2 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3 * 2000 Wim Taymans <wtay@chello.be>
5 * gstbuffer.c: Buffer operations
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., 59 Temple Place - Suite 330,
20 * Boston, MA 02111-1307, USA.
23 #include "gst_private.h"
25 #include "gstatomic_impl.h"
26 #include "gstdata_private.h"
27 #include "gstbuffer.h"
28 #include "gstmemchunk.h"
31 GType _gst_buffer_type;
33 #ifndef GST_DISABLE_TRACE
34 /* #define GST_WITH_ALLOC_TRACE */
37 static GstAllocTrace *_gst_buffer_trace;
40 static GstMemChunk *chunk;
43 _gst_buffer_initialize (void)
45 _gst_buffer_type = g_boxed_type_register_static ("GstBuffer",
46 (GBoxedCopyFunc) gst_data_copy, (GBoxedFreeFunc) gst_data_unref);
48 #ifndef GST_DISABLE_TRACE
49 _gst_buffer_trace = gst_alloc_trace_register (GST_BUFFER_TRACE_NAME);
52 chunk = gst_mem_chunk_new ("GstBufferChunk", sizeof (GstBuffer),
53 sizeof (GstBuffer) * 200, 0);
55 GST_CAT_LOG (GST_CAT_BUFFER, "Buffers are initialized now");
59 gst_buffer_get_type (void)
61 return _gst_buffer_type;
65 _gst_buffer_sub_free (GstBuffer * buffer)
67 gst_data_unref (GST_DATA (buffer->buffer_private));
69 GST_BUFFER_DATA (buffer) = NULL;
70 GST_BUFFER_SIZE (buffer) = 0;
72 _GST_DATA_DISPOSE (GST_DATA (buffer));
74 gst_mem_chunk_free (chunk, GST_DATA (buffer));
75 #ifndef GST_DISABLE_TRACE
76 gst_alloc_trace_free (_gst_buffer_trace, buffer);
81 * gst_buffer_default_free:
82 * @buffer: a #GstBuffer to free.
84 * Frees the memory associated with the buffer including the buffer data,
85 * unless the GST_BUFFER_DONTFREE flags was set or the buffer data is NULL.
88 gst_buffer_default_free (GstBuffer * buffer)
90 g_return_if_fail (buffer != NULL);
93 if (GST_BUFFER_FREE_DATA_FUNC (buffer)) {
94 GST_BUFFER_FREE_DATA_FUNC (buffer) (buffer);
95 } else if (!GST_BUFFER_FLAG_IS_SET (buffer, GST_BUFFER_DONTFREE)) {
96 g_free (GST_BUFFER_DATA (buffer));
99 /* set to safe values */
100 GST_BUFFER_DATA (buffer) = NULL;
101 GST_BUFFER_SIZE (buffer) = 0;
103 _GST_DATA_DISPOSE (GST_DATA (buffer));
105 gst_mem_chunk_free (chunk, GST_DATA (buffer));
106 #ifndef GST_DISABLE_TRACE
107 gst_alloc_trace_free (_gst_buffer_trace, buffer);
113 * @dest: buffer to stamp
114 * @src: buffer to stamp from
116 * Copies additional information (timestamps and offsets) from one buffer to
120 gst_buffer_stamp (GstBuffer * dest, const GstBuffer * src)
122 g_return_if_fail (dest != NULL);
123 g_return_if_fail (src != NULL);
125 GST_BUFFER_TIMESTAMP (dest) = GST_BUFFER_TIMESTAMP (src);
126 GST_BUFFER_DURATION (dest) = GST_BUFFER_DURATION (src);
127 GST_BUFFER_OFFSET (dest) = GST_BUFFER_OFFSET (src);
128 GST_BUFFER_OFFSET_END (dest) = GST_BUFFER_OFFSET_END (src);
132 * gst_buffer_default_copy:
133 * @buffer: a #GstBuffer to make a copy of.
135 * Make a full newly allocated copy of the given buffer, data and all.
137 * Returns: the new #GstBuffer.
140 gst_buffer_default_copy (GstBuffer * buffer)
144 g_return_val_if_fail (buffer != NULL, NULL);
146 /* create a fresh new buffer */
147 copy = gst_mem_chunk_alloc (chunk);
148 #ifndef GST_DISABLE_TRACE
149 gst_alloc_trace_new (_gst_buffer_trace, copy);
152 _GST_DATA_INIT (GST_DATA (copy),
155 (GstDataFreeFunction) gst_buffer_default_free,
156 (GstDataCopyFunction) gst_buffer_default_copy);
158 /* we simply copy everything from our parent */
159 GST_BUFFER_DATA (copy) = g_memdup (GST_BUFFER_DATA (buffer),
160 GST_BUFFER_SIZE (buffer));
161 GST_BUFFER_SIZE (copy) = GST_BUFFER_SIZE (buffer);
162 GST_BUFFER_MAXSIZE (copy) = GST_BUFFER_SIZE (buffer);
164 gst_buffer_stamp (copy, buffer);
165 GST_BUFFER_FREE_DATA_FUNC (copy) = NULL;
166 GST_BUFFER_PRIVATE (copy) = NULL;
174 * Creates a newly allocated buffer without any data.
176 * Returns: the new #GstBuffer.
179 gst_buffer_new (void)
183 newbuf = gst_mem_chunk_alloc (chunk);
184 #ifndef GST_DISABLE_TRACE
185 gst_alloc_trace_new (_gst_buffer_trace, newbuf);
188 GST_CAT_LOG (GST_CAT_BUFFER, "new %p", newbuf);
190 _GST_DATA_INIT (GST_DATA (newbuf),
193 (GstDataFreeFunction) gst_buffer_default_free,
194 (GstDataCopyFunction) gst_buffer_default_copy);
196 GST_BUFFER_DATA (newbuf) = NULL;
197 GST_BUFFER_SIZE (newbuf) = 0;
198 GST_BUFFER_MAXSIZE (newbuf) = GST_BUFFER_MAXSIZE_NONE;
199 GST_BUFFER_TIMESTAMP (newbuf) = GST_CLOCK_TIME_NONE;
200 GST_BUFFER_DURATION (newbuf) = GST_CLOCK_TIME_NONE;
201 GST_BUFFER_OFFSET (newbuf) = GST_BUFFER_OFFSET_NONE;
202 GST_BUFFER_OFFSET_END (newbuf) = GST_BUFFER_OFFSET_NONE;
203 GST_BUFFER_FREE_DATA_FUNC (newbuf) = NULL;
204 GST_BUFFER_PRIVATE (newbuf) = NULL;
210 * gst_buffer_new_and_alloc:
211 * @size: the size of the new buffer's data.
213 * Creates a newly allocated buffer with data of the given size.
215 * Returns: the new #GstBuffer.
218 gst_buffer_new_and_alloc (guint size)
222 newbuf = gst_buffer_new ();
224 GST_BUFFER_DATA (newbuf) = g_malloc (size);
225 GST_BUFFER_SIZE (newbuf) = size;
226 GST_BUFFER_MAXSIZE (newbuf) = size;
232 * gst_buffer_create_sub:
233 * @parent: a parent #GstBuffer to create a subbuffer from.
234 * @offset: the offset into parent #GstBuffer.
235 * @size: the size of the new #GstBuffer sub-buffer (with size > 0).
237 * Creates a sub-buffer from the parent at a given offset.
238 * This sub-buffer uses the actual memory space of the parent buffer.
239 * This function will copy the offset and timestamp field when the
240 * offset is 0, else they are set to _NONE.
241 * The duration field of the new buffer are set to GST_CLOCK_TIME_NONE.
243 * Returns: the new #GstBuffer, or NULL if there was an error.
246 gst_buffer_create_sub (GstBuffer * parent, guint offset, guint size)
249 gpointer buffer_data;
251 g_return_val_if_fail (parent != NULL, NULL);
252 g_return_val_if_fail (GST_BUFFER_REFCOUNT_VALUE (parent) > 0, NULL);
253 g_return_val_if_fail (size > 0, NULL);
254 g_return_val_if_fail (parent->size >= offset + size, NULL);
256 /* remember the data for the new buffer */
257 buffer_data = parent->data + offset;
258 /* make sure we're child not child from a child buffer */
259 while (GST_BUFFER_FLAG_IS_SET (parent, GST_BUFFER_SUBBUFFER)) {
260 parent = GST_BUFFER (parent->buffer_private);
262 /* ref the real parent */
263 gst_data_ref (GST_DATA (parent));
265 /* create the new buffer */
266 buffer = gst_mem_chunk_alloc (chunk);
267 #ifndef GST_DISABLE_TRACE
268 gst_alloc_trace_new (_gst_buffer_trace, buffer);
271 GST_CAT_LOG (GST_CAT_BUFFER, "new subbuffer %p (parent %p)", buffer, parent);
273 /* make sure nobody overwrites data in the new buffer
274 * by setting the READONLY flag */
275 _GST_DATA_INIT (GST_DATA (buffer),
277 GST_DATA_FLAG_SHIFT (GST_BUFFER_SUBBUFFER) |
278 GST_DATA_FLAG_SHIFT (GST_DATA_READONLY),
279 (GstDataFreeFunction) _gst_buffer_sub_free,
280 (GstDataCopyFunction) gst_buffer_default_copy);
282 /* set the right values in the child */
283 GST_BUFFER_DATA (buffer) = buffer_data;
284 GST_BUFFER_SIZE (buffer) = size;
285 GST_BUFFER_MAXSIZE (buffer) = size;
286 GST_BUFFER_FREE_DATA_FUNC (buffer) = NULL;
287 GST_BUFFER_PRIVATE (buffer) = parent;
288 /* we can copy the timestamp and offset if the new buffer starts at
291 GST_BUFFER_TIMESTAMP (buffer) = GST_BUFFER_TIMESTAMP (parent);
292 GST_BUFFER_OFFSET (buffer) = GST_BUFFER_OFFSET (parent);
294 GST_BUFFER_TIMESTAMP (buffer) = GST_CLOCK_TIME_NONE;
295 GST_BUFFER_OFFSET (buffer) = GST_BUFFER_OFFSET_NONE;
298 GST_BUFFER_DURATION (buffer) = GST_CLOCK_TIME_NONE;
299 GST_BUFFER_OFFSET_END (buffer) = GST_BUFFER_OFFSET_NONE;
301 if (GST_BUFFER_FLAG_IS_SET (parent, GST_BUFFER_DONTKEEP)) {
302 GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_DONTKEEP);
304 if (GST_BUFFER_FLAG_IS_SET (parent, GST_BUFFER_READONLY)) {
305 GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_READONLY);
314 * @buf1: a first source #GstBuffer to merge.
315 * @buf2: the second source #GstBuffer to merge.
317 * Create a new buffer that is the concatenation of the two source
318 * buffers. The original source buffers will not be modified or
321 * WARNING: Incorrect use of this function can lead to memory leaks.
322 * It is recommended to use gst_buffer_join() instead of this function.
324 * If the buffers point to contiguous areas of memory, the buffer
325 * is created without copying the data.
327 * Returns: the new #GstBuffer that's the concatenation of the source buffers.
330 gst_buffer_merge (GstBuffer * buf1, GstBuffer * buf2)
334 /* we're just a specific case of the more general gst_buffer_span() */
335 result = gst_buffer_span (buf1, 0, buf2, buf1->size + buf2->size);
342 * @buf1: a first source #GstBuffer to merge.
343 * @buf2: the second source #GstBuffer to merge.
345 * Create a new buffer that is the concatenation of the two source
346 * buffers. The original buffers are unreferenced.
348 * If the buffers point to contiguous areas of memory, the buffer
349 * is created without copying the data.
351 * Returns: the new #GstBuffer that's the concatenation of the source buffers.
354 gst_buffer_join (GstBuffer * buf1, GstBuffer * buf2)
358 /* we're just a specific case of the more general gst_buffer_span() */
359 result = gst_buffer_span (buf1, 0, buf2, buf1->size + buf2->size);
361 gst_buffer_unref (buf1);
362 gst_buffer_unref (buf2);
368 * gst_buffer_is_span_fast:
369 * @buf1: a first source #GstBuffer.
370 * @buf2: the second source #GstBuffer.
372 * Determines whether a gst_buffer_span() can be done without copying
373 * the contents, that is, whether the data areas are contiguous.
375 * Returns: TRUE if the buffers are contiguous,
376 * FALSE if a copy would be required.
379 gst_buffer_is_span_fast (GstBuffer * buf1, GstBuffer * buf2)
381 g_return_val_if_fail (buf1 != NULL && buf2 != NULL, FALSE);
382 g_return_val_if_fail (GST_BUFFER_REFCOUNT_VALUE (buf1) > 0, FALSE);
383 g_return_val_if_fail (GST_BUFFER_REFCOUNT_VALUE (buf2) > 0, FALSE);
385 /* it's only fast if we have subbuffers of the same parent */
386 return ((GST_BUFFER_FLAG_IS_SET (buf1, GST_BUFFER_SUBBUFFER)) &&
387 (GST_BUFFER_FLAG_IS_SET (buf2, GST_BUFFER_SUBBUFFER)) &&
388 (buf1->buffer_private == buf2->buffer_private) &&
389 ((buf1->data + buf1->size) == buf2->data));
394 * @buf1: a first source #GstBuffer to merge.
395 * @offset: the offset in the first buffer from where the new
396 * buffer should start.
397 * @buf2: the second source #GstBuffer to merge.
398 * @len: the total length of the new buffer.
400 * Creates a new buffer that consists of part of buf1 and buf2.
401 * Logically, buf1 and buf2 are concatenated into a single larger
402 * buffer, and a new buffer is created at the given offset inside
403 * this space, with a given length.
405 * If the two source buffers are children of the same larger buffer,
406 * and are contiguous, the new buffer will be a child of the shared
407 * parent, and thus no copying is necessary. you can use
408 * gst_buffer_is_span_fast() to determine if a memcpy will be needed.
410 * Returns: the new #GstBuffer that spans the two source buffers.
413 gst_buffer_span (GstBuffer * buf1, guint32 offset, GstBuffer * buf2,
418 g_return_val_if_fail (buf1 != NULL && buf2 != NULL, FALSE);
419 g_return_val_if_fail (GST_BUFFER_REFCOUNT_VALUE (buf1) > 0, NULL);
420 g_return_val_if_fail (GST_BUFFER_REFCOUNT_VALUE (buf2) > 0, NULL);
421 g_return_val_if_fail (len > 0, NULL);
422 g_return_val_if_fail (len <= buf1->size + buf2->size - offset, NULL);
424 /* if the two buffers have the same parent and are adjacent */
425 if (gst_buffer_is_span_fast (buf1, buf2)) {
426 GstBuffer *parent = GST_BUFFER (buf1->buffer_private);
428 /* we simply create a subbuffer of the common parent */
429 newbuf = gst_buffer_create_sub (parent,
430 buf1->data - parent->data + offset, len);
432 GST_CAT_DEBUG (GST_CAT_BUFFER,
433 "slow path taken while spanning buffers %p and %p", buf1, buf2);
434 /* otherwise we simply have to brute-force copy the buffers */
435 newbuf = gst_buffer_new_and_alloc (len);
437 /* copy the first buffer's data across */
438 memcpy (newbuf->data, buf1->data + offset, buf1->size - offset);
439 /* copy the second buffer's data across */
440 memcpy (newbuf->data + (buf1->size - offset), buf2->data,
441 len - (buf1->size - offset));
442 /* if the offset is 0, the new buffer has the same timestamp as buf1 */
444 GST_BUFFER_OFFSET (newbuf) = GST_BUFFER_OFFSET (buf1);
445 GST_BUFFER_TIMESTAMP (newbuf) = GST_BUFFER_TIMESTAMP (buf1);
448 /* if we completely merged the two buffers (appended), we can
449 * calculate the duration too. Also make sure we's not messing with
450 * invalid DURATIONS */
451 if (offset == 0 && buf1->size + buf2->size == len) {
452 if (GST_BUFFER_DURATION_IS_VALID (buf1) &&
453 GST_BUFFER_DURATION_IS_VALID (buf2)) {
455 GST_BUFFER_DURATION (newbuf) = GST_BUFFER_DURATION (buf1) +
456 GST_BUFFER_DURATION (buf2);
458 if (GST_BUFFER_OFFSET_END_IS_VALID (buf2)) {
460 GST_BUFFER_OFFSET_END (newbuf) = GST_BUFFER_OFFSET_END (buf2);