[FFmpeg-cvslog] avfilter/vf_v360: add sinusoidal format
Paul B Mahol
git at videolan.org
Wed Sep 25 14:07:45 EEST 2019
ffmpeg | branch: master | Paul B Mahol <onemda at gmail.com> | Wed Sep 25 12:01:54 2019 +0200| [0d05aa052cdd11706c4461b6b2e733e1d65525d6] | committer: Paul B Mahol
avfilter/vf_v360: add sinusoidal format
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=0d05aa052cdd11706c4461b6b2e733e1d65525d6
---
doc/filters.texi | 3 ++
libavfilter/v360.h | 1 +
libavfilter/vf_v360.c | 80 +++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 84 insertions(+)
diff --git a/doc/filters.texi b/doc/filters.texi
index e41384aed8..32453675c1 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -18072,6 +18072,9 @@ Ball format, gives significant distortion toward the back.
@item hammer
Hammer-Aitoff map projection format.
+ at item sinusoidal
+Sinusoidal map projection format.
+
@end table
@item interp
diff --git a/libavfilter/v360.h b/libavfilter/v360.h
index d328b6d5e1..4d78543f60 100644
--- a/libavfilter/v360.h
+++ b/libavfilter/v360.h
@@ -42,6 +42,7 @@ enum Projections {
MERCATOR,
BALL,
HAMMER,
+ SINUSOIDAL,
NB_PROJECTIONS,
};
diff --git a/libavfilter/vf_v360.c b/libavfilter/vf_v360.c
index 71500e7e3b..a28a03de6c 100644
--- a/libavfilter/vf_v360.c
+++ b/libavfilter/vf_v360.c
@@ -68,6 +68,7 @@ static const AVOption v360_options[] = {
{ "mercator", "mercator", 0, AV_OPT_TYPE_CONST, {.i64=MERCATOR}, 0, 0, FLAGS, "in" },
{ "ball", "ball", 0, AV_OPT_TYPE_CONST, {.i64=BALL}, 0, 0, FLAGS, "in" },
{ "hammer", "hammer", 0, AV_OPT_TYPE_CONST, {.i64=HAMMER}, 0, 0, FLAGS, "in" },
+ {"sinusoidal", "sinusoidal", 0, AV_OPT_TYPE_CONST, {.i64=SINUSOIDAL}, 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" },
{ "equirect", "equirectangular", 0, AV_OPT_TYPE_CONST, {.i64=EQUIRECTANGULAR}, 0, 0, FLAGS, "out" },
@@ -85,6 +86,7 @@ static const AVOption v360_options[] = {
{ "mercator", "mercator", 0, AV_OPT_TYPE_CONST, {.i64=MERCATOR}, 0, 0, FLAGS, "out" },
{ "ball", "ball", 0, AV_OPT_TYPE_CONST, {.i64=BALL}, 0, 0, FLAGS, "out" },
{ "hammer", "hammer", 0, AV_OPT_TYPE_CONST, {.i64=HAMMER}, 0, 0, FLAGS, "out" },
+ {"sinusoidal", "sinusoidal", 0, AV_OPT_TYPE_CONST, {.i64=SINUSOIDAL}, 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" },
@@ -1750,6 +1752,72 @@ static void xyz_to_hammer(const V360Context *s,
}
/**
+ * Calculate 3D coordinates on sphere for corresponding frame position in sinusoidal format.
+ *
+ * @param s filter private context
+ * @param i horizontal position on frame [0, width)
+ * @param j vertical position on frame [0, height)
+ * @param width frame width
+ * @param height frame height
+ * @param vec coordinates on sphere
+ */
+static void sinusoidal_to_xyz(const V360Context *s,
+ int i, int j, int width, int height,
+ float *vec)
+{
+ const float theta = ((2.f * j) / height - 1.f) * M_PI_2;
+ const float phi = ((2.f * i) / width - 1.f) * M_PI / cosf(theta);
+
+ 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;
+
+ normalize_vector(vec);
+}
+
+/**
+ * Calculate frame position in sinusoidal format for corresponding 3D coordinates on sphere.
+ *
+ * @param s filter private 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_sinusoidal(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 theta = asinf(-vec[1]) * s->input_mirror_modifier[1];
+ const float phi = atan2f(vec[0], -vec[2]) * s->input_mirror_modifier[0] * cosf(theta);
+ float uf, vf;
+ int ui, vi;
+
+ 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 (int i = -1; i < 3; i++) {
+ for (int 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 equi-angular cubemap input format.
*
* @param ctx filter context
@@ -2612,6 +2680,12 @@ static int config_output(AVFilterLink *outlink)
wf = w;
hf = h;
break;
+ case SINUSOIDAL:
+ s->in_transform = xyz_to_sinusoidal;
+ err = 0;
+ wf = w;
+ hf = h;
+ break;
default:
av_log(ctx, AV_LOG_ERROR, "Specified input format is not handled.\n");
return AVERROR_BUG;
@@ -2694,6 +2768,12 @@ static int config_output(AVFilterLink *outlink)
w = roundf(wf);
h = roundf(hf);
break;
+ case SINUSOIDAL:
+ s->out_transform = sinusoidal_to_xyz;
+ prepare_out = NULL;
+ w = roundf(wf);
+ h = roundf(hf);
+ break;
default:
av_log(ctx, AV_LOG_ERROR, "Specified output format is not handled.\n");
return AVERROR_BUG;
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