{"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" },
{ "tsp", "truncated square pyramid", 0, AV_OPT_TYPE_CONST, {.i64=TSPYRAMID}, 0, 0, FLAGS, "out" },
+ { "hequirect", "half equirectangular", 0, AV_OPT_TYPE_CONST, {.i64=HEQUIRECTANGULAR},0, 0, FLAGS, "out" },
+ { "he", "half equirectangular", 0, AV_OPT_TYPE_CONST, {.i64=HEQUIRECTANGULAR},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" },
return 1;
}
+/**
+ * Calculate 3D coordinates on sphere for corresponding frame position in half equirectangular 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 hequirect_to_xyz(const V360Context *s,
+ int i, int j, int width, int height,
+ float *vec)
+{
+ const float phi = ((2.f * i + 0.5f) / width - 1.f) * M_PI_2;
+ const float theta = ((2.f * j + 0.5f) / height - 1.f) * M_PI_2;
+
+ 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;
+
+ return 1;
+}
+
/**
* Prepare data for processing stereographic output format.
*
w = lrintf(wf);
h = lrintf(hf);
break;
+ case HEQUIRECTANGULAR:
+ s->out_transform = hequirect_to_xyz;
+ prepare_out = NULL;
+ w = lrintf(wf / 2.f);
+ h = lrintf(hf);
+ break;
default:
av_log(ctx, AV_LOG_ERROR, "Specified output format is not handled.\n");
return AVERROR_BUG;