[FFmpeg-devel] [PATCH v3 1/3] avfilter: add v360 filter
Eugene Lyapustin
unishifft at gmail.com
Thu Aug 15 03:56:11 EEST 2019
Signed-off-by: Eugene Lyapustin <unishifft at gmail.com>
---
doc/filters.texi | 137 +++
libavfilter/Makefile | 1 +
libavfilter/allfilters.c | 1 +
libavfilter/vf_v360.c | 1857 ++++++++++++++++++++++++++++++++++++++
4 files changed, 1996 insertions(+)
create mode 100644 libavfilter/vf_v360.c
diff --git a/doc/filters.texi b/doc/filters.texi
index e081cdc7bc..6168a3502a 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -17879,6 +17879,143 @@ Force a constant quantization parameter. If not set, the filter will use the QP
from the video stream (if available).
@end table
+ at section v360
+
+Convert 360 videos between various formats.
+
+The filter accepts the following options:
+
+ at table @option
+
+ at item input
+ at item output
+Set format of the input/output video.
+
+Available formats:
+
+ at table @samp
+
+ at item e
+Equirectangular projection.
+
+ at item c3x2
+ at item c6x1
+Cubemap with 3x2/6x1 layout.
+
+Format specific options:
+
+ at table @option
+ at item in_forder
+ at item out_forder
+Set order of faces for the input/output cubemap. Choose one direction for each position.
+
+Designation of directions:
+ at table @samp
+ at item r
+right
+ at item l
+left
+ at item u
+up
+ at item d
+down
+ at item f
+forward
+ at item b
+back
+ at end table
+
+Default value is @b{@samp{rludfb}}.
+
+ at item in_frot
+ at item out_frot
+Set rotation of faces for the input/output cubemap. Choose one angle for each position.
+
+Designation of angles:
+ at table @samp
+ at item 0
+0 degrees clockwise
+ at item 1
+90 degrees clockwise
+ at item 2
+180 degrees clockwise
+ at item 4
+270 degrees clockwise
+ at end table
+
+Default value is @b{@samp{000000}}.
+ at end table
+
+ at item eac
+Equi-Angular Cubemap.
+
+ at item flat
+Regular video. @i{(output only)}
+
+Format specific options:
+ at table @option
+ at item h_fov
+ at item v_fov
+Set horizontal/vertical field of view. Values in degrees.
+ at end table
+ at end table
+
+ at item interp
+Set interpolation method.@*
+ at i{Note: more complex interpolation methods require much more memory to run.}
+
+Available methods:
+
+ at table @samp
+ at item near
+ at item nearest
+Nearest neighbour.
+ at item line
+ at item linear
+Bilinear interpolation.
+ at item cube
+ at item cubic
+Bicubic interpolation.
+ at item lanc
+ at item lanczos
+Lanczos interpolation.
+ at end table
+
+Default value is @b{@samp{line}}.
+
+ at item w
+ at item h
+Set the output video resolution.
+
+Default resolution depends on formats.
+
+ at item yaw
+ at item pitch
+ at item roll
+Set rotation for the output video. Values in degrees.
+
+ at item hflip
+ at item vflip
+ at item dflip
+Flip the output video horizontally/vertically/in-depth. Boolean values.
+
+ at end table
+
+ at subsection Examples
+
+ at itemize
+ at item
+Convert equirectangular video to cubemap with 3x2 layout using bicubic interpolation:
+ at example
+ffmpeg -i input.mkv -vf v360=e:c3x2:cubic output.mkv
+ at end example
+ at item
+Extract back view of Equi-Angular Cubemap:
+ at example
+ffmpeg -i input.mkv -vf v360=eac:flat:yaw=180 output.mkv
+ at end example
+ at end itemize
+
@section vaguedenoiser
Apply a wavelet based denoiser.
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index efc7bbb153..345f7c95cd 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -410,6 +410,7 @@ OBJS-$(CONFIG_UNSHARP_FILTER) += vf_unsharp.o
OBJS-$(CONFIG_UNSHARP_OPENCL_FILTER) += vf_unsharp_opencl.o opencl.o \
opencl/unsharp.o
OBJS-$(CONFIG_USPP_FILTER) += vf_uspp.o
+OBJS-$(CONFIG_V360_FILTER) += vf_v360.o
OBJS-$(CONFIG_VAGUEDENOISER_FILTER) += vf_vaguedenoiser.o
OBJS-$(CONFIG_VECTORSCOPE_FILTER) += vf_vectorscope.o
OBJS-$(CONFIG_VFLIP_FILTER) += vf_vflip.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index abd726d616..5799fb4b3c 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -390,6 +390,7 @@ extern AVFilter ff_vf_unpremultiply;
extern AVFilter ff_vf_unsharp;
extern AVFilter ff_vf_unsharp_opencl;
extern AVFilter ff_vf_uspp;
+extern AVFilter ff_vf_v360;
extern AVFilter ff_vf_vaguedenoiser;
extern AVFilter ff_vf_vectorscope;
extern AVFilter ff_vf_vflip;
diff --git a/libavfilter/vf_v360.c b/libavfilter/vf_v360.c
new file mode 100644
index 0000000000..d23bcd32f8
--- /dev/null
+++ b/libavfilter/vf_v360.c
@@ -0,0 +1,1857 @@
+/*
+ * Copyright (c) 2019 Eugene Lyapustin
+ *
+ * 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
+ * 360 video conversion filter.
+ * Principle of operation:
+ *
+ * (for each pixel in output frame)\n
+ * 1) Calculate OpenGL-like coordinates (x, y, z) for pixel position (i, j)\n
+ * 2) Apply 360 operations (rotation, mirror) to (x, y, z)\n
+ * 3) Calculate pixel position (u, v) in input frame\n
+ * 4) Calculate interpolation window and weight for each pixel
+ *
+ * (for each frame)\n
+ * 5) Remap input frame to output frame using precalculated data\n
+ */
+
+#include "libavutil/eval.h"
+#include "libavutil/imgutils.h"
+#include "libavutil/pixdesc.h"
+#include "libavutil/opt.h"
+#include "avfilter.h"
+#include "formats.h"
+#include "internal.h"
+#include "video.h"
+
+enum Projections {
+ EQUIRECTANGULAR,
+ CUBEMAP_3_2,
+ CUBEMAP_6_1,
+ EQUIANGULAR,
+ FLAT,
+ NB_PROJECTIONS,
+};
+
+enum InterpMethod {
+ NEAREST,
+ BILINEAR,
+ BICUBIC,
+ LANCZOS,
+ NB_INTERP_METHODS,
+};
+
+enum Faces {
+ TOP_LEFT,
+ TOP_MIDDLE,
+ TOP_RIGHT,
+ BOTTOM_LEFT,
+ BOTTOM_MIDDLE,
+ BOTTOM_RIGHT,
+ NB_FACES,
+};
+
+enum Direction {
+ RIGHT, ///< Axis +X
+ LEFT, ///< Axis -X
+ UP, ///< Axis +Y
+ DOWN, ///< Axis -Y
+ FRONT, ///< Axis -Z
+ BACK, ///< Axis +Z
+ NB_DIRECTIONS,
+};
+
+enum Rotation {
+ ROT_0,
+ ROT_90,
+ ROT_180,
+ ROT_270,
+ NB_ROTATIONS,
+};
+
+typedef struct V360Context {
+ const AVClass *class;
+ int in, out;
+ int interp;
+ int width, height;
+ char* in_forder;
+ char* out_forder;
+ char* in_frot;
+ char* out_frot;
+
+ int in_cubemap_face_order[6];
+ int out_cubemap_direction_order[6];
+ int in_cubemap_face_rotation[6];
+ int out_cubemap_face_rotation[6];
+
+ float yaw, pitch, roll;
+
+ int h_flip, v_flip, d_flip;
+
+ float h_fov, v_fov;
+ float flat_range[3];
+
+ int planewidth[4], planeheight[4];
+ int inplanewidth[4], inplaneheight[4];
+ int nb_planes;
+
+ void *remap[4];
+
+ int (*remap_slice)(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs);
+} V360Context;
+
+typedef struct ThreadData {
+ V360Context *s;
+ AVFrame *in;
+ AVFrame *out;
+ int nb_planes;
+} ThreadData;
+
+#define OFFSET(x) offsetof(V360Context, x)
+#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
+
+static const AVOption v360_options[] = {
+ { "input", "set input projection", OFFSET(in), AV_OPT_TYPE_INT, {.i64=EQUIRECTANGULAR}, 0, NB_PROJECTIONS-1, FLAGS, "in" },
+ { "e", "equirectangular", 0, AV_OPT_TYPE_CONST, {.i64=EQUIRECTANGULAR}, 0, 0, FLAGS, "in" },
+ { "c3x2", "cubemap3x2", 0, AV_OPT_TYPE_CONST, {.i64=CUBEMAP_3_2}, 0, 0, FLAGS, "in" },
+ { "c6x1", "cubemap6x1", 0, AV_OPT_TYPE_CONST, {.i64=CUBEMAP_6_1}, 0, 0, FLAGS, "in" },
+ { "eac", "equi-angular", 0, AV_OPT_TYPE_CONST, {.i64=EQUIANGULAR}, 0, 0, FLAGS, "in" },
+ { "output", "set output projection", OFFSET(out), AV_OPT_TYPE_INT, {.i64=CUBEMAP_3_2}, 0, NB_PROJECTIONS-1, FLAGS, "out" },
+ { "e", "equirectangular", 0, AV_OPT_TYPE_CONST, {.i64=EQUIRECTANGULAR}, 0, 0, FLAGS, "out" },
+ { "c3x2", "cubemap3x2", 0, AV_OPT_TYPE_CONST, {.i64=CUBEMAP_3_2}, 0, 0, FLAGS, "out" },
+ { "c6x1", "cubemap6x1", 0, AV_OPT_TYPE_CONST, {.i64=CUBEMAP_6_1}, 0, 0, FLAGS, "out" },
+ { "eac", "equi-angular", 0, AV_OPT_TYPE_CONST, {.i64=EQUIANGULAR}, 0, 0, FLAGS, "out" },
+ { "flat", "regular video", 0, AV_OPT_TYPE_CONST, {.i64=FLAT}, 0, 0, FLAGS, "out" },
+ { "interp", "set interpolation method", OFFSET(interp), AV_OPT_TYPE_INT, {.i64=BILINEAR}, 0, NB_INTERP_METHODS-1, FLAGS, "interp" },
+ { "near", "nearest neighbour", 0, AV_OPT_TYPE_CONST, {.i64=NEAREST}, 0, 0, FLAGS, "interp" },
+ { "nearest", "nearest neighbour", 0, AV_OPT_TYPE_CONST, {.i64=NEAREST}, 0, 0, FLAGS, "interp" },
+ { "line", "bilinear interpolation", 0, AV_OPT_TYPE_CONST, {.i64=BILINEAR}, 0, 0, FLAGS, "interp" },
+ { "linear", "bilinear interpolation", 0, AV_OPT_TYPE_CONST, {.i64=BILINEAR}, 0, 0, FLAGS, "interp" },
+ { "cube", "bicubic interpolation", 0, AV_OPT_TYPE_CONST, {.i64=BICUBIC}, 0, 0, FLAGS, "interp" },
+ { "cubic", "bicubic interpolation", 0, AV_OPT_TYPE_CONST, {.i64=BICUBIC}, 0, 0, FLAGS, "interp" },
+ { "lanc", "lanczos interpolation", 0, AV_OPT_TYPE_CONST, {.i64=LANCZOS}, 0, 0, FLAGS, "interp" },
+ { "lanczos", "lanczos interpolation", 0, AV_OPT_TYPE_CONST, {.i64=LANCZOS}, 0, 0, FLAGS, "interp" },
+ { "w", "output width", OFFSET(width), AV_OPT_TYPE_INT, {.i64=0}, 0, INT_MAX, FLAGS, "w"},
+ { "h", "output height", OFFSET(height), AV_OPT_TYPE_INT, {.i64=0}, 0, INT_MAX, FLAGS, "h"},
+ { "in_forder", "input cubemap face order", OFFSET(in_forder), AV_OPT_TYPE_STRING, {.str="rludfb"}, 0, NB_DIRECTIONS-1, FLAGS, "in_forder"},
+ {"out_forder", "output cubemap face order", OFFSET(out_forder), AV_OPT_TYPE_STRING, {.str="rludfb"}, 0, NB_DIRECTIONS-1, FLAGS, "out_forder"},
+ { "in_frot", "input cubemap face rotation", OFFSET(in_frot), AV_OPT_TYPE_STRING, {.str="000000"}, 0, NB_DIRECTIONS-1, FLAGS, "in_frot"},
+ { "out_frot", "output cubemap face rotation",OFFSET(out_frot), AV_OPT_TYPE_STRING, {.str="000000"}, 0, NB_DIRECTIONS-1, FLAGS, "out_frot"},
+ { "yaw", "yaw rotation", OFFSET(yaw), AV_OPT_TYPE_FLOAT, {.dbl=0.f}, -180.f, 180.f, FLAGS, "yaw"},
+ { "pitch", "pitch rotation", OFFSET(pitch), AV_OPT_TYPE_FLOAT, {.dbl=0.f}, -180.f, 180.f, FLAGS, "pitch"},
+ { "roll", "roll rotation", OFFSET(roll), AV_OPT_TYPE_FLOAT, {.dbl=0.f}, -180.f, 180.f, FLAGS, "roll"},
+ { "h_fov", "horizontal field of view", OFFSET(h_fov), AV_OPT_TYPE_FLOAT, {.dbl=90.f}, 0.f, 180.f, FLAGS, "h_fov"},
+ { "v_fov", "vertical field of view", OFFSET(v_fov), AV_OPT_TYPE_FLOAT, {.dbl=45.f}, 0.f, 90.f, FLAGS, "v_fov"},
+ { "h_flip", "flip video horizontally", OFFSET(h_flip), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, FLAGS, "h_flip"},
+ { "v_flip", "flip video vertically", OFFSET(v_flip), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, FLAGS, "v_flip"},
+ { "d_flip", "flip video indepth", OFFSET(d_flip), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, FLAGS, "d_flip"},
+ { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(v360);
+
+static int query_formats(AVFilterContext *ctx)
+{
+ static const enum AVPixelFormat pix_fmts[] = {
+ // YUVA444
+ AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUVA444P9,
+ AV_PIX_FMT_YUVA444P10, AV_PIX_FMT_YUVA444P12,
+ AV_PIX_FMT_YUVA444P16,
+
+ // YUVA422
+ AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUVA422P9,
+ AV_PIX_FMT_YUVA422P10, AV_PIX_FMT_YUVA422P12,
+ AV_PIX_FMT_YUVA422P16,
+
+ // YUVA420
+ AV_PIX_FMT_YUVA420P, AV_PIX_FMT_YUVA420P9,
+ AV_PIX_FMT_YUVA420P10, AV_PIX_FMT_YUVA420P16,
+
+ // YUVJ
+ AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ440P,
+ AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUVJ420P,
+ AV_PIX_FMT_YUVJ411P,
+
+ // YUV444
+ AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV444P9,
+ AV_PIX_FMT_YUV444P10, AV_PIX_FMT_YUV444P12,
+ AV_PIX_FMT_YUV444P14, AV_PIX_FMT_YUV444P16,
+
+ // YUV440
+ AV_PIX_FMT_YUV440P, AV_PIX_FMT_YUV440P10,
+ AV_PIX_FMT_YUV440P12,
+
+ // YUV422
+ AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV422P9,
+ AV_PIX_FMT_YUV422P10, AV_PIX_FMT_YUV422P12,
+ AV_PIX_FMT_YUV422P14, AV_PIX_FMT_YUV422P16,
+
+ // YUV420
+ AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV420P9,
+ AV_PIX_FMT_YUV420P10, AV_PIX_FMT_YUV420P12,
+ AV_PIX_FMT_YUV420P14, AV_PIX_FMT_YUV420P16,
+
+ // YUV411
+ AV_PIX_FMT_YUV411P,
+
+ // YUV410
+ AV_PIX_FMT_YUV410P,
+
+ // GBR
+ AV_PIX_FMT_GBRP, AV_PIX_FMT_GBRP9,
+ AV_PIX_FMT_GBRP10, AV_PIX_FMT_GBRP12,
+ AV_PIX_FMT_GBRP14, AV_PIX_FMT_GBRP16,
+
+ // GBRA
+ AV_PIX_FMT_GBRAP, AV_PIX_FMT_GBRAP10,
+ AV_PIX_FMT_GBRAP12, AV_PIX_FMT_GBRAP16,
+
+ // GRAY
+ AV_PIX_FMT_GRAY8, AV_PIX_FMT_GRAY9,
+ AV_PIX_FMT_GRAY10, AV_PIX_FMT_GRAY12,
+ AV_PIX_FMT_GRAY14, AV_PIX_FMT_GRAY16,
+
+ AV_PIX_FMT_NONE
+ };
+
+ AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts);
+ if (!fmts_list)
+ return AVERROR(ENOMEM);
+ return ff_set_common_formats(ctx, fmts_list);
+}
+
+typedef struct XYRemap1 {
+ uint16_t u;
+ uint16_t v;
+} XYRemap1;
+
+/**
+ * Generate no-interpolation remapping function with a given pixel depth.
+ *
+ * @param bits number of bits per pixel
+ * @param div number of bytes per pixel
+ */
+#define DEFINE_REMAP1(bits, div) \
+static int remap1_##bits##bit_slice(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs) \
+{ \
+ ThreadData *td = (ThreadData*)arg; \
+ const V360Context *s = td->s; \
+ const AVFrame *in = td->in; \
+ AVFrame *out = td->out; \
+ \
+ int plane, x, y; \
+ \
+ for (plane = 0; plane < td->nb_planes; plane++) { \
+ const int in_linesize = in->linesize[plane] / div; \
+ const int out_linesize = out->linesize[plane] / div; \
+ const uint##bits##_t *src = (const uint##bits##_t *)in->data[plane]; \
+ uint##bits##_t *dst = (uint##bits##_t *)out->data[plane]; \
+ const XYRemap1 *remap = s->remap[plane]; \
+ const int width = s->planewidth[plane]; \
+ const int height = s->planeheight[plane]; \
+ \
+ const int slice_start = (height * jobnr ) / nb_jobs; \
+ const int slice_end = (height * (jobnr + 1)) / nb_jobs; \
+ \
+ for (y = slice_start; y < slice_end; y++) { \
+ uint##bits##_t *d = dst + y * out_linesize; \
+ for (x = 0; x < width; x++) { \
+ const XYRemap1 *r = &remap[y * width + x]; \
+ \
+ *d++ = src[r->v * in_linesize + r->u]; \
+ } \
+ } \
+ } \
+ \
+ return 0; \
+}
+
+DEFINE_REMAP1( 8, 1)
+DEFINE_REMAP1(16, 2)
+
+typedef struct XYRemap2 {
+ uint16_t u[2][2];
+ uint16_t v[2][2];
+ float ker[2][2];
+} XYRemap2;
+
+typedef struct XYRemap4 {
+ uint16_t u[4][4];
+ uint16_t v[4][4];
+ float ker[4][4];
+} XYRemap4;
+
+/**
+ * Generate remapping function with a given window size and pixel depth.
+ *
+ * @param window_size size of interpolation window
+ * @param bits number of bits per pixel
+ * @param div number of bytes per pixel
+ */
+#define DEFINE_REMAP(window_size, bits, div) \
+static int remap##window_size##_##bits##bit_slice(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs) \
+{ \
+ ThreadData *td = (ThreadData*)arg; \
+ const V360Context *s = td->s; \
+ const AVFrame *in = td->in; \
+ AVFrame *out = td->out; \
+ \
+ int plane, x, y, i, j; \
+ \
+ for (plane = 0; plane < td->nb_planes; plane++) { \
+ const int in_linesize = in->linesize[plane] / div; \
+ const int out_linesize = out->linesize[plane] / div; \
+ const uint##bits##_t *src = (const uint##bits##_t *)in->data[plane]; \
+ uint##bits##_t *dst = (uint##bits##_t *)out->data[plane]; \
+ const XYRemap##window_size *remap = s->remap[plane]; \
+ const int width = s->planewidth[plane]; \
+ const int height = s->planeheight[plane]; \
+ \
+ const int slice_start = (height * jobnr ) / nb_jobs; \
+ const int slice_end = (height * (jobnr + 1)) / nb_jobs; \
+ \
+ for (y = slice_start; y < slice_end; y++) { \
+ uint##bits##_t *d = dst + y * out_linesize; \
+ for (x = 0; x < width; x++) { \
+ const XYRemap##window_size *r = &remap[y * width + x]; \
+ float tmp = 0.f; \
+ \
+ for (i = 0; i < window_size; i++) { \
+ for (j = 0; j < window_size; j++) { \
+ tmp += r->ker[i][j] * src[r->v[i][j] * in_linesize + r->u[i][j]]; \
+ } \
+ } \
+ \
+ *d++ = av_clip_uint##bits(roundf(tmp)); \
+ } \
+ } \
+ } \
+ \
+ return 0; \
+}
+
+DEFINE_REMAP(2, 8, 1)
+DEFINE_REMAP(4, 8, 1)
+DEFINE_REMAP(2, 16, 2)
+DEFINE_REMAP(4, 16, 2)
+
+/**
+ * Save nearest pixel coordinates for remapping.
+ *
+ * @param du horizontal relative coordinate
+ * @param dv vertical relative coordinate
+ * @param shift shift for remap array
+ * @param r_tmp calculated 4x4 window
+ * @param r_void remap data
+ */
+static void nearest_kernel(float du, float dv, int shift, const XYRemap4 *r_tmp, void *r_void)
+{
+ XYRemap1 *r = (XYRemap1*)r_void + shift;
+ const int i = roundf(dv) + 1;
+ const int j = roundf(du) + 1;
+
+ r->u = r_tmp->u[i][j];
+ r->v = r_tmp->v[i][j];
+}
+
+/**
+ * Calculate kernel for bilinear interpolation.
+ *
+ * @param du horizontal relative coordinate
+ * @param dv vertical relative coordinate
+ * @param shift shift for remap array
+ * @param r_tmp calculated 4x4 window
+ * @param r_void remap data
+ */
+static void bilinear_kernel(float du, float dv, int shift, const XYRemap4 *r_tmp, void *r_void)
+{
+ XYRemap2 *r = (XYRemap2*)r_void + shift;
+ int i, j;
+
+ for (i = 0; i < 2; i++) {
+ for (j = 0; j < 2; j++) {
+ r->u[i][j] = r_tmp->u[i + 1][j + 1];
+ r->v[i][j] = r_tmp->v[i + 1][j + 1];
+ }
+ }
+
+ r->ker[0][0] = (1.f - du) * (1.f - dv);
+ r->ker[0][1] = du * (1.f - dv);
+ r->ker[1][0] = (1.f - du) * dv;
+ r->ker[1][1] = du * dv;
+}
+
+/**
+ * Calculate 1-dimensional cubic coefficients.
+ *
+ * @param t relative coordinate
+ * @param coeffs coefficients
+ */
+static inline void calculate_bicubic_coeffs(float t, float *coeffs)
+{
+ const float tt = t * t;
+ const float ttt = t * t * t;
+
+ coeffs[0] = - t / 3.f + tt / 2.f - ttt / 6.f;
+ coeffs[1] = 1.f - t / 2.f - tt + ttt / 2.f;
+ coeffs[2] = t + tt / 2.f - ttt / 2.f;
+ coeffs[3] = - t / 6.f + ttt / 6.f;
+}
+
+/**
+ * Calculate kernel for bicubic interpolation.
+ *
+ * @param du horizontal relative coordinate
+ * @param dv vertical relative coordinate
+ * @param shift shift for remap array
+ * @param r_tmp calculated 4x4 window
+ * @param r_void remap data
+ */
+static void bicubic_kernel(float du, float dv, int shift, const XYRemap4 *r_tmp, void *r_void)
+{
+ XYRemap4 *r = (XYRemap4*)r_void + shift;
+ int i, j;
+ float du_coeffs[4];
+ float dv_coeffs[4];
+
+ calculate_bicubic_coeffs(du, du_coeffs);
+ calculate_bicubic_coeffs(dv, dv_coeffs);
+
+ for (i = 0; i < 4; i++) {
+ for (j = 0; j < 4; j++) {
+ r->u[i][j] = r_tmp->u[i][j];
+ r->v[i][j] = r_tmp->v[i][j];
+ r->ker[i][j] = du_coeffs[j] * dv_coeffs[i];
+ }
+ }
+}
+
+/**
+ * Calculate 1-dimensional lanczos coefficients.
+ *
+ * @param t relative coordinate
+ * @param coeffs coefficients
+ */
+static inline void calculate_lanczos_coeffs(float t, float *coeffs)
+{
+ int i;
+ float sum = 0.f;
+
+ for (i = 0; i < 4; i++) {
+ const float x = M_PI * (t - i + 1);
+ if (x == 0.f) {
+ coeffs[i] = 1.f;
+ } else {
+ coeffs[i] = sinf(x) * sinf(x / 2.f) / (x * x / 2.f);
+ }
+ sum += coeffs[i];
+ }
+
+ for (i = 0; i < 4; i++) {
+ coeffs[i] /= sum;
+ }
+}
+
+/**
+ * Calculate kernel for lanczos interpolation.
+ *
+ * @param du horizontal relative coordinate
+ * @param dv vertical relative coordinate
+ * @param shift shift for remap array
+ * @param r_tmp calculated 4x4 window
+ * @param r_void remap data
+ */
+static void lanczos_kernel(float du, float dv, int shift, const XYRemap4 *r_tmp, void *r_void)
+{
+ XYRemap4 *r = (XYRemap4*)r_void + shift;
+ int i, j;
+ float du_coeffs[4];
+ float dv_coeffs[4];
+
+ calculate_lanczos_coeffs(du, du_coeffs);
+ calculate_lanczos_coeffs(dv, dv_coeffs);
+
+ for (i = 0; i < 4; i++) {
+ for (j = 0; j < 4; j++) {
+ r->u[i][j] = r_tmp->u[i][j];
+ r->v[i][j] = r_tmp->v[i][j];
+ r->ker[i][j] = du_coeffs[j] * dv_coeffs[i];
+ }
+ }
+}
+
+/**
+ * Modulo operation with only positive remainders.
+ *
+ * @param a dividend
+ * @param b divisor
+ *
+ * @return positive remainder of (a / b)
+ */
+static inline int mod(int a, int b)
+{
+ const int res = a % b;
+ if (res < 0) {
+ return res + b;
+ } else {
+ return res;
+ }
+}
+
+/**
+ * Convert char to corresponding direction.
+ * Used for cubemap options.
+ */
+static int get_direction(char c)
+{
+ switch (c) {
+ case 'r':
+ return RIGHT;
+ case 'l':
+ return LEFT;
+ case 'u':
+ return UP;
+ case 'd':
+ return DOWN;
+ case 'f':
+ return FRONT;
+ case 'b':
+ return BACK;
+ default:
+ return -1;
+ }
+}
+
+/**
+ * Convert char to corresponding rotation angle.
+ * Used for cubemap options.
+ */
+static int get_rotation(char c)
+{
+ switch (c) {
+ case '0':
+ return ROT_0;
+ case '1':
+ return ROT_90;
+ case '2':
+ return ROT_180;
+ case '3':
+ return ROT_270;
+ default:
+ return -1;
+ }
+}
+
+/**
+ * Prepare data for processing cubemap input format.
+ *
+ * @param ctx filter context
+ *
+ * @return error code
+ */
+static int prepare_cube_in(AVFilterContext *ctx)
+{
+ V360Context *s = ctx->priv;
+
+ for (int face = 0; face < NB_FACES; face++) {
+ const char c = s->in_forder[face];
+ int direction;
+
+ if (c == '\0') {
+ av_log(ctx, AV_LOG_ERROR,
+ "Incomplete in_forder option. Direction for all 6 faces should be specified.\n");
+ return AVERROR(EINVAL);
+ }
+
+ direction = get_direction(c);
+ if (direction == -1) {
+ av_log(ctx, AV_LOG_ERROR,
+ "Incorrect direction symbol '%c' in in_forder option.\n", c);
+ return AVERROR(EINVAL);
+ }
+
+ s->in_cubemap_face_order[direction] = face;
+ }
+
+ for (int face = 0; face < NB_FACES; face++) {
+ const char c = s->in_frot[face];
+ int rotation;
+
+ if (c == '\0') {
+ av_log(ctx, AV_LOG_ERROR,
+ "Incomplete in_frot option. Rotation for all 6 faces should be specified.\n");
+ return AVERROR(EINVAL);
+ }
+
+ rotation = get_rotation(c);
+ if (rotation == -1) {
+ av_log(ctx, AV_LOG_ERROR,
+ "Incorrect rotation symbol '%c' in in_frot option.\n", c);
+ return AVERROR(EINVAL);
+ }
+
+ s->in_cubemap_face_rotation[face] = rotation;
+ }
+
+ return 0;
+}
+
+/**
+ * Prepare data for processing cubemap output format.
+ *
+ * @param ctx filter context
+ *
+ * @return error code
+ */
+static int prepare_cube_out(AVFilterContext *ctx)
+{
+ V360Context *s = ctx->priv;
+
+ for (int face = 0; face < NB_FACES; face++) {
+ const char c = s->out_forder[face];
+ int direction;
+
+ if (c == '\0') {
+ av_log(ctx, AV_LOG_ERROR,
+ "Incomplete out_forder option. Direction for all 6 faces should be specified.\n");
+ return AVERROR(EINVAL);
+ }
+
+ direction = get_direction(c);
+ if (direction == -1) {
+ av_log(ctx, AV_LOG_ERROR,
+ "Incorrect direction symbol '%c' in out_forder option.\n", c);
+ return AVERROR(EINVAL);
+ }
+
+ s->out_cubemap_direction_order[face] = direction;
+ }
+
+ for (int face = 0; face < NB_FACES; face++) {
+ const char c = s->out_frot[face];
+ int rotation;
+
+ if (c == '\0') {
+ av_log(ctx, AV_LOG_ERROR,
+ "Incomplete out_frot option. Rotation for all 6 faces should be specified.\n");
+ return AVERROR(EINVAL);
+ }
+
+ rotation = get_rotation(c);
+ if (rotation == -1) {
+ av_log(ctx, AV_LOG_ERROR,
+ "Incorrect rotation symbol '%c' in out_frot option.\n", c);
+ return AVERROR(EINVAL);
+ }
+
+ s->out_cubemap_face_rotation[face] = rotation;
+ }
+
+ return 0;
+}
+
+static inline void rotate_cube_face(float *uf, float *vf, int rotation)
+{
+ float tmp;
+
+ switch (rotation) {
+ case ROT_0:
+ break;
+ case ROT_90:
+ tmp = *uf;
+ *uf = -*vf;
+ *vf = tmp;
+ break;
+ case ROT_180:
+ *uf = -*uf;
+ *vf = -*vf;
+ break;
+ case ROT_270:
+ tmp = -*uf;
+ *uf = *vf;
+ *vf = tmp;
+ break;
+ }
+}
+
+static inline void rotate_cube_face_inverse(float *uf, float *vf, int rotation)
+{
+ float tmp;
+
+ switch (rotation) {
+ case ROT_0:
+ break;
+ case ROT_90:
+ tmp = -*uf;
+ *uf = *vf;
+ *vf = tmp;
+ break;
+ case ROT_180:
+ *uf = -*uf;
+ *vf = -*vf;
+ break;
+ case ROT_270:
+ tmp = *uf;
+ *uf = -*vf;
+ *vf = tmp;
+ break;
+ }
+}
+
+/**
+ * Calculate 3D coordinates on sphere for corresponding cubemap position.
+ * Common operation for every cubemap.
+ *
+ * @param s filter context
+ * @param uf horizontal cubemap coordinate [0, 1)
+ * @param vf vertical cubemap coordinate [0, 1)
+ * @param face face of cubemap
+ * @param vec coordinates on sphere
+ */
+static void cube_to_xyz(const V360Context *s,
+ float uf, float vf, int face,
+ float *vec)
+{
+ const int direction = s->out_cubemap_direction_order[face];
+ float norm;
+ float l_x, l_y, l_z;
+
+ rotate_cube_face_inverse(&uf, &vf, s->out_cubemap_face_rotation[face]);
+
+ switch (direction) {
+ case RIGHT:
+ l_x = 1.f;
+ l_y = -vf;
+ l_z = uf;
+ break;
+ case LEFT:
+ l_x = -1.f;
+ l_y = -vf;
+ l_z = -uf;
+ break;
+ case UP:
+ l_x = uf;
+ l_y = 1.f;
+ l_z = -vf;
+ break;
+ case DOWN:
+ l_x = uf;
+ l_y = -1.f;
+ l_z = vf;
+ break;
+ case FRONT:
+ l_x = uf;
+ l_y = -vf;
+ l_z = -1.f;
+ break;
+ case BACK:
+ l_x = -uf;
+ l_y = -vf;
+ l_z = 1.f;
+ break;
+ }
+
+ norm = sqrtf(l_x * l_x + l_y * l_y + l_z * l_z);
+ vec[0] = l_x / norm;
+ vec[1] = l_y / norm;
+ vec[2] = l_z / norm;
+}
+
+/**
+ * Calculate cubemap position for corresponding 3D coordinates on sphere.
+ * Common operation for every cubemap.
+ *
+ * @param s filter context
+ * @param vec coordinated on sphere
+ * @param uf horizontal cubemap coordinate [0, 1)
+ * @param vf vertical cubemap coordinate [0, 1)
+ * @param direction direction of view
+ */
+static void xyz_to_cube(const V360Context *s,
+ const float *vec,
+ float *uf, float *vf, int *direction)
+{
+ const float phi = atan2f(vec[0], -vec[2]);
+ const float theta = asinf(-vec[1]);
+ float phi_norm, theta_threshold;
+ int face;
+
+ if (phi >= -M_PI_4 && phi < M_PI_4) {
+ *direction = FRONT;
+ phi_norm = phi;
+ } else if (phi >= -(M_PI_2 + M_PI_4) && phi < -M_PI_4) {
+ *direction = LEFT;
+ phi_norm = phi + M_PI_2;
+ } else if (phi >= M_PI_4 && phi < M_PI_2 + M_PI_4) {
+ *direction = RIGHT;
+ phi_norm = phi - M_PI_2;
+ } else {
+ *direction = BACK;
+ phi_norm = phi + ((phi > 0.f) ? -M_PI : M_PI);
+ }
+
+ theta_threshold = atanf(cosf(phi_norm));
+ if (theta > theta_threshold) {
+ *direction = DOWN;
+ } else if (theta < -theta_threshold) {
+ *direction = UP;
+ }
+
+ switch (*direction) {
+ case RIGHT:
+ *uf = vec[2] / vec[0];
+ *vf = -vec[1] / vec[0];
+ break;
+ case LEFT:
+ *uf = vec[2] / vec[0];
+ *vf = vec[1] / vec[0];
+ break;
+ case UP:
+ *uf = vec[0] / vec[1];
+ *vf = -vec[2] / vec[1];
+ break;
+ case DOWN:
+ *uf = -vec[0] / vec[1];
+ *vf = -vec[2] / vec[1];
+ break;
+ case FRONT:
+ *uf = -vec[0] / vec[2];
+ *vf = vec[1] / vec[2];
+ break;
+ case BACK:
+ *uf = -vec[0] / vec[2];
+ *vf = -vec[1] / vec[2];
+ break;
+ }
+
+ face = s->in_cubemap_face_order[*direction];
+ rotate_cube_face(uf, vf, s->in_cubemap_face_rotation[face]);
+}
+
+/**
+ * Find position on another cube face in case of overflow/underflow.
+ * Used for calculation of interpolation window.
+ *
+ * @param s filter context
+ * @param uf horizontal cubemap coordinate
+ * @param vf vertical cubemap coordinate
+ * @param direction direction of view
+ * @param new_uf new horizontal cubemap coordinate
+ * @param new_vf new vertical cubemap coordinate
+ * @param face face position on cubemap
+ */
+static void process_cube_coordinates(const V360Context *s,
+ float uf, float vf, int direction,
+ float *new_uf, float *new_vf, int *face)
+{
+ /*
+ * Cubemap orientation
+ *
+ * width
+ * <------->
+ * +-------+
+ * | | U
+ * | up | h ------->
+ * +-------+-------+-------+-------+ ^ e |
+ * | | | | | | i V |
+ * | left | front | right | back | | g |
+ * +-------+-------+-------+-------+ v h v
+ * | | t
+ * | down |
+ * +-------+
+ */
+
+ *face = s->in_cubemap_face_order[direction];
+ rotate_cube_face_inverse(&uf, &vf, s->in_cubemap_face_rotation[*face]);
+
+ if ((uf < -1.f || uf >= 1.f) && (vf < -1.f || vf >= 1.f)) {
+ // There are no pixels to use in this case
+ *new_uf = uf;
+ *new_vf = vf;
+ } else if (uf < -1.f) {
+ uf += 2.f;
+ switch (direction) {
+ case RIGHT:
+ direction = FRONT;
+ *new_uf = uf;
+ *new_vf = vf;
+ break;
+ case LEFT:
+ direction = BACK;
+ *new_uf = uf;
+ *new_vf = vf;
+ break;
+ case UP:
+ direction = LEFT;
+ *new_uf = vf;
+ *new_vf = -uf;
+ break;
+ case DOWN:
+ direction = LEFT;
+ *new_uf = -vf;
+ *new_vf = uf;
+ break;
+ case FRONT:
+ direction = LEFT;
+ *new_uf = uf;
+ *new_vf = vf;
+ break;
+ case BACK:
+ direction = RIGHT;
+ *new_uf = uf;
+ *new_vf = vf;
+ break;
+ }
+ } else if (uf >= 1.f) {
+ uf -= 2.f;
+ switch (direction) {
+ case RIGHT:
+ direction = BACK;
+ *new_uf = uf;
+ *new_vf = vf;
+ break;
+ case LEFT:
+ direction = FRONT;
+ *new_uf = uf;
+ *new_vf = vf;
+ break;
+ case UP:
+ direction = RIGHT;
+ *new_uf = -vf;
+ *new_vf = uf;
+ break;
+ case DOWN:
+ direction = RIGHT;
+ *new_uf = vf;
+ *new_vf = -uf;
+ break;
+ case FRONT:
+ direction = RIGHT;
+ *new_uf = uf;
+ *new_vf = vf;
+ break;
+ case BACK:
+ direction = LEFT;
+ *new_uf = uf;
+ *new_vf = vf;
+ break;
+ }
+ } else if (vf < -1.f) {
+ vf += 2.f;
+ switch (direction) {
+ case RIGHT:
+ direction = UP;
+ *new_uf = vf;
+ *new_vf = -uf;
+ break;
+ case LEFT:
+ direction = UP;
+ *new_uf = -vf;
+ *new_vf = uf;
+ break;
+ case UP:
+ direction = BACK;
+ *new_uf = -uf;
+ *new_vf = -vf;
+ break;
+ case DOWN:
+ direction = FRONT;
+ *new_uf = uf;
+ *new_vf = vf;
+ break;
+ case FRONT:
+ direction = UP;
+ *new_uf = uf;
+ *new_vf = vf;
+ break;
+ case BACK:
+ direction = UP;
+ *new_uf = -uf;
+ *new_vf = -vf;
+ break;
+ }
+ } else if (vf >= 1.f) {
+ vf -= 2.f;
+ switch (direction) {
+ case RIGHT:
+ direction = DOWN;
+ *new_uf = -vf;
+ *new_vf = uf;
+ break;
+ case LEFT:
+ direction = DOWN;
+ *new_uf = vf;
+ *new_vf = -uf;
+ break;
+ case UP:
+ direction = FRONT;
+ *new_uf = uf;
+ *new_vf = vf;
+ break;
+ case DOWN:
+ direction = BACK;
+ *new_uf = -uf;
+ *new_vf = -vf;
+ break;
+ case FRONT:
+ direction = DOWN;
+ *new_uf = uf;
+ *new_vf = vf;
+ break;
+ case BACK:
+ direction = DOWN;
+ *new_uf = -uf;
+ *new_vf = -vf;
+ break;
+ }
+ } else {
+ // Inside cube face
+ *new_uf = uf;
+ *new_vf = vf;
+ }
+
+ *face = s->in_cubemap_face_order[direction];
+ rotate_cube_face(new_uf, new_vf, s->in_cubemap_face_rotation[*face]);
+}
+
+/**
+ * Calculate 3D coordinates on sphere for corresponding frame position in cubemap3x2 format.
+ *
+ * @param s filter context
+ * @param i horizontal position on frame [0, height)
+ * @param j vertical position on frame [0, width)
+ * @param width frame width
+ * @param height frame height
+ * @param vec coordinates on sphere
+ */
+static void cube3x2_to_xyz(const V360Context *s,
+ int i, int j, int width, int height,
+ float *vec)
+{
+ const float ew = width / 3.f;
+ const float eh = height / 2.f;
+
+ const int u_face = floorf(i / ew);
+ const int v_face = floorf(j / eh);
+ const int face = u_face + 3 * v_face;
+
+ const int u_shift = ceilf(ew * u_face);
+ const int v_shift = ceilf(eh * v_face);
+ const int ewi = ceilf(ew * (u_face + 1)) - u_shift;
+ const int ehi = ceilf(eh * (v_face + 1)) - v_shift;
+
+ const float uf = 2.f * (i - u_shift) / ewi - 1.f;
+ const float vf = 2.f * (j - v_shift) / ehi - 1.f;
+
+ cube_to_xyz(s, uf, vf, face, vec);
+}
+
+/**
+ * Calculate frame position in cubemap3x2 format for corresponding 3D coordinates on sphere.
+ *
+ * @param s filter context
+ * @param vec coordinates on sphere
+ * @param width frame width
+ * @param height frame height
+ * @param us horizontal coordinates for interpolation window
+ * @param vs vertical coordinates for interpolation window
+ * @param du horizontal relative coordinate
+ * @param dv vertical relative coordinate
+ */
+static void xyz_to_cube3x2(const V360Context *s,
+ const float *vec, int width, int height,
+ uint16_t us[4][4], uint16_t vs[4][4], float *du, float *dv)
+{
+ const float ew = width / 3.f;
+ const float eh = height / 2.f;
+ float uf, vf;
+ int ui, vi;
+ int ewi, ehi;
+ int i, j;
+ int direction, face;
+ int u_face, v_face;
+
+ xyz_to_cube(s, vec, &uf, &vf, &direction);
+
+ face = s->in_cubemap_face_order[direction];
+ u_face = face % 3;
+ v_face = face / 3;
+ ewi = ceilf(ew * (u_face + 1)) - ceilf(ew * u_face);
+ ehi = ceilf(eh * (v_face + 1)) - ceilf(eh * v_face);
+
+ uf = 0.5f * ewi * (uf + 1.f);
+ vf = 0.5f * ehi * (vf + 1.f);
+
+ ui = floorf(uf);
+ vi = floorf(vf);
+
+ *du = uf - ui;
+ *dv = vf - vi;
+
+ for (i = -1; i < 3; i++) {
+ for (j = -1; j < 3; j++) {
+ float u, v;
+ int u_shift, v_shift;
+ int new_ewi, new_ehi;
+
+ process_cube_coordinates(s, 2.f * (ui + j) / ewi - 1.f,
+ 2.f * (vi + i) / ehi - 1.f,
+ direction, &u, &v, &face);
+ u_face = face % 3;
+ v_face = face / 3;
+ u_shift = ceilf(ew * u_face);
+ v_shift = ceilf(eh * v_face);
+ new_ewi = ceilf(ew * (u_face + 1)) - u_shift;
+ new_ehi = ceilf(eh * (v_face + 1)) - v_shift;
+
+ us[i + 1][j + 1] = u_shift + av_clip(roundf(0.5f * new_ewi * (u + 1.f)), 0, new_ewi - 1);
+ vs[i + 1][j + 1] = v_shift + av_clip(roundf(0.5f * new_ehi * (v + 1.f)), 0, new_ehi - 1);
+ }
+ }
+}
+
+/**
+ * Calculate 3D coordinates on sphere for corresponding frame position in cubemap6x1 format.
+ *
+ * @param s filter context
+ * @param i horizontal position on frame [0, height)
+ * @param j vertical position on frame [0, width)
+ * @param width frame width
+ * @param height frame height
+ * @param vec coordinates on sphere
+ */
+static void cube6x1_to_xyz(const V360Context *s,
+ int i, int j, int width, int height,
+ float *vec)
+{
+ const float ew = width / 6.f;
+ const float eh = height;
+
+ const int face = floorf(i / ew);
+
+ const int u_shift = ceilf(ew * face);
+ const int ewi = ceilf(ew * (face + 1)) - u_shift;
+
+ const float uf = 2.f * (i - u_shift) / ewi - 1.f;
+ const float vf = 2.f * j / eh - 1.f;
+
+ cube_to_xyz(s, uf, vf, face, vec);
+}
+
+/**
+ * Calculate frame position in cubemap6x1 format for corresponding 3D coordinates on sphere.
+ *
+ * @param s filter context
+ * @param vec coordinates on sphere
+ * @param width frame width
+ * @param height frame height
+ * @param us horizontal coordinates for interpolation window
+ * @param vs vertical coordinates for interpolation window
+ * @param du horizontal relative coordinate
+ * @param dv vertical relative coordinate
+ */
+static void xyz_to_cube6x1(const V360Context *s,
+ const float *vec, int width, int height,
+ uint16_t us[4][4], uint16_t vs[4][4], float *du, float *dv)
+{
+ const float ew = width / 6.f;
+ const float eh = height;
+ float uf, vf;
+ int ui, vi;
+ int ewi;
+ int i, j;
+ int direction, face;
+
+ xyz_to_cube(s, vec, &uf, &vf, &direction);
+
+ face = s->in_cubemap_face_order[direction];
+ ewi = ceilf(ew * (face + 1)) - ceilf(ew * face);
+
+ uf = 0.5f * ewi * (uf + 1.f);
+ vf = 0.5f * eh * (vf + 1.f);
+
+ ui = floorf(uf);
+ vi = floorf(vf);
+
+ *du = uf - ui;
+ *dv = vf - vi;
+
+ for (i = -1; i < 3; i++) {
+ for (j = -1; j < 3; j++) {
+ float u, v;
+ int u_shift;
+ int new_ewi;
+
+ process_cube_coordinates(s, 2.f * (ui + j) / ewi - 1.f,
+ 2.f * (vi + i) / eh - 1.f,
+ direction, &u, &v, &face);
+ u_shift = ceilf(ew * face);
+ new_ewi = ceilf(ew * (face + 1)) - u_shift;
+
+ us[i + 1][j + 1] = u_shift + av_clip(roundf(0.5f * new_ewi * (u + 1.f)), 0, new_ewi - 1);
+ vs[i + 1][j + 1] = av_clip(roundf(0.5f * eh * (v + 1.f)), 0, eh - 1);
+ }
+ }
+}
+
+/**
+ * Calculate 3D coordinates on sphere for corresponding frame position in equirectangular format.
+ *
+ * @param s filter context
+ * @param i horizontal position on frame [0, height)
+ * @param j vertical position on frame [0, width)
+ * @param width frame width
+ * @param height frame height
+ * @param vec coordinates on sphere
+ */
+static void equirect_to_xyz(const V360Context *s,
+ int i, int j, int width, int height,
+ float *vec)
+{
+ const float phi = ((2.f * i) / width - 1.f) * M_PI;
+ const float theta = ((2.f * j) / height - 1.f) * M_PI_2;
+
+ const float sin_phi = sinf(phi);
+ const float cos_phi = cosf(phi);
+ const float sin_theta = sinf(theta);
+ const float cos_theta = cosf(theta);
+
+ vec[0] = cos_theta * sin_phi;
+ vec[1] = -sin_theta;
+ vec[2] = -cos_theta * cos_phi;
+}
+
+/**
+ * Calculate frame position in equirectangular format for corresponding 3D coordinates on sphere.
+ *
+ * @param s filter context
+ * @param vec coordinates on sphere
+ * @param width frame width
+ * @param height frame height
+ * @param us horizontal coordinates for interpolation window
+ * @param vs vertical coordinates for interpolation window
+ * @param du horizontal relative coordinate
+ * @param dv vertical relative coordinate
+ */
+static void xyz_to_equirect(const V360Context *s,
+ const float *vec, int width, int height,
+ uint16_t us[4][4], uint16_t vs[4][4], float *du, float *dv)
+{
+ const float phi = atan2f(vec[0], -vec[2]);
+ const float theta = asinf(-vec[1]);
+ float uf, vf;
+ int ui, vi;
+ int i, j;
+
+ uf = (phi / M_PI + 1.f) * width / 2.f;
+ vf = (theta / M_PI_2 + 1.f) * height / 2.f;
+ ui = floorf(uf);
+ vi = floorf(vf);
+
+ *du = uf - ui;
+ *dv = vf - vi;
+
+ for (i = -1; i < 3; i++) {
+ for (j = -1; j < 3; j++) {
+ us[i + 1][j + 1] = mod(ui + j, width);
+ vs[i + 1][j + 1] = av_clip(vi + i, 0, height - 1);
+ }
+ }
+}
+
+/**
+ * Prepare data for processing equi-angular cubemap input format.
+ *
+ * @param ctx filter context
+
+ * @return error code
+ */
+static int prepare_eac_in(AVFilterContext *ctx)
+{
+ V360Context *s = ctx->priv;
+
+ s->in_cubemap_face_order[RIGHT] = TOP_RIGHT;
+ s->in_cubemap_face_order[LEFT] = TOP_LEFT;
+ s->in_cubemap_face_order[UP] = BOTTOM_RIGHT;
+ s->in_cubemap_face_order[DOWN] = BOTTOM_LEFT;
+ s->in_cubemap_face_order[FRONT] = TOP_MIDDLE;
+ s->in_cubemap_face_order[BACK] = BOTTOM_MIDDLE;
+
+ s->in_cubemap_face_rotation[TOP_LEFT] = ROT_0;
+ s->in_cubemap_face_rotation[TOP_MIDDLE] = ROT_0;
+ s->in_cubemap_face_rotation[TOP_RIGHT] = ROT_0;
+ s->in_cubemap_face_rotation[BOTTOM_LEFT] = ROT_270;
+ s->in_cubemap_face_rotation[BOTTOM_MIDDLE] = ROT_90;
+ s->in_cubemap_face_rotation[BOTTOM_RIGHT] = ROT_270;
+
+ return 0;
+}
+
+/**
+ * Prepare data for processing equi-angular cubemap output format.
+ *
+ * @param ctx filter context
+ *
+ * @return error code
+ */
+static int prepare_eac_out(AVFilterContext *ctx)
+{
+ V360Context *s = ctx->priv;
+
+ s->out_cubemap_direction_order[TOP_LEFT] = LEFT;
+ s->out_cubemap_direction_order[TOP_MIDDLE] = FRONT;
+ s->out_cubemap_direction_order[TOP_RIGHT] = RIGHT;
+ s->out_cubemap_direction_order[BOTTOM_LEFT] = DOWN;
+ s->out_cubemap_direction_order[BOTTOM_MIDDLE] = BACK;
+ s->out_cubemap_direction_order[BOTTOM_RIGHT] = UP;
+
+ s->out_cubemap_face_rotation[TOP_LEFT] = ROT_0;
+ s->out_cubemap_face_rotation[TOP_MIDDLE] = ROT_0;
+ s->out_cubemap_face_rotation[TOP_RIGHT] = ROT_0;
+ s->out_cubemap_face_rotation[BOTTOM_LEFT] = ROT_270;
+ s->out_cubemap_face_rotation[BOTTOM_MIDDLE] = ROT_90;
+ s->out_cubemap_face_rotation[BOTTOM_RIGHT] = ROT_270;
+
+ return 0;
+}
+
+/**
+ * Calculate 3D coordinates on sphere for corresponding frame position in equi-angular cubemap format.
+ *
+ * @param s filter context
+ * @param i horizontal position on frame [0, height)
+ * @param j vertical position on frame [0, width)
+ * @param width frame width
+ * @param height frame height
+ * @param vec coordinates on sphere
+ */
+static void eac_to_xyz(const V360Context *s,
+ int i, int j, int width, int height,
+ float *vec)
+{
+ const float pixel_pad = 2;
+ const float u_pad = pixel_pad / width;
+ const float v_pad = pixel_pad / height;
+
+ int u_face, v_face, face;
+
+ float l_x, l_y, l_z;
+ float norm;
+
+ float uf = (float)i / width;
+ float vf = (float)j / height;
+
+ // EAC has 2-pixel padding on faces except between faces on the same row
+ // Padding pixels seems not to be stretched with tangent as regular pixels
+ // Formulas below approximate original padding as close as I could get experimentally
+
+ // Horizontal padding
+ uf = 3.f * (uf - u_pad) / (1.f - 2.f * u_pad);
+ if (uf < 0.f) {
+ u_face = 0;
+ uf -= 0.5f;
+ } else if (uf >= 3.f) {
+ u_face = 2;
+ uf -= 2.5f;
+ } else {
+ u_face = floorf(uf);
+ uf = fmodf(uf, 1.f) - 0.5f;
+ }
+
+ // Vertical padding
+ v_face = floorf(vf * 2.f);
+ vf = (vf - v_pad - 0.5f * v_face) / (0.5f - 2.f * v_pad) - 0.5f;
+
+ if (uf >= -0.5f && uf < 0.5f) {
+ uf = tanf(M_PI_2 * uf);
+ } else {
+ uf = 2.f * uf;
+ }
+ if (vf >= -0.5f && vf < 0.5f) {
+ vf = tanf(M_PI_2 * vf);
+ } else {
+ vf = 2.f * vf;
+ }
+
+ face = u_face + 3 * v_face;
+
+ switch (face) {
+ case TOP_LEFT:
+ l_x = -1.f;
+ l_y = -vf;
+ l_z = -uf;
+ break;
+ case TOP_MIDDLE:
+ l_x = uf;
+ l_y = -vf;
+ l_z = -1.f;
+ break;
+ case TOP_RIGHT:
+ l_x = 1.f;
+ l_y = -vf;
+ l_z = uf;
+ break;
+ case BOTTOM_LEFT:
+ l_x = -vf;
+ l_y = -1.f;
+ l_z = uf;
+ break;
+ case BOTTOM_MIDDLE:
+ l_x = -vf;
+ l_y = uf;
+ l_z = 1.f;
+ break;
+ case BOTTOM_RIGHT:
+ l_x = -vf;
+ l_y = 1.f;
+ l_z = -uf;
+ break;
+ }
+
+ norm = sqrtf(l_x * l_x + l_y * l_y + l_z * l_z);
+ vec[0] = l_x / norm;
+ vec[1] = l_y / norm;
+ vec[2] = l_z / norm;
+}
+
+/**
+ * Calculate frame position in equi-angular cubemap format for corresponding 3D coordinates on sphere.
+ *
+ * @param s filter context
+ * @param vec coordinates on sphere
+ * @param width frame width
+ * @param height frame height
+ * @param us horizontal coordinates for interpolation window
+ * @param vs vertical coordinates for interpolation window
+ * @param du horizontal relative coordinate
+ * @param dv vertical relative coordinate
+ */
+static void xyz_to_eac(const V360Context *s,
+ const float *vec, int width, int height,
+ uint16_t us[4][4], uint16_t vs[4][4], float *du, float *dv)
+{
+ const float pixel_pad = 2;
+ const float u_pad = pixel_pad / width;
+ const float v_pad = pixel_pad / height;
+
+ float uf, vf;
+ int ui, vi;
+ int i, j;
+ int direction, face;
+ int u_face, v_face;
+
+ xyz_to_cube(s, vec, &uf, &vf, &direction);
+
+ face = s->in_cubemap_face_order[direction];
+ u_face = face % 3;
+ v_face = face / 3;
+
+ uf = M_2_PI * atanf(uf) + 0.5f;
+ vf = M_2_PI * atanf(vf) + 0.5f;
+
+ // These formulas are inversed from eac_to_xyz ones
+ uf = (uf + u_face) * (1.f - 2.f * u_pad) / 3.f + u_pad;
+ vf = vf * (0.5f - 2.f * v_pad) + v_pad + 0.5f * v_face;
+
+ uf *= width;
+ vf *= height;
+
+ ui = floorf(uf);
+ vi = floorf(vf);
+
+ *du = uf - ui;
+ *dv = vf - vi;
+
+ for (i = -1; i < 3; i++) {
+ for (j = -1; j < 3; j++) {
+ us[i + 1][j + 1] = av_clip(ui + j, 0, width - 1);
+ vs[i + 1][j + 1] = av_clip(vi + i, 0, height - 1);
+ }
+ }
+}
+
+/**
+ * Prepare data for processing flat output format.
+ *
+ * @param ctx filter context
+ *
+ * @return error code
+ */
+static int prepare_flat_out(AVFilterContext *ctx)
+{
+ V360Context *s = ctx->priv;
+
+ const float h_angle = 0.5f * s->h_fov * M_PI / 180.f;
+ const float v_angle = 0.5f * s->v_fov * M_PI / 180.f;
+
+ const float sin_phi = sinf(h_angle);
+ const float cos_phi = cosf(h_angle);
+ const float sin_theta = sinf(v_angle);
+ const float cos_theta = cosf(v_angle);
+
+ s->flat_range[0] = cos_theta * sin_phi;
+ s->flat_range[1] = sin_theta;
+ s->flat_range[2] = -cos_theta * cos_phi;
+
+ return 0;
+}
+
+/**
+ * Calculate 3D coordinates on sphere for corresponding frame position in flat format.
+ *
+ * @param s filter context
+ * @param i horizontal position on frame [0, height)
+ * @param j vertical position on frame [0, width)
+ * @param width frame width
+ * @param height frame height
+ * @param vec coordinates on sphere
+ */
+static void flat_to_xyz(const V360Context *s,
+ int i, int j, int width, int height,
+ float *vec)
+{
+ const float l_x = s->flat_range[0] * (2.f * i / width - 1.f);
+ const float l_y = -s->flat_range[1] * (2.f * j / height - 1.f);
+ const float l_z = s->flat_range[2];
+
+ const float norm = sqrtf(l_x * l_x + l_y * l_y + l_z * l_z);
+
+ vec[0] = l_x / norm;
+ vec[1] = l_y / norm;
+ vec[2] = l_z / norm;
+}
+
+/**
+ * Calculate rotation matrix for yaw/pitch/roll angles.
+ */
+static inline void calculate_rotation_matrix(float yaw, float pitch, float roll,
+ float rot_mat[3][3])
+{
+ const float yaw_rad = yaw * M_PI / 180.f;
+ const float pitch_rad = pitch * M_PI / 180.f;
+ const float roll_rad = roll * M_PI / 180.f;
+
+ const float sin_yaw = sinf(-yaw_rad);
+ const float cos_yaw = cosf(-yaw_rad);
+ const float sin_pitch = sinf(pitch_rad);
+ const float cos_pitch = cosf(pitch_rad);
+ const float sin_roll = sinf(roll_rad);
+ const float cos_roll = cosf(roll_rad);
+
+ rot_mat[0][0] = sin_yaw * sin_pitch * sin_roll + cos_yaw * cos_roll;
+ rot_mat[0][1] = sin_yaw * sin_pitch * cos_roll - cos_yaw * sin_roll;
+ rot_mat[0][2] = sin_yaw * cos_pitch;
+
+ rot_mat[1][0] = cos_pitch * sin_roll;
+ rot_mat[1][1] = cos_pitch * cos_roll;
+ rot_mat[1][2] = -sin_pitch;
+
+ rot_mat[2][0] = cos_yaw * sin_pitch * sin_roll - sin_yaw * cos_roll;
+ rot_mat[2][1] = cos_yaw * sin_pitch * cos_roll + sin_yaw * sin_roll;
+ rot_mat[2][2] = cos_yaw * cos_pitch;
+}
+
+/**
+ * Rotate vector with given rotation matrix.
+ *
+ * @param rot_mat rotation matrix
+ * @param vec vector
+ */
+static inline void rotate(const float rot_mat[3][3],
+ float *vec)
+{
+ const float x_tmp = vec[0] * rot_mat[0][0] + vec[1] * rot_mat[0][1] + vec[2] * rot_mat[0][2];
+ const float y_tmp = vec[0] * rot_mat[1][0] + vec[1] * rot_mat[1][1] + vec[2] * rot_mat[1][2];
+ const float z_tmp = vec[0] * rot_mat[2][0] + vec[1] * rot_mat[2][1] + vec[2] * rot_mat[2][2];
+
+ vec[0] = x_tmp;
+ vec[1] = y_tmp;
+ vec[2] = z_tmp;
+}
+
+static inline void set_mirror_modifier(int h_flip, int v_flip, int d_flip,
+ float *modifier)
+{
+ modifier[0] = h_flip ? -1.f : 1.f;
+ modifier[1] = v_flip ? -1.f : 1.f;
+ modifier[2] = d_flip ? -1.f : 1.f;
+}
+
+static inline void mirror(const float *modifier,
+ float *vec)
+{
+ vec[0] *= modifier[0];
+ vec[1] *= modifier[1];
+ vec[2] *= modifier[2];
+}
+
+static int config_output(AVFilterLink *outlink)
+{
+ AVFilterContext *ctx = outlink->src;
+ AVFilterLink *inlink = ctx->inputs[0];
+ V360Context *s = ctx->priv;
+ const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
+ const int depth = desc->comp[0].depth;
+ float remap_data_size = 0.f;
+ int sizeof_remap;
+ int err;
+ int p, h, w;
+ float hf, wf;
+ float mirror_modifier[3];
+ void (*in_transform)(const V360Context *s,
+ const float *vec, int width, int height,
+ uint16_t us[4][4], uint16_t vs[4][4], float *du, float *dv);
+ void (*out_transform)(const V360Context *s,
+ int i, int j, int width, int height,
+ float *vec);
+ void (*calculate_kernel)(float du, float dv, int shift, const XYRemap4 *r_tmp, void *r);
+ float rot_mat[3][3];
+
+ switch (s->interp) {
+ case NEAREST:
+ calculate_kernel = nearest_kernel;
+ s->remap_slice = depth <= 8 ? remap1_8bit_slice : remap1_16bit_slice;
+ sizeof_remap = sizeof(XYRemap1);
+ break;
+ case BILINEAR:
+ calculate_kernel = bilinear_kernel;
+ s->remap_slice = depth <= 8 ? remap2_8bit_slice : remap2_16bit_slice;
+ sizeof_remap = sizeof(XYRemap2);
+ break;
+ case BICUBIC:
+ calculate_kernel = bicubic_kernel;
+ s->remap_slice = depth <= 8 ? remap4_8bit_slice : remap4_16bit_slice;
+ sizeof_remap = sizeof(XYRemap4);
+ break;
+ case LANCZOS:
+ calculate_kernel = lanczos_kernel;
+ s->remap_slice = depth <= 8 ? remap4_8bit_slice : remap4_16bit_slice;
+ sizeof_remap = sizeof(XYRemap4);
+ break;
+ }
+
+ switch (s->in) {
+ case EQUIRECTANGULAR:
+ in_transform = xyz_to_equirect;
+ err = 0;
+ wf = inlink->w;
+ hf = inlink->h;
+ break;
+ case CUBEMAP_3_2:
+ in_transform = xyz_to_cube3x2;
+ err = prepare_cube_in(ctx);
+ wf = inlink->w / 3.f * 4.f;
+ hf = inlink->h;
+ break;
+ case CUBEMAP_6_1:
+ in_transform = xyz_to_cube6x1;
+ err = prepare_cube_in(ctx);
+ wf = inlink->w / 3.f * 2.f;
+ hf = inlink->h * 2.f;
+ break;
+ case EQUIANGULAR:
+ in_transform = xyz_to_eac;
+ err = prepare_eac_in(ctx);
+ wf = inlink->w;
+ hf = inlink->h / 9.f * 8.f;
+ break;
+ case FLAT:
+ av_log(ctx, AV_LOG_ERROR, "Flat format is not accepted as input.\n");
+ return AVERROR(EINVAL);
+ default:
+ av_log(ctx, AV_LOG_ERROR, "Specified input format is not handled.\n");
+ return AVERROR_BUG;
+ }
+
+ if (err != 0) {
+ return err;
+ }
+
+ switch (s->out) {
+ case EQUIRECTANGULAR:
+ out_transform = equirect_to_xyz;
+ err = 0;
+ w = roundf(wf);
+ h = roundf(hf);
+ break;
+ case CUBEMAP_3_2:
+ out_transform = cube3x2_to_xyz;
+ err = prepare_cube_out(ctx);
+ w = roundf(wf / 4.f * 3.f);
+ h = roundf(hf);
+ break;
+ case CUBEMAP_6_1:
+ out_transform = cube6x1_to_xyz;
+ err = prepare_cube_out(ctx);
+ w = roundf(wf / 2.f * 3.f);
+ h = roundf(hf / 2.f);
+ break;
+ case EQUIANGULAR:
+ out_transform = eac_to_xyz;
+ err = prepare_eac_out(ctx);
+ w = roundf(wf);
+ h = roundf(hf / 8.f * 9.f);
+ break;
+ case FLAT:
+ out_transform = flat_to_xyz;
+ err = prepare_flat_out(ctx);
+ w = roundf(wf * s->flat_range[0] / s->flat_range[1] / 2.f);
+ h = roundf(hf);
+ break;
+ default:
+ av_log(ctx, AV_LOG_ERROR, "Specified output format is not handled.\n");
+ return AVERROR_BUG;
+ }
+
+ if (err != 0) {
+ return err;
+ }
+
+ // Override resolution with user values if specified
+ if (s->width > 0 && s->height > 0) {
+ w = s->width;
+ h = s->height;
+ } else if (s->width > 0 || s->height > 0) {
+ av_log(ctx, AV_LOG_ERROR, "Both width and height values should be specified.\n");
+ return AVERROR(EINVAL);
+ }
+
+ s->planeheight[1] = s->planeheight[2] = FF_CEIL_RSHIFT(h, desc->log2_chroma_h);
+ s->planeheight[0] = s->planeheight[3] = h;
+ s->planewidth[1] = s->planewidth[2] = FF_CEIL_RSHIFT(w, desc->log2_chroma_w);
+ s->planewidth[0] = s->planewidth[3] = w;
+
+ outlink->h = h;
+ outlink->w = w;
+
+ s->inplaneheight[1] = s->inplaneheight[2] = FF_CEIL_RSHIFT(inlink->h, desc->log2_chroma_h);
+ s->inplaneheight[0] = s->inplaneheight[3] = inlink->h;
+ s->inplanewidth[1] = s->inplanewidth[2] = FF_CEIL_RSHIFT(inlink->w, desc->log2_chroma_w);
+ s->inplanewidth[0] = s->inplanewidth[3] = inlink->w;
+ s->nb_planes = av_pix_fmt_count_planes(inlink->format);
+
+ for (p = 0; p < s->nb_planes; p++) {
+ remap_data_size += (float)s->planewidth[p] * s->planeheight[p] * sizeof_remap;
+ }
+
+ for (p = 0; p < s->nb_planes; p++) {
+ s->remap[p] = av_calloc(s->planewidth[p] * s->planeheight[p], sizeof_remap);
+ if (!s->remap[p]) {
+ av_log(ctx, AV_LOG_ERROR,
+ "Not enough memory to allocate remap data. Need at least %.3f GiB.\n",
+ remap_data_size / (1024 * 1024 * 1024));
+ return AVERROR(ENOMEM);
+ }
+ }
+
+ calculate_rotation_matrix(s->yaw, s->pitch, s->roll, rot_mat);
+ set_mirror_modifier(s->h_flip, s->v_flip, s->d_flip, mirror_modifier);
+
+ // Calculate remap data
+ for (p = 0; p < s->nb_planes; p++) {
+ const int width = s->planewidth[p];
+ const int height = s->planeheight[p];
+ const int in_width = s->inplanewidth[p];
+ const int in_height = s->inplaneheight[p];
+ void *r = s->remap[p];
+ float du, dv;
+ float vec[3];
+ XYRemap4 r_tmp;
+ int i, j;
+
+ for (i = 0; i < width; i++) {
+ for (j = 0; j < height; j++) {
+ out_transform(s, i, j, width, height, vec);
+ rotate(rot_mat, vec);
+ mirror(mirror_modifier, vec);
+ in_transform(s, vec, in_width, in_height, r_tmp.u, r_tmp.v, &du, &dv);
+ calculate_kernel(du, dv, j * width + i, &r_tmp, r);
+ }
+ }
+ }
+
+ return 0;
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *in)
+{
+ AVFilterContext *ctx = inlink->dst;
+ AVFilterLink *outlink = ctx->outputs[0];
+ V360Context *s = ctx->priv;
+ AVFrame *out;
+ ThreadData td;
+
+ out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
+ if (!out) {
+ av_frame_free(&in);
+ return AVERROR(ENOMEM);
+ }
+ av_frame_copy_props(out, in);
+
+ td.s = s;
+ td.in = in;
+ td.out = out;
+ td.nb_planes = s->nb_planes;
+
+ ctx->internal->execute(ctx, s->remap_slice, &td, NULL, FFMIN(outlink->h, ff_filter_get_nb_threads(ctx)));
+
+ av_frame_free(&in);
+ return ff_filter_frame(outlink, out);
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+ V360Context *s = ctx->priv;
+ int p;
+
+ for (p = 0; p < s->nb_planes; p++)
+ av_freep(&s->remap[p]);
+}
+
+static const AVFilterPad inputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .filter_frame = filter_frame,
+ },
+ { NULL }
+};
+
+static const AVFilterPad outputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .config_props = config_output,
+ },
+ { NULL }
+};
+
+AVFilter ff_vf_v360 = {
+ .name = "v360",
+ .description = NULL_IF_CONFIG_SMALL("Convert 360 projection of video."),
+ .priv_size = sizeof(V360Context),
+ .uninit = uninit,
+ .query_formats = query_formats,
+ .inputs = inputs,
+ .outputs = outputs,
+ .priv_class = &v360_class,
+ .flags = AVFILTER_FLAG_SLICE_THREADS,
+};
--
2.22.0
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