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 * @title: GstBufferList
27 * @short_description: Lists of buffers for data-passing
28 * @see_also: #GstPad, #GstMiniObject
30 * Buffer lists are an object containing a list of buffers.
32 * Buffer lists are created with gst_buffer_list_new() and filled with data
33 * using a gst_buffer_list_insert().
35 * Buffer lists can be pushed on a srcpad with gst_pad_push_list(). This is
36 * interesting when multiple buffers need to be pushed in one go because it
37 * can reduce the amount of overhead for pushing each buffer individually.
39 #include "gst_private.h"
41 #include "gstbuffer.h"
42 #include "gstbufferlist.h"
45 #define GST_CAT_DEFAULT GST_CAT_BUFFER_LIST
47 #define GST_BUFFER_LIST_IS_USING_DYNAMIC_ARRAY(list) \
48 ((list)->buffers != &(list)->arr[0])
53 * Opaque list of grouped buffers.
57 GstMiniObject mini_object;
65 /* one-item array, in reality more items are pre-allocated
66 * as part of the GstBufferList structure, and that
67 * pre-allocated array extends beyond the declared struct */
71 GType _gst_buffer_list_type = 0;
73 GST_DEFINE_MINI_OBJECT_TYPE (GstBufferList, gst_buffer_list);
76 _priv_gst_buffer_list_initialize (void)
78 _gst_buffer_list_type = gst_buffer_list_get_type ();
81 static GstBufferList *
82 _gst_buffer_list_copy (GstBufferList * list)
87 len = list->n_buffers;
88 copy = gst_buffer_list_new_sized (list->n_allocated);
90 /* add and ref all buffers in the array */
91 for (i = 0; i < len; i++)
92 copy->buffers[i] = gst_buffer_ref (list->buffers[i]);
94 copy->n_buffers = len;
100 _gst_buffer_list_free (GstBufferList * list)
104 GST_LOG ("free %p", list);
106 /* unrefs all buffers too */
107 len = list->n_buffers;
108 for (i = 0; i < len; i++)
109 gst_buffer_unref (list->buffers[i]);
111 if (GST_BUFFER_LIST_IS_USING_DYNAMIC_ARRAY (list))
112 g_free (list->buffers);
114 g_slice_free1 (list->slice_size, list);
118 gst_buffer_list_init (GstBufferList * list, guint n_allocated, gsize slice_size)
120 gst_mini_object_init (GST_MINI_OBJECT_CAST (list), 0, _gst_buffer_list_type,
121 (GstMiniObjectCopyFunction) _gst_buffer_list_copy, NULL,
122 (GstMiniObjectFreeFunction) _gst_buffer_list_free);
124 list->buffers = &list->arr[0];
126 list->n_allocated = n_allocated;
127 list->slice_size = slice_size;
129 GST_LOG ("init %p", list);
133 * gst_buffer_list_new_sized:
134 * @size: an initial reserved size
136 * Creates a new, empty #GstBufferList. The caller is responsible for unreffing
137 * the returned #GstBufferList. The list will have @size space preallocated so
138 * that memory reallocations can be avoided.
140 * Free-function: gst_buffer_list_unref
142 * Returns: (transfer full): the new #GstBufferList. gst_buffer_list_unref()
146 gst_buffer_list_new_sized (guint size)
152 n_allocated = GST_ROUND_UP_16 (size);
154 slice_size = sizeof (GstBufferList) + (n_allocated - 1) * sizeof (gpointer);
156 list = g_slice_alloc0 (slice_size);
158 GST_LOG ("new %p", list);
160 gst_buffer_list_init (list, n_allocated, slice_size);
166 * gst_buffer_list_new:
168 * Creates a new, empty #GstBufferList. The caller is responsible for unreffing
169 * the returned #GstBufferList.
171 * Free-function: gst_buffer_list_unref
173 * Returns: (transfer full): the new #GstBufferList. gst_buffer_list_unref()
177 gst_buffer_list_new (void)
179 return gst_buffer_list_new_sized (8);
183 * gst_buffer_list_length:
184 * @list: a #GstBufferList
186 * Returns the number of buffers in @list.
188 * Returns: the number of buffers in the buffer list
191 gst_buffer_list_length (GstBufferList * list)
193 g_return_val_if_fail (GST_IS_BUFFER_LIST (list), 0);
195 return list->n_buffers;
199 gst_buffer_list_remove_range_internal (GstBufferList * list, guint idx,
200 guint length, gboolean unref_old)
205 for (i = idx; i < idx + length; ++i)
206 gst_buffer_unref (list->buffers[i]);
209 if (idx + length != list->n_buffers) {
210 memmove (&list->buffers[idx], &list->buffers[idx + length],
211 (list->n_buffers - (idx + length)) * sizeof (void *));
214 list->n_buffers -= length;
218 * gst_buffer_list_foreach:
219 * @list: a #GstBufferList
220 * @func: (scope call): a #GstBufferListFunc to call
221 * @user_data: (closure): user data passed to @func
223 * Call @func with @data for each buffer in @list.
225 * @func can modify the passed buffer pointer or its contents. The return value
226 * of @func define if this function returns or if the remaining buffers in
227 * the list should be skipped.
229 * Returns: %TRUE when @func returned %TRUE for each buffer in @list or when
233 gst_buffer_list_foreach (GstBufferList * list, GstBufferListFunc func,
239 g_return_val_if_fail (GST_IS_BUFFER_LIST (list), FALSE);
240 g_return_val_if_fail (func != NULL, FALSE);
242 len = list->n_buffers;
243 for (i = 0; i < len;) {
244 GstBuffer *buf, *buf_ret;
246 buf = buf_ret = list->buffers[i];
247 ret = func (&buf_ret, i, user_data);
249 /* Check if the function changed the buffer */
250 if (buf != buf_ret) {
251 if (buf_ret == NULL) {
252 gst_buffer_list_remove_range_internal (list, i, 1, FALSE);
255 list->buffers[i] = buf_ret;
262 /* If the buffer was not removed by func go to the next buffer */
270 * gst_buffer_list_get:
271 * @list: a #GstBufferList
274 * Get the buffer at @idx.
276 * You must make sure that @idx does not exceed the number of
279 * Returns: (transfer none) (nullable): the buffer at @idx in @group
280 * or %NULL when there is no buffer. The buffer remains valid as
281 * long as @list is valid and buffer is not removed from the list.
284 gst_buffer_list_get (GstBufferList * list, guint idx)
286 g_return_val_if_fail (GST_IS_BUFFER_LIST (list), NULL);
287 g_return_val_if_fail (idx < list->n_buffers, NULL);
289 return list->buffers[idx];
293 * gst_buffer_list_get_writable:
294 * @list: a (writable) #GstBufferList
297 * Gets the buffer at @idx, ensuring it is a writable buffer.
299 * You must make sure that @idx does not exceed the number of
302 * Returns: (transfer none) (nullable): the buffer at @idx in @group.
303 * The returned buffer remains valid as long as @list is valid and
304 * the buffer is not removed from the list.
309 gst_buffer_list_get_writable (GstBufferList * list, guint idx)
313 g_return_val_if_fail (GST_IS_BUFFER_LIST (list), NULL);
314 g_return_val_if_fail (gst_buffer_list_is_writable (list), NULL);
315 g_return_val_if_fail (idx < list->n_buffers, NULL);
317 p_buf = &list->buffers[idx];
318 return (*p_buf = gst_buffer_make_writable (*p_buf));
322 * gst_buffer_list_add:
323 * @l: a #GstBufferList
326 * Append @b at the end of @l.
329 * gst_buffer_list_insert:
330 * @list: a #GstBufferList
332 * @buffer: (transfer full): a #GstBuffer
334 * Insert @buffer at @idx in @list. Other buffers are moved to make room for
337 * A -1 value for @idx will append the buffer at the end.
340 gst_buffer_list_insert (GstBufferList * list, gint idx, GstBuffer * buffer)
344 g_return_if_fail (GST_IS_BUFFER_LIST (list));
345 g_return_if_fail (buffer != NULL);
346 g_return_if_fail (gst_buffer_list_is_writable (list));
348 if (idx == -1 && list->n_buffers < list->n_allocated) {
349 list->buffers[list->n_buffers++] = buffer;
353 if (idx == -1 || idx > list->n_buffers)
354 idx = list->n_buffers;
356 want_alloc = list->n_buffers + 1;
358 if (want_alloc > list->n_allocated) {
359 want_alloc = MAX (GST_ROUND_UP_16 (want_alloc), list->n_allocated * 2);
361 if (GST_BUFFER_LIST_IS_USING_DYNAMIC_ARRAY (list)) {
362 list->buffers = g_renew (GstBuffer *, list->buffers, want_alloc);
364 list->buffers = g_new0 (GstBuffer *, want_alloc);
365 memcpy (list->buffers, &list->arr[0], list->n_buffers * sizeof (void *));
366 GST_CAT_LOG (GST_CAT_PERFORMANCE, "exceeding pre-alloced array");
369 list->n_allocated = want_alloc;
372 if (idx < list->n_buffers) {
373 memmove (&list->buffers[idx + 1], &list->buffers[idx],
374 (list->n_buffers - idx) * sizeof (void *));
378 list->buffers[idx] = buffer;
382 * gst_buffer_list_remove:
383 * @list: a #GstBufferList
385 * @length: the amount to remove
387 * Remove @length buffers starting from @idx in @list. The following buffers
388 * are moved to close the gap.
391 gst_buffer_list_remove (GstBufferList * list, guint idx, guint length)
393 g_return_if_fail (GST_IS_BUFFER_LIST (list));
394 g_return_if_fail (idx < list->n_buffers);
395 g_return_if_fail (idx + length <= list->n_buffers);
396 g_return_if_fail (gst_buffer_list_is_writable (list));
398 gst_buffer_list_remove_range_internal (list, idx, length, TRUE);
402 * gst_buffer_list_copy_deep:
403 * @list: a #GstBufferList
405 * Create a copy of the given buffer list. This will make a newly allocated
406 * copy of the buffer that the source buffer list contains.
408 * Returns: (transfer full): a new copy of @list.
413 gst_buffer_list_copy_deep (const GstBufferList * list)
416 GstBufferList *result = NULL;
418 g_return_val_if_fail (GST_IS_BUFFER_LIST (list), NULL);
420 result = gst_buffer_list_new ();
422 len = list->n_buffers;
423 for (i = 0; i < len; i++) {
424 GstBuffer *old = list->buffers[i];
425 GstBuffer *new = gst_buffer_copy_deep (old);
427 if (G_LIKELY (new)) {
428 gst_buffer_list_insert (result, i, new);
431 ("Failed to deep copy buffer %p while deep "
432 "copying buffer list %p. Buffer list copy "
433 "will be incomplete", old, list);
441 * gst_buffer_list_calculate_size:
442 * @list: a #GstBufferList
444 * Calculates the size of the data contained in buffer list by adding the
445 * size of all buffers.
447 * Returns: the size of the data contained in buffer list in bytes.
452 gst_buffer_list_calculate_size (GstBufferList * list)
458 g_return_val_if_fail (GST_IS_BUFFER_LIST (list), 0);
461 buffers = list->buffers;
463 for (i = 0; i < n; ++i)
464 size += gst_buffer_get_size (buffers[i]);