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[FFmpeg-devel] lavfi/vf_v360: add missing 0.5 subpixel shift

Message ID 2372164d-7c0b-4b19-9ee4-7755f762e74f.huangyuxing.hyx@alibaba-inc.com
State New
Headers show
Series [FFmpeg-devel] lavfi/vf_v360: add missing 0.5 subpixel shift
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Checks

Context Check Description
andriy/configure warning Failed to apply patch
andriy/configure warning Failed to apply patch

Commit Message

黄宇星(凌怀) July 13, 2021, 8:29 a.m. UTC
Signed-off-by: 凌怀 <huangyuxing.hyx@alibaba-inc.com>
---
 libavfilter/vf_v360.c | 49 ++++++++++++++++++++++++++++++-------------
 1 file changed, 35 insertions(+), 14 deletions(-)

     const float phi   = atan2f(vec[0], vec[2]);
     const float theta = asinf(vec[1]);
-    const float uf = (phi   / s->iflat_range[0] + 1.f) * width  / 2.f;
-    const float vf = (theta / s->iflat_range[1] + 1.f) * height / 2.f;
+    const float uf = (phi   / s->iflat_range[0] + 1.f) * width  / 2.f - 0.5f;
+    const float vf = (theta / s->iflat_range[1] + 1.f) * height / 2.f - 0.5f;
     const int ui = floorf(uf);
     const int vi = floorf(vf);
@@ -2866,7 +2866,7 @@ static int fisheye_to_xyz(const V360Context *s,
                           int i, int j, int width, int height,
                           float *vec)
 {
-    const float uf = s->flat_range[0] * ((2.f * i) / width  - 1.f);
+    const float uf = s->flat_range[0] * ((2.f * i + 1.f) / width  - 1.f);
     const float vf = s->flat_range[1] * ((2.f * j + 1.f) / height - 1.f);
     const float phi   = atan2f(vf, uf);
@@ -2932,6 +2932,9 @@ static int xyz_to_fisheye(const V360Context *s,
     uf = (uf + 0.5f) * width;
     vf = (vf + 0.5f) * height;
+    uf -= 0.5f;
+    vf -= 0.5f;
+
     ui = floorf(uf);
     vi = floorf(vf);
@@ -3007,8 +3010,8 @@ static int xyz_to_pannini(const V360Context *s,
     const float x = S * sinf(phi);
     const float y = S * tanf(theta);
-    const float uf = (x + 1.f) * width  / 2.f;
-    const float vf = (y + 1.f) * height / 2.f;
+    const float uf = (x + 1.f) * width  / 2.f - 0.5f;
+    const float vf = (y + 1.f) * height / 2.f - 0.5f;
     const int ui = floorf(uf);
     const int vi = floorf(vf);
@@ -3115,8 +3118,8 @@ static int xyz_to_cylindrical(const V360Context *s,
     const float phi   = atan2f(vec[0], vec[2]) / s->iflat_range[0];
     const float theta = asinf(vec[1]);
-    const float uf = (phi + 1.f) * (width - 1) / 2.f;
-    const float vf = (tanf(theta) / s->iflat_range[1] + 1.f) * height / 2.f;
+    const float uf = (phi + 1.f) * (width - 1) / 2.f - 0.5f;
+    const float vf = (tanf(theta) / s->iflat_range[1] + 1.f) * height / 2.f - 0.5f;
     const int ui = floorf(uf);
     const int vi = floorf(vf);
@@ -3225,8 +3228,8 @@ static int xyz_to_cylindricalea(const V360Context *s,
     const float phi   = atan2f(vec[0], vec[2]) / s->iflat_range[0];
     const float theta = asinf(vec[1]);
-    const float uf = (phi + 1.f) * (width - 1) / 2.f;
-    const float vf = (sinf(theta) / s->iflat_range[1] + 1.f) * height / 2.f;
+    const float uf = (phi + 1.f) * (width - 1) / 2.f - 0.5f;
+    const float vf = (sinf(theta) / s->iflat_range[1] + 1.f) * height / 2.f - 0.5f;
     const int ui = floorf(uf);
     const int vi = floorf(vf);
@@ -3361,6 +3364,9 @@ static int xyz_to_tetrahedron(const V360Context *s,
     uf *= width;
     vf *= height;
+    uf -= 0.5f;
+    vf -= 0.5f;
+
     ui = floorf(uf);
     vi = floorf(vf);
@@ -3397,7 +3403,7 @@ static int dfisheye_to_xyz(const V360Context *s,
     const int ei = i >= ew ? i - ew : i;
     const float m = i >= ew ? 1.f : -1.f;
-    const float uf = s->flat_range[0] * ((2.f * ei) / ew - 1.f);
+    const float uf = s->flat_range[0] * ((2.f * ei + 1.f) / ew - 1.f);
     const float vf = s->flat_range[1] * ((2.f * j + 1.f) / eh - 1.f);
     const float h     = hypotf(uf, vf);
@@ -3452,6 +3458,9 @@ static int xyz_to_dfisheye(const V360Context *s,
         uf = ew - uf;
     }
+    uf -= 0.5f;
+    vf -= 0.5f;
+
     ui = floorf(uf);
     vi = floorf(vf);
@@ -3491,8 +3500,8 @@ static int barrel_to_xyz(const V360Context *s,
         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 phi   = ((2.f * i + 1.f) / ew - 1.f) * M_PI        / scale;
+        const float theta = ((2.f * j + 1.f) / eh - 1.f) * theta_range / scale;
         const float sin_phi   = sinf(phi);
         const float cos_phi   = cosf(phi);
@@ -3596,6 +3605,9 @@ static int xyz_to_barrel(const V360Context *s,
         vf = 0.5f * eh * (vf * scale + 1.f);
     }
+    uf -= 0.5f;
+    vf -= 0.5f;
+
     ui = floorf(uf);
     vi = floorf(vf);
@@ -3692,6 +3704,9 @@ static int xyz_to_barrelsplit(const V360Context *s,
         vf = height * 0.25f * (vf * scaleh + 1.f) + v_offset;
     }
+    uf -= 0.5f;
+    vf -= 0.5f;
+
     ui = floorf(uf);
     vi = floorf(vf);
@@ -3910,6 +3925,9 @@ static int xyz_to_tspyramid(const V360Context *s,
     uf *= width;
     vf *= height;
+    uf -= 0.5f;
+    vf -= 0.5f;
+
     ui = floorf(uf);
     vi = floorf(vf);
@@ -3995,6 +4013,9 @@ static int xyz_to_octahedron(const V360Context *s,
     uf *= width;
     vf *= height;
+    uf -= 0.5f;
+    vf -= 0.5f;
+
     ui = floorf(uf);
     vi = floorf(vf);

Comments

Paul B Mahol July 17, 2021, 8:57 a.m. UTC | #1
Hi,

I'm unable to apply this patch, please send it via attachment to new mail
in this same thread.
diff mbox series

Patch

diff --git a/libavfilter/vf_v360.c b/libavfilter/vf_v360.c
index 0c47883d4d..c0dafe6bbe 100644
--- a/libavfilter/vf_v360.c
+++ b/libavfilter/vf_v360.c
@@ -1790,8 +1790,8 @@  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 phi   = ((2.f * i + 1.0f) / width  - 1.f) * M_PI_2;
+    const float theta = ((2.f * j + 1.0f) / height - 1.f) * M_PI_2;
     const float sin_phi   = sinf(phi);
     const float cos_phi   = cosf(phi);
@@ -2158,8 +2158,8 @@  static int xyz_to_equirect(const V360Context *s,