2 * Copyright (C) 2009 Axis Communications <dev-gstreamer at axis dot com>
3 * @author Jonas Holmberg <jonas dot holmberg at axis dot com>
5 * gstbufferlist.c: Buffer list
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Library General Public
9 * License as published by the Free Software Foundation; either
10 * version 2 of the License, or (at your option) any later version.
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Library General Public License for more details.
17 * You should have received a copy of the GNU Library General Public
18 * License along with this library; if not, write to the
19 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
20 * Boston, MA 02110-1301, USA.
24 * SECTION:gstbufferlist
25 * @short_description: Lists of buffers for data-passing
26 * @see_also: #GstPad, #GstMiniObject
28 * Buffer lists are an object containing a list of buffers.
30 * Buffer lists are created with gst_buffer_list_new() and filled with data
31 * using a gst_buffer_list_insert().
33 * Buffer lists can be pushed on a srcpad with gst_pad_push_list(). This is
34 * interesting when multiple buffers need to be pushed in one go because it
35 * can reduce the amount of overhead for pushing each buffer individually.
37 * Last reviewed on 2012-03-28 (0.11.3)
39 #include "gst_private.h"
41 #include "gstbuffer.h"
42 #include "gstbufferlist.h"
44 #define GST_CAT_DEFAULT GST_CAT_BUFFER_LIST
49 * Opaque list of grouped buffers.
53 GstMiniObject mini_object;
58 GType _gst_buffer_list_type = 0;
60 GST_DEFINE_MINI_OBJECT_TYPE (GstBufferList, gst_buffer_list);
63 _priv_gst_buffer_list_initialize (void)
65 _gst_buffer_list_type = gst_buffer_list_get_type ();
68 static GstBufferList *
69 _gst_buffer_list_copy (GstBufferList * list)
74 len = list->array->len;
75 copy = gst_buffer_list_new_sized (len);
77 /* add and ref all buffers in the array */
78 for (i = 0; i < len; i++) {
79 GstBuffer *buf = g_array_index (list->array, GstBuffer *, i);
80 buf = gst_buffer_ref (buf);
81 g_array_append_val (copy->array, buf);
87 _gst_buffer_list_free (GstBufferList * list)
90 GST_LOG ("free %p", list);
92 /* unrefs all buffers too */
93 len = list->array->len;
94 for (i = 0; i < len; i++)
95 gst_buffer_unref (g_array_index (list->array, GstBuffer *, i));
96 g_array_free (list->array, TRUE);
98 g_slice_free1 (sizeof (GstBufferList), list);
102 gst_buffer_list_init (GstBufferList * list, guint asize)
104 gst_mini_object_init (GST_MINI_OBJECT_CAST (list), 0, _gst_buffer_list_type,
105 (GstMiniObjectCopyFunction) _gst_buffer_list_copy, NULL,
106 (GstMiniObjectFreeFunction) _gst_buffer_list_free);
108 list->array = g_array_sized_new (FALSE, FALSE, sizeof (GstBuffer *), asize);
110 GST_LOG ("init %p", list);
114 * gst_buffer_list_new_sized:
115 * @size: an initial reserved size
117 * Creates a new, empty #GstBufferList. The caller is responsible for unreffing
118 * the returned #GstBufferList. The list will have @size space preallocated so
119 * that memory reallocations can be avoided.
121 * Free-function: gst_buffer_list_unref
123 * Returns: (transfer full): the new #GstBufferList. gst_buffer_list_unref()
127 gst_buffer_list_new_sized (guint size)
131 list = g_slice_new0 (GstBufferList);
133 GST_LOG ("new %p", list);
135 gst_buffer_list_init (list, size);
141 * gst_buffer_list_new:
143 * Creates a new, empty #GstBufferList. The caller is responsible for unreffing
144 * the returned #GstBufferList.
146 * Free-function: gst_buffer_list_unref
148 * Returns: (transfer full): the new #GstBufferList. gst_buffer_list_unref()
152 gst_buffer_list_new (void)
154 return gst_buffer_list_new_sized (8);
158 * gst_buffer_list_length:
159 * @list: a #GstBufferList
161 * Returns the number of buffers in @list.
163 * Returns: the number of buffers in the buffer list
166 gst_buffer_list_length (GstBufferList * list)
168 g_return_val_if_fail (GST_IS_BUFFER_LIST (list), 0);
170 return list->array->len;
174 * gst_buffer_list_foreach:
175 * @list: a #GstBufferList
176 * @func: (scope call): a #GstBufferListFunc to call
177 * @user_data: (closure): user data passed to @func
179 * Call @func with @data for each buffer in @list.
181 * @func can modify the passed buffer pointer or its contents. The return value
182 * of @func define if this function returns or if the remaining buffers in
183 * the list should be skipped.
185 * Returns: %TRUE when @func returned %TRUE for each buffer in @list or when
189 gst_buffer_list_foreach (GstBufferList * list, GstBufferListFunc func,
195 g_return_val_if_fail (GST_IS_BUFFER_LIST (list), FALSE);
196 g_return_val_if_fail (func != NULL, FALSE);
198 len = list->array->len;
199 for (i = 0; i < len;) {
200 GstBuffer *buf, *buf_ret;
202 buf = buf_ret = g_array_index (list->array, GstBuffer *, i);
203 ret = func (&buf_ret, i, user_data);
205 /* Check if the function changed the buffer */
206 if (buf != buf_ret) {
207 if (buf_ret == NULL) {
208 g_array_remove_index (list->array, i);
211 g_array_index (list->array, GstBuffer *, i) = buf_ret;
218 /* If the buffer was not removed by func go to the next buffer */
226 * gst_buffer_list_get:
227 * @list: a #GstBufferList
230 * Get the buffer at @idx.
232 * Returns: (transfer none): the buffer at @idx in @group or NULL when there
233 * is no buffer. The buffer remains valid as long as @list is valid.
236 gst_buffer_list_get (GstBufferList * list, guint idx)
240 g_return_val_if_fail (GST_IS_BUFFER_LIST (list), NULL);
241 g_return_val_if_fail (idx < list->array->len, NULL);
243 buf = g_array_index (list->array, GstBuffer *, idx);
249 * gst_buffer_list_add:
250 * @l: a #GstBufferList
253 * Append @b at the end of @l.
256 * gst_buffer_list_insert:
257 * @list: a #GstBufferList
259 * @buffer: (transfer full): a #GstBuffer
261 * Insert @buffer at @idx in @list. Other buffers are moved to make room for
264 * A -1 value for @idx will append the buffer at the end.
267 gst_buffer_list_insert (GstBufferList * list, gint idx, GstBuffer * buffer)
269 g_return_if_fail (GST_IS_BUFFER_LIST (list));
270 g_return_if_fail (buffer != NULL);
273 g_array_append_val (list->array, buffer);
275 g_return_if_fail (idx < list->array->len);
276 g_array_insert_val (list->array, idx, buffer);
281 * gst_buffer_list_remove:
282 * @list: a #GstBufferList
284 * @length: the amount to remove
286 * Remove @length buffers starting from @idx in @list. The following buffers are
287 * moved to close the gap.
290 gst_buffer_list_remove (GstBufferList * list, guint idx, guint length)
292 g_return_if_fail (GST_IS_BUFFER_LIST (list));
293 g_return_if_fail (idx < list->array->len);
295 g_array_remove_range (list->array, idx, length);