mdw@git.distorted.org.uk Git - disorder/blob - plugins/tracklength-gstreamer.c

   1 /*
   2  * This file is part of DisOrder.
   3  * Copyright (C) 2018 Mark Wooding
   4  *
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, either version 3 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18 /** @file plugins/tracklength-gstreamer.c
  19  * @brief Plugin to compute track lengths using GStreamer
  20  */
  21 #include "tracklength.h"
  22
  23 /* Ugh.  It turns out that libxml tries to define a function called
  24  * `attribute', and it's included by GStreamer for some unimaginable reason.
  25  * So undefine it here.  We'll want GCC attributes for special effects, but
  26  * can take care of ourselves.
  27  */
  28 #undef attribute
  29
  30 #include <glib.h>
  31 #include <gst/gst.h>
  32 #include <gst/pbutils/gstdiscoverer.h>
  33
  34 /* The only application we have for `attribute' is declaring function
  35  * arguments as being unused, because we have a lot of callback functions
  36  * which are meant to comply with an externally defined interface.
  37  */
  38 #ifdef __GNUC__
  39 #  define UNUSED __attribute__((unused))
  40 #endif
  41
  42 #define END ((void *)0)
  43
  44 static GstDiscoverer *disco = 0;
  45
  46 long disorder_tracklength(const char UNUSED *track, const char *path) {
  47   GError *err = 0;
  48   gchar *dir = 0, *abs = 0, *uri = 0;
  49   GstDiscovererInfo *info = 0;
  50   long length = -1;
  51   GstClockTime t;
  52
  53   if (!path) goto end;
  54
  55   if(!disco) {
  56     gst_init(0, 0);
  57     disco = gst_discoverer_new(5*GST_SECOND, &err); if(!disco) goto end;
  58   }
  59
  60   if (g_path_is_absolute(path))
  61     uri = g_filename_to_uri(path, 0, &err);
  62   else {
  63     dir = g_get_current_dir();
  64     abs = g_build_filename(dir, path, END);
  65     uri = g_filename_to_uri(abs, 0, &err);
  66   }
  67   if(!uri) goto end;
  68
  69   info = gst_discoverer_discover_uri(disco, uri, &err); if(!info) goto end;
  70   switch(gst_discoverer_info_get_result(info)) {
  71   case GST_DISCOVERER_OK:
  72     t = gst_discoverer_info_get_duration(info);
  73     length = (t + GST_SECOND/2)/GST_SECOND;
  74     break;
  75   case GST_DISCOVERER_TIMEOUT:
  76     disorder_info("discovery timed out probing `%s'", path);
  77     goto swallow_error;
  78   case GST_DISCOVERER_MISSING_PLUGINS:
  79     disorder_info("unrecognized file `%s' (missing plugins?)", path);
  80     goto swallow_error;
  81   swallow_error:
  82     if(err) { g_error_free(err); err = 0; }
  83     length = 0;
  84     break;
  85   default:
  86     goto end;
  87   }
  88
  89 end:
  90   if(err) {
  91     disorder_error(0, "error probing `%s': %s", path, err->message);
  92     g_error_free(err);
  93   }
  94   if(info) gst_discoverer_info_unref(info);
  95   g_free(dir); g_free(abs); g_free(uri);
  96   return length;
  97 }
  98
  99 #ifdef STANDALONE
 100 int main(int argc, char *argv[]) {
 101   int i;
 102
 103   for(i = 1; i < argc; i++)
 104     printf("%s: %ld\n", argv[i], disorder_tracklength(0, argv[i]));
 105   return (0);
 106 }
 107 #endif
 108
 109 /*
 110 Local Variables:
 111 c-basic-offset:2
 112 comment-column:40
 113 fill-column:79
 114 End:
 115 */