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>
5 * 2008 Tim-Philipp Müller <tim centricular net>
7 * gstparse.c: get a pipeline from a text pipeline description
9 * This library is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Library General Public
11 * License as published by the Free Software Foundation; either
12 * version 2 of the License, or (at your option) any later version.
14 * This library is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * Library General Public License for more details.
19 * You should have received a copy of the GNU Library General Public
20 * License along with this library; if not, write to the
21 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
22 * Boston, MA 02111-1307, USA.
27 * @short_description: Get a pipeline from a text pipeline description
29 * These function allow to create a pipeline based on the syntax used in the
34 #include "gst_private.h"
41 extern GstElement *_gst_parse_launch (const gchar *, GError **,
42 GstParseContext *, GstParseFlags);
45 * gst_parse_error_quark:
47 * Get the error quark used by the parsing subsystem.
49 * Returns: the quark of the parse errors.
52 gst_parse_error_quark (void)
54 static GQuark quark = 0;
57 quark = g_quark_from_static_string ("gst_parse_error");
63 * gst_parse_context_new:
65 * Allocates a parse context for use with gst_parse_launch_full() or
66 * gst_parse_launchv_full().
68 * Returns: a newly-allocated parse context. Free with gst_parse_context_free()
69 * when no longer needed.
74 gst_parse_context_new (void)
76 #ifndef GST_DISABLE_PARSE
79 ctx = g_slice_new (GstParseContext);
80 ctx->missing_elements = NULL;
89 * gst_parse_context_free:
90 * @context: a #GstParseContext
92 * Frees a parse context previously allocated with gst_parse_context_new().
97 gst_parse_context_free (GstParseContext * context)
99 #ifndef GST_DISABLE_PARSE
101 g_list_foreach (context->missing_elements, (GFunc) g_free, NULL);
102 g_list_free (context->missing_elements);
103 g_slice_free (GstParseContext, context);
109 * gst_parse_context_get_missing_elements:
110 * @context: a #GstParseContext
112 * Retrieve missing elements from a previous run of gst_parse_launch_full()
113 * or gst_parse_launchv_full(). Will only return results if an error code
114 * of %GST_PARSE_ERROR_NO_SUCH_ELEMENT was returned.
116 * Returns: a NULL-terminated array of element factory name strings of
117 * missing elements. Free with g_strfreev() when no longer needed.
122 gst_parse_context_get_missing_elements (GstParseContext * context)
124 #ifndef GST_DISABLE_PARSE
129 g_return_val_if_fail (context != NULL, NULL);
131 len = g_list_length (context->missing_elements);
133 if (G_UNLIKELY (len == 0))
136 arr = g_new (gchar *, len + 1);
138 for (i = 0, l = context->missing_elements; l != NULL; l = l->next, ++i)
139 arr[i] = g_strdup (l->data);
149 #ifndef GST_DISABLE_PARSE
151 _gst_parse_escape (const gchar * str)
153 GString *gstr = NULL;
155 g_return_val_if_fail (str != NULL, NULL);
157 gstr = g_string_sized_new (strlen (str));
161 g_string_append_c (gstr, '\\');
162 g_string_append_c (gstr, *str);
166 return g_string_free (gstr, FALSE);
168 #endif /* !GST_DISABLE_PARSE */
172 * @argv: null-terminated array of arguments
173 * @error: pointer to a #GError
175 * Create a new element based on command line syntax.
176 * @error will contain an error message if an erroneuos pipeline is specified.
177 * An error does not mean that the pipeline could not be constructed.
179 * Returns: a new element on success and %NULL on failure.
182 gst_parse_launchv (const gchar ** argv, GError ** error)
184 return gst_parse_launchv_full (argv, NULL, 0, error);
188 * gst_parse_launchv_full:
189 * @argv: null-terminated array of arguments
190 * @context: a parse context allocated with gst_parse_context_new(), or %NULL
191 * @flags: parsing options, or #GST_PARSE_FLAG_NONE
192 * @error: pointer to a #GError (which must be initialised to %NULL)
194 * Create a new element based on command line syntax.
195 * @error will contain an error message if an erroneous pipeline is specified.
196 * An error does not mean that the pipeline could not be constructed.
198 * Returns: a new element on success; on failure, either %NULL or a
199 * partially-constructed bin or element will be returned and @error will be set
200 * (unless you passed #GST_PARSE_FLAG_FATAL_ERRORS in @flags, then %NULL will
201 * always be returned on failure)
206 gst_parse_launchv_full (const gchar ** argv, GstParseContext * context,
207 GstParseFlags flags, GError ** error)
209 #ifndef GST_DISABLE_PARSE
212 const gchar **argvp, *arg;
215 g_return_val_if_fail (argv != NULL, NULL);
216 g_return_val_if_fail (error == NULL || *error == NULL, NULL);
218 /* let's give it a nice size. */
219 str = g_string_sized_new (1024);
224 tmp = _gst_parse_escape (arg);
225 g_string_append (str, tmp);
227 g_string_append_c (str, ' ');
231 element = gst_parse_launch_full (str->str, context, flags, error);
233 g_string_free (str, TRUE);
237 /* gst_parse_launch_full() will set a GST_CORE_ERROR_DISABLED error for us */
238 return gst_parse_launch_full ("", NULL, 0, error);
244 * @pipeline_description: the command line describing the pipeline
245 * @error: the error message in case of an erroneous pipeline.
247 * Create a new pipeline based on command line syntax.
248 * Please note that you might get a return value that is not %NULL even though
249 * the @error is set. In this case there was a recoverable parsing error and you
250 * can try to play the pipeline.
252 * Returns: a new element on success, %NULL on failure. If more than one toplevel
253 * element is specified by the @pipeline_description, all elements are put into
254 * a #GstPipeline, which than is returned.
257 gst_parse_launch (const gchar * pipeline_description, GError ** error)
259 return gst_parse_launch_full (pipeline_description, NULL, 0, error);
263 * gst_parse_launch_full:
264 * @pipeline_description: the command line describing the pipeline
265 * @context: a parse context allocated with gst_parse_context_new(), or %NULL
266 * @flags: parsing options, or #GST_PARSE_FLAG_NONE
267 * @error: the error message in case of an erroneous pipeline.
269 * Create a new pipeline based on command line syntax.
270 * Please note that you might get a return value that is not %NULL even though
271 * the @error is set. In this case there was a recoverable parsing error and you
272 * can try to play the pipeline.
274 * Returns: a new element on success, %NULL on failure. If more than one toplevel
275 * element is specified by the @pipeline_description, all elements are put into
276 * a #GstPipeline, which then is returned.
281 gst_parse_launch_full (const gchar * pipeline_description,
282 GstParseContext * context, GstParseFlags flags, GError ** error)
284 #ifndef GST_DISABLE_PARSE
287 g_return_val_if_fail (pipeline_description != NULL, NULL);
288 g_return_val_if_fail (error == NULL || *error == NULL, NULL);
290 GST_CAT_INFO (GST_CAT_PIPELINE, "parsing pipeline description '%s'",
291 pipeline_description);
293 element = _gst_parse_launch (pipeline_description, error, context, flags);
295 /* don't return partially constructed pipeline if FATAL_ERRORS was given */
296 if (G_UNLIKELY (error != NULL && *error != NULL && element != NULL)) {
297 if ((flags & GST_PARSE_FLAG_FATAL_ERRORS)) {
298 gst_object_unref (element);
307 GST_WARNING ("Disabled API called");
309 msg = gst_error_get_message (GST_CORE_ERROR, GST_CORE_ERROR_DISABLED);
310 g_set_error (error, GST_CORE_ERROR, GST_CORE_ERROR_DISABLED, "%s", msg);