gstreamer/gst/gstbuffermeta.h
Wim Taymans 8468dadc77 buffermeta: add beginnings of buffer metadata
Add first implementation of arbitrary buffer metadata. We use a simple linked
linked of slice allocated metadata chunks. Future implementations could use
something more performant.
Add get, remove, iterate methods to handle the metadata.
2011-02-25 10:34:47 +01:00

139 lines
4.1 KiB
C

/* GStreamer
* Copyright (C) 2009 Wim Taymans <wim.taymans@gmail.be>
*
* gstbuffermeta.h: Header for Buffer Metadata structures
*
* 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.
*/
#ifndef __GST_BUFFER_META_H__
#define __GST_BUFFER_META_H__
G_BEGIN_DECLS
typedef struct _GstBufferMeta GstBufferMeta;
typedef struct _GstBufferMetaInfo GstBufferMetaInfo;
/**
* GstBufferMeta:
* @info: pointer to the #GstBufferMetaInfo
*
* Base structure for buffer metadata. Custom metadata will put this structure
* as the first member of their structure.
*/
struct _GstBufferMeta {
const GstBufferMetaInfo *info;
};
/**
* GST_BUFFER_META_TRACE_NAME:
*
* The name used for tracing memory allocations.
*/
#define GST_BUFFER_META_TRACE_NAME "GstBufferMeta"
/**
* GstMetaInitFunction:
* @meta: a #GstMeta
* @buffer: a #GstBuffer
*
* Function called when @meta is initialized in @buffer.
*/
typedef void (*GstMetaInitFunction) (GstBufferMeta *meta, GstBuffer *buffer);
/**
* GstMetaFreeFunction:
* @meta: a #GstMeta
* @buffer: a #GstBuffer
*
* Function called when @meta is freed in @buffer.
*/
typedef void (*GstMetaFreeFunction) (GstBufferMeta *meta, GstBuffer *buffer);
/**
* GstMetaCopyFunction:
* @copy: a #GstBuffer
* @meta: a #GstMeta
* @buffer: a #GstBuffer
*
* Function called when a copy of @buffer is made and @meta should be copied to
* @copy.
*/
typedef void (*GstMetaCopyFunction) (GstBuffer *copy, GstBufferMeta *meta,
const GstBuffer *buffer);
/**
* GstMetaSubFunction:
* @subbuf: a #GstBuffer
* @meta: a #GstMeta
* @buffer: a #GstBuffer
* @offset: subbuffer offset
* @size: subbuffer size
*
* Function called for each @meta in @buffer as a result from creating a
* subbuffer @subbuf from @buffer at @offset and with @size. An
* implementation could decide to copy and update the metadata on @subbuf.
*/
typedef void (*GstMetaSubFunction) (GstBuffer *subbuf, GstBufferMeta *meta,
GstBuffer *buffer, guint offset, guint size);
/**
* GstMetaSerializeFunction:
* @meta: a #GstMeta
*/
typedef gchar * (*GstMetaSerializeFunction) (GstBufferMeta *meta);
/**
* GstMetaDeserializeFunction:
* @meta: a #GstMeta
*/
typedef gboolean (*GstMetaDeserializeFunction) (GstBufferMeta *meta,
const gchar *s);
/**
* GstBufferMetaInfo:
* @name: tag indentifying the metadata
* @size: size of the metadata
* @init_func: function for initializing the metadata
* @free_func: function for freeing the metadata
* @copy_func: function for copying the metadata
* @sub_func: function for when a subbuffer is taken
* @serialize_func: function for serializing
* @deserialize_func: function for deserializing
*
* The #GstBufferMetaInfo provides infomation about a specific metadata
* structure.
*/
struct _GstBufferMetaInfo {
const gchar *name;
gsize size;
GstMetaInitFunction init_func;
GstMetaFreeFunction free_func;
GstMetaCopyFunction copy_func;
GstMetaSubFunction sub_func;
GstMetaSerializeFunction serialize_func;
GstMetaDeserializeFunction deserialize_func;
};
void _gst_buffer_meta_init (void);
const GstBufferMetaInfo * gst_buffer_meta_register_info (const GstBufferMetaInfo *info);
const GstBufferMetaInfo * gst_buffer_meta_get_info (const gchar * name);
G_END_DECLS
#endif /* __GST_BUFFER_META_H__ */