gstreamer/gst/gstparse.c

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/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wtay@chello.be>
* 2002 Andy Wingo <wingo@pobox.com>
*
* 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 utillity.
*/
#include "gst_private.h"
#include <string.h>
#include "gstparse.h"
#include "gsterror.h"
#include "gstinfo.h"
extern GstElement *_gst_parse_launch (const gchar *, GError **);
/**
* 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;
}
#ifndef GST_DISABLE_PARSE
static gchar *
_gst_parse_escape (const gchar * str)
{
GString *gstr = NULL;
gchar *newstr = 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++;
}
newstr = gstr->str;
g_string_free (gstr, FALSE);
return newstr;
}
#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)
{
#ifndef GST_DISABLE_PARSE
GstElement *element;
GString *str;
const gchar **argvp, *arg;
gchar *tmp;
g_return_val_if_fail (argv != 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 (str->str, error);
g_string_free (str, TRUE);
return element;
#else
gchar *msg;
GST_WARNING ("Disabled API called: gst_parse_launchv()");
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
}
/**
* 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)
{
#ifndef GST_DISABLE_PARSE
GstElement *element;
g_return_val_if_fail (pipeline_description != NULL, NULL);
GST_CAT_INFO (GST_CAT_PIPELINE, "parsing pipeline description %s",
pipeline_description);
element = _gst_parse_launch (pipeline_description, error);
return element;
#else
gchar *msg;
GST_WARNING ("Disabled API called: gst_parse_launch()");
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
}