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 /* this file makes too much noise for most debugging sessions */
24 #define GST_DEBUG_FORCE_DISABLE
25 #include "gst_private.h"
27 #include "gstatomic_impl.h"
28 #include "gstdata_private.h"
29 #include "gstbuffer.h"
30 #include "gstmemchunk.h"
32 #include "gstbufferpool-default.h"
34 GType _gst_buffer_type;
35 GType _gst_buffer_pool_type;
37 #ifndef GST_DISABLE_TRACE
38 /* #define GST_WITH_ALLOC_TRACE */
41 static GstAllocTrace *_gst_buffer_trace;
42 static GstAllocTrace *_gst_buffer_pool_trace;
45 static GstMemChunk *chunk;
48 _gst_buffer_initialize (void)
50 _gst_buffer_type = g_boxed_type_register_static ("GstBuffer",
51 (GBoxedCopyFunc) gst_data_ref,
52 (GBoxedFreeFunc) gst_data_unref);
54 _gst_buffer_pool_type = g_boxed_type_register_static ("GstBufferPool",
55 (GBoxedCopyFunc) gst_data_ref,
56 (GBoxedFreeFunc) gst_data_unref);
58 #ifndef GST_DISABLE_TRACE
59 _gst_buffer_trace = gst_alloc_trace_register (GST_BUFFER_TRACE_NAME);
60 _gst_buffer_pool_trace = gst_alloc_trace_register (GST_BUFFER_POOL_TRACE_NAME);
63 chunk = gst_mem_chunk_new ("GstBufferChunk", sizeof (GstBuffer),
64 sizeof (GstBuffer) * 200, 0);
66 GST_INFO (GST_CAT_BUFFER, "Buffers are initialized now");
70 gst_buffer_get_type (void)
72 return _gst_buffer_type;
76 _gst_buffer_free_to_pool (GstBuffer *buffer)
78 GstBufferPool *pool = buffer->pool;
80 pool->buffer_free (pool, buffer, pool->user_data);
82 gst_data_unref (GST_DATA (pool));
86 _gst_buffer_sub_free (GstBuffer *buffer)
88 gst_data_unref (GST_DATA (buffer->pool_private));
90 GST_BUFFER_DATA (buffer) = NULL;
91 GST_BUFFER_SIZE (buffer) = 0;
93 _GST_DATA_DISPOSE (GST_DATA (buffer));
95 gst_mem_chunk_free (chunk, GST_DATA (buffer));
96 #ifndef GST_DISABLE_TRACE
97 gst_alloc_trace_free (_gst_buffer_trace, buffer);
102 * gst_buffer_default_free:
103 * @buffer: a #GstBuffer to free.
105 * Frees the memory associated with the buffer including the buffer data,
106 * unless the GST_BUFFER_DONTFREE flags was set or the buffer data is NULL.
107 * This function is used by buffer pools.
110 gst_buffer_default_free (GstBuffer *buffer)
112 g_return_if_fail (buffer != NULL);
115 if (!GST_BUFFER_FLAG_IS_SET (buffer, GST_BUFFER_DONTFREE) && GST_BUFFER_DATA (buffer))
116 g_free (GST_BUFFER_DATA (buffer));
118 /* set to safe values */
119 GST_BUFFER_DATA (buffer) = NULL;
120 GST_BUFFER_SIZE (buffer) = 0;
122 _GST_DATA_DISPOSE (GST_DATA (buffer));
124 gst_mem_chunk_free (chunk, GST_DATA (buffer));
125 #ifndef GST_DISABLE_TRACE
126 gst_alloc_trace_free (_gst_buffer_trace, buffer);
131 _gst_buffer_copy_from_pool (GstBuffer *buffer)
133 return buffer->pool->buffer_copy (buffer->pool, buffer, buffer->pool->user_data);
137 * gst_buffer_default_copy:
138 * @buffer: a #GstBuffer to make a copy of.
140 * Make a full newly allocated copy of the given buffer, data and all.
141 * This function is used by buffer pools.
143 * Returns: the new #GstBuffer.
146 gst_buffer_default_copy (GstBuffer *buffer)
150 g_return_val_if_fail (buffer != NULL, NULL);
152 /* create a fresh new buffer */
153 copy = gst_mem_chunk_alloc (chunk);
154 #ifndef GST_DISABLE_TRACE
155 gst_alloc_trace_new (_gst_buffer_trace, copy);
158 _GST_DATA_INIT (GST_DATA (copy),
161 (GstDataFreeFunction) gst_buffer_default_free,
162 (GstDataCopyFunction) gst_buffer_default_copy);
164 /* we simply copy everything from our parent */
165 GST_BUFFER_DATA (copy) = g_memdup (GST_BUFFER_DATA (buffer),
166 GST_BUFFER_SIZE (buffer));
167 GST_BUFFER_SIZE (copy) = GST_BUFFER_SIZE (buffer);
168 GST_BUFFER_MAXSIZE (copy) = GST_BUFFER_MAXSIZE (buffer);
169 GST_BUFFER_TIMESTAMP (copy) = GST_BUFFER_TIMESTAMP (buffer);
170 GST_BUFFER_OFFSET (copy) = GST_BUFFER_OFFSET (buffer);
171 GST_BUFFER_BUFFERPOOL (copy) = NULL;
172 GST_BUFFER_POOL_PRIVATE (copy) = NULL;
180 * Creates a newly allocated buffer without any data.
182 * Returns: the new #GstBuffer.
185 gst_buffer_new (void)
189 buf = gst_mem_chunk_alloc0 (chunk);
190 #ifndef GST_DISABLE_TRACE
191 gst_alloc_trace_new (_gst_buffer_trace, buf);
194 GST_DEBUG (GST_CAT_BUFFER, "new %p", buf);
196 _GST_DATA_INIT (GST_DATA (buf),
199 (GstDataFreeFunction) gst_buffer_default_free,
200 (GstDataCopyFunction) gst_buffer_default_copy);
202 GST_BUFFER_DATA (buf) = NULL;
203 GST_BUFFER_SIZE (buf) = 0;
204 GST_BUFFER_MAXSIZE (buf) = 0;
205 GST_BUFFER_TIMESTAMP (buf) = GST_CLOCK_TIME_NONE;
206 GST_BUFFER_OFFSET (buf) = 0;
207 GST_BUFFER_BUFFERPOOL (buf) = NULL;
208 GST_BUFFER_POOL_PRIVATE (buf) = NULL;
214 * gst_buffer_new_and_alloc:
215 * @size: the size of the new buffer's data.
217 * Creates a newly allocated buffer with data of the given size.
219 * Returns: the new #GstBuffer.
222 gst_buffer_new_and_alloc (guint size)
226 new = gst_buffer_new ();
228 GST_BUFFER_DATA (new) = g_malloc (size);
229 GST_BUFFER_SIZE (new) = size;
235 * gst_buffer_new_from_pool:
236 * @pool: a #GstBufferPool to use.
237 * @offset: the offset of the new buffer.
238 * @size: the size of the new buffer.
240 * Creates a newly allocated buffer using the specified buffer pool,
243 * Returns: the new #GstBuffer, or NULL if there was an error.
246 gst_buffer_new_from_pool (GstBufferPool *pool,
247 guint64 offset, guint size)
251 g_return_val_if_fail (pool != NULL, NULL);
253 buffer = pool->buffer_new (pool, offset, size, pool->user_data);
257 GST_BUFFER_BUFFERPOOL (buffer) = pool;
258 gst_data_ref (GST_DATA (pool));
260 /* override the buffer refcount functions with those from the pool (if any) */
261 if (pool->buffer_free)
262 GST_DATA (buffer)->free = (GstDataFreeFunction)_gst_buffer_free_to_pool;
263 if (pool->buffer_copy)
264 GST_DATA (buffer)->copy = (GstDataCopyFunction)_gst_buffer_copy_from_pool;
270 * gst_buffer_create_sub:
271 * @parent: a parent #GstBuffer to create a subbuffer from.
272 * @offset: the offset into parent #GstBuffer.
273 * @size: the size of the new #GstBuffer sub-buffer (with size > 0).
275 * Creates a sub-buffer from the parent at a given offset.
276 * This sub-buffer uses the actual memory space of the parent buffer.
278 * Returns: the new #GstBuffer, or NULL if there was an error.
281 gst_buffer_create_sub (GstBuffer *parent, guint offset, guint size)
284 gpointer buffer_data;
285 guint64 parent_offset;
287 g_return_val_if_fail (parent != NULL, NULL);
288 g_return_val_if_fail (GST_BUFFER_REFCOUNT_VALUE (parent) > 0, NULL);
289 g_return_val_if_fail (size > 0, NULL);
290 g_return_val_if_fail (parent->size >= offset + size, NULL);
292 /* remember the data for the new buffer */
293 buffer_data = parent->data + offset;
294 parent_offset = GST_BUFFER_OFFSET (parent);
295 /* make sure we're child not child from a child buffer */
296 while (GST_BUFFER_FLAG_IS_SET (parent, GST_BUFFER_SUBBUFFER)) {
297 parent = GST_BUFFER (parent->pool_private);
299 /* ref the real parent */
300 gst_data_ref (GST_DATA (parent));
301 /* make sure nobody overwrites data in the parent */
302 GST_DATA_FLAG_SET (parent, GST_DATA_READONLY);
304 /* create the new buffer */
305 buffer = gst_mem_chunk_alloc (chunk);
306 #ifndef GST_DISABLE_TRACE
307 gst_alloc_trace_new (_gst_buffer_trace, buffer);
310 GST_DEBUG (GST_CAT_BUFFER, "new %p", buf);
312 /* make sure nobody overwrites data in the new buffer
313 * by setting the READONLY flag */
314 _GST_DATA_INIT (GST_DATA (buffer),
316 GST_DATA_FLAG_SHIFT (GST_BUFFER_SUBBUFFER) |
317 GST_DATA_FLAG_SHIFT (GST_DATA_READONLY),
318 (GstDataFreeFunction) _gst_buffer_sub_free,
319 (GstDataCopyFunction) gst_buffer_default_copy);
321 /* set the right values in the child */
322 GST_BUFFER_DATA (buffer) = buffer_data;
323 GST_BUFFER_SIZE (buffer) = size;
324 GST_BUFFER_MAXSIZE (buffer) = size;
325 GST_BUFFER_TIMESTAMP (buffer) = GST_CLOCK_TIME_NONE;
326 GST_BUFFER_OFFSET (buffer) = parent_offset + offset;
327 GST_BUFFER_BUFFERPOOL (buffer) = NULL;
328 GST_BUFFER_POOL_PRIVATE (buffer) = parent;
336 * @buf1: a first source #GstBuffer to merge.
337 * @buf2: the second source #GstBuffer to merge.
339 * Create a new buffer that is the concatenation of the two source
340 * buffers. The original source buffers will not be modified or
343 * Internally is nothing more than a specialized gst_buffer_span(),
344 * so the same optimizations can occur.
346 * Returns: the new #GstBuffer that's the concatenation of the source buffers.
349 gst_buffer_merge (GstBuffer *buf1, GstBuffer *buf2)
353 /* we're just a specific case of the more general gst_buffer_span() */
354 result = gst_buffer_span (buf1, 0, buf2, buf1->size + buf2->size);
360 * gst_buffer_is_span_fast:
361 * @buf1: a first source #GstBuffer.
362 * @buf2: the second source #GstBuffer.
364 * Determines whether a gst_buffer_span() is free (as in free beer),
365 * or requires a memcpy.
367 * Returns: TRUE if the buffers are contiguous,
368 * FALSE if a copy would be required.
371 gst_buffer_is_span_fast (GstBuffer *buf1, GstBuffer *buf2)
373 g_return_val_if_fail (buf1 != NULL && buf2 != NULL, FALSE);
374 g_return_val_if_fail (GST_BUFFER_REFCOUNT_VALUE (buf1) > 0, FALSE);
375 g_return_val_if_fail (GST_BUFFER_REFCOUNT_VALUE (buf2) > 0, FALSE);
377 /* it's only fast if we have subbuffers of the same parent */
378 return ((GST_BUFFER_FLAG_IS_SET (buf1, GST_BUFFER_SUBBUFFER)) &&
379 (GST_BUFFER_FLAG_IS_SET (buf2, GST_BUFFER_SUBBUFFER)) &&
380 (buf1->pool_private == buf2->pool_private) &&
381 ((buf1->data + buf1->size) == buf2->data));
386 * @buf1: a first source #GstBuffer to merge.
387 * @offset: the offset in the first buffer from where the new
388 * buffer should start.
389 * @buf2: the second source #GstBuffer to merge.
390 * @len: the total length of the new buffer.
392 * Creates a new buffer that consists of part of buf1 and buf2.
393 * Logically, buf1 and buf2 are concatenated into a single larger
394 * buffer, and a new buffer is created at the given offset inside
395 * this space, with a given length.
397 * If the two source buffers are children of the same larger buffer,
398 * and are contiguous, the new buffer will be a child of the shared
399 * parent, and thus no copying is necessary. you can use
400 * gst_buffer_is_span_fast() to determine if a memcpy will be needed.
402 * Returns: the new #GstBuffer that spans the two source buffers.
405 gst_buffer_span (GstBuffer *buf1, guint32 offset, GstBuffer *buf2, guint32 len)
409 g_return_val_if_fail (buf1 != NULL && buf2 != NULL, FALSE);
410 g_return_val_if_fail (GST_BUFFER_REFCOUNT_VALUE (buf1) > 0, NULL);
411 g_return_val_if_fail (GST_BUFFER_REFCOUNT_VALUE (buf2) > 0, NULL);
412 g_return_val_if_fail (len > 0, NULL);
414 /* if the two buffers have the same parent and are adjacent */
415 if (gst_buffer_is_span_fast (buf1, buf2)) {
416 GstBuffer *parent = GST_BUFFER (buf1->pool_private);
417 /* we simply create a subbuffer of the common parent */
418 newbuf = gst_buffer_create_sub (parent,
419 buf1->data - parent->data + offset, len);
422 GST_DEBUG (GST_CAT_BUFFER, "slow path taken while spanning buffers %p and %p",
424 /* otherwise we simply have to brute-force copy the buffers */
425 newbuf = gst_buffer_new_and_alloc (len);
427 /* copy relevant stuff from data struct of buffer1 */
428 GST_BUFFER_OFFSET (newbuf) = GST_BUFFER_OFFSET (buf1) + offset;
430 /* copy the first buffer's data across */
431 memcpy (newbuf->data, buf1->data + offset, buf1->size - offset);
432 /* copy the second buffer's data across */
433 memcpy (newbuf->data + (buf1->size - offset), buf2->data,
434 len - (buf1->size - offset));
436 /* if the offset is 0, the new buffer has the same timestamp as buf1 */
438 GST_BUFFER_TIMESTAMP (newbuf) = GST_BUFFER_TIMESTAMP (buf1);
444 gst_buffer_pool_get_type (void)
446 return _gst_buffer_pool_type;
450 * gst_buffer_pool_default_free:
451 * @pool: a #GstBufferPool to free.
453 * Frees the memory associated with the bufferpool.
456 gst_buffer_pool_default_free (GstBufferPool *pool)
458 g_return_if_fail (pool != NULL);
460 _GST_DATA_DISPOSE (GST_DATA (pool));
462 #ifndef GST_DISABLE_TRACE
463 gst_alloc_trace_free (_gst_buffer_pool_trace, pool);
468 * gst_buffer_pool_new:
469 * @free: the #GstDataFreeFunction to free the buffer pool.
470 * @copy: the #GstDataCopyFunction to copy the buffer pool.
471 * @buffer_new: the #GstBufferPoolBufferNewFunction to create a new buffer
473 * @buffer_copy: the #GstBufferPoolBufferCopyFunction to copy a buffer
475 * @buffer_free: the #GstBufferPoolBufferFreeFunction to free a buffer
477 * @user_data: the user data gpointer passed to buffer_* functions.
479 * Creates a new buffer pool with the given functions.
481 * Returns: a new #GstBufferPool, or NULL on error.
484 gst_buffer_pool_new (GstDataFreeFunction free,
485 GstDataCopyFunction copy,
486 GstBufferPoolBufferNewFunction buffer_new,
487 GstBufferPoolBufferCopyFunction buffer_copy,
488 GstBufferPoolBufferFreeFunction buffer_free,
493 /* we need at least a buffer_new function */
494 g_return_val_if_fail (buffer_new != NULL, NULL);
496 pool = g_new0 (GstBufferPool, 1);
497 #ifndef GST_DISABLE_TRACE
498 gst_alloc_trace_new (_gst_buffer_pool_trace, pool);
501 GST_DEBUG (GST_CAT_BUFFER, "allocating new buffer pool %p\n", pool);
503 /* init data struct */
504 _GST_DATA_INIT (GST_DATA (pool),
505 _gst_buffer_pool_type,
507 (free ? free : (GstDataFreeFunction) gst_buffer_pool_default_free),
511 pool->buffer_new = buffer_new;
512 pool->buffer_copy = buffer_copy;
513 pool->buffer_free = buffer_free;
514 pool->user_data = user_data;
520 * gst_buffer_pool_is_active:
521 * @pool: the #GstBufferPool to query.
523 * Queries if the given buffer pool is active.
525 * Returns: TRUE if the pool is active.
528 gst_buffer_pool_is_active (GstBufferPool *pool)
530 g_return_val_if_fail (pool != NULL, FALSE);
536 * gst_buffer_pool_set_active:
537 * @pool: a #GstBufferPool to set the activity status on.
538 * @active: the new status of the pool.
540 * Sets the given pool to the active or inactive state depending on the
544 gst_buffer_pool_set_active (GstBufferPool *pool, gboolean active)
546 g_return_if_fail (pool != NULL);
548 pool->active = active;
552 * gst_buffer_pool_set_user_data:
553 * @pool: the #GstBufferPool to set the user data for.
554 * @user_data: the user_data to set on the buffer pool.
556 * Sets the given user data on the buffer pool.
559 gst_buffer_pool_set_user_data (GstBufferPool *pool, gpointer user_data)
561 g_return_if_fail (pool != NULL);
563 pool->user_data = user_data;
567 * gst_buffer_pool_get_user_data:
568 * @pool: the #GstBufferPool to get the user data for.
570 * Gets the user data of the buffer pool.
572 * Returns: the user data associated with this buffer pool.
575 gst_buffer_pool_get_user_data (GstBufferPool *pool)
577 g_return_val_if_fail (pool != NULL, NULL);
579 return pool->user_data;