2 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3 * 2000 Wim Taymans <wtay@chello.be>
4 * 2002 Andy Wingo <wingo@pobox.com>
6 * gstparse.c: get a pipeline from a text pipeline description
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Library General Public
10 * License as published by the Free Software Foundation; either
11 * version 2 of the License, or (at your option) any later version.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Library General Public License for more details.
18 * You should have received a copy of the GNU Library General Public
19 * License along with this library; if not, write to the
20 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
21 * Boston, MA 02111-1307, USA.
26 * @short_description: Get a pipeline from a text pipeline description
28 * These function allow to create a pipeline based on the syntax used in the
29 * gst-launch utillity.
33 #include "gst_private.h"
39 #ifndef HAVE_MT_SAVE_FLEX
40 /* the need for the mutex will go away with flex 2.5.6 */
41 static gboolean flex_busy = FALSE;
42 static GStaticRecMutex flex_lock = G_STATIC_REC_MUTEX_INIT;
45 extern GstElement *_gst_parse_launch (const gchar *, GError **);
48 * gst_parse_error_quark:
50 * Get the error quark used by the parsing subsystem.
52 * Returns: the quark of the parse errors.
55 gst_parse_error_quark (void)
57 static GQuark quark = 0;
60 quark = g_quark_from_static_string ("gst_parse_error");
65 _gst_parse_escape (const gchar * str)
70 g_return_val_if_fail (str != NULL, NULL);
72 gstr = g_string_sized_new (strlen (str));
76 g_string_append_c (gstr, '\\');
77 g_string_append_c (gstr, *str);
82 g_string_free (gstr, FALSE);
89 * @argv: null-terminated array of arguments
90 * @error: pointer to a #GError
92 * Create a new element based on command line syntax.
93 * @error will contain an error message if an erroneuos pipeline is specified.
94 * An error does not mean that the pipeline could not be constructed.
96 * Returns: a new element on success and %NULL on failure.
99 gst_parse_launchv (const gchar ** argv, GError ** error)
103 const gchar **argvp, *arg;
106 g_return_val_if_fail (argv != NULL, NULL);
108 /* let's give it a nice size. */
109 str = g_string_sized_new (1024);
114 tmp = _gst_parse_escape (arg);
115 g_string_append (str, tmp);
117 g_string_append (str, " ");
121 element = gst_parse_launch (str->str, error);
123 g_string_free (str, TRUE);
130 * @pipeline_description: the command line describing the pipeline
131 * @error: the error message in case of an erroneous pipeline.
133 * Create a new pipeline based on command line syntax.
134 * Please note that you might get a return value that is not %NULL even though
135 * the @error is set. In this case there was a recoverable parsing error and you
136 * can try to play the pipeline.
138 * Returns: a new element on success, %NULL on failure. If more than one toplevel
139 * element is specified by the @pipeline_description, all elements are put into
140 * a #GstPipeline, which than is returned.
143 gst_parse_launch (const gchar * pipeline_description, GError ** error)
147 g_return_val_if_fail (pipeline_description != NULL, NULL);
149 GST_CAT_INFO (GST_CAT_PIPELINE, "parsing pipeline description %s",
150 pipeline_description);
152 #ifndef HAVE_MT_SAVE_FLEX
153 g_static_rec_mutex_lock (&flex_lock);
159 element = _gst_parse_launch (pipeline_description, error);
161 #ifndef HAVE_MT_SAVE_FLEX
163 g_static_rec_mutex_unlock (&flex_lock);
169 #ifndef HAVE_MT_SAVE_FLEX
172 GST_WARNING ("calls to gst_parse_launch() cannot be nested");
173 g_static_rec_mutex_unlock (&flex_lock);
174 g_warning ("calls to gst_parse_launch() cannot be nested");