While no decoder currently exports spherical information, this type represents a frame property that has to be passed through from container to frames.
Signed-off-by: Vittorio Giovara <vittorio.giov...@gmail.com> --- The specification got updated while this was in the works. So I updated the description of yaw, pitch, roll and added a paragraph about the coordinate system. Please CC. Vittorio libavutil/Makefile | 2 + libavutil/avutil.h | 6 +++ libavutil/frame.h | 8 ++- libavutil/spherical.c | 34 +++++++++++++ libavutil/spherical.h | 136 ++++++++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 185 insertions(+), 1 deletion(-) create mode 100644 libavutil/spherical.c create mode 100644 libavutil/spherical.h diff --git a/libavutil/Makefile b/libavutil/Makefile index c61ca9c..6474a30 100644 --- a/libavutil/Makefile +++ b/libavutil/Makefile @@ -63,6 +63,7 @@ HEADERS = adler32.h \ samplefmt.h \ sha.h \ sha512.h \ + spherical.h \ stereo3d.h \ threadmessage.h \ time.h \ @@ -140,6 +141,7 @@ OBJS = adler32.o \ samplefmt.o \ sha.o \ sha512.o \ + spherical.o \ stereo3d.o \ threadmessage.o \ time.o \ diff --git a/libavutil/avutil.h b/libavutil/avutil.h index 29dd830..e9aaa03 100644 --- a/libavutil/avutil.h +++ b/libavutil/avutil.h @@ -118,6 +118,12 @@ * * @} * + * @defgroup lavu_video Video related + * + * @{ + * + * @} + * * @defgroup lavu_audio Audio related * * @{ diff --git a/libavutil/frame.h b/libavutil/frame.h index 8e51361..b450092 100644 --- a/libavutil/frame.h +++ b/libavutil/frame.h @@ -120,7 +120,13 @@ enum AVFrameSideDataType { * The GOP timecode in 25 bit timecode format. Data format is 64-bit integer. * This is set on the first frame of a GOP that has a temporal reference of 0. */ - AV_FRAME_DATA_GOP_TIMECODE + AV_FRAME_DATA_GOP_TIMECODE, + + /** + * The data represents the AVSphericalMapping structure defined in + * libavutil/spherical.h. + */ + AV_FRAME_DATA_SPHERICAL, }; enum AVActiveFormatDescription { diff --git a/libavutil/spherical.c b/libavutil/spherical.c new file mode 100644 index 0000000..816452c --- /dev/null +++ b/libavutil/spherical.c @@ -0,0 +1,34 @@ +/* + * Copyright (c) 2016 Vittorio Giovara <vittorio.giov...@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 + */ + +#include "mem.h" +#include "spherical.h" + +AVSphericalMapping *av_spherical_alloc(size_t *size) +{ + AVSphericalMapping *spherical = av_mallocz(sizeof(AVSphericalMapping)); + if (!spherical) + return NULL; + + if (size) + *size = sizeof(*spherical); + + return spherical; +} diff --git a/libavutil/spherical.h b/libavutil/spherical.h new file mode 100644 index 0000000..39db57b --- /dev/null +++ b/libavutil/spherical.h @@ -0,0 +1,136 @@ +/* + * Copyright (c) 2016 Vittorio Giovara <vittorio.giov...@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 + +/** + * @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, +}; + +/** + * 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 points the viewer towards the left. + * A positive pitch points the viewer downwards. + * A positive roll tilts the viewer to the 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]. + /** + * @} + */ +} 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); + +/** + * @} + * @} + */ + +#endif /* AVUTIL_SPHERICAL_H */ -- 2.10.0 _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel