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>
---
Revised documentation of the new type, removed bounding rectangle values,
as I misinterpreted what they actually did.
Vittorio
libavutil/Makefile | 2 +
libavutil/avutil.h | 6 +++
libavutil/frame.h | 8 ++-
libavutil/spherical.c | 34 +++++++++++++
libavutil/spherical.h | 133 ++++++++++++++++++++++++++++++++++++++++++++++++++
5 files changed, 182 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..9a61cb3
--- /dev/null
+++ b/libavutil/spherical.h
@@ -0,0 +1,133 @@
+/*
+ * 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.
+ *
+ * A positive yaw moves the left half of the frame forward.
+ * A positive pitch moves the bottom half of the frame upward.
+ * A positive roll moves the left half of the frame downward.
+ * 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 | | | z|
+ * i | ^ | |
+ * t 0 +-------------X-------------+ 0 Roll 0|_____ right
+ * c | | | / x
+ * h | | | y/
+ * | | | forward
+ * -90 +-------------+-------------+ -180
+ *
+ * X - the default camera center
+ * ^ - the default up vector
+ * @endcode
+ *
+ * The order of transformation is always yaw, followed by pitch, and
+ * finally by roll.
+ */
+ 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
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