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_free_to_pool (GstBuffer *buffer)
72 GstBufferPool *pool = buffer->pool;
74 pool->buffer_free (pool, buffer, pool->user_data);
76 gst_data_unref (GST_DATA (pool));
80 _gst_buffer_sub_free (GstBuffer *buffer)
82 gst_data_unref (GST_DATA (buffer->pool_private));
84 GST_BUFFER_DATA (buffer) = NULL;
85 GST_BUFFER_SIZE (buffer) = 0;
87 _GST_DATA_DISPOSE (GST_DATA (buffer));
89 gst_mem_chunk_free (chunk, GST_DATA (buffer));
90 #ifndef GST_DISABLE_TRACE
91 gst_alloc_trace_free (_gst_buffer_trace, buffer);
96 * gst_buffer_default_free:
97 * @buffer: a #GstBuffer to free.
99 * Frees the memory associated with the buffer including the buffer data,
100 * unless the GST_BUFFER_DONTFREE flags was set or the buffer data is NULL.
101 * This function is used by buffer pools.
104 gst_buffer_default_free (GstBuffer *buffer)
106 g_return_if_fail (buffer != NULL);
109 if (!GST_BUFFER_FLAG_IS_SET (buffer, GST_BUFFER_DONTFREE) && GST_BUFFER_DATA (buffer))
110 g_free (GST_BUFFER_DATA (buffer));
112 /* set to safe values */
113 GST_BUFFER_DATA (buffer) = NULL;
114 GST_BUFFER_SIZE (buffer) = 0;
116 _GST_DATA_DISPOSE (GST_DATA (buffer));
118 gst_mem_chunk_free (chunk, GST_DATA (buffer));
119 #ifndef GST_DISABLE_TRACE
120 gst_alloc_trace_free (_gst_buffer_trace, buffer);
125 _gst_buffer_copy_from_pool (GstBuffer *buffer)
127 return buffer->pool->buffer_copy (buffer->pool, buffer, buffer->pool->user_data);
131 * gst_buffer_default_copy:
132 * @buffer: a #GstBuffer to make a copy of.
134 * Make a full newly allocated copy of the given buffer, data and all.
135 * This function is used by buffer pools.
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_buffer_new ();
149 /* we simply copy everything from our parent */
150 GST_BUFFER_DATA (copy) = g_memdup (GST_BUFFER_DATA (buffer),
151 GST_BUFFER_SIZE (buffer));
152 GST_BUFFER_SIZE (copy) = GST_BUFFER_SIZE (buffer);
153 GST_BUFFER_MAXSIZE (copy) = GST_BUFFER_MAXSIZE (buffer);
154 GST_BUFFER_TIMESTAMP (copy) = GST_BUFFER_TIMESTAMP (buffer);
155 GST_BUFFER_OFFSET (copy) = GST_BUFFER_OFFSET (buffer);
163 * Creates a newly allocated buffer without any data.
165 * Returns: the new #GstBuffer.
168 gst_buffer_new (void)
172 buf = gst_mem_chunk_alloc0 (chunk);
173 #ifndef GST_DISABLE_TRACE
174 gst_alloc_trace_new (_gst_buffer_trace, buf);
177 GST_DEBUG (GST_CAT_BUFFER, "new %p", buf);
179 _GST_DATA_INIT (GST_DATA (buf),
182 (GstDataFreeFunction) gst_buffer_default_free,
183 (GstDataCopyFunction) gst_buffer_default_copy);
185 GST_BUFFER_BUFFERPOOL (buf) = NULL;
186 GST_BUFFER_POOL_PRIVATE (buf) = NULL;
192 * gst_buffer_new_and_alloc:
193 * @size: the size of the new buffer's data.
195 * Creates a newly allocated buffer with data of the given size.
197 * Returns: the new #GstBuffer.
200 gst_buffer_new_and_alloc (guint size)
204 new = gst_buffer_new ();
206 GST_BUFFER_DATA (new) = g_malloc (size);
207 GST_BUFFER_SIZE (new) = size;
213 * gst_buffer_new_from_pool:
214 * @pool: a #GstBufferPool to use.
215 * @offset: the offset of the new buffer.
216 * @size: the size of the new buffer.
218 * Creates a newly allocated buffer using the specified buffer pool,
221 * Returns: the new #GstBuffer, or NULL if there was an error.
224 gst_buffer_new_from_pool (GstBufferPool *pool,
225 guint64 offset, guint size)
229 g_return_val_if_fail (pool != NULL, NULL);
231 buffer = pool->buffer_new (pool, offset, size, pool->user_data);
235 GST_BUFFER_BUFFERPOOL (buffer) = pool;
236 gst_data_ref (GST_DATA (pool));
238 /* override the buffer refcount functions with those from the pool (if any) */
239 if (pool->buffer_free)
240 GST_DATA (buffer)->free = (GstDataFreeFunction)_gst_buffer_free_to_pool;
241 if (pool->buffer_copy)
242 GST_DATA (buffer)->copy = (GstDataCopyFunction)_gst_buffer_copy_from_pool;
248 * gst_buffer_create_sub:
249 * @parent: a parent #GstBuffer to create a subbuffer from.
250 * @offset: the offset into parent #GstBuffer.
251 * @size: the size of the new #GstBuffer sub-buffer (with size > 0).
253 * Creates a sub-buffer from the parent at a given offset.
254 * This sub-buffer uses the actual memory space of the parent buffer.
256 * Returns: the new #GstBuffer, or NULL if there was an error.
259 gst_buffer_create_sub (GstBuffer *parent, guint offset, guint size)
262 gpointer buffer_data;
263 guint64 parent_offset;
265 g_return_val_if_fail (parent != NULL, NULL);
266 g_return_val_if_fail (GST_BUFFER_REFCOUNT_VALUE (parent) > 0, NULL);
267 g_return_val_if_fail (size > 0, NULL);
268 g_return_val_if_fail (parent->size >= offset + size, NULL);
270 /* remember the data for the new buffer */
271 buffer_data = parent->data + offset;
272 parent_offset = GST_BUFFER_OFFSET (parent);
273 /* make sure we're child not child from a child buffer */
274 while (GST_BUFFER_FLAG_IS_SET (parent, GST_BUFFER_SUBBUFFER)) {
275 parent = GST_BUFFER (parent->pool_private);
277 /* ref the real parent */
278 gst_data_ref (GST_DATA (parent));
279 /* make sure nobody overwrites data in the parent */
280 if (!GST_DATA_IS_READONLY (parent))
281 GST_DATA_FLAG_SET(parent, GST_DATA_READONLY);
283 /* create the new buffer */
284 buffer = gst_mem_chunk_alloc0 (chunk);
285 #ifndef GST_DISABLE_TRACE
286 gst_alloc_trace_new (_gst_buffer_trace, buffer);
289 GST_DEBUG (GST_CAT_BUFFER, "new %p", buf);
291 /* make sure nobody overwrites data in the new buffer
292 * by setting the READONLY flag */
293 _GST_DATA_INIT (GST_DATA (buffer),
295 GST_DATA_FLAG_SHIFT (GST_BUFFER_SUBBUFFER) |
296 GST_DATA_FLAG_SHIFT (GST_DATA_READONLY),
297 (GstDataFreeFunction) _gst_buffer_sub_free,
298 (GstDataCopyFunction) gst_buffer_default_copy);
300 GST_BUFFER_OFFSET (buffer) = parent_offset + offset;
301 GST_BUFFER_TIMESTAMP (buffer) = -1;
302 GST_BUFFER_BUFFERPOOL (buffer) = NULL;
303 GST_BUFFER_POOL_PRIVATE (buffer) = parent;
305 /* set the right values in the child */
306 buffer->data = buffer_data;
315 * @buf1: a first source #GstBuffer to merge.
316 * @buf2: the second source #GstBuffer to merge.
318 * Create a new buffer that is the concatenation of the two source
319 * buffers. The original source buffers will not be modified or
322 * Internally is nothing more than a specialized gst_buffer_span(),
323 * so the same optimizations can occur.
325 * Returns: the new #GstBuffer that's the concatenation of the source buffers.
328 gst_buffer_merge (GstBuffer *buf1, GstBuffer *buf2)
332 /* we're just a specific case of the more general gst_buffer_span() */
333 result = gst_buffer_span (buf1, 0, buf2, buf1->size + buf2->size);
339 * gst_buffer_is_span_fast:
340 * @buf1: a first source #GstBuffer.
341 * @buf2: the second source #GstBuffer.
343 * Determines whether a gst_buffer_span() is free (as in free beer),
344 * or requires a memcpy.
346 * Returns: TRUE if the buffers are contiguous,
347 * FALSE if a copy would be required.
350 gst_buffer_is_span_fast (GstBuffer *buf1, GstBuffer *buf2)
352 g_return_val_if_fail (buf1 != NULL && buf2 != NULL, FALSE);
353 g_return_val_if_fail (GST_BUFFER_REFCOUNT_VALUE (buf1) > 0, FALSE);
354 g_return_val_if_fail (GST_BUFFER_REFCOUNT_VALUE (buf2) > 0, FALSE);
356 /* it's only fast if we have subbuffers of the same parent */
357 return ((GST_BUFFER_FLAG_IS_SET (buf1, GST_BUFFER_SUBBUFFER)) &&
358 (GST_BUFFER_FLAG_IS_SET (buf2, GST_BUFFER_SUBBUFFER)) &&
359 (buf1->pool_private == buf2->pool_private) &&
360 ((buf1->data + buf1->size) == buf2->data));
365 * @buf1: a first source #GstBuffer to merge.
366 * @offset: the offset in the first buffer from where the new
367 * buffer should start.
368 * @buf2: the second source #GstBuffer to merge.
369 * @len: the total length of the new buffer.
371 * Creates a new buffer that consists of part of buf1 and buf2.
372 * Logically, buf1 and buf2 are concatenated into a single larger
373 * buffer, and a new buffer is created at the given offset inside
374 * this space, with a given length.
376 * If the two source buffers are children of the same larger buffer,
377 * and are contiguous, the new buffer will be a child of the shared
378 * parent, and thus no copying is necessary. you can use
379 * gst_buffer_is_span_fast() to determine if a memcpy will be needed.
381 * Returns: the new #GstBuffer that spans the two source buffers.
384 gst_buffer_span (GstBuffer *buf1, guint32 offset, GstBuffer *buf2, guint32 len)
388 g_return_val_if_fail (buf1 != NULL && buf2 != NULL, FALSE);
389 g_return_val_if_fail (GST_BUFFER_REFCOUNT_VALUE (buf1) > 0, NULL);
390 g_return_val_if_fail (GST_BUFFER_REFCOUNT_VALUE (buf2) > 0, NULL);
391 g_return_val_if_fail (len > 0, NULL);
393 /* if the two buffers have the same parent and are adjacent */
394 if (gst_buffer_is_span_fast (buf1, buf2)) {
395 GstBuffer *parent = GST_BUFFER (buf1->pool_private);
396 /* we simply create a subbuffer of the common parent */
397 newbuf = gst_buffer_create_sub (parent,
398 buf1->data - parent->data + offset, len);
401 GST_DEBUG (GST_CAT_BUFFER, "slow path taken while spanning buffers %p and %p",
403 /* otherwise we simply have to brute-force copy the buffers */
404 newbuf = gst_buffer_new_and_alloc (len);
406 /* copy relevant stuff from data struct of buffer1 */
407 GST_BUFFER_OFFSET (newbuf) = GST_BUFFER_OFFSET (buf1) + offset;
409 /* copy the first buffer's data across */
410 memcpy (newbuf->data, buf1->data + offset, buf1->size - offset);
411 /* copy the second buffer's data across */
412 memcpy (newbuf->data + (buf1->size - offset), buf2->data,
413 len - (buf1->size - offset));
415 /* if the offset is 0, the new buffer has the same timestamp as buf1 */
417 GST_BUFFER_TIMESTAMP (newbuf) = GST_BUFFER_TIMESTAMP (buf1);
423 * gst_buffer_pool_default_free:
424 * @pool: a #GstBufferPool to free.
426 * Frees the memory associated with the bufferpool.
429 gst_buffer_pool_default_free (GstBufferPool *pool)
431 g_return_if_fail (pool != NULL);
433 _GST_DATA_DISPOSE (GST_DATA (pool));
435 #ifndef GST_DISABLE_TRACE
436 gst_alloc_trace_free (_gst_buffer_pool_trace, pool);
441 * gst_buffer_pool_new:
442 * @free: the #GstDataFreeFunction to free the buffer pool.
443 * @copy: the #GstDataCopyFunction to copy the buffer pool.
444 * @buffer_new: the #GstBufferPoolBufferNewFunction to create a new buffer
446 * @buffer_copy: the #GstBufferPoolBufferCopyFunction to copy a buffer
448 * @buffer_free: the #GstBufferPoolBufferFreeFunction to free a buffer
450 * @user_data: the user data gpointer passed to buffer_* functions.
452 * Creates a new buffer pool with the given functions.
454 * Returns: a new #GstBufferPool, or NULL on error.
457 gst_buffer_pool_new (GstDataFreeFunction free,
458 GstDataCopyFunction copy,
459 GstBufferPoolBufferNewFunction buffer_new,
460 GstBufferPoolBufferCopyFunction buffer_copy,
461 GstBufferPoolBufferFreeFunction buffer_free,
466 /* we need at least a buffer_new function */
467 g_return_val_if_fail (buffer_new != NULL, NULL);
469 pool = g_new0 (GstBufferPool, 1);
470 #ifndef GST_DISABLE_TRACE
471 gst_alloc_trace_new (_gst_buffer_pool_trace, pool);
474 GST_DEBUG (GST_CAT_BUFFER, "allocating new buffer pool %p\n", pool);
476 /* init data struct */
477 _GST_DATA_INIT (GST_DATA (pool),
478 _gst_buffer_pool_type,
480 (free ? free : (GstDataFreeFunction) gst_buffer_pool_default_free),
484 pool->buffer_new = buffer_new;
485 pool->buffer_copy = buffer_copy;
486 pool->buffer_free = buffer_free;
487 pool->user_data = user_data;
493 * gst_buffer_pool_is_active:
494 * @pool: the #GstBufferPool to query.
496 * Queries if the given buffer pool is active.
498 * Returns: TRUE if the pool is active.
501 gst_buffer_pool_is_active (GstBufferPool *pool)
503 g_return_val_if_fail (pool != NULL, FALSE);
509 * gst_buffer_pool_set_active:
510 * @pool: a #GstBufferPool to set the activity status on.
511 * @active: the new status of the pool.
513 * Sets the given pool to the active or inactive state depending on the
517 gst_buffer_pool_set_active (GstBufferPool *pool, gboolean active)
519 g_return_if_fail (pool != NULL);
521 pool->active = active;
525 * gst_buffer_pool_set_user_data:
526 * @pool: the #GstBufferPool to set the user data for.
527 * @user_data: the user_data to set on the buffer pool.
529 * Sets the given user data on the buffer pool.
532 gst_buffer_pool_set_user_data (GstBufferPool *pool, gpointer user_data)
534 g_return_if_fail (pool != NULL);
536 pool->user_data = user_data;
540 * gst_buffer_pool_get_user_data:
541 * @pool: the #GstBufferPool to get the user data for.
543 * Gets the user data of the buffer pool.
545 * Returns: the user data associated with this buffer pool.
548 gst_buffer_pool_get_user_data (GstBufferPool *pool)
550 g_return_val_if_fail (pool != NULL, NULL);
552 return pool->user_data;