!gst_alloc_trace_available ()) {
      g_warning ("Trace not available (recompile with trace enabled).");
    }
    gst_alloc_trace_set_flags_all (GST_ALLOC_TRACE_LIVE |
        GST_ALLOC_TRACE_MEM_LIVE);
    gst_alloc_trace_print_live ();
  }

  /* make a null-terminated version of argv */
  argvn = g_new0 (char *, argc);
  memcpy (argvn, argv + 1, sizeof (char *) * (argc - 1));
  {
    pipeline =
        (GstElement *) gst_parse_launchv ((const gchar **) argvn, &error);
  }
  g_free (argvn);

  if (!pipeline) {
    if (error) {
      g_printerr (_("ERROR: pipeline could not be constructed: %s.\n"),
          GST_STR_NULL (error->message));
      g_error_free (error);
    } else {
      g_printerr (_("ERROR: pipeline could not be constructed.\n"));
    }
    return 1;
  } else if (error) {
    g_printerr (_("WARNING: erroneous pipeline: %s\n"),
        GST_STR_NULL (error->message));
    g_error_free (error);
    return 1;
  }

  if (verbose) {
    gchar **exclude_list =
        exclude_args ? g_strsplit (exclude_args, ",", 0) : NULL;
    g_signal_connect (pipeline, "deep-notify",
        G_CALLBACK (gst_object_default_deep_notify), exclude_list);
  }

  if (!savefile) {
    GstState state, pending;
    GstStateChangeReturn ret;
    GstBus *bus;

    /* If the top-level object is not a pipeline, place it in a pipeline. */
    if (!GST_IS_PIPELINE (pipeline)) {
      GstElement *real_pipeline = gst_element_factory_make ("pipeline", NULL);

      if (real_pipeline == NULL) {
        g_printerr (_("ERROR: the 'pipeline' element wasn't found.\n"));
        return 1;
      }
      gst_bin_add (GST_BIN (real_pipeline), pipeline);
      pipeline = real_pipeline;
    }

    bus = gst_element_get_bus (pipeline);
    gst_bus_set_sync_handler (bus, bus_sync_handler, (gpointer) pipeline);
    gst_object_unref (bus);

    PRINT (_("Setting pipeline to PAUSED ...\n"));
    ret = gst_element_set_state (pipeline, GST_STATE_PAUSED);

    switch (ret) {
      case GST_STATE_CHANGE_FAILURE:
        g_printerr (_("ERROR: Pipeline doesn't want to pause.\n"));
        res = -1;
        event_loop (pipeline, FALSE, GST_STATE_VOID_PENDING);
        goto end;
      case GST_STATE_CHANGE_NO_PREROLL:
        PRINT (_("Pipeline is live and does not need PREROLL ...\n"));
        is_live = TRUE;
        break;
      case GST_STATE_CHANGE_ASYNC:
        PRINT (_("Pipeline is PREROLLING ...\n"));
        caught_error = event_loop (pipeline, TRUE, GST_STATE_PAUSED);
        if (caught_error) {
          g_printerr (_("ERROR: pipeline doesn't want to preroll.\n"));
          goto end;
        }
        state = GST_STATE_PAUSED;
        /* fallthrough */
      case GST_STATE_CHANGE_SUCCESS:
        PRINT (_("Pipeline is PREROLLED ...\n"));
        break;
    }

    caught_error = event_loop (pipeline, FALSE, GST_STATE_PLAYING);

    if (caught_error) {
      g_printerr (_("ERROR: pipeline doesn't want to preroll.\n"));
    } else {
      GstClockTime tfthen, tfnow;
      GstClockTimeDiff diff;

      PRINT (_("Setting pipeline to PLAYING ...\n"));

      if (gst_element_set_state (pipeline,
              GST_STATE_PLAYING) == GST_STATE_CHANGE_FAILURE) {
        GstMessage *err_msg;
        GstBus *bus;

        g_printerr (_("ERROR: pipeline doesn't want to play.\n"));
        bus = gst_element_get_bus (pipeline);
        if ((err_msg = gst_bus_poll (bus, GST_MESSAGE_ERROR, 0))) {
          print_error_message (err_msg);
          gst_message_unref (err_msg);
        }
        gst_object_unref (bus);
        res = -1;
        goto end;
      }

      tfthen = gst_util_get_timestamp ();
      caught_error = event_loop (pipeline, TRUE, GST_STATE_PLAYING);
      if (eos_on_shutdown && caught_error == ELR_INTERRUPT) {
        PRINT (_("EOS on shutdown enabled -- Forcing EOS on the pipeline\n"));
        waiting_eos = TRUE;
        gst_element_send_event (pipeline, gst_event_new_eos ());
        PRINT (_("Waiting for EOS...\n"));
        caught_error = event_loop (pipeline, TRUE, GST_STATE_PLAYING);

        if (caught_error == ELR_NO_ERROR) {
          /* we got EOS */
          PRINT (_("EOS received - stopping pipeline...\n"));
        } else if (caught_error == ELR_ERROR) {
          PRINT (_("An error happened while waiting for EOS\n"));
        }
      }
      tfnow = gst_util_get_timestamp ();

      diff = GST_CLOCK_DIFF (tfthen, tfnow);

      PRINT (_("Execution ended after %" G_GUINT64_FORMAT " ns.\n"), diff);
    }

    PRINT (_("Setting pipeline to PAUSED ...\n"));
    gst_element_set_state (pipeline, GST_STATE_PAUSED);
    if (caught_error == ELR_NO_ERROR)
      gst_element_get_state (pipeline, &state, &pending, GST_CLOCK_TIME_NONE);

    /* iterate mainloop to process pending stuff */
    while (g_main_context_iteration (NULL, FALSE));

    PRINT (_("Setting pipeline to READY ...\n"));
    gst_element_set_state (pipeline, GST_STATE_READY);
    gst_element_get_state (pipeline, &state, &pending, GST_CLOCK_TIME_NONE);

  end:
    PRINT (_("Setting pipeline to NULL ...\n"));
    gst_element_set_state (pipeline, GST_STATE_NULL);
    gst_element_get_state (pipeline, &state, &pending, GST_CLOCK_TIME_NONE);
  }

  PRINT (_("Freeing pipeline ...\n"));
  gst_object_unref (pipeline);

  gst_deinit ();
  if (trace)
    gst_alloc_trace_print_live ();

  return res;
}