[FFmpeg-cvslog] avfilter/vf_v360: add truncated square pyramid input format
Paul B Mahol
git at videolan.org
Mon Mar 2 20:18:19 EET 2020
ffmpeg | branch: master | Paul B Mahol <onemda at gmail.com> | Mon Mar 2 19:05:13 2020 +0100| [6e1913a02e6fffa56b597a4a6e6a1f3fd6aca72e] | committer: Paul B Mahol
avfilter/vf_v360: add truncated square pyramid input format
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=6e1913a02e6fffa56b597a4a6e6a1f3fd6aca72e
---
doc/filters.texi | 2 +-
libavfilter/vf_v360.c | 77 +++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 78 insertions(+), 1 deletion(-)
diff --git a/doc/filters.texi b/doc/filters.texi
index 10fac14eff..b4f3e1ab42 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -19029,7 +19029,7 @@ Set perspective parameter.
Tetrahedron projection.
@item tsp
-Truncated square pyramid projection. @i{(output only)}
+Truncated square pyramid projection.
@end table
diff --git a/libavfilter/vf_v360.c b/libavfilter/vf_v360.c
index a522582c70..5cbf8c95b1 100644
--- a/libavfilter/vf_v360.c
+++ b/libavfilter/vf_v360.c
@@ -77,6 +77,7 @@ static const AVOption v360_options[] = {
{"cylindrical", "cylindrical", 0, AV_OPT_TYPE_CONST, {.i64=CYLINDRICAL}, 0, 0, FLAGS, "in" },
{"tetrahedron", "tetrahedron", 0, AV_OPT_TYPE_CONST, {.i64=TETRAHEDRON}, 0, 0, FLAGS, "in" },
{"barrelsplit", "barrel split facebook's 360 format", 0, AV_OPT_TYPE_CONST, {.i64=BARREL_SPLIT}, 0, 0, FLAGS, "in" },
+ { "tsp", "truncated square pyramid", 0, AV_OPT_TYPE_CONST, {.i64=TSPYRAMID}, 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" },
@@ -3286,6 +3287,76 @@ static int tspyramid_to_xyz(const V360Context *s,
return 1;
}
+/**
+ * Calculate frame position in tspyramid 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 int xyz_to_tspyramid(const V360Context *s,
+ const float *vec, int width, int height,
+ int16_t us[4][4], int16_t vs[4][4], float *du, float *dv)
+{
+ float uf, vf;
+ int ui, vi;
+ int face;
+
+ xyz_to_cube(s, vec, &uf, &vf, &face);
+
+ uf = (uf + 1.f) * 0.5f;
+ vf = (vf + 1.f) * 0.5f;
+
+ switch (face) {
+ case UP:
+ uf = 0.1875f * vf - 0.375f * uf * vf - 0.125f * uf + 0.8125f;
+ vf = 0.375f - 0.375f * vf;
+ break;
+ case FRONT:
+ uf = 0.5f * uf;
+ break;
+ case DOWN:
+ uf = 1.f - 0.1875f * vf - 0.5f * uf + 0.375f * uf * vf;
+ vf = 1.f - 0.375f * vf;
+ break;
+ case LEFT:
+ vf = 0.25f * vf + 0.75f * uf * vf - 0.375f * uf + 0.375f;
+ uf = 0.1875f * uf + 0.8125f;
+ break;
+ case RIGHT:
+ vf = 0.375f * uf - 0.75f * uf * vf + vf;
+ uf = 0.1875f * uf + 0.5f;
+ break;
+ case BACK:
+ uf = 0.125f * uf + 0.6875f;
+ vf = 0.25f * vf + 0.375f;
+ break;
+ }
+
+ uf *= width;
+ vf *= height;
+
+ ui = floorf(uf);
+ vi = floorf(vf);
+
+ *du = uf - ui;
+ *dv = vf - vi;
+
+ for (int i = 0; i < 4; i++) {
+ for (int j = 0; j < 4; j++) {
+ us[i][j] = reflectx(ui + j - 1, vi + i - 1, width, height);
+ vs[i][j] = reflecty(vi + i - 1, height);
+ }
+ }
+
+ return 1;
+}
+
static void multiply_matrix(float c[3][3], const float a[3][3], const float b[3][3])
{
for (int i = 0; i < 3; i++) {
@@ -3727,6 +3798,12 @@ static int config_output(AVFilterLink *outlink)
wf = w * 4.f / 3.f;
hf = h;
break;
+ case TSPYRAMID:
+ s->in_transform = xyz_to_tspyramid;
+ err = 0;
+ wf = w;
+ hf = h;
+ break;
default:
av_log(ctx, AV_LOG_ERROR, "Specified input format is not handled.\n");
return AVERROR_BUG;
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