[FFmpeg-cvslog] Add transformation matrix API.
Vittorio Giovara
git at videolan.org
Mon May 19 19:20:33 CEST 2014
ffmpeg | branch: master | Vittorio Giovara <vittorio.giovara at gmail.com> | Thu May 15 22:06:49 2014 -0400| [bddd8cbf68551f6405b2bf77cc3e212af9fbe834] | committer: Anton Khirnov
Add transformation matrix API.
Add AV_PKT_DATA_DISPLAYMATRIX and AV_FRAME_DATA_DISPLAYMATRIX as stream and
frame side data (respectively) to describe a display transformation matrix
for linear transformation operations on the decoded video.
Add functions to easily extract a rotation angle from a matrix and
conversely to setup a matrix for a given rotation angle.
Signed-off-by: Anton Khirnov <anton at khirnov.net>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=bddd8cbf68551f6405b2bf77cc3e212af9fbe834
---
Changelog | 1 +
doc/APIchanges | 8 ++++++
libavcodec/avcodec.h | 9 ++++++
libavcodec/utils.c | 9 ++++++
libavutil/Makefile | 2 ++
libavutil/display.c | 64 +++++++++++++++++++++++++++++++++++++++++
libavutil/display.h | 77 ++++++++++++++++++++++++++++++++++++++++++++++++++
libavutil/frame.h | 8 ++++++
libavutil/version.h | 2 +-
9 files changed, 179 insertions(+), 1 deletion(-)
diff --git a/Changelog b/Changelog
index 0348ff7..f157f7d 100644
--- a/Changelog
+++ b/Changelog
@@ -26,6 +26,7 @@ version <next>:
- support for decoding through DXVA2 in avconv
- libbs2b-based stereo-to-binaural audio filter
- native Opus decoder
+- display matrix export and rotation api
version 10:
diff --git a/doc/APIchanges b/doc/APIchanges
index 309bd46..b5defe4 100644
--- a/doc/APIchanges
+++ b/doc/APIchanges
@@ -13,6 +13,14 @@ libavutil: 2013-12-xx
API changes, most recent first:
+2014-05-xx - xxxxxxx - lavu 53.15.0 - frame.h, display.h
+ Add AV_FRAME_DATA_DISPLAYMATRIX for exporting frame-level
+ spatial rendering on video frames for proper display.
+
+2014-05-xx - xxxxxxx - lavc 55.52.0 - avcodec.h
+ Add AV_PKT_DATA_DISPLAYMATRIX for exporting packet-level
+ spatial rendering on video frames for proper display.
+
2014-05-xx - xxxxxxx - lavf 55.17.1 - avformat.h
Deprecate AVStream.pts and the AVFrac struct, which was its only use case.
Those fields were poorly defined and not meant to be public, so there is
diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index 5640710..f8d815f 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -959,6 +959,15 @@ enum AVPacketSideDataType {
* ReplayGain information in form of the AVReplayGain struct.
*/
AV_PKT_DATA_REPLAYGAIN,
+
+ /**
+ * This side data contains a 3x3 transformation matrix describing an affine
+ * transformation that needs to be applied to the decoded video frames for
+ * correct presentation.
+ *
+ * See libavutil/display.h for a detailed description of the data.
+ */
+ AV_PKT_DATA_DISPLAYMATRIX,
};
typedef struct AVPacketSideData {
diff --git a/libavcodec/utils.c b/libavcodec/utils.c
index 71cbc57..cb456d5 100644
--- a/libavcodec/utils.c
+++ b/libavcodec/utils.c
@@ -598,6 +598,15 @@ int ff_decode_frame_props(AVCodecContext *avctx, AVFrame *frame)
memcpy(frame_sd->data, packet_sd, size);
}
+ /* copy the displaymatrix to the output frame */
+ packet_sd = av_packet_get_side_data(pkt, AV_PKT_DATA_DISPLAYMATRIX, &size);
+ if (packet_sd) {
+ frame_sd = av_frame_new_side_data(frame, AV_FRAME_DATA_DISPLAYMATRIX, size);
+ if (!frame_sd)
+ return AVERROR(ENOMEM);
+
+ memcpy(frame_sd->data, packet_sd, size);
+ }
return 0;
}
diff --git a/libavutil/Makefile b/libavutil/Makefile
index d5c1636..0f8ed08 100644
--- a/libavutil/Makefile
+++ b/libavutil/Makefile
@@ -16,6 +16,7 @@ HEADERS = adler32.h \
common.h \
cpu.h \
crc.h \
+ display.h \
downmix_info.h \
error.h \
eval.h \
@@ -69,6 +70,7 @@ OBJS = adler32.o \
cpu.o \
crc.o \
des.o \
+ display.o \
downmix_info.o \
error.o \
eval.o \
diff --git a/libavutil/display.c b/libavutil/display.c
new file mode 100644
index 0000000..ae6c1c2
--- /dev/null
+++ b/libavutil/display.c
@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 2014 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 <stdint.h>
+#include <string.h>
+#include <math.h>
+
+#include "display.h"
+
+// fixed point to double
+#define CONV_FP(x) ((double) (x)) / (1 << 16)
+
+// double to fixed point
+#define CONV_DB(x) (int32_t) ((x) * (1 << 16))
+
+double av_display_rotation_get(const int32_t matrix[9])
+{
+ double rotation, scale[2];
+
+ scale[0] = sqrt(CONV_FP(matrix[0]) * CONV_FP(matrix[0]) +
+ CONV_FP(matrix[3]) * CONV_FP(matrix[3]));
+ scale[1] = sqrt(CONV_FP(matrix[1]) * CONV_FP(matrix[1]) +
+ CONV_FP(matrix[4]) * CONV_FP(matrix[4]));
+
+ if (scale[0] == 0.0 || scale[1] == 0.0)
+ return NAN;
+
+ rotation = atan2(CONV_FP(matrix[1]) / scale[1],
+ CONV_FP(matrix[0]) / scale[0]) * 180 / M_PI;
+
+ return rotation;
+}
+
+void av_display_rotation_set(int32_t matrix[9], double angle)
+{
+ double radians = angle * M_PI / 180.0f;
+ double c = cos(radians);
+ double s = sin(radians);
+
+ memset(matrix, 0, 9 * sizeof(int32_t));
+
+ matrix[0] = CONV_DB(c);
+ matrix[1] = CONV_DB(-s);
+ matrix[3] = CONV_DB(s);
+ matrix[4] = CONV_DB(c);
+ matrix[8] = 1 << 30;
+}
diff --git a/libavutil/display.h b/libavutil/display.h
new file mode 100644
index 0000000..ea762a4
--- /dev/null
+++ b/libavutil/display.h
@@ -0,0 +1,77 @@
+/*
+ * Copyright (c) 2014 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
+ */
+
+#ifndef AVUTIL_DISPLAY_H
+#define AVUTIL_DISPLAY_H
+
+#include <stdint.h>
+
+/**
+ * The display transformation matrix specifies an affine transformation that
+ * should be applied to video frames for correct presentation. It is compatible
+ * with the matrices stored in the ISO/IEC 14496-12 container format.
+ *
+ * The data is a 3x3 matrix represented as a 9-element array:
+ *
+ * | a b u |
+ * (a, b, u, c, d, v, x, y, w) -> | c d v |
+ * | x y w |
+ *
+ * All numbers are stored in native endianness, as 16.16 fixed-point values,
+ * except for u, v and w, which are stored as 2.30 fixed-point values.
+ *
+ * The transformation maps a point (p, q) in the source (pre-transformation)
+ * frame to the point (p', q') in the destination (post-transformation) frame as
+ * follows:
+ * | a b u |
+ * (p, q, 1) . | c d v | = z * (p', q', 1)
+ * | x y w |
+ *
+ * The transformation can also be more explicitly written in components as
+ * follows:
+ * p' = (a * p + c * q + x) / z;
+ * q' = (b * p + d * q + y) / z;
+ * z = u * p + v * q + w
+ */
+
+/**
+ * Extract the rotation component of the transformation matrix.
+ *
+ * @param matrix the transformation matrix
+ * @return the angle (in degrees) by which the transformation rotates the frame.
+ * The angle will be in range [-180.0, 180.0], or NaN if the matrix is
+ * singular.
+ *
+ * @note floating point numbers are inherently inexact, so callers are
+ * recommended to round the return value to nearest integer before use.
+ */
+double av_display_rotation_get(const int32_t matrix[9]);
+
+/**
+ * Initialize a transformation matrix describing a pure rotation by the
+ * specified angle (in degrees).
+ *
+ * @param matrix an allocated transformation matrix (will be fully overwritten
+ * by this function)
+ * @param angle rotation angle in degrees.
+ */
+void av_display_rotation_set(int32_t matrix[9], double angle);
+
+#endif /* AVUTIL_DISPLAY_H */
diff --git a/libavutil/frame.h b/libavutil/frame.h
index 3bec8e5..958cd26 100644
--- a/libavutil/frame.h
+++ b/libavutil/frame.h
@@ -73,6 +73,14 @@ enum AVFrameSideDataType {
* ReplayGain information in the form of the AVReplayGain struct.
*/
AV_FRAME_DATA_REPLAYGAIN,
+ /**
+ * This side data contains a 3x3 transformation matrix describing an affine
+ * transformation that needs to be applied to the frame for correct
+ * presentation.
+ *
+ * See libavutil/display.h for a detailed description of the data.
+ */
+ AV_FRAME_DATA_DISPLAYMATRIX,
};
typedef struct AVFrameSideData {
diff --git a/libavutil/version.h b/libavutil/version.h
index 43e7947..f35dabc 100644
--- a/libavutil/version.h
+++ b/libavutil/version.h
@@ -54,7 +54,7 @@
*/
#define LIBAVUTIL_VERSION_MAJOR 53
-#define LIBAVUTIL_VERSION_MINOR 14
+#define LIBAVUTIL_VERSION_MINOR 15
#define LIBAVUTIL_VERSION_MICRO 0
#define LIBAVUTIL_VERSION_INT AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \
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