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 several measures to create
33 * somewhat dynamic pipelines. Due to that such pipelines are not always
34 * reusable (set the state to NULL and back to PLAYING).
37 #include "gst_private.h"
43 #ifndef GST_DISABLE_PARSE
44 #include "parse/types.h"
47 static GstParseContext *
48 gst_parse_context_copy (const GstParseContext * context)
50 GstParseContext *ret = NULL;
51 #ifndef GST_DISABLE_PARSE
53 ret = gst_parse_context_new ();
55 GQueue missing_copy = G_QUEUE_INIT;
58 for (l = context->missing_elements; l != NULL; l = l->next)
59 g_queue_push_tail (&missing_copy, g_strdup ((const gchar *) l->data));
61 ret->missing_elements = missing_copy.head;
67 G_DEFINE_BOXED_TYPE (GstParseContext, gst_parse_context,
68 (GBoxedCopyFunc) gst_parse_context_copy,
69 (GBoxedFreeFunc) gst_parse_context_free);
72 * gst_parse_error_quark:
74 * Get the error quark used by the parsing subsystem.
76 * Returns: the quark of the parse errors.
79 gst_parse_error_quark (void)
81 static GQuark quark = 0;
84 quark = g_quark_from_static_string ("gst_parse_error");
90 * gst_parse_context_new:
92 * Allocates a parse context for use with gst_parse_launch_full() or
93 * gst_parse_launchv_full().
95 * Free-function: gst_parse_context_free
97 * Returns: (transfer full): a newly-allocated parse context. Free with
98 * gst_parse_context_free() when no longer needed.
103 gst_parse_context_new (void)
105 #ifndef GST_DISABLE_PARSE
106 GstParseContext *ctx;
108 ctx = g_slice_new (GstParseContext);
109 ctx->missing_elements = NULL;
118 * gst_parse_context_free:
119 * @context: (transfer full): a #GstParseContext
121 * Frees a parse context previously allocated with gst_parse_context_new().
126 gst_parse_context_free (GstParseContext * context)
128 #ifndef GST_DISABLE_PARSE
130 g_list_foreach (context->missing_elements, (GFunc) g_free, NULL);
131 g_list_free (context->missing_elements);
132 g_slice_free (GstParseContext, context);
138 * gst_parse_context_get_missing_elements:
139 * @context: a #GstParseContext
141 * Retrieve missing elements from a previous run of gst_parse_launch_full()
142 * or gst_parse_launchv_full(). Will only return results if an error code
143 * of %GST_PARSE_ERROR_NO_SUCH_ELEMENT was returned.
145 * Returns: (transfer full) (array zero-terminated=1) (element-type gchar*): a
146 * NULL-terminated array of element factory name strings of missing
147 * elements. Free with g_strfreev() when no longer needed.
152 gst_parse_context_get_missing_elements (GstParseContext * context)
154 #ifndef GST_DISABLE_PARSE
159 g_return_val_if_fail (context != NULL, NULL);
161 len = g_list_length (context->missing_elements);
163 if (G_UNLIKELY (len == 0))
166 arr = g_new (gchar *, len + 1);
168 for (i = 0, l = context->missing_elements; l != NULL; l = l->next, ++i)
169 arr[i] = g_strdup (l->data);
179 #ifndef GST_DISABLE_PARSE
181 _gst_parse_escape (const gchar * str)
183 GString *gstr = NULL;
185 g_return_val_if_fail (str != NULL, NULL);
187 gstr = g_string_sized_new (strlen (str));
191 g_string_append_c (gstr, '\\');
192 g_string_append_c (gstr, *str);
196 return g_string_free (gstr, FALSE);
198 #endif /* !GST_DISABLE_PARSE */
202 * @argv: (in) (array zero-terminated=1): null-terminated array of arguments
203 * @error: pointer to a #GError
205 * Create a new element based on command line syntax.
206 * @error will contain an error message if an erroneuos pipeline is specified.
207 * An error does not mean that the pipeline could not be constructed.
209 * Returns: (transfer full): a new element on success and %NULL on failure.
212 gst_parse_launchv (const gchar ** argv, GError ** error)
214 return gst_parse_launchv_full (argv, NULL, GST_PARSE_FLAG_NONE, error);
218 * gst_parse_launchv_full:
219 * @argv: (in) (array zero-terminated=1): null-terminated array of arguments
220 * @context: (allow-none): a parse context allocated with
221 * gst_parse_context_new(), or %NULL
222 * @flags: parsing options, or #GST_PARSE_FLAG_NONE
223 * @error: pointer to a #GError (which must be initialised to %NULL)
225 * Create a new element based on command line syntax.
226 * @error will contain an error message if an erroneous pipeline is specified.
227 * An error does not mean that the pipeline could not be constructed.
229 * Returns: (transfer full): a new element on success; on failure, either %NULL
230 * or a partially-constructed bin or element will be returned and @error will
231 * be set (unless you passed #GST_PARSE_FLAG_FATAL_ERRORS in @flags, then
232 * %NULL will always be returned on failure)
237 gst_parse_launchv_full (const gchar ** argv, GstParseContext * context,
238 GstParseFlags flags, GError ** error)
240 #ifndef GST_DISABLE_PARSE
243 const gchar **argvp, *arg;
246 g_return_val_if_fail (argv != NULL, NULL);
247 g_return_val_if_fail (error == NULL || *error == NULL, NULL);
249 /* let's give it a nice size. */
250 str = g_string_sized_new (1024);
255 tmp = _gst_parse_escape (arg);
256 g_string_append (str, tmp);
258 g_string_append_c (str, ' ');
262 element = gst_parse_launch_full (str->str, context, flags, error);
264 g_string_free (str, TRUE);
268 /* gst_parse_launch_full() will set a GST_CORE_ERROR_DISABLED error for us */
269 return gst_parse_launch_full ("", NULL, 0, error);
275 * @pipeline_description: the command line describing the pipeline
276 * @error: the error message in case of an erroneous pipeline.
278 * Create a new pipeline based on command line syntax.
279 * Please note that you might get a return value that is not %NULL even though
280 * the @error is set. In this case there was a recoverable parsing error and you
281 * can try to play the pipeline.
283 * Returns: (transfer floating): a new element on success, %NULL on failure. If
284 * more than one toplevel element is specified by the @pipeline_description,
285 * all elements are put into a #GstPipeline, which than is returned.
288 gst_parse_launch (const gchar * pipeline_description, GError ** error)
290 return gst_parse_launch_full (pipeline_description, NULL, GST_PARSE_FLAG_NONE,
295 * gst_parse_launch_full:
296 * @pipeline_description: the command line describing the pipeline
297 * @context: (allow-none): a parse context allocated with
298 * gst_parse_context_new(), or %NULL
299 * @flags: parsing options, or #GST_PARSE_FLAG_NONE
300 * @error: the error message in case of an erroneous pipeline.
302 * Create a new pipeline based on command line syntax.
303 * Please note that you might get a return value that is not %NULL even though
304 * the @error is set. In this case there was a recoverable parsing error and you
305 * can try to play the pipeline.
307 * Returns: (transfer full): a new element on success, %NULL on failure. If
308 * more than one toplevel element is specified by the @pipeline_description,
309 * all elements are put into a #GstPipeline, which then is returned.
314 gst_parse_launch_full (const gchar * pipeline_description,
315 GstParseContext * context, GstParseFlags flags, GError ** error)
317 #ifndef GST_DISABLE_PARSE
320 g_return_val_if_fail (pipeline_description != NULL, NULL);
321 g_return_val_if_fail (error == NULL || *error == NULL, NULL);
323 GST_CAT_INFO (GST_CAT_PIPELINE, "parsing pipeline description '%s'",
324 pipeline_description);
326 element = priv_gst_parse_launch (pipeline_description, error, context, flags);
328 /* don't return partially constructed pipeline if FATAL_ERRORS was given */
329 if (G_UNLIKELY (error != NULL && *error != NULL && element != NULL)) {
330 if ((flags & GST_PARSE_FLAG_FATAL_ERRORS)) {
331 gst_object_unref (element);
340 GST_WARNING ("Disabled API called");
342 msg = gst_error_get_message (GST_CORE_ERROR, GST_CORE_ERROR_DISABLED);
343 g_set_error (error, GST_CORE_ERROR, GST_CORE_ERROR_DISABLED, "%s", msg);