232 lines
7.8 KiB
C
Executable file
232 lines
7.8 KiB
C
Executable file
/*
|
|
* Copyright (c) 2016 Vittorio Giovara <vittorio.giovara@gmail.com>
|
|
*
|
|
* This file is part of FFmpeg.
|
|
*
|
|
* FFmpeg is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Lesser General Public
|
|
* License as published by the Free Software Foundation; either
|
|
* version 2.1 of the License, or (at your option) any later version.
|
|
*
|
|
* FFmpeg 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
|
|
* Lesser General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Lesser General Public
|
|
* License along with FFmpeg; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
|
|
/**
|
|
* @file
|
|
* Spherical video
|
|
*/
|
|
|
|
#ifndef AVUTIL_SPHERICAL_H
|
|
#define AVUTIL_SPHERICAL_H
|
|
|
|
#include <stddef.h>
|
|
#include <stdint.h>
|
|
|
|
/**
|
|
* @addtogroup lavu_video
|
|
* @{
|
|
*
|
|
* @defgroup lavu_video_spherical Spherical video mapping
|
|
* @{
|
|
*/
|
|
|
|
/**
|
|
* @addtogroup lavu_video_spherical
|
|
* A spherical video file contains surfaces that need to be mapped onto a
|
|
* sphere. Depending on how the frame was converted, a different distortion
|
|
* transformation or surface recomposition function needs to be applied before
|
|
* the video should be mapped and displayed.
|
|
*/
|
|
|
|
/**
|
|
* Projection of the video surface(s) on a sphere.
|
|
*/
|
|
enum AVSphericalProjection {
|
|
/**
|
|
* Video represents a sphere mapped on a flat surface using
|
|
* equirectangular projection.
|
|
*/
|
|
AV_SPHERICAL_EQUIRECTANGULAR,
|
|
|
|
/**
|
|
* Video frame is split into 6 faces of a cube, and arranged on a
|
|
* 3x2 layout. Faces are oriented upwards for the front, left, right,
|
|
* and back faces. The up face is oriented so the top of the face is
|
|
* forwards and the down face is oriented so the top of the face is
|
|
* to the back.
|
|
*/
|
|
AV_SPHERICAL_CUBEMAP,
|
|
|
|
/**
|
|
* Video represents a portion of a sphere mapped on a flat surface
|
|
* using equirectangular projection. The @ref bounding fields indicate
|
|
* the position of the current video in a larger surface.
|
|
*/
|
|
AV_SPHERICAL_EQUIRECTANGULAR_TILE,
|
|
};
|
|
|
|
/**
|
|
* This structure describes how to handle spherical videos, outlining
|
|
* information about projection, initial layout, and any other view modifier.
|
|
*
|
|
* @note The struct must be allocated with av_spherical_alloc() and
|
|
* its size is not a part of the public ABI.
|
|
*/
|
|
typedef struct AVSphericalMapping {
|
|
/**
|
|
* Projection type.
|
|
*/
|
|
enum AVSphericalProjection projection;
|
|
|
|
/**
|
|
* @name Initial orientation
|
|
* @{
|
|
* There fields describe additional rotations applied to the sphere after
|
|
* the video frame is mapped onto it. The sphere is rotated around the
|
|
* viewer, who remains stationary. The order of transformation is always
|
|
* yaw, followed by pitch, and finally by roll.
|
|
*
|
|
* The coordinate system matches the one defined in OpenGL, where the
|
|
* forward vector (z) is coming out of screen, and it is equivalent to
|
|
* a rotation matrix of R = r_y(yaw) * r_x(pitch) * r_z(roll).
|
|
*
|
|
* A positive yaw rotates the portion of the sphere in front of the viewer
|
|
* toward their right. A positive pitch rotates the portion of the sphere
|
|
* in front of the viewer upwards. A positive roll tilts the portion of
|
|
* the sphere in front of the viewer to the viewer's right.
|
|
*
|
|
* These values are exported as 16.16 fixed point.
|
|
*
|
|
* See this equirectangular projection as example:
|
|
*
|
|
* @code{.unparsed}
|
|
* Yaw
|
|
* -180 0 180
|
|
* 90 +-------------+-------------+ 180
|
|
* | | | up
|
|
* P | | | y| forward
|
|
* i | ^ | | /z
|
|
* t 0 +-------------X-------------+ 0 Roll | /
|
|
* c | | | | /
|
|
* h | | | 0|/_____right
|
|
* | | | x
|
|
* -90 +-------------+-------------+ -180
|
|
*
|
|
* X - the default camera center
|
|
* ^ - the default up vector
|
|
* @endcode
|
|
*/
|
|
int32_t yaw; ///< Rotation around the up vector [-180, 180].
|
|
int32_t pitch; ///< Rotation around the right vector [-90, 90].
|
|
int32_t roll; ///< Rotation around the forward vector [-180, 180].
|
|
/**
|
|
* @}
|
|
*/
|
|
|
|
/**
|
|
* @name Bounding rectangle
|
|
* @anchor bounding
|
|
* @{
|
|
* These fields indicate the location of the current tile, and where
|
|
* it should be mapped relative to the original surface. They are
|
|
* exported as 0.32 fixed point, and can be converted to classic
|
|
* pixel values with av_spherical_bounds().
|
|
*
|
|
* @code{.unparsed}
|
|
* +----------------+----------+
|
|
* | |bound_top |
|
|
* | +--------+ |
|
|
* | bound_left |tile | |
|
|
* +<---------->| |<--->+bound_right
|
|
* | +--------+ |
|
|
* | | |
|
|
* | bound_bottom| |
|
|
* +----------------+----------+
|
|
* @endcode
|
|
*
|
|
* If needed, the original video surface dimensions can be derived
|
|
* by adding the current stream or frame size to the related bounds,
|
|
* like in the following example:
|
|
*
|
|
* @code{c}
|
|
* original_width = tile->width + bound_left + bound_right;
|
|
* original_height = tile->height + bound_top + bound_bottom;
|
|
* @endcode
|
|
*
|
|
* @note These values are valid only for the tiled equirectangular
|
|
* projection type (@ref AV_SPHERICAL_EQUIRECTANGULAR_TILE),
|
|
* and should be ignored in all other cases.
|
|
*/
|
|
uint32_t bound_left; ///< Distance from the left edge
|
|
uint32_t bound_top; ///< Distance from the top edge
|
|
uint32_t bound_right; ///< Distance from the right edge
|
|
uint32_t bound_bottom; ///< Distance from the bottom edge
|
|
/**
|
|
* @}
|
|
*/
|
|
|
|
/**
|
|
* Number of pixels to pad from the edge of each cube face.
|
|
*
|
|
* @note This value is valid for only for the cubemap projection type
|
|
* (@ref AV_SPHERICAL_CUBEMAP), and should be ignored in all other
|
|
* cases.
|
|
*/
|
|
uint32_t padding;
|
|
} AVSphericalMapping;
|
|
|
|
/**
|
|
* Allocate a AVSphericalVideo structure and initialize its fields to default
|
|
* values.
|
|
*
|
|
* @return the newly allocated struct or NULL on failure
|
|
*/
|
|
AVSphericalMapping *av_spherical_alloc(size_t *size);
|
|
|
|
/**
|
|
* Convert the @ref bounding fields from an AVSphericalVideo
|
|
* from 0.32 fixed point to pixels.
|
|
*
|
|
* @param map The AVSphericalVideo map to read bound values from.
|
|
* @param width Width of the current frame or stream.
|
|
* @param height Height of the current frame or stream.
|
|
* @param left Pixels from the left edge.
|
|
* @param top Pixels from the top edge.
|
|
* @param right Pixels from the right edge.
|
|
* @param bottom Pixels from the bottom edge.
|
|
*/
|
|
void av_spherical_tile_bounds(const AVSphericalMapping *map,
|
|
size_t width, size_t height,
|
|
size_t *left, size_t *top,
|
|
size_t *right, size_t *bottom);
|
|
|
|
/**
|
|
* Provide a human-readable name of a given AVSphericalProjection.
|
|
*
|
|
* @param projection The input AVSphericalProjection.
|
|
*
|
|
* @return The name of the AVSphericalProjection, or "unknown".
|
|
*/
|
|
const char *av_spherical_projection_name(enum AVSphericalProjection projection);
|
|
|
|
/**
|
|
* Get the AVSphericalProjection form a human-readable name.
|
|
*
|
|
* @param name The input string.
|
|
*
|
|
* @return The AVSphericalProjection value, or -1 if not found.
|
|
*/
|
|
int av_spherical_from_name(const char *name);
|
|
/**
|
|
* @}
|
|
* @}
|
|
*/
|
|
|
|
#endif /* AVUTIL_SPHERICAL_H */
|