From 580d68f90e4cd363ad75d187a7b42f7951733f79 Mon Sep 17 00:00:00 2001 From: Paul B Mahol Date: Tue, 3 Mar 2020 12:21:16 +0100 Subject: avfilter/vf_v360: add half equirectangular input format --- libavfilter/vf_v360.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) (limited to 'libavfilter') diff --git a/libavfilter/vf_v360.c b/libavfilter/vf_v360.c index 3d4ee25216..05c558d97d 100644 --- a/libavfilter/vf_v360.c +++ b/libavfilter/vf_v360.c @@ -78,6 +78,8 @@ static const AVOption v360_options[] = { {"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" }, + { "hequirect", "half equirectangular", 0, AV_OPT_TYPE_CONST, {.i64=HEQUIRECTANGULAR},0, 0, FLAGS, "in" }, + { "he", "half equirectangular", 0, AV_OPT_TYPE_CONST, {.i64=HEQUIRECTANGULAR},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" }, @@ -1800,6 +1802,46 @@ static int xyz_to_equirect(const V360Context *s, return 1; } +/** + * Calculate frame position in half equirectangular 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_hequirect(const V360Context *s, + const float *vec, int width, int height, + int16_t us[4][4], int16_t vs[4][4], float *du, float *dv) +{ + const float phi = atan2f(vec[0], -vec[2]) * s->input_mirror_modifier[0]; + const float theta = asinf(-vec[1]) * s->input_mirror_modifier[1]; + + const float uf = (phi / M_PI_2 + 1.f) * width / 2.f; + const float vf = (theta / M_PI_2 + 1.f) * height / 2.f; + + const int ui = floorf(uf); + const int vi = floorf(vf); + + const int visible = phi >= -M_PI_2 && phi <= M_PI_2; + + *du = uf - ui; + *dv = vf - vi; + + for (int i = 0; i < 4; i++) { + for (int j = 0; j < 4; j++) { + us[i][j] = av_clip(ui + j - 1, 0, width - 1); + vs[i][j] = av_clip(vi + i - 1, 0, height - 1); + } + } + + return visible; +} + /** * Prepare data for processing flat input format. * @@ -3835,6 +3877,12 @@ static int config_output(AVFilterLink *outlink) wf = w; hf = h; break; + case HEQUIRECTANGULAR: + s->in_transform = xyz_to_hequirect; + err = 0; + wf = w * 2.f; + hf = h; + break; default: av_log(ctx, AV_LOG_ERROR, "Specified input format is not handled.\n"); return AVERROR_BUG; -- cgit v1.2.3