gstreamer/gst/gstbuffer.c
Wim Taymans 4dd1a6b173 gst/gstbuffer.*: Added Comment to a flag. copy relevant flags in _buffer_copy.
Original commit message from CVS:
* gst/gstbuffer.c: (gst_buffer_default_copy):
* gst/gstbuffer.h:
Added Comment to a flag.
copy relevant flags in _buffer_copy.
2004-05-20 17:44:03 +00:00

483 lines
14 KiB
C

/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wtay@chello.be>
*
* gstbuffer.c: Buffer operations
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include "gst_private.h"
#include "gstatomic_impl.h"
#include "gstdata_private.h"
#include "gstbuffer.h"
#include "gstmemchunk.h"
#include "gstinfo.h"
GType _gst_buffer_type;
#ifndef GST_DISABLE_TRACE
/* #define GST_WITH_ALLOC_TRACE */
#include "gsttrace.h"
static GstAllocTrace *_gst_buffer_trace;
#endif
static GstMemChunk *chunk;
static GstBuffer *gst_buffer_alloc_chunk (void);
static void gst_buffer_free_chunk (GstBuffer * buffer);
void
_gst_buffer_initialize (void)
{
gst_buffer_get_type ();
#ifndef GST_DISABLE_TRACE
_gst_buffer_trace = gst_alloc_trace_register (GST_BUFFER_TRACE_NAME);
#endif
chunk = gst_mem_chunk_new ("GstBufferChunk", sizeof (GstBuffer),
sizeof (GstBuffer) * 200, 0);
GST_CAT_LOG (GST_CAT_BUFFER, "Buffers are initialized now");
}
GType
gst_buffer_get_type (void)
{
if (_gst_buffer_type == 0) {
_gst_buffer_type = g_boxed_type_register_static ("GstBuffer",
(GBoxedCopyFunc) gst_data_copy, (GBoxedFreeFunc) gst_data_unref);
}
return _gst_buffer_type;
}
static void
_gst_buffer_sub_free (GstBuffer * buffer)
{
gst_data_unref (GST_DATA (buffer->buffer_private));
GST_BUFFER_DATA (buffer) = NULL;
GST_BUFFER_SIZE (buffer) = 0;
_GST_DATA_DISPOSE (GST_DATA (buffer));
gst_buffer_free_chunk (buffer);
}
/**
* gst_buffer_default_free:
* @buffer: a #GstBuffer to free.
*
* Frees the memory associated with the buffer including the buffer data,
* unless the GST_BUFFER_DONTFREE flags was set or the buffer data is NULL.
*/
void
gst_buffer_default_free (GstBuffer * buffer)
{
g_return_if_fail (buffer != NULL);
/* free our data */
if (GST_BUFFER_FREE_DATA_FUNC (buffer)) {
GST_BUFFER_FREE_DATA_FUNC (buffer) (buffer);
} else if (!GST_BUFFER_FLAG_IS_SET (buffer, GST_BUFFER_DONTFREE)) {
g_free (GST_BUFFER_DATA (buffer));
}
/* set to safe values */
GST_BUFFER_DATA (buffer) = NULL;
GST_BUFFER_SIZE (buffer) = 0;
_GST_DATA_DISPOSE (GST_DATA (buffer));
gst_buffer_free_chunk (buffer);
}
/**
* gst_buffer_stamp:
* @dest: buffer to stamp
* @src: buffer to stamp from
*
* Copies additional information (timestamps and offsets) from one buffer to
* the other.
*/
void
gst_buffer_stamp (GstBuffer * dest, const GstBuffer * src)
{
g_return_if_fail (dest != NULL);
g_return_if_fail (src != NULL);
GST_BUFFER_TIMESTAMP (dest) = GST_BUFFER_TIMESTAMP (src);
GST_BUFFER_DURATION (dest) = GST_BUFFER_DURATION (src);
GST_BUFFER_OFFSET (dest) = GST_BUFFER_OFFSET (src);
GST_BUFFER_OFFSET_END (dest) = GST_BUFFER_OFFSET_END (src);
}
/**
* gst_buffer_default_copy:
* @buffer: a #GstBuffer to make a copy of.
*
* Make a full newly allocated copy of the given buffer, data and all.
*
* Returns: the new #GstBuffer.
*/
GstBuffer *
gst_buffer_default_copy (GstBuffer * buffer)
{
GstBuffer *copy;
guint16 flags;
g_return_val_if_fail (buffer != NULL, NULL);
/* create a fresh new buffer */
copy = gst_buffer_alloc_chunk ();
/* copy relevant flags */
flags = GST_DATA_FLAG_SHIFT (GST_BUFFER_KEY_UNIT) |
GST_DATA_FLAG_SHIFT (GST_BUFFER_IN_CAPS);
_GST_DATA_INIT (GST_DATA (copy),
_gst_buffer_type,
flags,
(GstDataFreeFunction) gst_buffer_default_free,
(GstDataCopyFunction) gst_buffer_default_copy);
/* we simply copy everything from our parent */
GST_BUFFER_DATA (copy) = g_memdup (GST_BUFFER_DATA (buffer),
GST_BUFFER_SIZE (buffer));
GST_BUFFER_SIZE (copy) = GST_BUFFER_SIZE (buffer);
GST_BUFFER_MAXSIZE (copy) = GST_BUFFER_SIZE (buffer);
gst_buffer_stamp (copy, buffer);
GST_BUFFER_FREE_DATA_FUNC (copy) = NULL;
GST_BUFFER_PRIVATE (copy) = NULL;
return copy;
}
static GstBuffer *
gst_buffer_alloc_chunk (void)
{
GstBuffer *newbuf;
newbuf = gst_mem_chunk_alloc (chunk);
#ifndef GST_DISABLE_TRACE
gst_alloc_trace_new (_gst_buffer_trace, newbuf);
#endif
return newbuf;
}
static void
gst_buffer_free_chunk (GstBuffer * buffer)
{
gst_mem_chunk_free (chunk, GST_DATA (buffer));
#ifndef GST_DISABLE_TRACE
gst_alloc_trace_free (_gst_buffer_trace, buffer);
#endif
}
/**
* gst_buffer_new:
*
* Creates a newly allocated buffer without any data.
*
* Returns: the new #GstBuffer.
*/
GstBuffer *
gst_buffer_new (void)
{
GstBuffer *newbuf;
newbuf = gst_buffer_alloc_chunk ();
GST_CAT_LOG (GST_CAT_BUFFER, "new %p", newbuf);
_GST_DATA_INIT (GST_DATA (newbuf),
_gst_buffer_type,
0,
(GstDataFreeFunction) gst_buffer_default_free,
(GstDataCopyFunction) gst_buffer_default_copy);
GST_BUFFER_DATA (newbuf) = NULL;
GST_BUFFER_SIZE (newbuf) = 0;
GST_BUFFER_MAXSIZE (newbuf) = GST_BUFFER_MAXSIZE_NONE;
GST_BUFFER_TIMESTAMP (newbuf) = GST_CLOCK_TIME_NONE;
GST_BUFFER_DURATION (newbuf) = GST_CLOCK_TIME_NONE;
GST_BUFFER_OFFSET (newbuf) = GST_BUFFER_OFFSET_NONE;
GST_BUFFER_OFFSET_END (newbuf) = GST_BUFFER_OFFSET_NONE;
GST_BUFFER_FREE_DATA_FUNC (newbuf) = NULL;
GST_BUFFER_PRIVATE (newbuf) = NULL;
return newbuf;
}
/**
* gst_buffer_new_and_alloc:
* @size: the size of the new buffer's data.
*
* Creates a newly allocated buffer with data of the given size.
*
* Returns: the new #GstBuffer.
*/
GstBuffer *
gst_buffer_new_and_alloc (guint size)
{
GstBuffer *newbuf;
newbuf = gst_buffer_new ();
GST_BUFFER_DATA (newbuf) = g_malloc (size);
GST_BUFFER_SIZE (newbuf) = size;
GST_BUFFER_MAXSIZE (newbuf) = size;
return newbuf;
}
/**
* gst_buffer_create_sub:
* @parent: a parent #GstBuffer to create a subbuffer from.
* @offset: the offset into parent #GstBuffer.
* @size: the size of the new #GstBuffer sub-buffer (with size > 0).
*
* Creates a sub-buffer from the parent at a given offset.
* This sub-buffer uses the actual memory space of the parent buffer.
* This function will copy the offset and timestamp field when the
* offset is 0, else they are set to _NONE.
* The duration field of the new buffer are set to GST_CLOCK_TIME_NONE.
*
* Returns: the new #GstBuffer, or NULL if there was an error.
*/
GstBuffer *
gst_buffer_create_sub (GstBuffer * parent, guint offset, guint size)
{
GstBuffer *buffer;
gpointer buffer_data;
g_return_val_if_fail (parent != NULL, NULL);
g_return_val_if_fail (GST_BUFFER_REFCOUNT_VALUE (parent) > 0, NULL);
g_return_val_if_fail (size > 0, NULL);
g_return_val_if_fail (parent->size >= offset + size, NULL);
/* remember the data for the new buffer */
buffer_data = parent->data + offset;
/* make sure we're child not child from a child buffer */
while (GST_BUFFER_FLAG_IS_SET (parent, GST_BUFFER_SUBBUFFER)) {
parent = GST_BUFFER (parent->buffer_private);
}
/* ref the real parent */
gst_data_ref (GST_DATA (parent));
/* create the new buffer */
buffer = gst_buffer_alloc_chunk ();
GST_CAT_LOG (GST_CAT_BUFFER, "new subbuffer %p (parent %p)", buffer, parent);
/* make sure nobody overwrites data in the new buffer
* by setting the READONLY flag */
_GST_DATA_INIT (GST_DATA (buffer),
_gst_buffer_type,
GST_DATA_FLAG_SHIFT (GST_BUFFER_SUBBUFFER) |
GST_DATA_FLAG_SHIFT (GST_DATA_READONLY),
(GstDataFreeFunction) _gst_buffer_sub_free,
(GstDataCopyFunction) gst_buffer_default_copy);
/* set the right values in the child */
GST_BUFFER_DATA (buffer) = buffer_data;
GST_BUFFER_SIZE (buffer) = size;
GST_BUFFER_MAXSIZE (buffer) = size;
GST_BUFFER_FREE_DATA_FUNC (buffer) = NULL;
GST_BUFFER_PRIVATE (buffer) = parent;
/* we can copy the timestamp and offset if the new buffer starts at
* offset 0 */
if (offset == 0) {
GST_BUFFER_TIMESTAMP (buffer) = GST_BUFFER_TIMESTAMP (parent);
GST_BUFFER_OFFSET (buffer) = GST_BUFFER_OFFSET (parent);
} else {
GST_BUFFER_TIMESTAMP (buffer) = GST_CLOCK_TIME_NONE;
GST_BUFFER_OFFSET (buffer) = GST_BUFFER_OFFSET_NONE;
}
GST_BUFFER_DURATION (buffer) = GST_CLOCK_TIME_NONE;
GST_BUFFER_OFFSET_END (buffer) = GST_BUFFER_OFFSET_NONE;
if (GST_BUFFER_FLAG_IS_SET (parent, GST_BUFFER_DONTKEEP)) {
GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_DONTKEEP);
}
if (GST_BUFFER_FLAG_IS_SET (parent, GST_BUFFER_READONLY)) {
GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_READONLY);
}
return buffer;
}
/**
* gst_buffer_merge:
* @buf1: a first source #GstBuffer to merge.
* @buf2: the second source #GstBuffer to merge.
*
* Create a new buffer that is the concatenation of the two source
* buffers. The original source buffers will not be modified or
* unref'd.
*
* WARNING: Incorrect use of this function can lead to memory leaks.
* It is recommended to use gst_buffer_join() instead of this function.
*
* If the buffers point to contiguous areas of memory, the buffer
* is created without copying the data.
*
* Returns: the new #GstBuffer that's the concatenation of the source buffers.
*/
GstBuffer *
gst_buffer_merge (GstBuffer * buf1, GstBuffer * buf2)
{
GstBuffer *result;
/* we're just a specific case of the more general gst_buffer_span() */
result = gst_buffer_span (buf1, 0, buf2, buf1->size + buf2->size);
return result;
}
/**
* gst_buffer_join:
* @buf1: a first source #GstBuffer to merge.
* @buf2: the second source #GstBuffer to merge.
*
* Create a new buffer that is the concatenation of the two source
* buffers. The original buffers are unreferenced.
*
* If the buffers point to contiguous areas of memory, the buffer
* is created without copying the data.
*
* Returns: the new #GstBuffer that's the concatenation of the source buffers.
*/
GstBuffer *
gst_buffer_join (GstBuffer * buf1, GstBuffer * buf2)
{
GstBuffer *result;
/* we're just a specific case of the more general gst_buffer_span() */
result = gst_buffer_span (buf1, 0, buf2, buf1->size + buf2->size);
gst_buffer_unref (buf1);
gst_buffer_unref (buf2);
return result;
}
/**
* gst_buffer_is_span_fast:
* @buf1: a first source #GstBuffer.
* @buf2: the second source #GstBuffer.
*
* Determines whether a gst_buffer_span() can be done without copying
* the contents, that is, whether the data areas are contiguous.
*
* Returns: TRUE if the buffers are contiguous,
* FALSE if a copy would be required.
*/
gboolean
gst_buffer_is_span_fast (GstBuffer * buf1, GstBuffer * buf2)
{
g_return_val_if_fail (buf1 != NULL && buf2 != NULL, FALSE);
g_return_val_if_fail (GST_BUFFER_REFCOUNT_VALUE (buf1) > 0, FALSE);
g_return_val_if_fail (GST_BUFFER_REFCOUNT_VALUE (buf2) > 0, FALSE);
/* it's only fast if we have subbuffers of the same parent */
return ((GST_BUFFER_FLAG_IS_SET (buf1, GST_BUFFER_SUBBUFFER)) &&
(GST_BUFFER_FLAG_IS_SET (buf2, GST_BUFFER_SUBBUFFER)) &&
(buf1->buffer_private == buf2->buffer_private) &&
((buf1->data + buf1->size) == buf2->data));
}
/**
* gst_buffer_span:
* @buf1: a first source #GstBuffer to merge.
* @offset: the offset in the first buffer from where the new
* buffer should start.
* @buf2: the second source #GstBuffer to merge.
* @len: the total length of the new buffer.
*
* Creates a new buffer that consists of part of buf1 and buf2.
* Logically, buf1 and buf2 are concatenated into a single larger
* buffer, and a new buffer is created at the given offset inside
* this space, with a given length.
*
* If the two source buffers are children of the same larger buffer,
* and are contiguous, the new buffer will be a child of the shared
* parent, and thus no copying is necessary. you can use
* gst_buffer_is_span_fast() to determine if a memcpy will be needed.
*
* Returns: the new #GstBuffer that spans the two source buffers.
*/
GstBuffer *
gst_buffer_span (GstBuffer * buf1, guint32 offset, GstBuffer * buf2,
guint32 len)
{
GstBuffer *newbuf;
g_return_val_if_fail (buf1 != NULL && buf2 != NULL, FALSE);
g_return_val_if_fail (GST_BUFFER_REFCOUNT_VALUE (buf1) > 0, NULL);
g_return_val_if_fail (GST_BUFFER_REFCOUNT_VALUE (buf2) > 0, NULL);
g_return_val_if_fail (len > 0, NULL);
g_return_val_if_fail (len <= buf1->size + buf2->size - offset, NULL);
/* if the two buffers have the same parent and are adjacent */
if (gst_buffer_is_span_fast (buf1, buf2)) {
GstBuffer *parent = GST_BUFFER (buf1->buffer_private);
/* we simply create a subbuffer of the common parent */
newbuf = gst_buffer_create_sub (parent,
buf1->data - parent->data + offset, len);
} else {
GST_CAT_DEBUG (GST_CAT_BUFFER,
"slow path taken while spanning buffers %p and %p", buf1, buf2);
/* otherwise we simply have to brute-force copy the buffers */
newbuf = gst_buffer_new_and_alloc (len);
/* copy the first buffer's data across */
memcpy (newbuf->data, buf1->data + offset, buf1->size - offset);
/* copy the second buffer's data across */
memcpy (newbuf->data + (buf1->size - offset), buf2->data,
len - (buf1->size - offset));
/* if the offset is 0, the new buffer has the same timestamp as buf1 */
if (offset == 0) {
GST_BUFFER_OFFSET (newbuf) = GST_BUFFER_OFFSET (buf1);
GST_BUFFER_TIMESTAMP (newbuf) = GST_BUFFER_TIMESTAMP (buf1);
}
}
/* if we completely merged the two buffers (appended), we can
* calculate the duration too. Also make sure we's not messing with
* invalid DURATIONS */
if (offset == 0 && buf1->size + buf2->size == len) {
if (GST_BUFFER_DURATION_IS_VALID (buf1) &&
GST_BUFFER_DURATION_IS_VALID (buf2)) {
/* add duration */
GST_BUFFER_DURATION (newbuf) = GST_BUFFER_DURATION (buf1) +
GST_BUFFER_DURATION (buf2);
}
if (GST_BUFFER_OFFSET_END_IS_VALID (buf2)) {
/* add offset_end */
GST_BUFFER_OFFSET_END (newbuf) = GST_BUFFER_OFFSET_END (buf2);
}
}
return newbuf;
}