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
30 * gst-launch utility (see man-page for syntax documentation).
32 * Please note that these functions take serveral meassures to create even
33 * somewhat dynamic pipelines. Due to that such pipelines are not always
34 * reuseable (set the state to NULL and back to PLAYING).
37 #include "gst_private.h"
43 #ifndef GST_DISABLE_PARSE
44 #include "parse/types.h"
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");
66 * gst_parse_context_new:
68 * Allocates a parse context for use with gst_parse_launch_full() or
69 * gst_parse_launchv_full().
71 * Returns: a newly-allocated parse context. Free with gst_parse_context_free()
72 * when no longer needed.
77 gst_parse_context_new (void)
79 #ifndef GST_DISABLE_PARSE
82 ctx = g_slice_new (GstParseContext);
83 ctx->missing_elements = NULL;
92 * gst_parse_context_free:
93 * @context: a #GstParseContext
95 * Frees a parse context previously allocated with gst_parse_context_new().
100 gst_parse_context_free (GstParseContext * context)
102 #ifndef GST_DISABLE_PARSE
104 g_list_foreach (context->missing_elements, (GFunc) g_free, NULL);
105 g_list_free (context->missing_elements);
106 g_slice_free (GstParseContext, context);
112 * gst_parse_context_get_missing_elements:
113 * @context: a #GstParseContext
115 * Retrieve missing elements from a previous run of gst_parse_launch_full()
116 * or gst_parse_launchv_full(). Will only return results if an error code
117 * of %GST_PARSE_ERROR_NO_SUCH_ELEMENT was returned.
119 * Returns: a NULL-terminated array of element factory name strings of
120 * missing elements. Free with g_strfreev() when no longer needed.
125 gst_parse_context_get_missing_elements (GstParseContext * context)
127 #ifndef GST_DISABLE_PARSE
132 g_return_val_if_fail (context != NULL, NULL);
134 len = g_list_length (context->missing_elements);
136 if (G_UNLIKELY (len == 0))
139 arr = g_new (gchar *, len + 1);
141 for (i = 0, l = context->missing_elements; l != NULL; l = l->next, ++i)
142 arr[i] = g_strdup (l->data);
152 #ifndef GST_DISABLE_PARSE
154 _gst_parse_escape (const gchar * str)
156 GString *gstr = NULL;
158 g_return_val_if_fail (str != NULL, NULL);
160 gstr = g_string_sized_new (strlen (str));
164 g_string_append_c (gstr, '\\');
165 g_string_append_c (gstr, *str);
169 return g_string_free (gstr, FALSE);
171 #endif /* !GST_DISABLE_PARSE */
175 * @argv: null-terminated array of arguments
176 * @error: pointer to a #GError
178 * Create a new element based on command line syntax.
179 * @error will contain an error message if an erroneuos pipeline is specified.
180 * An error does not mean that the pipeline could not be constructed.
182 * Returns: a new element on success and %NULL on failure.
185 gst_parse_launchv (const gchar ** argv, GError ** error)
187 return gst_parse_launchv_full (argv, NULL, 0, error);
191 * gst_parse_launchv_full:
192 * @argv: null-terminated array of arguments
193 * @context: a parse context allocated with gst_parse_context_new(), or %NULL
194 * @flags: parsing options, or #GST_PARSE_FLAG_NONE
195 * @error: pointer to a #GError (which must be initialised to %NULL)
197 * Create a new element based on command line syntax.
198 * @error will contain an error message if an erroneous pipeline is specified.
199 * An error does not mean that the pipeline could not be constructed.
201 * Returns: a new element on success; on failure, either %NULL or a
202 * partially-constructed bin or element will be returned and @error will be set
203 * (unless you passed #GST_PARSE_FLAG_FATAL_ERRORS in @flags, then %NULL will
204 * always be returned on failure)
209 gst_parse_launchv_full (const gchar ** argv, GstParseContext * context,
210 GstParseFlags flags, GError ** error)
212 #ifndef GST_DISABLE_PARSE
215 const gchar **argvp, *arg;
218 g_return_val_if_fail (argv != NULL, NULL);
219 g_return_val_if_fail (error == NULL || *error == NULL, NULL);
221 /* let's give it a nice size. */
222 str = g_string_sized_new (1024);
227 tmp = _gst_parse_escape (arg);
228 g_string_append (str, tmp);
230 g_string_append_c (str, ' ');
234 element = gst_parse_launch_full (str->str, context, flags, error);
236 g_string_free (str, TRUE);
240 /* gst_parse_launch_full() will set a GST_CORE_ERROR_DISABLED error for us */
241 return gst_parse_launch_full ("", NULL, 0, error);
247 * @pipeline_description: the command line describing the pipeline
248 * @error: the error message in case of an erroneous pipeline.
250 * Create a new pipeline based on command line syntax.
251 * Please note that you might get a return value that is not %NULL even though
252 * the @error is set. In this case there was a recoverable parsing error and you
253 * can try to play the pipeline.
255 * Returns: a new element on success, %NULL on failure. If more than one toplevel
256 * element is specified by the @pipeline_description, all elements are put into
257 * a #GstPipeline, which than is returned.
260 gst_parse_launch (const gchar * pipeline_description, GError ** error)
262 return gst_parse_launch_full (pipeline_description, NULL, 0, error);
266 * gst_parse_launch_full:
267 * @pipeline_description: the command line describing the pipeline
268 * @context: a parse context allocated with gst_parse_context_new(), or %NULL
269 * @flags: parsing options, or #GST_PARSE_FLAG_NONE
270 * @error: the error message in case of an erroneous pipeline.
272 * Create a new pipeline based on command line syntax.
273 * Please note that you might get a return value that is not %NULL even though
274 * the @error is set. In this case there was a recoverable parsing error and you
275 * can try to play the pipeline.
277 * Returns: a new element on success, %NULL on failure. If more than one toplevel
278 * element is specified by the @pipeline_description, all elements are put into
279 * a #GstPipeline, which then is returned.
284 gst_parse_launch_full (const gchar * pipeline_description,
285 GstParseContext * context, GstParseFlags flags, GError ** error)
287 #ifndef GST_DISABLE_PARSE
290 g_return_val_if_fail (pipeline_description != NULL, NULL);
291 g_return_val_if_fail (error == NULL || *error == NULL, NULL);
293 GST_CAT_INFO (GST_CAT_PIPELINE, "parsing pipeline description '%s'",
294 pipeline_description);
296 element = _gst_parse_launch (pipeline_description, error, context, flags);
298 /* don't return partially constructed pipeline if FATAL_ERRORS was given */
299 if (G_UNLIKELY (error != NULL && *error != NULL && element != NULL)) {
300 if ((flags & GST_PARSE_FLAG_FATAL_ERRORS)) {
301 gst_object_unref (element);
310 GST_WARNING ("Disabled API called");
312 msg = gst_error_get_message (GST_CORE_ERROR, GST_CORE_ERROR_DISABLED);
313 g_set_error (error, GST_CORE_ERROR, GST_CORE_ERROR_DISABLED, "%s", msg);