From b0a9960a772a5f978fc9f52552932c6a2ab3405c Mon Sep 17 00:00:00 2001 From: Paul B Mahol <onemda@gmail.com> Date: Wed, 26 Feb 2020 14:37:39 +0100 Subject: [PATCH] avfilter/vf_v360: add barrel split format output support --- doc/filters.texi | 3 +- libavfilter/v360.h | 1 + libavfilter/vf_v360.c | 95 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 98 insertions(+), 1 deletion(-) diff --git a/doc/filters.texi b/doc/filters.texi index 586ed9034b..1453ecd8b1 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -18932,7 +18932,8 @@ Default value is @b{@samp{0}}. @item barrel @item fb -Facebook's 360 format. +@item barrelsplit +Facebook's 360 formats. @item sg Stereographic format. diff --git a/libavfilter/v360.h b/libavfilter/v360.h index 97008fb3da..e1f131c9a8 100644 --- a/libavfilter/v360.h +++ b/libavfilter/v360.h @@ -48,6 +48,7 @@ enum Projections { CYLINDRICAL, PERSPECTIVE, TETRAHEDRON, + BARREL_SPLIT, NB_PROJECTIONS, }; diff --git a/libavfilter/vf_v360.c b/libavfilter/vf_v360.c index e946135f75..1dae2a3e4c 100644 --- a/libavfilter/vf_v360.c +++ b/libavfilter/vf_v360.c @@ -99,6 +99,7 @@ static const AVOption v360_options[] = { {"cylindrical", "cylindrical", 0, AV_OPT_TYPE_CONST, {.i64=CYLINDRICAL}, 0, 0, FLAGS, "out" }, {"perspective", "perspective", 0, AV_OPT_TYPE_CONST, {.i64=PERSPECTIVE}, 0, 0, FLAGS, "out" }, {"tetrahedron", "tetrahedron", 0, AV_OPT_TYPE_CONST, {.i64=TETRAHEDRON}, 0, 0, FLAGS, "out" }, + {"barrelsplit", "barrel split facebook's 360 format", 0, AV_OPT_TYPE_CONST, {.i64=BARREL_SPLIT}, 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" }, @@ -2997,6 +2998,93 @@ static int xyz_to_barrel(const V360Context *s, return 1; } +/** + * Calculate 3D coordinates on sphere for corresponding frame position in barrel split facebook's 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 int barrelsplit_to_xyz(const V360Context *s, + int i, int j, int width, int height, + float *vec) +{ + const float scale = 1.01f; + const float x = (i + 0.5f) / width; + const float y = (j + 0.5f) / height; + float l_x, l_y, l_z; + + if (x <= 2.f / 3.f) { + const float back = floorf(y * 2.f); + + const float phi = ((3.f / 2.f * x - 0.5f) * scale - back + 1.f) * M_PI; + const float theta = (y - 0.25f - 0.5f * back) * scale * M_PI; + + const float sin_phi = sinf(phi); + const float cos_phi = cosf(phi); + const float sin_theta = sinf(theta); + const float cos_theta = cosf(theta); + + l_x = -cos_theta * sin_phi; + l_y = -sin_theta; + l_z = cos_theta * cos_phi; + } else { + const int face = floorf(y * 4.f); + float uf, vf; + + uf = x * 3.f - 2.f; + uf = (uf - 0.5f) * scale + 0.5f; + + switch (face) { + case 0: + vf = y * 2.f; + uf = 1.f - uf; + vf = (0.5f - vf) * scale; + + l_x = 0.5f - uf; + l_y = 0.5f; + l_z = -0.5f + vf; + break; + case 1: + vf = y * 2.f; + uf = 1.f - uf; + vf = 1.f - (vf - 0.5f) * scale; + + l_x = 0.5f - uf; + l_y = -0.5f; + l_z = 0.5f - vf; + break; + case 2: + vf = y * 2.f - 0.5f; + vf = 1.f - (1.f - vf) * scale; + + l_x = 0.5f - uf; + l_y = 0.5f; + l_z = -0.5f + vf; + break; + case 3: + vf = y * 2.f - 1.5f; + vf = vf * scale; + + l_x = 0.5f - uf; + l_y = -0.5f; + l_z = 0.5f - vf; + break; + } + } + + vec[0] = l_x; + vec[1] = l_y; + vec[2] = l_z; + + normalize_vector(vec); + + 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++) { @@ -3368,6 +3456,7 @@ static int config_output(AVFilterLink *outlink) wf = w; hf = h; break; + case BARREL_SPLIT: case PERSPECTIVE: case PANNINI: av_log(ctx, AV_LOG_ERROR, "Supplied format is not accepted as input.\n"); @@ -3550,6 +3639,12 @@ static int config_output(AVFilterLink *outlink) w = lrintf(wf); h = lrintf(hf); break; + case BARREL_SPLIT: + s->out_transform = barrelsplit_to_xyz; + prepare_out = NULL; + w = lrintf(wf / 4.f * 3.f); + h = lrintf(hf); + break; default: av_log(ctx, AV_LOG_ERROR, "Specified output format is not handled.\n"); return AVERROR_BUG;