gstreamer/gst/gstbuffer.c
Erik Walthinsen 7c51d6e0ca Cleaned up the docs a bit.
Original commit message from CVS:
Cleaned up the docs a bit.
2001-01-06 22:05:15 +00:00

397 lines
9.5 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.
*/
/* this file makes too much noise for most debugging sessions */
#define GST_DEBUG_FORCE_DISABLE
#include "gst_private.h"
#include "gstbuffer.h"
GMemChunk *_gst_buffer_chunk;
GMutex *chunck_lock;
void
_gst_buffer_initialize (void)
{
_gst_buffer_chunk = g_mem_chunk_new ("GstBuffer", sizeof(GstBuffer),
sizeof(GstBuffer) * 16, G_ALLOC_AND_FREE);
chunck_lock = g_mutex_new ();
}
/**
* gst_buffer_new:
*
* Create a new buffer.
*
* Returns: new buffer
*/
GstBuffer*
gst_buffer_new(void)
{
GstBuffer *buffer;
g_mutex_lock (chunck_lock);
buffer = g_mem_chunk_alloc (_gst_buffer_chunk);
g_mutex_unlock (chunck_lock);
GST_INFO (GST_CAT_BUFFER,"creating new buffer %p",buffer);
// g_print("allocating new mutex\n");
buffer->lock = g_mutex_new ();
#ifdef HAVE_ATOMIC_H
atomic_set (&buffer->refcount, 1);
#else
buffer->refcount = 1;
#endif
buffer->flags = 0;
buffer->type = 0;
buffer->data = NULL;
buffer->size = 0;
buffer->maxsize = 0;
buffer->offset = 0;
buffer->timestamp = 0;
buffer->metas = NULL;
buffer->parent = NULL;
buffer->pool = NULL;
return buffer;
}
/**
* gst_buffer_new_from_pool:
* @pool: the buffer pool to use
*
* Create a new buffer using the specified bufferpool.
*
* Returns: new buffer
*/
GstBuffer*
gst_buffer_new_from_pool (GstBufferPool *pool)
{
return gst_buffer_pool_new_buffer (pool);
}
/**
* gst_buffer_create_sub:
* @parent: parent buffer
* @offset: offset into parent buffer
* @size: size of new subbuffer
*
* Creates a sub-buffer from the parent at a given offset.
*
* Returns: new buffer
*/
GstBuffer*
gst_buffer_create_sub (GstBuffer *parent,
guint32 offset,
guint32 size)
{
GstBuffer *buffer;
g_return_val_if_fail (parent != NULL, NULL);
g_return_val_if_fail (size > 0, NULL);
g_return_val_if_fail ((offset+size) <= parent->size, NULL);
g_mutex_lock (chunck_lock);
buffer = g_mem_chunk_alloc (_gst_buffer_chunk);
g_mutex_unlock (chunck_lock);
GST_INFO (GST_CAT_BUFFER,"creating new subbuffer %p from parent %p", buffer, parent);
buffer->lock = g_mutex_new ();
#ifdef HAVE_ATOMIC_H
atomic_set (&buffer->refcount, 1);
#else
buffer->refcount = 1;
#endif
// copy flags and type from parent, for lack of better
buffer->flags = parent->flags;
buffer->type = parent->type;
// set the data pointer, size, offset, and maxsize
buffer->data = parent->data + offset;
buffer->size = size;
buffer->offset = parent->offset + offset;
buffer->maxsize = parent->size - offset;
// again, for lack of better, copy parent's timestamp
buffer->timestamp = parent->timestamp;
// no metas, this is sane I think
buffer->metas = NULL;
// set parentage and reference the parent
buffer->parent = parent;
gst_buffer_ref (parent);
buffer->pool = NULL;
// return the new subbuffer
return buffer;
}
/**
* gst_buffer_append:
* @buffer: a buffer
* @append: the buffer to append
*
* Creates a new buffer by appending the data of append to the
* existing data of buffer.
*
* Returns: new buffer
*/
GstBuffer*
gst_buffer_append (GstBuffer *buffer,
GstBuffer *append)
{
guint size;
GstBuffer *newbuf;
g_return_val_if_fail (buffer != NULL, NULL);
g_return_val_if_fail (append != NULL, NULL);
g_return_val_if_fail (buffer->pool == NULL, NULL);
GST_INFO (GST_CAT_BUFFER,"appending buffers %p and %p",buffer,append);
GST_BUFFER_LOCK (buffer);
// the buffer is not used by anyone else
if (GST_BUFFER_REFCOUNT (buffer) == 1 && buffer->parent == NULL
&& !GST_BUFFER_FLAG_IS_SET (buffer, GST_BUFFER_DONTFREE)) {
// save the old size
size = buffer->size;
buffer->size += append->size;
buffer->data = g_realloc (buffer->data, buffer->size);
memcpy(buffer->data + size, append->data, append->size);
GST_BUFFER_UNLOCK (buffer);
}
// the buffer is used, create a new one
else {
newbuf = gst_buffer_new ();
newbuf->size = buffer->size+append->size;
newbuf->data = g_malloc (newbuf->size);
memcpy (newbuf->data, buffer->data, buffer->size);
memcpy (newbuf->data+buffer->size, append->data, append->size);
GST_BUFFER_UNLOCK (buffer);
gst_buffer_unref (buffer);
buffer = newbuf;
}
return buffer;
}
/**
* gst_buffer_destroy:
* @buffer: the GstBuffer to destroy
*
* destroy the buffer
*/
void gst_buffer_destroy (GstBuffer *buffer)
{
GSList *metas;
g_return_if_fail (buffer != NULL);
GST_INFO (GST_CAT_BUFFER,"freeing %sbuffer %p", (buffer->parent?"sub":""),buffer);
// free the data only if there is some, DONTFREE isn't set, and not sub
if (GST_BUFFER_DATA (buffer) &&
!GST_BUFFER_FLAG_IS_SET (buffer, GST_BUFFER_DONTFREE) &&
(buffer->parent == NULL)) {
g_free (GST_BUFFER_DATA (buffer));
// g_print("freed data in buffer\n");
}
// unreference any metadata attached to this buffer
metas = buffer->metas;
while (metas) {
gst_meta_unref ((GstMeta *)(metas->data));
metas = g_slist_next (metas);
}
g_slist_free (buffer->metas);
// unreference the parent if there is one
if (buffer->parent != NULL)
gst_buffer_unref (buffer->parent);
g_mutex_free (buffer->lock);
//g_print("freed mutex\n");
// remove it entirely from memory
g_mutex_lock (chunck_lock);
g_mem_chunk_free (_gst_buffer_chunk,buffer);
g_mutex_unlock (chunck_lock);
}
/**
* gst_buffer_ref:
* @buffer: the GstBuffer to reference
*
* Increment the refcount of this buffer.
*/
void
gst_buffer_ref (GstBuffer *buffer)
{
g_return_if_fail (buffer != NULL);
GST_DEBUG (0,"referencing buffer %p\n", buffer);
#ifdef HAVE_ATOMIC_H
//g_return_if_fail(atomic_read(&(buffer->refcount)) > 0);
atomic_inc (&(buffer->refcount));
#else
g_return_if_fail (buffer->refcount > 0);
GST_BUFFER_LOCK (buffer);
buffer->refcount++;
GST_BUFFER_UNLOCK (buffer);
#endif
}
/**
* gst_buffer_ref_by_count:
* @buffer: the GstBuffer to reference
* @count: a number
*
* Increment the refcount of this buffer by the given number.
*/
void
gst_buffer_ref_by_count (GstBuffer *buffer, int count)
{
g_return_if_fail (buffer != NULL);
g_return_if_fail (count > 0);
#ifdef HAVE_ATOMIC_H
g_return_if_fail (atomic_read (&(buffer->refcount)) > 0);
atomic_add (count, &(buffer->refcount));
#else
g_return_if_fail (buffer->refcount > 0);
GST_BUFFER_LOCK (buffer);
buffer->refcount += count;
GST_BUFFER_UNLOCK (buffer);
#endif
}
/**
* gst_buffer_unref:
* @buffer: the GstBuffer to unref
*
* Decrement the refcount of this buffer. If the refcount is
* zero, the buffer will be destroyed.
*/
void
gst_buffer_unref (GstBuffer *buffer)
{
gint zero;
g_return_if_fail (buffer != NULL);
GST_DEBUG (0,"unreferencing buffer %p\n", buffer);
#ifdef HAVE_ATOMIC_H
g_return_if_fail (atomic_read (&(buffer->refcount)) > 0);
zero = atomic_dec_and_test (&(buffer->refcount));
#else
g_return_if_fail (buffer->refcount > 0);
GST_BUFFER_LOCK (buffer);
buffer->refcount--;
zero = (buffer->refcount == 0);
GST_BUFFER_UNLOCK (buffer);
#endif
/* if we ended up with the refcount at zero, destroy the buffer */
if (zero) {
// if it came from a pool, give it back
if (buffer->pool != NULL) {
gst_buffer_pool_destroy_buffer (buffer->pool, buffer);
return;
}
else {
gst_buffer_destroy (buffer);
}
}
}
/**
* gst_buffer_add_meta:
* @buffer: the GstBuffer to add the metadata to
* @meta: the metadata to add to this buffer
*
* Add the meta data to the buffer.
*/
void
gst_buffer_add_meta (GstBuffer *buffer, GstMeta *meta)
{
g_return_if_fail (buffer != NULL);
g_return_if_fail (meta != NULL);
gst_meta_ref (meta);
buffer->metas = g_slist_append (buffer->metas,meta);
}
/**
* gst_buffer_get_metas:
* @buffer: the GstBuffer to get the metadata from
*
* Get the metadatas from the buffer.
*
* Returns: a GSList of metadata
*/
GSList*
gst_buffer_get_metas (GstBuffer *buffer)
{
g_return_val_if_fail (buffer != NULL, NULL);
return buffer->metas;
}
/**
* gst_buffer_get_first_meta:
* @buffer: the GstBuffer to get the metadata from
*
* Get the first metadata from the buffer.
*
* Returns: the first metadata from the buffer
*/
GstMeta*
gst_buffer_get_first_meta (GstBuffer *buffer)
{
g_return_val_if_fail (buffer != NULL, NULL);
if (buffer->metas == NULL)
return NULL;
return GST_META (buffer->metas->data);
}
/**
* gst_buffer_remove_meta:
* @buffer: the GstBuffer to remove the metadata from
* @meta: the metadata to remove
*
* Remove the given metadata from the buffer.
*/
void
gst_buffer_remove_meta (GstBuffer *buffer, GstMeta *meta)
{
g_return_if_fail (buffer != NULL);
g_return_if_fail (meta != NULL);
buffer->metas = g_slist_remove (buffer->metas, meta);
gst_meta_unref (meta);
}