gstreamer/gst/gstmeta.h
2011-09-26 20:47:35 +02:00

151 lines
4.9 KiB
C

/* GStreamer
* Copyright (C) 2009 Wim Taymans <wim.taymans@gmail.be>
*
* gstmeta.h: Header for 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_META_H__
#define __GST_META_H__
G_BEGIN_DECLS
typedef struct _GstMeta GstMeta;
typedef struct _GstMetaInfo GstMetaInfo;
/**
* GstMeta:
* @info: pointer to the #GstMetaInfo
*
* Base structure for metadata. Custom metadata will put this structure
* as the first member of their structure.
*/
struct _GstMeta {
const GstMetaInfo *info;
};
/**
* GST_META_TRACE_NAME:
*
* The name used for tracing memory allocations.
*/
#define GST_META_TRACE_NAME "GstMeta"
/**
* GstMetaInitFunction:
* @meta: a #GstMeta
* @params: parameters passed to the init function
* @buffer: a #GstBuffer
*
* Function called when @meta is initialized in @buffer.
*/
typedef gboolean (*GstMetaInitFunction) (GstMeta *meta, gpointer params, GstBuffer *buffer);
/**
* GstMetaFreeFunction:
* @meta: a #GstMeta
* @buffer: a #GstBuffer
*
* Function called when @meta is freed in @buffer.
*/
typedef void (*GstMetaFreeFunction) (GstMeta *meta, GstBuffer *buffer);
typedef void (*GstMetaCopyFunction) (GstBuffer *dest, GstMeta *meta,
GstBuffer *buffer, gsize offset, gsize size);
/**
* GstMetaTransformFunction:
* @transbuf: a #GstBuffer
* @meta: a #GstMeta
* @buffer: a #GstBuffer
* @data: transform specific data.
*
* Function called for each @meta in @buffer as a result of performing a
* transformation on @transbuf. Additional type specific transform data
* is passed to the function.
*
* Implementations should check the type of the transform @data and parse
* additional type specific field that should be used to perform the transform.
*/
typedef void (*GstMetaTransformFunction) (GstBuffer *transbuf, GstMeta *meta,
GstBuffer *buffer, gpointer data);
/**
* GstMetaInfo:
* @api: tag indentifying the metadata structure and api
* @type: type indentifying the implementor of the api
* @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
* @transform_func: function for transforming the metadata
*
* The #GstMetaInfo provides information about a specific metadata
* structure.
*/
struct _GstMetaInfo {
GQuark api;
GType type;
gsize size;
GstMetaInitFunction init_func;
GstMetaFreeFunction free_func;
GstMetaCopyFunction copy_func;
GstMetaTransformFunction transform_func;
};
const GstMetaInfo * gst_meta_register (const gchar *api, const gchar *impl,
gsize size,
GstMetaInitFunction init_func,
GstMetaFreeFunction free_func,
GstMetaCopyFunction copy_func,
GstMetaTransformFunction transform_func);
const GstMetaInfo * gst_meta_get_info (const gchar * impl);
/* default metadata */
/* timing metadata */
typedef struct _GstMetaTiming GstMetaTiming;
const GstMetaInfo *gst_meta_timing_get_info(void);
#define GST_META_TIMING_INFO (gst_meta_timing_get_info())
/**
* GstMetaTiming:
* @meta: parent metadata
* @dts: the decoding timestamp
* @pts: the presentation timestamp
* @duration: the duration
* @clock_rate: the clock rate of the dts, pts and duration values
*
* Extra timing metadata
*/
struct _GstMetaTiming {
GstMeta meta; /* common meta header */
GstClockTime dts; /* decoding timestamp */
GstClockTime pts; /* presentation timestamp */
GstClockTime duration; /* duration of the data */
GstClockTime clock_rate; /* clock rate for the above values */
};
#define gst_buffer_get_meta_timing(b) ((GstMetaTiming*)gst_buffer_get_meta((b),GST_META_TIMING_INFO))
#define gst_buffer_add_meta_timing(b) ((GstMetaTiming*)gst_buffer_add_meta((b),GST_META_TIMING_INFO,NULL))
G_END_DECLS
#endif /* __GST_META_H__ */