gstreamer/gst/gstbuffer.c

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/* Gnome-Streamer
* Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
*
* 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/gstbuffer.h>
//#define DEBUG(format,args...) g_print("DEBUG: " format, ##args)
#define DEBUG(format,args...)
GMemChunk *_gst_buffer_chunk;
void _gst_buffer_initialize() {
_gst_buffer_chunk = g_mem_chunk_new("GstBuffer",sizeof(GstBuffer),
sizeof(GstBuffer)*16,G_ALLOC_AND_FREE);
}
/**
* gst_buffer_new:
*
* Create a new buffer.
*
* Returns: new buffer
*/
GstBuffer *gst_buffer_new() {
GstBuffer *buffer;
buffer = g_mem_chunk_alloc(_gst_buffer_chunk);
DEBUG("BUF: allocating new buffer %p\n",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;
return buffer;
}
/**
* 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_if_fail(parent != NULL);
g_return_if_fail(size > 0);
g_return_if_fail((offset+size) <= parent->size);
buffer = g_mem_chunk_alloc(_gst_buffer_chunk);
DEBUG("BUF: allocating new subbuffer %p, parent %p\n",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 = 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);
// return the new subbuffer
return buffer;
}
void gst_buffer_destroy(GstBuffer *buffer) {
GSList *metas;
g_return_if_fail(buffer != NULL);
if (buffer->parent != NULL)
DEBUG("BUF: freeing subbuffer %p\n",buffer);
else
DEBUG("BUF: freeing buffer %p\n",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_mem_chunk_free(_gst_buffer_chunk,buffer);
}
void gst_buffer_ref(GstBuffer *buffer) {
g_return_if_fail(buffer != NULL);
DEBUG("BUF: 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
}
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
}
void gst_buffer_unref(GstBuffer *buffer) {
int zero;
g_return_if_fail(buffer != NULL);
DEBUG("BUF: 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)
gst_buffer_destroy(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);
}
GSList *gst_buffer_get_metas(GstBuffer *buffer) {
g_return_if_fail(buffer != NULL);
return buffer->metas;
}
GstMeta *gst_buffer_get_first_meta(GstBuffer *buffer) {
g_return_if_fail(buffer != NULL);
if (buffer->metas == NULL)
return NULL;
return GST_META(buffer->metas->data);
}
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);
}