gstreamer/tools/ges-launch.c

/* GStreamer Editing Services
 * Copyright (C) 2010 Edward Hervey <bilboed@bilboed.com>
 *
 * 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., 51 Franklin St, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <glib.h>
#include <glib/gprintf.h>
#include <ges/ges.h>
#include <gst/pbutils/encoding-profile.h>

#include <locale.h>             /* for LC_ALL */

/* GLOBAL VARIABLE */
static guint repeat = 0;
static GESPipeline *pipeline = NULL;
static gboolean seenerrors = FALSE;
static gchar **new_paths = NULL;
static GMainLoop *mainloop;
static GHashTable *tried_uris;
static GESTrackType track_types = GES_TRACK_TYPE_AUDIO | GES_TRACK_TYPE_VIDEO;

static gchar *
ensure_uri (gchar * location)
{
  if (gst_uri_is_valid (location))
    return g_strdup (location);
  else
    return gst_filename_to_uri (location, NULL);
}

static guint
get_flags_from_string (GType type, const gchar * str_flags)
{
  guint i;
  gint flags = 0;
  GFlagsClass *class = g_type_class_ref (type);

  for (i = 0; i < class->n_values; i++) {
    if (g_strrstr (str_flags, class->values[i].value_nick)) {
      flags |= class->values[i].value;
    }
  }
  g_type_class_unref (class);

  return flags;
}

static gboolean
parse_track_type (const gchar * option_name, const gchar * value,
    gpointer udata, GError ** error)
{
  track_types = get_flags_from_string (GES_TYPE_TRACK_TYPE, value);

  if (track_types == 0)
    return FALSE;

  return TRUE;
}

static gboolean
thumbnail_cb (gpointer pipeline)
{
  static int i = 0;
  GESPipeline *p = (GESPipeline *) pipeline;
  gchar *filename;
  gboolean res;

  filename = g_strdup_printf ("thumbnail%d.jpg", i++);

  res = ges_pipeline_save_thumbnail (p, -1, -1,
      (gchar *) "image/jpeg", filename, NULL);

  g_free (filename);

  return res;
}

static gchar *
source_moved_cb (GESProject * project, GError * error, GESAsset * asset)
{
  gint i;
  const gchar *old_uri = ges_asset_get_id (asset);

  for (i = 0; new_paths[i] != NULL; i++) {
    gchar *basename, *res;

    basename = g_path_get_basename (old_uri);
    res = g_build_filename (new_paths[i], basename, NULL);
    g_free (basename);

    if (g_hash_table_lookup (tried_uris, res)) {
      GST_DEBUG ("File already tried: %s\n", res);
      g_free (res);
    } else {
      g_hash_table_add (tried_uris, g_strdup (res));
      return res;
    }
  }

  return NULL;
}

static void
error_loading_asset_cb (GESProject * project, GError * error,
    const gchar * failed_id, GType extractable_type)
{
  g_printerr ("Error loading asset %s: %s\n", failed_id, error->message);

  g_main_loop_quit (mainloop);
}

static gboolean
check_time (char *time)
{
  static GRegex *re = NULL;

  if (!re) {
    if (NULL == (re = g_regex_new ("^[0-9]+(.[0-9]+)?$", G_REGEX_EXTENDED, 0,
                NULL)))
      return FALSE;
  }

  if (g_regex_match (re, time, 0, NULL))
    return TRUE;
  return FALSE;
}

static guint64
str_to_time (char *time)
{
  if (check_time (time)) {
    return (guint64) (atof (time) * GST_SECOND);
  }
  GST_ERROR ("%s not a valid time", time);
  return 0;
}

static GESTimeline *
create_timeline (int nbargs, gchar ** argv, const gchar * proj_uri)
{
  GESLayer *layer;
  GESTrack *tracka = NULL, *trackv = NULL;
  GESTimeline *timeline;
  guint i;
  GESProject *project = ges_project_new (proj_uri);

  if (new_paths)
    g_signal_connect (project, "missing-uri",
        G_CALLBACK (source_moved_cb), NULL);

  g_signal_connect (project, "error-loading-asset",
      G_CALLBACK (error_loading_asset_cb), NULL);

  timeline = GES_TIMELINE (ges_asset_extract (GES_ASSET (project), NULL));

  if (proj_uri)
    return timeline;

  /* We are only going to be doing one layer of clips */
  layer = (GESLayer *) ges_layer_new ();

  /* Add the tracks and the layer to the timeline */
  if (!ges_timeline_add_layer (timeline, layer))
    goto build_failure;

  if (track_types & GES_TRACK_TYPE_AUDIO) {
    tracka = GES_TRACK (ges_audio_track_new ());
    if (!(ges_timeline_add_track (timeline, tracka)))
      goto build_failure;
  }

  if (track_types & GES_TRACK_TYPE_VIDEO) {
    trackv = GES_TRACK (ges_video_track_new ());

    if (!(ges_timeline_add_track (timeline, trackv)))
      goto build_failure;
  }

  /* Here we've finished initializing our timeline, we're
   * ready to start using it... by solely working with the layer !*/

  for (i = 0; i < nbargs / 3; i++) {
    GESClip *clip;

    char *source = argv[i * 3];
    char *arg0 = argv[(i * 3) + 1];
    guint64 duration = str_to_time (argv[(i * 3) + 2]);

    if (!g_strcmp0 ("+pattern", source)) {
      clip = GES_CLIP (ges_test_clip_new_for_nick (arg0));
      if (!clip) {
        g_error ("%s is an invalid pattern name!\n", arg0);
        goto build_failure;
      }

      g_object_set (G_OBJECT (clip), "duration", duration, NULL);

      g_printf ("Adding <pattern:%s> duration %" GST_TIME_FORMAT "\n", arg0,
          GST_TIME_ARGS (duration));
    }

    else if (!g_strcmp0 ("+transition", source)) {
      if (duration <= 0) {
        g_error ("durations must be greater than 0");
        goto build_failure;
      }

      clip = GES_CLIP (ges_transition_clip_new_for_nick (arg0));

      if (!clip) {
        g_error ("invalid transition type\n");
        goto build_failure;
      }

      g_object_set (G_OBJECT (clip), "duration", duration, NULL);

      g_printf ("Adding <transition:%s> duration %" GST_TIME_FORMAT "\n", arg0,
          GST_TIME_ARGS (duration));

    }

    else if (!g_strcmp0 ("+title", source)) {
      clip = GES_CLIP (ges_title_clip_new ());

      g_object_set (clip, "duration", duration, "text", arg0, NULL);

      g_printf ("Adding <title:%s> duration %" GST_TIME_FORMAT "\n", arg0,
          GST_TIME_ARGS (duration));
    }

    else {
      gchar *uri;
      GESAsset *asset;
      guint64 inpoint;

      GError *error = NULL;

      if (!(uri = ensure_uri (source))) {
        GST_ERROR ("couldn't create uri for '%s'", source);
        goto build_failure;
      }

      inpoint = str_to_time (argv[i * 3 + 1]);
      asset = GES_ASSET (ges_uri_clip_asset_request_sync (uri, &error));
      if (error) {
        g_printerr ("Can not create asset for %s", uri);

        return NULL;
      }

      ges_project_add_asset (project, asset);
      clip = GES_CLIP (ges_asset_extract (asset, &error));
      if (error) {
        g_printerr ("Can not extract asset for %s", uri);

        return NULL;
      }

      g_object_set (clip,
          "in-point", (guint64) inpoint, "duration", (guint64) duration, NULL);

      g_printf ("Adding clip %s inpoint:%" GST_TIME_FORMAT " duration:%"
          GST_TIME_FORMAT "\n", uri, GST_TIME_ARGS (inpoint),
          GST_TIME_ARGS (duration));

      g_free (uri);
    }

    g_object_set (G_OBJECT (clip), "start", ges_layer_get_duration (layer),
        NULL);
    ges_layer_add_clip (layer, clip);
  }

  return timeline;

build_failure:
  {
    gst_object_unref (timeline);
    return NULL;
  }
}

static GESPipeline *
create_pipeline (GESTimeline ** ret_timeline, gchar * load_path,
    gchar * save_path, int argc, char **argv)
{
  gchar *uri = NULL;
  GESPipeline *pipeline = NULL;
  GESTimeline *timeline = NULL;

  /* Timeline creation */
  if (load_path) {
    g_printf ("Loading project from : %s\n", load_path);

    if (!(uri = ensure_uri (load_path))) {
      g_error ("couldn't create uri for '%s'", load_path);
      goto failure;
    }
  }
  if (!(timeline = create_timeline (argc, argv, uri)))
    goto failure;

  ges_timeline_commit (timeline);

  if (uri)
    g_free (uri);

  /* save project if path is given. we do this now in case GES crashes or
   * hangs during playback. */
  if (save_path) {
    gchar *uri;
    if (!(uri = ensure_uri (save_path))) {
      g_error ("couldn't create uri for '%s", save_path);
      goto failure;
    }
    ges_timeline_save_to_uri (timeline, uri, NULL, TRUE, NULL);
    g_free (uri);
  }

  /* In order to view our timeline, let's grab a convenience pipeline to put
   * our timeline in. */
  pipeline = ges_pipeline_new ();

  /* Add the timeline to that pipeline */
  if (!ges_pipeline_set_timeline (pipeline, timeline))
    goto failure;

  *ret_timeline = timeline;
  return pipeline;

failure:
  {
    if (uri)
      g_free (uri);
    if (timeline)
      gst_object_unref (timeline);
    if (pipeline)
      gst_object_unref (pipeline);
    return NULL;
  }
}

static void
bus_message_cb (GstBus * bus, GstMessage * message, GMainLoop * mainloop)
{
  switch (GST_MESSAGE_TYPE (message)) {
    case GST_MESSAGE_WARNING:{
      GST_DEBUG_BIN_TO_DOT_FILE_WITH_TS (GST_BIN (pipeline),
          GST_DEBUG_GRAPH_SHOW_ALL, "ges-launch.warning");
      break;
    }
    case GST_MESSAGE_ERROR:{
      GError *err = NULL;
      gchar *dbg_info = NULL;

      gst_message_parse_error (message, &err, &dbg_info);
      GST_DEBUG_BIN_TO_DOT_FILE_WITH_TS (GST_BIN (pipeline),
          GST_DEBUG_GRAPH_SHOW_ALL, "ges-launch-error");
      g_printerr ("ERROR from element %s: %s\n", GST_OBJECT_NAME (message->src),
          err->message);
      g_printerr ("Debugging info: %s\n", (dbg_info) ? dbg_info : "none");
      g_error_free (err);
      g_free (dbg_info);
      seenerrors = TRUE;
      g_main_loop_quit (mainloop);
      break;
    }
    case GST_MESSAGE_EOS:
      if (repeat > 0) {
        g_printerr ("Looping again\n");
        if (!gst_element_seek_simple (GST_ELEMENT (pipeline), GST_FORMAT_TIME,
                GST_SEEK_FLAG_FLUSH, 0))
          g_printerr ("seeking failed\n");
        else
          g_printerr ("seeking succeeded\n");
        gst_element_set_state (GST_ELEMENT (pipeline), GST_STATE_PLAYING);
        g_printerr ("Looping set\n");
        repeat -= 1;
      } else {
        g_printerr ("Done\n");
        g_main_loop_quit (mainloop);
      }
      break;
    case GST_MESSAGE_STATE_CHANGED:
      if (GST_MESSAGE_SRC (message) == GST_OBJECT_CAST (pipeline)) {
        gchar *dump_name;
        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_name = g_strconcat ("ges-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);
        g_free (state_transition_name);
      }
      break;
    default:
      break;
  }
}

static void
print_enum (GType enum_type)
{
  GEnumClass *enum_class = G_ENUM_CLASS (g_type_class_ref (enum_type));
  guint i;

  GST_ERROR ("%d", enum_class->n_values);

  for (i = 0; i < enum_class->n_values; i++) {
    g_printf ("%s\n", enum_class->values[i].value_nick);
  }

  g_type_class_unref (enum_class);
}

static void
print_transition_list (void)
{
  print_enum (GES_VIDEO_STANDARD_TRANSITION_TYPE_TYPE);
}

static void
print_pattern_list (void)
{
  print_enum (GES_VIDEO_TEST_PATTERN_TYPE);
}

static gboolean
_print_position (void)
{
  gint64 position, duration;

  if (pipeline) {
    gst_element_query_position (GST_ELEMENT (pipeline), GST_FORMAT_TIME,
        &position);
    gst_element_query_duration (GST_ELEMENT (pipeline), GST_FORMAT_TIME,
        &duration);
    g_print ("<Position: %" GST_TIME_FORMAT " / %" GST_TIME_FORMAT "/>\r",
        GST_TIME_ARGS (position), GST_TIME_ARGS (duration));
  }

  return TRUE;
}

static GstEncodingProfile *
_parse_encoding_profile (const gchar * format)
{
  GstCaps *caps;
  char *preset_name = NULL;
  GstEncodingProfile *encoding_profile;
  gchar **restriction_format, **preset_v;

  guint i, presence = 0;
  GstCaps *restrictioncaps = NULL;
  gchar **strpresence_v, **strcaps_v = g_strsplit (format, ":", 0);

  if (strcaps_v[0] && *strcaps_v[0]) {
    caps = gst_caps_from_string (strcaps_v[0]);
    if (caps == NULL) {
      g_printerr ("Could not parse caps %s", strcaps_v[0]);
      return FALSE;
    }
    encoding_profile =
        GST_ENCODING_PROFILE (gst_encoding_container_profile_new
        ("User profile", "User profile", caps, NULL));
    gst_caps_unref (caps);
  } else {
    encoding_profile = NULL;
  }

  for (i = 1; strcaps_v[i]; i++) {
    GstEncodingProfile *profile = NULL;
    gchar *strcaps, *strpresence;

    restriction_format = g_strsplit (strcaps_v[i], "->", 0);
    if (restriction_format[1]) {
      restrictioncaps = gst_caps_from_string (restriction_format[0]);
      strcaps = g_strdup (restriction_format[1]);
    } else {
      restrictioncaps = NULL;
      strcaps = g_strdup (restriction_format[0]);
    }
    g_strfreev (restriction_format);

    preset_v = g_strsplit (strcaps, "+", 0);
    if (preset_v[1]) {
      strpresence = preset_v[1];
      g_free (strcaps);
      strcaps = g_strdup (preset_v[0]);
    } else {
      strpresence = preset_v[0];
    }

    strpresence_v = g_strsplit (strpresence, "|", 0);
    if (strpresence_v[1]) {     /* We have a presence */
      gchar *endptr;

      if (preset_v[1]) {        /* We have preset and presence */
        preset_name = g_strdup (strpresence_v[0]);
      } else {                  /* We have a presence but no preset */
        g_free (strcaps);
        strcaps = g_strdup (strpresence_v[0]);
      }

      presence = strtoll (strpresence_v[1], &endptr, 10);
      if (endptr == strpresence_v[1]) {
        g_printerr ("Wrong presence %s\n", strpresence_v[1]);

        return FALSE;
      }
    } else {                    /* We have no presence */
      if (preset_v[1]) {        /* Not presence but preset */
        preset_name = g_strdup (preset_v[1]);
        g_free (strcaps);
        strcaps = g_strdup (preset_v[0]);
      }                         /* Else we have no presence nor preset */
    }
    g_strfreev (strpresence_v);
    g_strfreev (preset_v);

    GST_DEBUG ("Creating preset with restrictions: %" GST_PTR_FORMAT
        ", caps: %s, preset %s, presence %d", restrictioncaps, strcaps,
        preset_name ? preset_name : "none", presence);

    caps = gst_caps_from_string (strcaps);
    g_free (strcaps);
    if (caps == NULL) {
      g_warning ("Could not create caps for %s", strcaps_v[i]);

      return FALSE;
    }

    if (g_str_has_prefix (strcaps_v[i], "audio/")) {
      profile = GST_ENCODING_PROFILE (gst_encoding_audio_profile_new (caps,
              preset_name, restrictioncaps, presence));
    } else if (g_str_has_prefix (strcaps_v[i], "video/") ||
        g_str_has_prefix (strcaps_v[i], "image/")) {
      profile = GST_ENCODING_PROFILE (gst_encoding_video_profile_new (caps,
              preset_name, restrictioncaps, presence));
    }

    g_free (preset_name);
    gst_caps_unref (caps);
    if (restrictioncaps)
      gst_caps_unref (restrictioncaps);

    if (profile == NULL) {
      g_warning ("No way to create a preset for caps: %s", strcaps_v[i]);

      return NULL;
    }

    if (encoding_profile) {
      if (gst_encoding_container_profile_add_profile
          (GST_ENCODING_CONTAINER_PROFILE (encoding_profile),
              profile) == FALSE) {
        g_warning ("Can not create a preset for caps: %s", strcaps_v[i]);

        return NULL;
      }
    } else {
      encoding_profile = profile;
    }
  }
  g_strfreev (strcaps_v);

  return encoding_profile;
}

int
main (int argc, gchar ** argv)
{
  GError *err = NULL;
  gchar *outputuri = NULL;
  const gchar *format = NULL;
  gchar *exclude_args = NULL;
  static gboolean smartrender = FALSE;
  static gboolean list_transitions = FALSE;
  static gboolean list_patterns = FALSE;
  static gdouble thumbinterval = 0;
  static gboolean verbose = FALSE;
  gchar *save_path = NULL;
  gchar *load_path = NULL;
  GOptionEntry options[] = {
    {"thumbnail", 'm', 0.0, G_OPTION_ARG_DOUBLE, &thumbinterval,
        "Take thumbnails every n seconds (saved in current directory)", "N"},
    {"smartrender", 's', 0, G_OPTION_ARG_NONE, &smartrender,
        "Render to outputuri, and avoid decoding/reencoding", NULL},
    {"outputuri", 'o', 0, G_OPTION_ARG_STRING, &outputuri,
        "URI to encode to", "URI (<protocol>://<location>)"},
    {"format", 'f', 0, G_OPTION_ARG_STRING, &format,
          "Set the properties to use for the encoding profile "
          "(in case of transcoding.) For example:\n"
          "video/mpegts:video/x-raw,width=1920,height=1080->video/x-h264:audio/x-ac3\n"
          "A preset name can be used by adding +presetname, eg:\n"
          "video/webm:video/x-vp8+mypreset:audio/x-vorbis\n"
          "The presence property of the profile can be specified with |<presence>, eg:\n"
          "video/webm:video/x-vp8|<presence>:audio/x-vorbis\n",
        "properties-values"},
    {"repeat", 'r', 0, G_OPTION_ARG_INT, &repeat,
        "Number of time to repeat timeline", NULL},
    {"list-transitions", 't', 0, G_OPTION_ARG_NONE, &list_transitions,
        "List valid transition types and exit", NULL},
    {"list-patterns", 'p', 0, G_OPTION_ARG_NONE, &list_patterns,
        "List patterns and exit", NULL},
    {"save", 'z', 0, G_OPTION_ARG_STRING, &save_path,
        "Save project to file before rendering", "<path>"},
    {"load", 'l', 0, G_OPTION_ARG_STRING, &load_path,
        "Load project from file before rendering", "<path>"},
    {"verbose", 0, 0, G_OPTION_ARG_NONE, &verbose,
        "Output status information and property notifications", NULL},
    {"exclude", 'X', 0, G_OPTION_ARG_NONE, &exclude_args,
        "Do not output status information of TYPE", "TYPE1,TYPE2,..."},
    {"sample-paths", 'P', 0, G_OPTION_ARG_STRING_ARRAY, &new_paths,
        "List of pathes to look assets in if they were moved"},
    {"track-types", 'P', 0, G_OPTION_ARG_CALLBACK, &parse_track_type,
        "Defines the track types to be created"},
    {NULL}
  };
  GOptionContext *ctx;
  GstBus *bus;
  GESTimeline *timeline;

  setlocale (LC_ALL, "");

  ctx = g_option_context_new ("- plays or renders a timeline.");
  g_option_context_set_summary (ctx,
      "ges-launch renders a timeline, which can be specified on the commandline,\n"
      "or loaded from a file using the -q option.\n\n"
      "A timeline is a list of files, patterns, and transitions to be rendered\n"
      "one after the other. Files and Patterns provide video and audio as the\n"
      "primary input, and transitions animate between the end of one file/pattern\n"
      "and the beginning of a new one. Hence, transitions can only be listed\n"
      "in between patterns or files.\n\n"
      "A file is a triplet of filename, inpoint (in seconds) and\n"
      "duration (in seconds). If the duration is 0, the full file length is used.\n\n"
      "Patterns and transitions are triplets that begin with either \"+pattern\"\n"
      "or \"+transition\", followed by a <type> and duration (in seconds, must be\n"
      "greater than 0)\n\n"
      "Durations in all cases can be fractions of a second.\n\n"
      "Example:\n"
      "ges-launch file1.avi 0 45 +transition crossfade 3.5 file2.avi 0 0");
  g_option_context_add_main_entries (ctx, options, NULL);
  g_option_context_add_group (ctx, gst_init_get_option_group ());

  if (!g_option_context_parse (ctx, &argc, &argv, &err)) {
    g_printerr ("Error initializing: %s\n", err->message);
    g_option_context_free (ctx);
    exit (1);
  }

  /* Initialize the GStreamer Editing Services */
  if (!ges_init ()) {
    g_printerr ("Error initializing GES\n");
    exit (1);
  }

  if (list_transitions) {
    print_transition_list ();
    exit (0);
  }

  if (list_patterns) {
    print_pattern_list ();
    exit (0);
  }

  tried_uris = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, NULL);
  if (((!load_path && (argc < 4)))) {
    g_printf ("%s", g_option_context_get_help (ctx, TRUE, NULL));
    g_option_context_free (ctx);
    exit (1);
  }

  g_option_context_free (ctx);

  /* Create the pipeline */
  pipeline =
      create_pipeline (&timeline, load_path, save_path, argc - 1, argv + 1);
  if (!pipeline)
    exit (1);

  /* Setup profile/encoding if needed */
  if (smartrender || outputuri) {
    GstEncodingProfile *prof = NULL;

    if (!format) {
      GESProject *proj =
          GES_PROJECT (ges_extractable_get_asset (GES_EXTRACTABLE (timeline)));
      const GList *profiles = ges_project_list_encoding_profiles (proj);

      prof = profiles ? profiles->data : NULL;
    }

    if (!prof) {
      if (format == NULL)
        format = "application/ogg:video/x-theora:audio/x-vorbis";

      prof = _parse_encoding_profile (format);
    }

    if (outputuri)
      outputuri = ensure_uri (outputuri);

    if (!prof || !ges_pipeline_set_render_settings (pipeline, outputuri, prof)
        || !ges_pipeline_set_mode (pipeline,
            smartrender ? GES_PIPELINE_MODE_SMART_RENDER :
            GES_PIPELINE_MODE_RENDER)) {
      g_free (outputuri);
      exit (1);
    }
    g_free (outputuri);

    gst_encoding_profile_unref (prof);
  } else {
    ges_pipeline_set_mode (pipeline, GES_PIPELINE_MODE_PREVIEW);
  }

  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);
  }

  /* Play the pipeline */
  mainloop = g_main_loop_new (NULL, FALSE);

  if (thumbinterval != 0.0) {
    g_printf ("thumbnailing every %f seconds\n", thumbinterval);
    g_timeout_add (1000 * thumbinterval, thumbnail_cb, pipeline);
  }

  bus = gst_pipeline_get_bus (GST_PIPELINE (pipeline));
  gst_bus_add_signal_watch (bus);
  g_signal_connect (bus, "message", G_CALLBACK (bus_message_cb), mainloop);

  if (gst_element_set_state (GST_ELEMENT (pipeline),
          GST_STATE_PLAYING) == GST_STATE_CHANGE_FAILURE) {
    g_error ("Failed to start the encoding\n");
    return 1;
  }
  g_timeout_add (100, (GSourceFunc) _print_position, NULL);
  g_main_loop_run (mainloop);

  gst_element_set_state (GST_ELEMENT (pipeline), GST_STATE_NULL);

  gst_object_unref (pipeline);

  g_hash_table_unref (tried_uris);
  return (int) seenerrors;
}