[FFmpeg-cvslog] lavu: Add AVSphericalMapping type and frame side data
Vittorio Giovara
git at videolan.org
Thu Apr 13 23:50:49 EEST 2017
ffmpeg | branch: master | Vittorio Giovara <vittorio.giovara at gmail.com> | Mon Nov 7 13:09:03 2016 -0500| [c70add61d1551bf31734f7ef7d87824ff5389280] | committer: Vittorio Giovara
lavu: Add AVSphericalMapping type and frame side data
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.giovara at gmail.com>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=c70add61d1551bf31734f7ef7d87824ff5389280
---
doc/APIchanges | 4 ++
libavutil/Makefile | 2 +
libavutil/frame.h | 6 +++
libavutil/spherical.c | 34 +++++++++++++
libavutil/spherical.h | 137 ++++++++++++++++++++++++++++++++++++++++++++++++++
libavutil/version.h | 2 +-
6 files changed, 184 insertions(+), 1 deletion(-)
diff --git a/doc/APIchanges b/doc/APIchanges
index 90c6500764..c330310cab 100644
--- a/doc/APIchanges
+++ b/doc/APIchanges
@@ -13,6 +13,10 @@ libavutil: 2015-08-28
API changes, most recent first:
+2016-xx-xx - xxxxxxx - lavu 55.30.0 - spherical.h
+ Add AV_FRAME_DATA_SPHERICAL value, av_spherical_alloc() API and
+ AVSphericalMapping type to export and describe spherical video properties.
+
2016-xx-xx - xxxxxxx - lavf 57.10.0 - avformat.h
Add av_stream_add_side_data().
diff --git a/libavutil/Makefile b/libavutil/Makefile
index fbcf1a757f..28372c9bef 100644
--- a/libavutil/Makefile
+++ b/libavutil/Makefile
@@ -48,6 +48,7 @@ HEADERS = adler32.h \
replaygain.h \
samplefmt.h \
sha.h \
+ spherical.h \
stereo3d.h \
time.h \
version.h \
@@ -102,6 +103,7 @@ OBJS = adler32.o \
rc4.o \
samplefmt.o \
sha.o \
+ spherical.o \
stereo3d.o \
time.o \
tree.o \
diff --git a/libavutil/frame.h b/libavutil/frame.h
index 12624d797f..4052199fd3 100644
--- a/libavutil/frame.h
+++ b/libavutil/frame.h
@@ -92,6 +92,12 @@ enum AVFrameSideDataType {
* enum AVAudioServiceType defined in avcodec.h.
*/
AV_FRAME_DATA_AUDIO_SERVICE_TYPE,
+
+ /**
+ * 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 0000000000..f6e53d1bd2
--- /dev/null
+++ b/libavutil/spherical.c
@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2016 Vittorio Giovara <vittorio.giovara at gmail.com>
+ *
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; 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 0000000000..8ecaefd946
--- /dev/null
+++ b/libavutil/spherical.h
@@ -0,0 +1,137 @@
+/*
+ * Copyright (c) 2016 Vittorio Giovara <vittorio.giovara at gmail.com>
+ *
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; 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 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].
+ /**
+ * @}
+ */
+} 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 */
diff --git a/libavutil/version.h b/libavutil/version.h
index f1102312ba..e9940f2518 100644
--- a/libavutil/version.h
+++ b/libavutil/version.h
@@ -54,7 +54,7 @@
*/
#define LIBAVUTIL_VERSION_MAJOR 55
-#define LIBAVUTIL_VERSION_MINOR 29
+#define LIBAVUTIL_VERSION_MINOR 30
#define LIBAVUTIL_VERSION_MICRO 0
#define LIBAVUTIL_VERSION_INT AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \
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