pipewire/spa/include/spa/buffer/meta.h

/* Simple Plugin API */
/* SPDX-FileCopyrightText: Copyright © 2018 Wim Taymans */
/* SPDX-License-Identifier: MIT */

#ifndef SPA_META_H
#define SPA_META_H

#ifdef __cplusplus
extern "C" {
#endif

#include <spa/utils/defs.h>
#include <spa/pod/pod.h>

/**
 * \addtogroup spa_buffer
 * \{
 */

enum spa_meta_type {
	SPA_META_Invalid,
	SPA_META_Header,		/**< struct spa_meta_header */
	SPA_META_VideoCrop,		/**< struct spa_meta_region with cropping data */
	SPA_META_VideoDamage,		/**< array of struct spa_meta_region with damage, where an invalid entry or end-of-array marks the end. */
	SPA_META_Bitmap,		/**< struct spa_meta_bitmap */
	SPA_META_Cursor,		/**< struct spa_meta_cursor */
	SPA_META_Control,		/**< metadata contains a spa_meta_control
					  *  associated with the data */
	SPA_META_Busy,			/**< don't write to buffer when count > 0 */
	SPA_META_VideoTransform,	/**< struct spa_meta_transform */
	SPA_META_SyncTimeline,		/**< struct spa_meta_sync_timeline */

	_SPA_META_LAST,			/**< not part of ABI/API */
};

/**
 * A metadata element.
 *
 * This structure is available on the buffer structure and contains
 * the type of the metadata and a pointer/size to the actual metadata
 * itself.
 */
struct spa_meta {
	uint32_t type;		/**< metadata type, one of enum spa_meta_type */
	uint32_t size;		/**< size of metadata */
	void *data;		/**< pointer to metadata */
};

static inline void *spa_meta_first(const struct spa_meta *m) {
	return m->data;
}
#define spa_meta_first spa_meta_first
static inline void *spa_meta_end(const struct spa_meta *m) {
	return SPA_PTROFF(m->data,m->size,void);
}
#define spa_meta_end spa_meta_end
#define spa_meta_check(p,m)	(SPA_PTROFF(p,sizeof(*(p)),void) <= spa_meta_end(m))

/**
 * Describes essential buffer header metadata such as flags and
 * timestamps.
 */
struct spa_meta_header {
#define SPA_META_HEADER_FLAG_DISCONT	(1 << 0)	/**< data is not continuous with previous buffer */
#define SPA_META_HEADER_FLAG_CORRUPTED	(1 << 1)	/**< data might be corrupted */
#define SPA_META_HEADER_FLAG_MARKER	(1 << 2)	/**< media specific marker */
#define SPA_META_HEADER_FLAG_HEADER	(1 << 3)	/**< data contains a codec specific header */
#define SPA_META_HEADER_FLAG_GAP	(1 << 4)	/**< data contains media neutral data */
#define SPA_META_HEADER_FLAG_DELTA_UNIT	(1 << 5)	/**< cannot be decoded independently */
	uint32_t flags;				/**< flags */
	uint32_t offset;			/**< offset in current cycle */
	int64_t pts;				/**< presentation timestamp in nanoseconds */
	int64_t dts_offset;			/**< decoding timestamp as a difference with pts */
	uint64_t seq;				/**< sequence number, increments with a
						  *  media specific frequency */
};

/** metadata structure for Region or an array of these for RegionArray */
struct spa_meta_region {
	struct spa_region region;
};

static inline bool spa_meta_region_is_valid(const struct spa_meta_region *m) {
	return m->region.size.width != 0 && m->region.size.height != 0;
}
#define spa_meta_region_is_valid spa_meta_region_is_valid

/** iterate all the items in a metadata */
#define spa_meta_for_each(pos,meta)					\
	for ((pos) = (__typeof(pos))spa_meta_first(meta);			\
	    spa_meta_check(pos, meta);					\
            (pos)++)

#define spa_meta_bitmap_is_valid(m)	((m)->format != 0)

/**
 * Bitmap information
 *
 * This metadata contains a bitmap image in the given format and size.
 * It is typically used for cursor images or other small images that are
 * better transferred inline.
 */
struct spa_meta_bitmap {
	uint32_t format;		/**< bitmap video format, one of enum spa_video_format. 0 is
					  *  and invalid format and should be handled as if there is
					  *  no new bitmap information. */
	struct spa_rectangle size;	/**< width and height of bitmap */
	int32_t stride;			/**< stride of bitmap data */
	uint32_t offset;		/**< offset of bitmap data in this structure. An offset of
					  *  0 means no image data (invisible), an offset >=
					  *  sizeof(struct spa_meta_bitmap) contains valid bitmap
					  *  info. */
};

#define spa_meta_cursor_is_valid(m)	((m)->id != 0)

/**
 * Cursor information
 *
 * Metadata to describe the position and appearance of a pointing device.
 */
struct spa_meta_cursor {
	uint32_t id;			/**< cursor id. an id of 0 is an invalid id and means that
					  *  there is no new cursor data */
	uint32_t flags;			/**< extra flags */
	struct spa_point position;	/**< position on screen */
	struct spa_point hotspot;	/**< offsets for hotspot in bitmap, this field has no meaning
					  *  when there is no valid bitmap (see below) */
	uint32_t bitmap_offset;		/**< offset of bitmap meta in this structure. When the offset
					  *  is 0, there is no new bitmap information. When the offset is
					  *  >= sizeof(struct spa_meta_cursor) there is a
					  *  struct spa_meta_bitmap at the offset. */
};

/** a timed set of events associated with the buffer */
struct spa_meta_control {
	struct spa_pod_sequence sequence;
};

/** a busy counter for the buffer */
struct spa_meta_busy {
	uint32_t flags;
	uint32_t count;			/**< number of users busy with the buffer */
};

enum spa_meta_videotransform_value {
	SPA_META_TRANSFORMATION_None = 0,	/**< no transform */
	SPA_META_TRANSFORMATION_90,		/**< 90 degree counter-clockwise */
	SPA_META_TRANSFORMATION_180,		/**< 180 degree counter-clockwise */
	SPA_META_TRANSFORMATION_270,		/**< 270 degree counter-clockwise */
	SPA_META_TRANSFORMATION_Flipped,	/**< 180 degree flipped around the vertical axis. Equivalent
						  * to a reflexion through the vertical line splitting the
						  * buffer in two equal sized parts */
	SPA_META_TRANSFORMATION_Flipped90,	/**< flip then rotate around 90 degree counter-clockwise */
	SPA_META_TRANSFORMATION_Flipped180,	/**< flip then rotate around 180 degree counter-clockwise */
	SPA_META_TRANSFORMATION_Flipped270,	/**< flip then rotate around 270 degree counter-clockwise */
};

/** a transformation of the buffer */
struct spa_meta_videotransform {
	uint32_t transform;			/**< orientation transformation that was applied to the buffer,
						  *  one of enum spa_meta_videotransform_value */
};

/**
 * A timeline point for explicit sync
 *
 * Metadata to describe the time on the timeline when the buffer
 * can be acquired and when it can be reused.
 *
 * This metadata will require negotiation of 2 extra fds for the acquire
 * and release timelines respectively.  One way to achieve this is to place
 * this metadata as SPA_PARAM_BUFFERS_metaType when negotiating a buffer
 * layout with 2 extra fds.
 */
struct spa_meta_sync_timeline {
	uint32_t flags;
	uint32_t padding;
	uint64_t acquire_point;			/**< the timeline acquire point, this is when the data
						  *  can be accessed. */
	uint64_t release_point;			/**< the timeline release point, this timeline point should
						  *  be signaled when the data is no longer accessed. */
};

/**
 * \}
 */

#ifdef __cplusplus
}  /* extern "C" */
#endif

#endif /* SPA_META_H */