2 * Copyright (C) 2009 Axis Communications <dev-gstreamer at axis dot com>
3 * @author Jonas Holmberg <jonas dot holmberg at axis dot com>
4 * Copyright (C) 2014 Tim-Philipp Müller <tim at centricular dot com>
6 * gstbufferlist.c: Buffer list
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Library General Public
10 * License as published by the Free Software Foundation; either
11 * version 2 of the License, or (at your option) any later version.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Library General Public License for more details.
18 * You should have received a copy of the GNU Library General Public
19 * License along with this library; if not, write to the
20 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
21 * Boston, MA 02110-1301, USA.
25 * SECTION:gstbufferlist
26 * @short_description: Lists of buffers for data-passing
27 * @see_also: #GstPad, #GstMiniObject
29 * Buffer lists are an object containing a list of buffers.
31 * Buffer lists are created with gst_buffer_list_new() and filled with data
32 * using a gst_buffer_list_insert().
34 * Buffer lists can be pushed on a srcpad with gst_pad_push_list(). This is
35 * interesting when multiple buffers need to be pushed in one go because it
36 * can reduce the amount of overhead for pushing each buffer individually.
38 #include "gst_private.h"
40 #include "gstbuffer.h"
41 #include "gstbufferlist.h"
44 #define GST_CAT_DEFAULT GST_CAT_BUFFER_LIST
46 #define GST_BUFFER_LIST_IS_USING_DYNAMIC_ARRAY(list) \
47 ((list)->buffers != &(list)->arr[0])
52 * Opaque list of grouped buffers.
56 GstMiniObject mini_object;
64 /* one-item array, in reality more items are pre-allocated
65 * as part of the GstBufferList structure, and that
66 * pre-allocated array extends beyond the declared struct */
70 GType _gst_buffer_list_type = 0;
72 GST_DEFINE_MINI_OBJECT_TYPE (GstBufferList, gst_buffer_list);
75 _priv_gst_buffer_list_initialize (void)
77 _gst_buffer_list_type = gst_buffer_list_get_type ();
80 static GstBufferList *
81 _gst_buffer_list_copy (GstBufferList * list)
86 len = list->n_buffers;
87 copy = gst_buffer_list_new_sized (list->n_allocated);
89 /* add and ref all buffers in the array */
90 for (i = 0; i < len; i++)
91 copy->buffers[i] = gst_buffer_ref (list->buffers[i]);
93 copy->n_buffers = len;
99 _gst_buffer_list_free (GstBufferList * list)
103 GST_LOG ("free %p", list);
105 /* unrefs all buffers too */
106 len = list->n_buffers;
107 for (i = 0; i < len; i++)
108 gst_buffer_unref (list->buffers[i]);
110 if (GST_BUFFER_LIST_IS_USING_DYNAMIC_ARRAY (list))
111 g_free (list->buffers);
113 g_slice_free1 (list->slice_size, list);
117 gst_buffer_list_init (GstBufferList * list, guint n_allocated, gsize slice_size)
119 gst_mini_object_init (GST_MINI_OBJECT_CAST (list), 0, _gst_buffer_list_type,
120 (GstMiniObjectCopyFunction) _gst_buffer_list_copy, NULL,
121 (GstMiniObjectFreeFunction) _gst_buffer_list_free);
123 list->buffers = &list->arr[0];
125 list->n_allocated = n_allocated;
126 list->slice_size = slice_size;
128 GST_LOG ("init %p", list);
132 * gst_buffer_list_new_sized:
133 * @size: an initial reserved size
135 * Creates a new, empty #GstBufferList. The caller is responsible for unreffing
136 * the returned #GstBufferList. The list will have @size space preallocated so
137 * that memory reallocations can be avoided.
139 * Free-function: gst_buffer_list_unref
141 * Returns: (transfer full): the new #GstBufferList. gst_buffer_list_unref()
145 gst_buffer_list_new_sized (guint size)
151 n_allocated = GST_ROUND_UP_16 (size);
153 slice_size = sizeof (GstBufferList) + (n_allocated - 1) * sizeof (gpointer);
155 list = g_slice_alloc0 (slice_size);
157 GST_LOG ("new %p", list);
159 gst_buffer_list_init (list, n_allocated, slice_size);
165 * gst_buffer_list_new:
167 * Creates a new, empty #GstBufferList. The caller is responsible for unreffing
168 * the returned #GstBufferList.
170 * Free-function: gst_buffer_list_unref
172 * Returns: (transfer full): the new #GstBufferList. gst_buffer_list_unref()
176 gst_buffer_list_new (void)
178 return gst_buffer_list_new_sized (8);
182 * gst_buffer_list_length:
183 * @list: a #GstBufferList
185 * Returns the number of buffers in @list.
187 * Returns: the number of buffers in the buffer list
190 gst_buffer_list_length (GstBufferList * list)
192 g_return_val_if_fail (GST_IS_BUFFER_LIST (list), 0);
194 return list->n_buffers;
198 gst_buffer_list_remove_range_internal (GstBufferList * list, guint idx,
199 guint length, gboolean unref_old)
204 for (i = idx; i < idx + length; ++i)
205 gst_buffer_unref (list->buffers[i]);
208 if (idx + length != list->n_buffers) {
209 memmove (&list->buffers[idx], &list->buffers[idx + length],
210 (list->n_buffers - (idx + length)) * sizeof (void *));
213 list->n_buffers -= length;
217 * gst_buffer_list_foreach:
218 * @list: a #GstBufferList
219 * @func: (scope call): a #GstBufferListFunc to call
220 * @user_data: (closure): user data passed to @func
222 * Call @func with @data for each buffer in @list.
224 * @func can modify the passed buffer pointer or its contents. The return value
225 * of @func define if this function returns or if the remaining buffers in
226 * the list should be skipped.
228 * Returns: %TRUE when @func returned %TRUE for each buffer in @list or when
232 gst_buffer_list_foreach (GstBufferList * list, GstBufferListFunc func,
238 g_return_val_if_fail (GST_IS_BUFFER_LIST (list), FALSE);
239 g_return_val_if_fail (func != NULL, FALSE);
241 len = list->n_buffers;
242 for (i = 0; i < len;) {
243 GstBuffer *buf, *buf_ret;
245 buf = buf_ret = list->buffers[i];
246 ret = func (&buf_ret, i, user_data);
248 /* Check if the function changed the buffer */
249 if (buf != buf_ret) {
250 if (buf_ret == NULL) {
251 gst_buffer_list_remove_range_internal (list, i, 1, FALSE);
254 list->buffers[i] = buf_ret;
261 /* If the buffer was not removed by func go to the next buffer */
269 * gst_buffer_list_get:
270 * @list: a #GstBufferList
273 * Get the buffer at @idx.
275 * Returns: (transfer none) (nullable): the buffer at @idx in @group
276 * or %NULL when there is no buffer. The buffer remains valid as
277 * long as @list is valid and buffer is not removed from the list.
280 gst_buffer_list_get (GstBufferList * list, guint idx)
282 g_return_val_if_fail (GST_IS_BUFFER_LIST (list), NULL);
283 g_return_val_if_fail (idx < list->n_buffers, NULL);
285 return list->buffers[idx];
289 * gst_buffer_list_add:
290 * @l: a #GstBufferList
293 * Append @b at the end of @l.
296 * gst_buffer_list_insert:
297 * @list: a #GstBufferList
299 * @buffer: (transfer full): a #GstBuffer
301 * Insert @buffer at @idx in @list. Other buffers are moved to make room for
304 * A -1 value for @idx will append the buffer at the end.
307 gst_buffer_list_insert (GstBufferList * list, gint idx, GstBuffer * buffer)
311 g_return_if_fail (GST_IS_BUFFER_LIST (list));
312 g_return_if_fail (buffer != NULL);
313 g_return_if_fail (gst_buffer_list_is_writable (list));
315 if (idx == -1 && list->n_buffers < list->n_allocated) {
316 list->buffers[list->n_buffers++] = buffer;
320 if (idx == -1 || idx > list->n_buffers)
321 idx = list->n_buffers;
323 want_alloc = list->n_buffers + 1;
325 if (want_alloc > list->n_allocated) {
326 want_alloc = MAX (GST_ROUND_UP_16 (want_alloc), list->n_allocated * 2);
328 if (GST_BUFFER_LIST_IS_USING_DYNAMIC_ARRAY (list)) {
329 list->buffers = g_renew (GstBuffer *, list->buffers, want_alloc);
331 list->buffers = g_new0 (GstBuffer *, want_alloc);
332 memcpy (list->buffers, &list->arr[0], list->n_buffers * sizeof (void *));
333 GST_CAT_LOG (GST_CAT_PERFORMANCE, "exceeding pre-alloced array");
336 list->n_allocated = want_alloc;
339 if (idx < list->n_buffers) {
340 memmove (&list->buffers[idx + 1], &list->buffers[idx],
341 (list->n_buffers - idx) * sizeof (void *));
345 list->buffers[idx] = buffer;
349 * gst_buffer_list_remove:
350 * @list: a #GstBufferList
352 * @length: the amount to remove
354 * Remove @length buffers starting from @idx in @list. The following buffers
355 * are moved to close the gap.
358 gst_buffer_list_remove (GstBufferList * list, guint idx, guint length)
360 g_return_if_fail (GST_IS_BUFFER_LIST (list));
361 g_return_if_fail (idx < list->n_buffers);
362 g_return_if_fail (idx + length <= list->n_buffers);
363 g_return_if_fail (gst_buffer_list_is_writable (list));
365 gst_buffer_list_remove_range_internal (list, idx, length, TRUE);
369 * gst_buffer_list_copy_deep:
370 * @list: a #GstBufferList
372 * Create a copy of the given buffer list. This will make a newly allocated
373 * copy of the buffer that the source buffer list contains.
375 * Returns: (transfer full): a new copy of @list.
380 gst_buffer_list_copy_deep (const GstBufferList * list)
383 GstBufferList *result = NULL;
385 g_return_val_if_fail (GST_IS_BUFFER_LIST (list), NULL);
387 result = gst_buffer_list_new ();
389 len = list->n_buffers;
390 for (i = 0; i < len; i++) {
391 GstBuffer *old = list->buffers[i];
392 GstBuffer *new = gst_buffer_copy_deep (old);
394 if (G_LIKELY (new)) {
395 gst_buffer_list_insert (result, i, new);
398 ("Failed to deep copy buffer %p while deep "
399 "copying buffer list %p. Buffer list copy "
400 "will be incomplete", old, list);