diff options
| -rw-r--r-- | doc/filters.texi | 3 | ||||
| -rw-r--r-- | libavfilter/vf_v360.c | 162 |
2 files changed, 165 insertions, 0 deletions
diff --git a/doc/filters.texi b/doc/filters.texi index 7759fe177b..2271749e49 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -18024,6 +18024,9 @@ No padding. Default value is @b{@samp{0}}. @end table +@item fb +Facebook's 360 format. + @end table @item interp diff --git a/libavfilter/vf_v360.c b/libavfilter/vf_v360.c index aad1afd129..9b7f0c109e 100644 --- a/libavfilter/vf_v360.c +++ b/libavfilter/vf_v360.c @@ -48,6 +48,7 @@ enum Projections { EQUIANGULAR, FLAT, DUAL_FISHEYE, + FACEBOOK, NB_PROJECTIONS, }; @@ -137,12 +138,14 @@ static const AVOption v360_options[] = { { "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" }, { "dfisheye", "dual fisheye", 0, AV_OPT_TYPE_CONST, {.i64=DUAL_FISHEYE}, 0, 0, FLAGS, "in" }, + { "fb", "facebook's 360 format", 0, AV_OPT_TYPE_CONST, {.i64=FACEBOOK}, 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" }, + { "fb", "facebook's 360 format", 0, AV_OPT_TYPE_CONST, {.i64=FACEBOOK}, 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" }, @@ -1647,6 +1650,153 @@ static void xyz_to_dfisheye(const V360Context *s, } /** + * Calculate 3D coordinates on sphere for corresponding frame position in facebook's 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 fb_to_xyz(const V360Context *s, + int i, int j, int width, int height, + float *vec) +{ + const float scale = 0.99f; + float l_x, l_y, l_z; + + if (i < 4 * width / 5) { + const float theta_range = M_PI / 4.f; + + const int ew = 4 * width / 5; + const int eh = height; + + const float phi = ((2.f * i) / ew - 1.f) * M_PI / scale; + const float theta = ((2.f * j) / eh - 1.f) * theta_range / scale; + + 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 ew = width / 5; + const int eh = height / 2; + + float uf, vf; + float norm; + + if (j < eh) { // UP + uf = 2.f * (i - 4 * ew) / ew - 1.f; + vf = 2.f * (j ) / eh - 1.f; + + uf /= scale; + vf /= scale; + + l_x = uf; + l_y = 1.f; + l_z = -vf; + } else { // DOWN + uf = 2.f * (i - 4 * ew) / ew - 1.f; + vf = 2.f * (j - eh) / eh - 1.f; + + uf /= scale; + vf /= scale; + + l_x = uf; + l_y = -1.f; + l_z = vf; + } + + norm = sqrtf(l_x * l_x + l_y * l_y + l_z * l_z); + + l_x /= norm; + l_y /= norm; + l_z /= norm; + } + + vec[0] = l_x; + vec[1] = l_y; + vec[2] = l_z; +} + +/** + * Calculate frame position in facebook's 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_fb(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 scale = 0.99f; + + const float phi = atan2f(vec[0], -vec[2]); + const float theta = asinf(-vec[1]); + const float theta_range = M_PI / 4.f; + + int ew, eh; + int u_shift, v_shift; + float uf, vf; + int ui, vi; + int i, j; + + if (theta > -theta_range && theta < theta_range) { + ew = 4 * width / 5; + eh = height; + + u_shift = 0; + v_shift = 0; + + uf = (phi / M_PI * scale + 1.f) * ew / 2.f; + vf = (theta / theta_range * scale + 1.f) * eh / 2.f; + } else { + ew = width / 5; + eh = height / 2; + + u_shift = 4 * ew; + + if (theta < 0.f) { // UP + uf = vec[0] / vec[1]; + vf = -vec[2] / vec[1]; + v_shift = 0; + } else { // DOWN + uf = -vec[0] / vec[1]; + vf = -vec[2] / vec[1]; + v_shift = eh; + } + + uf = 0.5f * ew * (uf * scale + 1.f); + vf = 0.5f * eh * (vf * scale + 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++) { + us[i + 1][j + 1] = u_shift + av_clip(ui + j, 0, ew - 1); + vs[i + 1][j + 1] = v_shift + av_clip(vi + i, 0, eh - 1); + } + } + +} + +/** * Calculate rotation matrix for yaw/pitch/roll angles. */ static inline void calculate_rotation_matrix(float yaw, float pitch, float roll, @@ -1789,6 +1939,12 @@ static int config_output(AVFilterLink *outlink) wf = inlink->w; hf = inlink->h; break; + case FACEBOOK: + in_transform = xyz_to_fb; + err = 0; + wf = inlink->w / 5.f * 4.f; + hf = inlink->h; + break; default: av_log(ctx, AV_LOG_ERROR, "Specified input format is not handled.\n"); return AVERROR_BUG; @@ -1832,6 +1988,12 @@ static int config_output(AVFilterLink *outlink) case DUAL_FISHEYE: av_log(ctx, AV_LOG_ERROR, "Dual fisheye format is not accepted as output.\n"); return AVERROR(EINVAL); + case FACEBOOK: + out_transform = fb_to_xyz; + err = 0; + w = roundf(wf / 4.f * 5.f); + h = roundf(hf); + break; default: av_log(ctx, AV_LOG_ERROR, "Specified output format is not handled.\n"); return AVERROR_BUG; |