/* GStreamer * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu> * 2000 Wim Taymans <wtay@chello.be> * 2002 Andy Wingo <wingo@pobox.com> * 2008 Tim-Philipp Müller <tim centricular net> * * gstparse.c: get a pipeline from a text pipeline description * * 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. */ /** * SECTION:gstparse * @short_description: Get a pipeline from a text pipeline description * * These function allow to create a pipeline based on the syntax used in the * gst-launch utility. */ #include "gst_private.h" #include <string.h> #include "gstparse.h" #include "gsterror.h" #include "gstinfo.h" #ifndef GST_DISABLE_PARSE #include "parse/types.h" #endif /** * gst_parse_error_quark: * * Get the error quark used by the parsing subsystem. * * Returns: the quark of the parse errors. */ GQuark gst_parse_error_quark (void) { static GQuark quark = 0; if (!quark) quark = g_quark_from_static_string ("gst_parse_error"); return quark; } /** * gst_parse_context_new: * * Allocates a parse context for use with gst_parse_launch_full() or * gst_parse_launchv_full(). * * Returns: a newly-allocated parse context. Free with gst_parse_context_free() * when no longer needed. * * Since: 0.10.20 */ GstParseContext * gst_parse_context_new (void) { #ifndef GST_DISABLE_PARSE GstParseContext *ctx; ctx = g_slice_new (GstParseContext); ctx->missing_elements = NULL; return ctx; #else return NULL; #endif } /** * gst_parse_context_free: * @context: a #GstParseContext * * Frees a parse context previously allocated with gst_parse_context_new(). * * Since: 0.10.20 */ void gst_parse_context_free (GstParseContext * context) { #ifndef GST_DISABLE_PARSE if (context) { g_list_foreach (context->missing_elements, (GFunc) g_free, NULL); g_list_free (context->missing_elements); g_slice_free (GstParseContext, context); } #endif } /** * gst_parse_context_get_missing_elements: * @context: a #GstParseContext * * Retrieve missing elements from a previous run of gst_parse_launch_full() * or gst_parse_launchv_full(). Will only return results if an error code * of %GST_PARSE_ERROR_NO_SUCH_ELEMENT was returned. * * Returns: a NULL-terminated array of element factory name strings of * missing elements. Free with g_strfreev() when no longer needed. * * Since: 0.10.20 */ gchar ** gst_parse_context_get_missing_elements (GstParseContext * context) { #ifndef GST_DISABLE_PARSE gchar **arr; GList *l; guint len, i; g_return_val_if_fail (context != NULL, NULL); len = g_list_length (context->missing_elements); if (G_UNLIKELY (len == 0)) return NULL; arr = g_new (gchar *, len + 1); for (i = 0, l = context->missing_elements; l != NULL; l = l->next, ++i) arr[i] = g_strdup (l->data); arr[i] = NULL; return arr; #else return NULL; #endif } #ifndef GST_DISABLE_PARSE static gchar * _gst_parse_escape (const gchar * str) { GString *gstr = NULL; g_return_val_if_fail (str != NULL, NULL); gstr = g_string_sized_new (strlen (str)); while (*str) { if (*str == ' ') g_string_append_c (gstr, '\\'); g_string_append_c (gstr, *str); str++; } return g_string_free (gstr, FALSE); } #endif /* !GST_DISABLE_PARSE */ /** * gst_parse_launchv: * @argv: null-terminated array of arguments * @error: pointer to a #GError * * Create a new element based on command line syntax. * @error will contain an error message if an erroneuos pipeline is specified. * An error does not mean that the pipeline could not be constructed. * * Returns: a new element on success and %NULL on failure. */ GstElement * gst_parse_launchv (const gchar ** argv, GError ** error) { return gst_parse_launchv_full (argv, NULL, 0, error); } /** * gst_parse_launchv_full: * @argv: null-terminated array of arguments * @context: a parse context allocated with gst_parse_context_new(), or %NULL * @flags: parsing options, or #GST_PARSE_FLAG_NONE * @error: pointer to a #GError (which must be initialised to %NULL) * * Create a new element based on command line syntax. * @error will contain an error message if an erroneous pipeline is specified. * An error does not mean that the pipeline could not be constructed. * * Returns: a new element on success; on failure, either %NULL or a * partially-constructed bin or element will be returned and @error will be set * (unless you passed #GST_PARSE_FLAG_FATAL_ERRORS in @flags, then %NULL will * always be returned on failure) * * Since: 0.10.20 */ GstElement * gst_parse_launchv_full (const gchar ** argv, GstParseContext * context, GstParseFlags flags, GError ** error) { #ifndef GST_DISABLE_PARSE GstElement *element; GString *str; const gchar **argvp, *arg; gchar *tmp; g_return_val_if_fail (argv != NULL, NULL); g_return_val_if_fail (error == NULL || *error == NULL, NULL); /* let's give it a nice size. */ str = g_string_sized_new (1024); argvp = argv; while (*argvp) { arg = *argvp; tmp = _gst_parse_escape (arg); g_string_append (str, tmp); g_free (tmp); g_string_append_c (str, ' '); argvp++; } element = gst_parse_launch_full (str->str, context, flags, error); g_string_free (str, TRUE); return element; #else /* gst_parse_launch_full() will set a GST_CORE_ERROR_DISABLED error for us */ return gst_parse_launch_full ("", NULL, 0, error); #endif } /** * gst_parse_launch: * @pipeline_description: the command line describing the pipeline * @error: the error message in case of an erroneous pipeline. * * Create a new pipeline based on command line syntax. * Please note that you might get a return value that is not %NULL even though * the @error is set. In this case there was a recoverable parsing error and you * can try to play the pipeline. * * Returns: a new element on success, %NULL on failure. If more than one toplevel * element is specified by the @pipeline_description, all elements are put into * a #GstPipeline, which than is returned. */ GstElement * gst_parse_launch (const gchar * pipeline_description, GError ** error) { return gst_parse_launch_full (pipeline_description, NULL, 0, error); } /** * gst_parse_launch_full: * @pipeline_description: the command line describing the pipeline * @context: a parse context allocated with gst_parse_context_new(), or %NULL * @flags: parsing options, or #GST_PARSE_FLAG_NONE * @error: the error message in case of an erroneous pipeline. * * Create a new pipeline based on command line syntax. * Please note that you might get a return value that is not %NULL even though * the @error is set. In this case there was a recoverable parsing error and you * can try to play the pipeline. * * Returns: a new element on success, %NULL on failure. If more than one toplevel * element is specified by the @pipeline_description, all elements are put into * a #GstPipeline, which then is returned. * * Since: 0.10.20 */ GstElement * gst_parse_launch_full (const gchar * pipeline_description, GstParseContext * context, GstParseFlags flags, GError ** error) { #ifndef GST_DISABLE_PARSE GstElement *element; g_return_val_if_fail (pipeline_description != NULL, NULL); g_return_val_if_fail (error == NULL || *error == NULL, NULL); GST_CAT_INFO (GST_CAT_PIPELINE, "parsing pipeline description '%s'", pipeline_description); element = _gst_parse_launch (pipeline_description, error, context, flags); /* don't return partially constructed pipeline if FATAL_ERRORS was given */ if (G_UNLIKELY (error != NULL && *error != NULL && element != NULL)) { if ((flags & GST_PARSE_FLAG_FATAL_ERRORS)) { gst_object_unref (element); element = NULL; } } return element; #else gchar *msg; GST_WARNING ("Disabled API called"); msg = gst_error_get_message (GST_CORE_ERROR, GST_CORE_ERROR_DISABLED); g_set_error (error, GST_CORE_ERROR, GST_CORE_ERROR_DISABLED, "%s", msg); g_free (msg); return NULL; #endif }