gstreamer/gst/gstmeta.h
Wim Taymans fa0d993372 meta: implement transform function
Replace subbuffer and copy vmethods by a more generic transform function that
can then be parametrised by transform specific data. This should allow us to
implement make-writable and more future transform functions.
2011-03-08 17:11:23 +00:00

233 lines
7.3 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
* @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);
/**
* GstMetaTransformType:
* @GST_META_TRANSFORM_NONE: invalid transform type
* @GST_META_TRANSFORM_COPY: copy transform
* @GST_META_TRANSFORM_MAKE_WRITABLE: make writable type
* @GST_META_TRANSFORM_TRIM: trim buffer
* @GST_META_TRANSFORM_CUSTOM: start of custom transform types
*
* Different default transform types.
*/
typedef enum {
GST_META_TRANSFORM_NONE = 0,
GST_META_TRANSFORM_COPY,
GST_META_TRANSFORM_MAKE_WRITABLE,
GST_META_TRANSFORM_TRIM,
GST_META_TRANSFORM_CUSTOM = 256
} GstMetaTransformType;
/**
* GstMetaTransformData:
* @type: a #GstMetaTransformType
*
* Common structure that should be put as the first field in the type specific
* structure for the #GstMetaTransformFunction. It contains the type of the
* transform that should be performed.
*/
typedef struct {
GstMetaTransformType type;
} GstMetaTransformData;
/**
* GstMetaTransformSubbuffer:
* @data: parent #GstMetaTransformData
* @offset: the offset of the subbuffer
* @size: the new size of the subbuffer
*
* The subbuffer specific extra info.
*/
typedef struct {
GstMetaTransformData data;
gsize offset;
gsize size;
} GstMetaTransformSubbuffer;
/**
* 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.
*
* If @data is NULL, the metadata should be shallow copied. This is done when
* gst_buffer_make_metadata_writable() is called.
*/
typedef void (*GstMetaTransformFunction) (GstBuffer *transbuf, GstMeta *meta,
GstBuffer *buffer, GstMetaTransformData *data);
/**
* GstMetaSerializeFunction:
* @meta: a #GstMeta
*/
typedef gchar * (*GstMetaSerializeFunction) (GstMeta *meta);
/**
* GstMetaDeserializeFunction:
* @meta: a #GstMeta
*/
typedef gboolean (*GstMetaDeserializeFunction) (GstMeta *meta,
const gchar *s);
/**
* GstMetaInfo:
* @api: tag indentifying the metadata structure and api
* @impl: tag 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
* @sub_func: function for when a subbuffer is taken
* @serialize_func: function for serializing
* @deserialize_func: function for deserializing
*
* The #GstMetaInfo provides information about a specific metadata
* structure.
*/
struct _GstMetaInfo {
GQuark api;
GQuark impl;
gsize size;
GstMetaInitFunction init_func;
GstMetaFreeFunction free_func;
GstMetaTransformFunction transform_func;
GstMetaSerializeFunction serialize_func;
GstMetaDeserializeFunction deserialize_func;
};
void _gst_meta_init (void);
const GstMetaInfo * gst_meta_register (const gchar *api, const gchar *impl,
gsize size,
GstMetaInitFunction init_func,
GstMetaFreeFunction free_func,
GstMetaTransformFunction transform_func,
GstMetaSerializeFunction serialize_func,
GstMetaDeserializeFunction deserialize_func);
const GstMetaInfo * gst_meta_get_info (const gchar * impl);
/* default metadata */
/* memory metadata */
typedef struct _GstMetaMemory GstMetaMemory;
const GstMetaInfo *gst_meta_memory_get_info(void);
#define GST_META_MEMORY_INFO (gst_meta_memory_get_info())
typedef enum {
GST_META_MAP_NONE = 0,
GST_META_MAP_READ = (1 << 0),
GST_META_MAP_WRITE = (1 << 1)
} GstMetaMapFlags;
struct _GstMetaMemory
{
GstMeta meta;
gpointer (*mmap_func) (GstMetaMemory *meta, gsize offset, gsize *size,
GstMetaMapFlags flags);
gboolean (*munmap_func) (GstMetaMemory *meta, gpointer data, gsize size);
};
#define gst_meta_memory_map(m,o,s,f) ((m)->mmap_func(m, o, s, f))
#define gst_meta_memory_unmap(m,d,s) ((m)->munmap_func(m, d, s))
#define gst_buffer_get_meta_memory(b) ((GstMetaMemory*)gst_buffer_get_meta((b),GST_META_MEMORY_INFO))
GstMetaMemory * gst_buffer_add_meta_memory (GstBuffer *buffer, gpointer data,
GFreeFunc free_func,
gsize size, gsize offset);
/* timing metadata */
typedef struct _GstMetaTiming GstMetaTiming;
const GstMetaInfo *gst_meta_timing_get_info(void);
#define GST_META_TIMING_INFO (gst_meta_timing_get_info())
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__ */