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 = 0;
33 #ifndef GST_DISABLE_TRACE
34 /* #define GST_WITH_ALLOC_TRACE */
37 static GstAllocTrace *_gst_buffer_trace;
40 static GstMemChunk *chunk;
42 static GstBuffer *gst_buffer_alloc_chunk (void);
43 static void gst_buffer_free_chunk (GstBuffer * buffer);
46 _gst_buffer_initialize (void)
48 gst_buffer_get_type ();
50 #ifndef GST_DISABLE_TRACE
51 _gst_buffer_trace = gst_alloc_trace_register (GST_BUFFER_TRACE_NAME);
54 chunk = gst_mem_chunk_new ("GstBufferChunk", sizeof (GstBuffer),
55 sizeof (GstBuffer) * 200, 0);
57 GST_CAT_LOG (GST_CAT_BUFFER, "Buffers are initialized now");
61 gst_buffer_get_type (void)
63 if (G_UNLIKELY (_gst_buffer_type == 0)) {
64 _gst_buffer_type = g_boxed_type_register_static ("GstBuffer",
65 (GBoxedCopyFunc) gst_data_copy, (GBoxedFreeFunc) gst_data_unref);
67 return _gst_buffer_type;
71 _gst_buffer_sub_free (GstBuffer * buffer)
73 gst_data_unref (GST_DATA (buffer->buffer_private));
75 GST_BUFFER_DATA (buffer) = NULL;
76 GST_BUFFER_SIZE (buffer) = 0;
77 if (GST_BUFFER_CAPS (buffer))
78 gst_caps_unref (GST_BUFFER_CAPS (buffer));
80 _GST_DATA_DISPOSE (GST_DATA (buffer));
82 gst_buffer_free_chunk (buffer);
86 * gst_buffer_default_free:
87 * @buffer: a #GstBuffer to free.
89 * Frees the memory associated with the buffer including the buffer data,
90 * unless the GST_BUFFER_DONTFREE flags was set or the buffer data is NULL.
95 gst_buffer_default_free (GstBuffer * buffer)
97 g_return_if_fail (buffer != NULL);
100 if (GST_BUFFER_FREE_DATA_FUNC (buffer)) {
101 GST_BUFFER_FREE_DATA_FUNC (buffer) (buffer);
102 } else if (!GST_BUFFER_FLAG_IS_SET (buffer, GST_BUFFER_DONTFREE)) {
103 g_free (GST_BUFFER_DATA (buffer));
106 /* set to safe values */
107 GST_BUFFER_DATA (buffer) = NULL;
108 GST_BUFFER_SIZE (buffer) = 0;
109 if (GST_BUFFER_CAPS (buffer))
110 gst_caps_unref (GST_BUFFER_CAPS (buffer));
112 _GST_DATA_DISPOSE (GST_DATA (buffer));
114 gst_buffer_free_chunk (buffer);
119 * gst_buffer_default_copy:
120 * @buffer: a #GstBuffer to make a copy of.
122 * Make a full newly allocated copy of the given buffer, data and all.
123 * Note that the caps on the buffer are not copied but their refcount
126 * Returns: the new #GstBuffer.
131 gst_buffer_default_copy (GstBuffer * buffer)
136 g_return_val_if_fail (buffer != NULL, NULL);
138 /* create a fresh new buffer */
139 copy = gst_buffer_alloc_chunk ();
141 GST_CAT_LOG (GST_CAT_BUFFER, "copy %p to %p", buffer, copy);
143 /* copy relevant flags */
144 flags = GST_DATA_FLAG_SHIFT (GST_BUFFER_PREROLL) |
145 GST_DATA_FLAG_SHIFT (GST_BUFFER_IN_CAPS) |
146 GST_DATA_FLAG_SHIFT (GST_BUFFER_DELTA_UNIT);
147 flags = GST_BUFFER_FLAGS (buffer) & flags;
149 _GST_DATA_INIT (GST_DATA (copy),
152 (GstDataFreeFunction) gst_buffer_default_free,
153 (GstDataCopyFunction) gst_buffer_default_copy);
155 /* we simply copy everything from our parent */
156 GST_BUFFER_DATA (copy) = g_memdup (GST_BUFFER_DATA (buffer),
157 GST_BUFFER_SIZE (buffer));
158 GST_BUFFER_SIZE (copy) = GST_BUFFER_SIZE (buffer);
159 GST_BUFFER_MAXSIZE (copy) = GST_BUFFER_SIZE (buffer);
161 GST_BUFFER_TIMESTAMP (copy) = GST_BUFFER_TIMESTAMP (buffer);
162 GST_BUFFER_DURATION (copy) = GST_BUFFER_DURATION (buffer);
163 GST_BUFFER_OFFSET (copy) = GST_BUFFER_OFFSET (buffer);
164 GST_BUFFER_OFFSET_END (copy) = GST_BUFFER_OFFSET_END (buffer);
166 GST_BUFFER_FREE_DATA_FUNC (copy) = NULL;
167 GST_BUFFER_PRIVATE (copy) = NULL;
168 if (GST_BUFFER_CAPS (buffer))
169 GST_BUFFER_CAPS (copy) = gst_caps_ref (GST_BUFFER_CAPS (buffer));
175 gst_buffer_alloc_chunk (void)
179 newbuf = gst_mem_chunk_alloc (chunk);
180 #ifndef GST_DISABLE_TRACE
181 gst_alloc_trace_new (_gst_buffer_trace, newbuf);
188 gst_buffer_free_chunk (GstBuffer * buffer)
190 gst_mem_chunk_free (chunk, GST_DATA (buffer));
191 #ifndef GST_DISABLE_TRACE
192 gst_alloc_trace_free (_gst_buffer_trace, buffer);
199 * Creates a newly allocated buffer without any data.
201 * Returns: the new #GstBuffer.
206 gst_buffer_new (void)
210 newbuf = gst_buffer_alloc_chunk ();
212 GST_CAT_LOG (GST_CAT_BUFFER, "new %p", newbuf);
214 _GST_DATA_INIT (GST_DATA (newbuf),
217 (GstDataFreeFunction) gst_buffer_default_free,
218 (GstDataCopyFunction) gst_buffer_default_copy);
220 GST_BUFFER_DATA (newbuf) = NULL;
221 GST_BUFFER_SIZE (newbuf) = 0;
222 GST_BUFFER_MAXSIZE (newbuf) = GST_BUFFER_MAXSIZE_NONE;
223 GST_BUFFER_TIMESTAMP (newbuf) = GST_CLOCK_TIME_NONE;
224 GST_BUFFER_DURATION (newbuf) = GST_CLOCK_TIME_NONE;
225 GST_BUFFER_OFFSET (newbuf) = GST_BUFFER_OFFSET_NONE;
226 GST_BUFFER_OFFSET_END (newbuf) = GST_BUFFER_OFFSET_NONE;
227 GST_BUFFER_FREE_DATA_FUNC (newbuf) = NULL;
228 GST_BUFFER_PRIVATE (newbuf) = NULL;
229 GST_BUFFER_CAPS (newbuf) = NULL;
235 * gst_buffer_new_and_alloc:
236 * @size: the size of the new buffer's data.
238 * Creates a newly allocated buffer with data of the given size.
240 * Returns: the new #GstBuffer.
245 gst_buffer_new_and_alloc (guint size)
249 newbuf = gst_buffer_new ();
251 GST_BUFFER_DATA (newbuf) = g_malloc (size);
252 GST_BUFFER_SIZE (newbuf) = size;
253 GST_BUFFER_MAXSIZE (newbuf) = size;
260 * gst_buffer_get_caps:
261 * @buffer: a #GstBuffer to get the caps of.
263 * Gets the media type of the buffer. This can be NULL if there
264 * is not media type attached to this buffer or when the media
265 * type is the same as the previous received buffer.
267 * This function does not increment the refcount of the caps. The
268 * caps pointer will therefore remain valid until the buffer is
271 * Returns: the #GstCaps, or NULL if there was an error or there
272 * were no caps on this buffer.
274 /* FIXME can we make this threadsafe without a lock on the buffer? */
276 gst_buffer_get_caps (GstBuffer * buffer)
278 g_return_val_if_fail (buffer != NULL, NULL);
280 return GST_BUFFER_CAPS (buffer);
284 * gst_buffer_set_caps:
285 * @buffer: a #GstBuffer to set the caps of.
286 * @caps: a #GstCaps to set.
288 * Sets the media type on the buffer. The caps' refcount will
289 * be increased and any previous caps on the buffer will be
292 /* FIXME can we make this threadsafe without a lock on the buffer? */
294 gst_buffer_set_caps (GstBuffer * buffer, GstCaps * caps)
298 g_return_if_fail (buffer != NULL);
301 oldcaps = GST_BUFFER_CAPS (buffer);
302 /* ref new caps if any */
304 caps = gst_caps_ref (caps);
306 GST_BUFFER_CAPS (buffer) = caps;
308 /* unref old caps if any */
310 gst_caps_unref (oldcaps);
315 * gst_buffer_create_sub:
316 * @parent: a parent #GstBuffer to create a subbuffer from.
317 * @offset: the offset into parent #GstBuffer.
318 * @size: the size of the new #GstBuffer sub-buffer (with size > 0).
320 * Creates a sub-buffer from the parent at a given offset.
321 * This sub-buffer uses the actual memory space of the parent buffer.
322 * This function will copy the offset and timestamp field when the
323 * offset is 0, else they are set to _NONE.
324 * The duration field of the new buffer are set to GST_CLOCK_TIME_NONE.
326 * Returns: the new #GstBuffer, or NULL if there was an error.
331 gst_buffer_create_sub (GstBuffer * parent, guint offset, guint size)
334 gpointer buffer_data;
336 g_return_val_if_fail (parent != NULL, NULL);
337 g_return_val_if_fail (GST_BUFFER_REFCOUNT_VALUE (parent) > 0, NULL);
338 g_return_val_if_fail (size > 0, NULL);
339 g_return_val_if_fail (parent->size >= offset + size, NULL);
341 /* remember the data for the new buffer */
342 buffer_data = parent->data + offset;
343 /* make sure we're child not child from a child buffer */
344 while (GST_BUFFER_FLAG_IS_SET (parent, GST_BUFFER_SUBBUFFER)) {
345 parent = GST_BUFFER (parent->buffer_private);
347 /* ref the real parent */
348 gst_data_ref (GST_DATA (parent));
350 /* create the new buffer */
351 buffer = gst_buffer_alloc_chunk ();
353 GST_CAT_LOG (GST_CAT_BUFFER, "new subbuffer %p (parent %p)", buffer, parent);
355 /* make sure nobody overwrites data in the new buffer
356 * by setting the READONLY flag */
357 _GST_DATA_INIT (GST_DATA (buffer),
359 GST_DATA_FLAG_SHIFT (GST_BUFFER_SUBBUFFER) |
360 GST_DATA_FLAG_SHIFT (GST_DATA_READONLY),
361 (GstDataFreeFunction) _gst_buffer_sub_free,
362 (GstDataCopyFunction) gst_buffer_default_copy);
364 /* set the right values in the child */
365 GST_BUFFER_DATA (buffer) = buffer_data;
366 GST_BUFFER_SIZE (buffer) = size;
367 GST_BUFFER_MAXSIZE (buffer) = size;
368 GST_BUFFER_FREE_DATA_FUNC (buffer) = NULL;
369 GST_BUFFER_PRIVATE (buffer) = parent;
370 /* we can copy the timestamp and offset if the new buffer starts at
373 GST_BUFFER_TIMESTAMP (buffer) = GST_BUFFER_TIMESTAMP (parent);
374 GST_BUFFER_OFFSET (buffer) = GST_BUFFER_OFFSET (parent);
376 GST_BUFFER_TIMESTAMP (buffer) = GST_CLOCK_TIME_NONE;
377 GST_BUFFER_OFFSET (buffer) = GST_BUFFER_OFFSET_NONE;
380 GST_BUFFER_DURATION (buffer) = GST_CLOCK_TIME_NONE;
381 GST_BUFFER_OFFSET_END (buffer) = GST_BUFFER_OFFSET_NONE;
383 if (GST_BUFFER_FLAG_IS_SET (parent, GST_BUFFER_READONLY)) {
384 GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_READONLY);
386 GST_BUFFER_CAPS (buffer) = NULL;
392 * gst_buffer_is_span_fast:
393 * @buf1: a first source #GstBuffer.
394 * @buf2: the second source #GstBuffer.
396 * Determines whether a gst_buffer_span() can be done without copying
397 * the contents, that is, whether the data areas are contiguous.
399 * Returns: TRUE if the buffers are contiguous,
400 * FALSE if a copy would be required.
405 gst_buffer_is_span_fast (GstBuffer * buf1, GstBuffer * buf2)
407 g_return_val_if_fail (buf1 != NULL && buf2 != NULL, FALSE);
408 g_return_val_if_fail (GST_BUFFER_REFCOUNT_VALUE (buf1) > 0, FALSE);
409 g_return_val_if_fail (GST_BUFFER_REFCOUNT_VALUE (buf2) > 0, FALSE);
411 /* it's only fast if we have subbuffers of the same parent */
412 return ((GST_BUFFER_FLAG_IS_SET (buf1, GST_BUFFER_SUBBUFFER)) &&
413 (GST_BUFFER_FLAG_IS_SET (buf2, GST_BUFFER_SUBBUFFER)) &&
414 (buf1->buffer_private == buf2->buffer_private) &&
415 ((buf1->data + buf1->size) == buf2->data));
420 * @buf1: a first source #GstBuffer to merge.
421 * @offset: the offset in the first buffer from where the new
422 * buffer should start.
423 * @buf2: the second source #GstBuffer to merge.
424 * @len: the total length of the new buffer.
426 * Creates a new buffer that consists of part of buf1 and buf2.
427 * Logically, buf1 and buf2 are concatenated into a single larger
428 * buffer, and a new buffer is created at the given offset inside
429 * this space, with a given length.
431 * If the two source buffers are children of the same larger buffer,
432 * and are contiguous, the new buffer will be a child of the shared
433 * parent, and thus no copying is necessary. you can use
434 * gst_buffer_is_span_fast() to determine if a memcpy will be needed.
436 * Returns: the new #GstBuffer that spans the two source buffers.
441 gst_buffer_span (GstBuffer * buf1, guint32 offset, GstBuffer * buf2,
446 g_return_val_if_fail (buf1 != NULL && buf2 != NULL, NULL);
447 g_return_val_if_fail (GST_BUFFER_REFCOUNT_VALUE (buf1) > 0, NULL);
448 g_return_val_if_fail (GST_BUFFER_REFCOUNT_VALUE (buf2) > 0, NULL);
449 g_return_val_if_fail (len > 0, NULL);
450 g_return_val_if_fail (len <= buf1->size + buf2->size - offset, NULL);
452 /* if the two buffers have the same parent and are adjacent */
453 if (gst_buffer_is_span_fast (buf1, buf2)) {
454 GstBuffer *parent = GST_BUFFER (buf1->buffer_private);
456 /* we simply create a subbuffer of the common parent */
457 newbuf = gst_buffer_create_sub (parent,
458 buf1->data - parent->data + offset, len);
460 GST_CAT_DEBUG (GST_CAT_BUFFER,
461 "slow path taken while spanning buffers %p and %p", buf1, buf2);
462 /* otherwise we simply have to brute-force copy the buffers */
463 newbuf = gst_buffer_new_and_alloc (len);
465 /* copy the first buffer's data across */
466 memcpy (newbuf->data, buf1->data + offset, buf1->size - offset);
467 /* copy the second buffer's data across */
468 memcpy (newbuf->data + (buf1->size - offset), buf2->data,
469 len - (buf1->size - offset));
470 /* if the offset is 0, the new buffer has the same timestamp as buf1 */
472 GST_BUFFER_OFFSET (newbuf) = GST_BUFFER_OFFSET (buf1);
473 GST_BUFFER_TIMESTAMP (newbuf) = GST_BUFFER_TIMESTAMP (buf1);
476 /* if we completely merged the two buffers (appended), we can
477 * calculate the duration too. Also make sure we's not messing with
478 * invalid DURATIONS */
479 if (offset == 0 && buf1->size + buf2->size == len) {
480 if (GST_BUFFER_DURATION_IS_VALID (buf1) &&
481 GST_BUFFER_DURATION_IS_VALID (buf2)) {
483 GST_BUFFER_DURATION (newbuf) = GST_BUFFER_DURATION (buf1) +
484 GST_BUFFER_DURATION (buf2);
486 if (GST_BUFFER_OFFSET_END_IS_VALID (buf2)) {
488 GST_BUFFER_OFFSET_END (newbuf) = GST_BUFFER_OFFSET_END (buf2);