gstreamer/gst/gstformat.c

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/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wim.taymans@chello.be>
* 2005 Wim Taymans <wim@fluendo.com>
*
* gstformat.c: GstFormat registration
*
* 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:gstformat
* @short_description: Dynamically register new data formats
* @see_also: #GstPad, #GstElement
*
* GstFormats functions are used to register a new format to the gstreamer core.
* Formats can be used to perform seeking or conversions/query operations.
*/
#include <string.h>
#include "gst_private.h"
#include "gstformat.h"
static GStaticMutex mutex = G_STATIC_MUTEX_INIT;
static GList *_gst_formats = NULL;
static GHashTable *_nick_to_format = NULL;
static GHashTable *_format_to_nick = NULL;
static guint32 _n_values = 1; /* we start from 1 because 0 reserved for UNDEFINED */
static GstFormatDefinition standard_definitions[] = {
{GST_FORMAT_DEFAULT, "default", "Default format for the media type"},
{GST_FORMAT_BYTES, "bytes", "Bytes"},
{GST_FORMAT_TIME, "time", "Time"},
{GST_FORMAT_BUFFERS, "buffers", "Buffers"},
{GST_FORMAT_PERCENT, "percent", "Percent"},
{0, NULL, NULL}
};
void
_gst_format_initialize (void)
{
GstFormatDefinition *standards = standard_definitions;
g_static_mutex_lock (&mutex);
if (_nick_to_format == NULL) {
_nick_to_format = g_hash_table_new (g_str_hash, g_str_equal);
_format_to_nick = g_hash_table_new (NULL, NULL);
}
while (standards->nick) {
g_hash_table_insert (_nick_to_format, standards->nick, standards);
g_hash_table_insert (_format_to_nick, GINT_TO_POINTER (standards->value),
standards);
_gst_formats = g_list_append (_gst_formats, standards);
standards++;
_n_values++;
}
g_static_mutex_unlock (&mutex);
}
/**
* gst_format_register:
* @nick: The nick of the new format
* @description: The description of the new format
*
* Create a new GstFormat based on the nick or return an
* already registered format with that nick.
*
* Returns: A new GstFormat or an already registered format
* with the same nick.
*
* MT safe.
*/
GstFormat
gst_format_register (const gchar * nick, const gchar * description)
{
GstFormatDefinition *format;
GstFormat query;
g_return_val_if_fail (nick != NULL, 0);
g_return_val_if_fail (description != NULL, 0);
query = gst_format_get_by_nick (nick);
if (query != GST_FORMAT_UNDEFINED)
return query;
format = g_new0 (GstFormatDefinition, 1);
format->value = _n_values;
format->nick = g_strdup (nick);
format->description = g_strdup (description);
g_static_mutex_lock (&mutex);
g_hash_table_insert (_nick_to_format, format->nick, format);
g_hash_table_insert (_format_to_nick, GINT_TO_POINTER (format->value),
format);
_gst_formats = g_list_append (_gst_formats, format);
_n_values++;
g_static_mutex_unlock (&mutex);
return format->value;
}
/**
* gst_format_get_by_nick:
* @nick: The nick of the format
*
* Return the format registered with the given nick.
*
* Returns: The format with @nick or GST_FORMAT_UNDEFINED
* if the format was not registered.
*/
GstFormat
gst_format_get_by_nick (const gchar * nick)
{
GstFormatDefinition *format;
g_return_val_if_fail (nick != NULL, 0);
g_static_mutex_lock (&mutex);
format = g_hash_table_lookup (_nick_to_format, nick);
g_static_mutex_unlock (&mutex);
if (format != NULL)
return format->value;
else
return GST_FORMAT_UNDEFINED;
}
/**
* gst_formats_contains:
* @formats: The format array to search
* @format: the format to find
*
* See if the given format is inside the format array.
*
* Returns: TRUE if the format is found inside the array
*/
gboolean
gst_formats_contains (const GstFormat * formats, GstFormat format)
{
if (!formats)
return FALSE;
while (*formats) {
if (*formats == format)
return TRUE;
formats++;
}
return FALSE;
}
/**
* gst_format_get_details:
* @format: The format to get details of
*
* Get details about the given format.
*
* Returns: The #GstFormatDefinition for @format or NULL on failure.
*
* MT safe.
*/
const GstFormatDefinition *
gst_format_get_details (GstFormat format)
{
const GstFormatDefinition *result;
g_static_mutex_lock (&mutex);
result = g_hash_table_lookup (_format_to_nick, GINT_TO_POINTER (format));
g_static_mutex_unlock (&mutex);
return result;
}
/**
* gst_format_iterate_definitions:
*
* Iterate all the registered formats. The format definition is read
* only.
*
* Returns: A GstIterator of #GstFormatDefinition.
*/
GstIterator *
gst_format_iterate_definitions (void)
{
GstIterator *result;
g_static_mutex_lock (&mutex);
result = gst_iterator_new_list (g_static_mutex_get_mutex (&mutex),
&_n_values, &_gst_formats, NULL, NULL, NULL);
g_static_mutex_unlock (&mutex);
return result;
}