Add an example that shows transcoding stats for mpeg audio to vorbis

Original commit message from CVS:
Add an example that shows transcoding stats for mpeg audio to vorbis

examples/stats/Makefile.am

@@ -0,0 +1,6 @@
+noinst_PROGRAMS = mp2ogg
+
+LDADD = $(GST_LIBS)
+AM_CFLAGS = $(GST_CFLAGS)
+
+

examples/stats/mp2ogg.c

@@ -0,0 +1,103 @@
+/* GStreamer
+ * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
+ *
+ * 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.
+ */
+
+#include <gst/gst.h>
+
+/* This example app demonstartes the use of pad query and convert to
+ * get usefull statistics about a plugin. In this case we monitor the
+ * compression status of mpeg audio to ogg vorbis transcoding.
+ */
+
+gint 
+main (gint argc, gchar *argv[]) 
+{
+  GstElement *pipeline;
+  GError *error = NULL;
+  gchar *description;
+  GstElement *encoder, *decoder;
+  GstPad *dec_sink, *enc_src;
+
+  gst_init (&argc, &argv);
+  
+  if (argc < 3) {
+    g_print ("usage: %s <inputfile> <outputfile>\n", argv[0]);
+    return -1;
+  }
+
+  description = g_strdup_printf ("filesrc location=\"%s\" ! mad name=decoder ! "
+		  "vorbisenc name=encoder ! filesink location=\"%s\"", argv[1], argv[2]);
+
+  pipeline = GST_ELEMENT (gst_parse_launch (description, &error));
+  if (!pipeline) {
+    if (error)
+       g_print ("ERROR: pipeline could not be constructed: %s\n", error->message);
+    else
+       g_print ("ERROR: pipeline could not be constructed\n");
+    return -1;
+  }
+
+  decoder = gst_bin_get_by_name (GST_BIN (pipeline), "decoder");
+  encoder = gst_bin_get_by_name (GST_BIN (pipeline), "encoder");
+
+  dec_sink = gst_element_get_pad (decoder, "sink");
+  enc_src = gst_element_get_pad (encoder, "src");
+  
+  if (gst_element_set_state (pipeline, GST_STATE_PLAYING) != GST_STATE_SUCCESS) {
+    g_print ("pipeline doesn't want to play\n");
+    return -1;
+  }
+
+  while (gst_bin_iterate (GST_BIN (pipeline))) {
+    gint64 position;
+    gint64 duration;
+    gint64 bitrate_enc, bitrate_dec;
+    GstFormat format;
+
+    format = GST_FORMAT_TIME;
+    /* get the position */
+    gst_pad_query (enc_src, GST_PAD_QUERY_POSITION, 
+		   &format, &position);
+
+    /* get the total duration */
+    gst_pad_query (enc_src, GST_PAD_QUERY_TOTAL, 
+		   &format, &duration);
+
+    format = GST_FORMAT_BYTES;
+    /* see how many bytes are genereated per 8 seconds (== bitrate) */
+    gst_pad_convert (enc_src, GST_FORMAT_TIME, 8 * GST_SECOND,
+		              &format, &bitrate_enc);
+
+    gst_pad_convert (dec_sink, GST_FORMAT_TIME, 8 * GST_SECOND,
+		              &format, &bitrate_dec);
+
+    g_print ("[%2dm %.2ds] of [%2dm %.2ds], "
+	     "src avg bitrate: %lld, dest avg birate: %lld, ratio [%02.2f]    \r",
+		    (gint)(position / (GST_SECOND * 60)), 
+		    (gint)(position / (GST_SECOND)) % 60, 
+		    (gint)(duration / (GST_SECOND * 60)), 
+		    (gint)(duration / (GST_SECOND)) % 60, 
+		    bitrate_dec,
+		    bitrate_enc,
+		    (gfloat)bitrate_dec/bitrate_enc);
+  }
+
+  g_print ("\n");
+  
+  return 0;
+}