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_ref,
47 (GBoxedFreeFunc) gst_data_unref);
49 #ifndef GST_DISABLE_TRACE
50 _gst_buffer_trace = gst_alloc_trace_register (GST_BUFFER_TRACE_NAME);
53 chunk = gst_mem_chunk_new ("GstBufferChunk", sizeof (GstBuffer),
54 sizeof (GstBuffer) * 200, 0);
56 GST_CAT_INFO (GST_CAT_BUFFER, "Buffers are initialized now");
60 gst_buffer_get_type (void)
62 return _gst_buffer_type;
66 _gst_buffer_sub_free (GstBuffer *buffer)
68 gst_data_unref (GST_DATA (buffer->buffer_private));
70 GST_BUFFER_DATA (buffer) = NULL;
71 GST_BUFFER_SIZE (buffer) = 0;
73 _GST_DATA_DISPOSE (GST_DATA (buffer));
75 gst_mem_chunk_free (chunk, GST_DATA (buffer));
76 #ifndef GST_DISABLE_TRACE
77 gst_alloc_trace_free (_gst_buffer_trace, buffer);
82 * gst_buffer_default_free:
83 * @buffer: a #GstBuffer to free.
85 * Frees the memory associated with the buffer including the buffer data,
86 * unless the GST_BUFFER_DONTFREE flags was set or the buffer data is NULL.
89 gst_buffer_default_free (GstBuffer *buffer)
91 g_return_if_fail (buffer != NULL);
94 if (!GST_BUFFER_FLAG_IS_SET (buffer, GST_BUFFER_DONTFREE) && GST_BUFFER_DATA (buffer))
95 g_free (GST_BUFFER_DATA (buffer));
97 /* set to safe values */
98 GST_BUFFER_DATA (buffer) = NULL;
99 GST_BUFFER_SIZE (buffer) = 0;
101 _GST_DATA_DISPOSE (GST_DATA (buffer));
103 gst_mem_chunk_free (chunk, GST_DATA (buffer));
104 #ifndef GST_DISABLE_TRACE
105 gst_alloc_trace_free (_gst_buffer_trace, buffer);
111 * @dest: buffer to stamp
112 * @src: buffer to stamp from
114 * Copies additional information (timestamps and offsets) from one buffer to
118 gst_buffer_stamp (GstBuffer *dest, const GstBuffer *src)
120 g_return_if_fail (dest != NULL);
121 g_return_if_fail (src != NULL);
123 GST_BUFFER_TIMESTAMP (dest) = GST_BUFFER_TIMESTAMP (src);
124 GST_BUFFER_DURATION (dest) = GST_BUFFER_DURATION (src);
125 GST_BUFFER_OFFSET (dest) = GST_BUFFER_OFFSET (src);
126 GST_BUFFER_OFFSET_END (dest) = GST_BUFFER_OFFSET_END (src);
129 * gst_buffer_default_copy:
130 * @buffer: a #GstBuffer to make a copy of.
132 * Make a full newly allocated copy of the given buffer, data and all.
134 * Returns: the new #GstBuffer.
137 gst_buffer_default_copy (GstBuffer *buffer)
141 g_return_val_if_fail (buffer != NULL, NULL);
143 /* create a fresh new buffer */
144 copy = gst_mem_chunk_alloc (chunk);
145 #ifndef GST_DISABLE_TRACE
146 gst_alloc_trace_new (_gst_buffer_trace, copy);
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_stamp (copy, buffer);
162 GST_BUFFER_FREE_DATA_FUNC (copy) = NULL;
163 GST_BUFFER_PRIVATE (copy) = NULL;
171 * Creates a newly allocated buffer without any data.
173 * Returns: the new #GstBuffer.
176 gst_buffer_new (void)
180 newbuf = gst_mem_chunk_alloc (chunk);
181 #ifndef GST_DISABLE_TRACE
182 gst_alloc_trace_new (_gst_buffer_trace, newbuf);
185 GST_CAT_LOG (GST_CAT_BUFFER, "new %p", newbuf);
187 _GST_DATA_INIT (GST_DATA (newbuf),
190 (GstDataFreeFunction) gst_buffer_default_free,
191 (GstDataCopyFunction) gst_buffer_default_copy);
193 GST_BUFFER_DATA (newbuf) = NULL;
194 GST_BUFFER_SIZE (newbuf) = 0;
195 GST_BUFFER_MAXSIZE (newbuf) = GST_BUFFER_MAXSIZE_NONE;
196 GST_BUFFER_TIMESTAMP (newbuf) = GST_CLOCK_TIME_NONE;
197 GST_BUFFER_DURATION (newbuf) = GST_CLOCK_TIME_NONE;
198 GST_BUFFER_OFFSET (newbuf) = GST_BUFFER_OFFSET_NONE;
199 GST_BUFFER_OFFSET_END (newbuf) = GST_BUFFER_OFFSET_NONE;
200 GST_BUFFER_FREE_DATA_FUNC (newbuf) = NULL;
201 GST_BUFFER_PRIVATE (newbuf) = NULL;
207 * gst_buffer_new_and_alloc:
208 * @size: the size of the new buffer's data.
210 * Creates a newly allocated buffer with data of the given size.
212 * Returns: the new #GstBuffer.
215 gst_buffer_new_and_alloc (guint size)
219 newbuf = gst_buffer_new ();
221 GST_BUFFER_DATA (newbuf) = g_malloc (size);
222 GST_BUFFER_SIZE (newbuf) = size;
223 GST_BUFFER_MAXSIZE (newbuf) = size;
229 * gst_buffer_create_sub:
230 * @parent: a parent #GstBuffer to create a subbuffer from.
231 * @offset: the offset into parent #GstBuffer.
232 * @size: the size of the new #GstBuffer sub-buffer (with size > 0).
234 * Creates a sub-buffer from the parent at a given offset.
235 * This sub-buffer uses the actual memory space of the parent buffer.
236 * This function will copy the offset and timestamp field when the
237 * offset is 0, else they are set to _NONE.
238 * The duration field of the new buffer are set to GST_CLOCK_TIME_NONE.
240 * Returns: the new #GstBuffer, or NULL if there was an error.
243 gst_buffer_create_sub (GstBuffer *parent, guint offset, guint size)
246 gpointer buffer_data;
248 g_return_val_if_fail (parent != NULL, NULL);
249 g_return_val_if_fail (GST_BUFFER_REFCOUNT_VALUE (parent) > 0, NULL);
250 g_return_val_if_fail (size > 0, NULL);
251 g_return_val_if_fail (parent->size >= offset + size, NULL);
253 /* remember the data for the new buffer */
254 buffer_data = parent->data + offset;
255 /* make sure we're child not child from a child buffer */
256 while (GST_BUFFER_FLAG_IS_SET (parent, GST_BUFFER_SUBBUFFER)) {
257 parent = GST_BUFFER (parent->buffer_private);
259 /* ref the real parent */
260 gst_data_ref (GST_DATA (parent));
262 /* create the new buffer */
263 buffer = gst_mem_chunk_alloc (chunk);
264 #ifndef GST_DISABLE_TRACE
265 gst_alloc_trace_new (_gst_buffer_trace, buffer);
268 GST_CAT_LOG (GST_CAT_BUFFER, "new subbuffer %p", buffer);
270 /* make sure nobody overwrites data in the new buffer
271 * by setting the READONLY flag */
272 _GST_DATA_INIT (GST_DATA (buffer),
274 GST_DATA_FLAG_SHIFT (GST_BUFFER_SUBBUFFER) |
275 GST_DATA_FLAG_SHIFT (GST_DATA_READONLY),
276 (GstDataFreeFunction) _gst_buffer_sub_free,
277 (GstDataCopyFunction) gst_buffer_default_copy);
279 /* set the right values in the child */
280 GST_BUFFER_DATA (buffer) = buffer_data;
281 GST_BUFFER_SIZE (buffer) = size;
282 GST_BUFFER_MAXSIZE (buffer) = size;
283 GST_BUFFER_FREE_DATA_FUNC (buffer) = NULL;
284 GST_BUFFER_PRIVATE (buffer) = parent;
285 /* we can copy the timestamp and offset if the new buffer starts at
288 GST_BUFFER_TIMESTAMP (buffer) = GST_BUFFER_TIMESTAMP (parent);
289 GST_BUFFER_OFFSET (buffer) = GST_BUFFER_OFFSET (parent);
292 GST_BUFFER_TIMESTAMP (buffer) = GST_CLOCK_TIME_NONE;
293 GST_BUFFER_OFFSET (buffer) = GST_BUFFER_OFFSET_NONE;
296 GST_BUFFER_DURATION (buffer) = GST_CLOCK_TIME_NONE;
297 GST_BUFFER_OFFSET_END (buffer) = GST_BUFFER_OFFSET_NONE;
299 if (GST_BUFFER_FLAG_IS_SET (parent, GST_BUFFER_DONTKEEP)) {
300 GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_DONTKEEP);
302 if (GST_BUFFER_FLAG_IS_SET (parent, GST_BUFFER_READONLY)) {
303 GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_READONLY);
312 * @buf1: a first source #GstBuffer to merge.
313 * @buf2: the second source #GstBuffer to merge.
315 * Create a new buffer that is the concatenation of the two source
316 * buffers. The original source buffers will not be modified or
319 * Internally is nothing more than a specialized gst_buffer_span(),
320 * so the same optimizations can occur.
322 * Returns: the new #GstBuffer that's the concatenation of the source buffers.
325 gst_buffer_merge (GstBuffer *buf1, GstBuffer *buf2)
329 /* we're just a specific case of the more general gst_buffer_span() */
330 result = gst_buffer_span (buf1, 0, buf2, buf1->size + buf2->size);
336 * gst_buffer_is_span_fast:
337 * @buf1: a first source #GstBuffer.
338 * @buf2: the second source #GstBuffer.
340 * Determines whether a gst_buffer_span() is free (as in free beer),
341 * or requires a memcpy.
343 * Returns: TRUE if the buffers are contiguous,
344 * FALSE if a copy would be required.
347 gst_buffer_is_span_fast (GstBuffer *buf1, GstBuffer *buf2)
349 g_return_val_if_fail (buf1 != NULL && buf2 != NULL, FALSE);
350 g_return_val_if_fail (GST_BUFFER_REFCOUNT_VALUE (buf1) > 0, FALSE);
351 g_return_val_if_fail (GST_BUFFER_REFCOUNT_VALUE (buf2) > 0, FALSE);
353 /* it's only fast if we have subbuffers of the same parent */
354 return ((GST_BUFFER_FLAG_IS_SET (buf1, GST_BUFFER_SUBBUFFER)) &&
355 (GST_BUFFER_FLAG_IS_SET (buf2, GST_BUFFER_SUBBUFFER)) &&
356 (buf1->buffer_private == buf2->buffer_private) &&
357 ((buf1->data + buf1->size) == buf2->data));
362 * @buf1: a first source #GstBuffer to merge.
363 * @offset: the offset in the first buffer from where the new
364 * buffer should start.
365 * @buf2: the second source #GstBuffer to merge.
366 * @len: the total length of the new buffer.
368 * Creates a new buffer that consists of part of buf1 and buf2.
369 * Logically, buf1 and buf2 are concatenated into a single larger
370 * buffer, and a new buffer is created at the given offset inside
371 * this space, with a given length.
373 * If the two source buffers are children of the same larger buffer,
374 * and are contiguous, the new buffer will be a child of the shared
375 * parent, and thus no copying is necessary. you can use
376 * gst_buffer_is_span_fast() to determine if a memcpy will be needed.
378 * Returns: the new #GstBuffer that spans the two source buffers.
381 gst_buffer_span (GstBuffer *buf1, guint32 offset, GstBuffer *buf2, guint32 len)
385 g_return_val_if_fail (buf1 != NULL && buf2 != NULL, FALSE);
386 g_return_val_if_fail (GST_BUFFER_REFCOUNT_VALUE (buf1) > 0, NULL);
387 g_return_val_if_fail (GST_BUFFER_REFCOUNT_VALUE (buf2) > 0, NULL);
388 g_return_val_if_fail (len > 0, NULL);
389 g_return_val_if_fail (len <= buf1->size + buf2->size - offset, NULL);
391 /* if the two buffers have the same parent and are adjacent */
392 if (gst_buffer_is_span_fast (buf1, buf2)) {
393 GstBuffer *parent = GST_BUFFER (buf1->buffer_private);
394 /* we simply create a subbuffer of the common parent */
395 newbuf = gst_buffer_create_sub (parent,
396 buf1->data - parent->data + offset, len);
399 GST_CAT_DEBUG (GST_CAT_BUFFER, "slow path taken while spanning buffers %p and %p",
401 /* otherwise we simply have to brute-force copy the buffers */
402 newbuf = gst_buffer_new_and_alloc (len);
404 /* copy the first buffer's data across */
405 memcpy (newbuf->data, buf1->data + offset, buf1->size - offset);
406 /* copy the second buffer's data across */
407 memcpy (newbuf->data + (buf1->size - offset), buf2->data,
408 len - (buf1->size - offset));
409 /* if the offset is 0, the new buffer has the same timestamp as buf1 */
411 GST_BUFFER_OFFSET (newbuf) = GST_BUFFER_OFFSET (buf1);
412 GST_BUFFER_TIMESTAMP (newbuf) = GST_BUFFER_TIMESTAMP (buf1);
415 /* if we completely merged the two buffers (appended), we can
416 * calculate the duration too. Also make sure we's not messing with
417 * invalid DURATIONS */
418 if (offset == 0 && buf1->size + buf2->size == len) {
419 if (GST_BUFFER_DURATION_IS_VALID (buf1) &&
420 GST_BUFFER_DURATION_IS_VALID (buf2)) {
422 GST_BUFFER_DURATION (newbuf) = GST_BUFFER_DURATION (buf1) +
423 GST_BUFFER_DURATION (buf2);
425 if (GST_BUFFER_OFFSET_END_IS_VALID (buf2)) {
427 GST_BUFFER_OFFSET_END (newbuf) = GST_BUFFER_OFFSET_END (buf2);