Fix #34782: Video Editor - Substract after transform fails
authorSergey Sharybin <sergey.vfx@gmail.com>
Thu, 28 Mar 2013 08:21:29 +0000 (08:21 +0000)
committerSergey Sharybin <sergey.vfx@gmail.com>
Thu, 28 Mar 2013 08:21:29 +0000 (08:21 +0000)
Couple of precision issues here:

- Interpolation was rounding trunkcating colors, and because
  of some precision issues value 254.999 became 254 leading
  to troubles later.

  Now color interpolaiton will do rounding to nearest int.

- Subtract was setting channels to something negative which
  confused color management (especially negative alpha),

  Now subtract effect will clamp channels to 0 from bottom
  and also do some tricks to prevent small alpha which
  could also confuse color management.

source/blender/blenkernel/intern/seqeffects.c
source/blender/blenlib/intern/math_interp.c

index a1dc19e1ff76f251a08bf9f4a9eb8c48cbd77fd6..b6b4501ca5ae3c8feb55264c0a4bc2e1187a38f7 100644 (file)
@@ -965,10 +965,13 @@ static void do_sub_effect_byte(float facf0, float facf1, int x, int y, unsigned
                        straight_uchar_to_premul_float(rt1, cp1);
                        straight_uchar_to_premul_float(rt2, cp2);
 
-                       tempc[0] = rt1[0] - fac1 * rt2[0];
-                       tempc[1] = rt1[1] - fac1 * rt2[1];
-                       tempc[2] = rt1[2] - fac1 * rt2[2];
-                       tempc[3] = rt1[3] - fac1 * rt2[3];
+                       tempc[0] = max_ff(rt1[0] - fac1 * rt2[0], 0.0f);
+                       tempc[1] = max_ff(rt1[1] - fac1 * rt2[1], 0.0f);
+                       tempc[2] = max_ff(rt1[2] - fac1 * rt2[2], 0.0f);
+                       tempc[3] = max_ff(rt1[3] - fac1 * rt2[3], 0.0f);
+
+                       if (tempc[3] < 1e-6)
+                               tempc[3] = 0.0f;
 
                        premul_float_to_straight_uchar(rt, tempc);
 
@@ -984,10 +987,13 @@ static void do_sub_effect_byte(float facf0, float facf1, int x, int y, unsigned
                        straight_uchar_to_premul_float(rt1, cp1);
                        straight_uchar_to_premul_float(rt2, cp2);
 
-                       tempc[0] = rt1[0] - fac3 * rt2[0];
-                       tempc[1] = rt1[1] - fac3 * rt2[1];
-                       tempc[2] = rt1[2] - fac3 * rt2[2];
-                       tempc[3] = rt1[3] - fac3 * rt2[3];
+                       tempc[0] = max_ff(rt1[0] - fac3 * rt2[0], 0.0f);
+                       tempc[1] = max_ff(rt1[1] - fac3 * rt2[1], 0.0f);
+                       tempc[2] = max_ff(rt1[2] - fac3 * rt2[2], 0.0f);
+                       tempc[3] = max_ff(rt1[3] - fac3 * rt2[3], 0.0f);
+
+                       if (tempc[3] < 1e-6)
+                               tempc[3] = 0.0f;
 
                        premul_float_to_straight_uchar(rt, tempc);
 
@@ -1011,22 +1017,34 @@ static void do_sub_effect_float(float facf0, float facf1, int x, int y, float *r
        fac3 = facf1;
 
        while (y--) {
-               x = xo * 4;
+               x = xo;
                while (x--) {
-                       *rt = *rt1 - fac1 * (*rt2);
+                       rt[0] = max_ff(rt1[0] - fac1 * rt2[0], 0.0f);
+                       rt[1] = max_ff(rt1[1] - fac1 * rt2[1], 0.0f);
+                       rt[2] = max_ff(rt1[2] - fac1 * rt2[2], 0.0f);
+                       rt[3] = max_ff(rt1[3] - fac1 * rt2[3], 0.0f);
 
-                       rt1++; rt2++; rt++;
+                       if (rt[3] < 1e-6)
+                               rt[3] = 0.0f;
+
+                       rt1 += 4; rt2 += 4; rt += 4;
                }
 
                if (y == 0)
                        break;
                y--;
 
-               x = xo * 4;
+               x = xo;
                while (x--) {
-                       *rt = *rt1 - fac3 * (*rt2);
+                       rt[0] = max_ff(rt1[0] - fac3 * rt2[0], 0.0f);
+                       rt[1] = max_ff(rt1[1] - fac3 * rt2[1], 0.0f);
+                       rt[2] = max_ff(rt1[2] - fac3 * rt2[2], 0.0f);
+                       rt[3] = max_ff(rt1[3] - fac3 * rt2[3], 0.0f);
 
-                       rt1++; rt2++; rt++;
+                       if (rt[3] < 1e-6)
+                               rt[3] = 0.0f;
+
+                       rt1 += 4; rt2 += 4; rt += 4;
                }
        }
 }
index 5a9e8244a469832543abec6f01034a8210fa9191..de192d436994e4a57e50976b9b68cf7fbef16515 100644 (file)
@@ -215,18 +215,18 @@ BLI_INLINE void bicubic_interpolation(const unsigned char *byte_buffer, const fl
        }
        else {
                if (components == 1) {
-                       byte_output[0] = out[0];
+                       byte_output[0] = out[0] + 0.5f;
                }
                else if (components == 3) {
-                       byte_output[0] = out[0];
-                       byte_output[1] = out[1];
-                       byte_output[2] = out[2];
+                       byte_output[0] = out[0] + 0.5f;
+                       byte_output[1] = out[1] + 0.5f;
+                       byte_output[2] = out[2] + 0.5f;
                }
                else {
-                       byte_output[0] = out[0];
-                       byte_output[1] = out[1];
-                       byte_output[2] = out[2];
-                       byte_output[3] = out[3];
+                       byte_output[0] = out[0] + 0.5f;
+                       byte_output[1] = out[1] + 0.5f;
+                       byte_output[2] = out[2] + 0.5f;
+                       byte_output[3] = out[3] + 0.5f;
                }
        }
 }
@@ -322,18 +322,18 @@ BLI_INLINE void bilinear_interpolation(const unsigned char *byte_buffer, const f
                a_b = a * b; ma_b = (1.0f - a) * b; a_mb = a * (1.0f - b); ma_mb = (1.0f - a) * (1.0f - b);
 
                if (components == 1) {
-                       byte_output[0] = ma_mb * row1[0] + a_mb * row3[0] + ma_b * row2[0] + a_b * row4[0];
+                       byte_output[0] = ma_mb * row1[0] + a_mb * row3[0] + ma_b * row2[0] + a_b * row4[0] + 0.5f;
                }
                else if (components == 3) {
-                       byte_output[0] = ma_mb * row1[0] + a_mb * row3[0] + ma_b * row2[0] + a_b * row4[0];
-                       byte_output[1] = ma_mb * row1[1] + a_mb * row3[1] + ma_b * row2[1] + a_b * row4[1];
-                       byte_output[2] = ma_mb * row1[2] + a_mb * row3[2] + ma_b * row2[2] + a_b * row4[2];
+                       byte_output[0] = ma_mb * row1[0] + a_mb * row3[0] + ma_b * row2[0] + a_b * row4[0] + 0.5f;
+                       byte_output[1] = ma_mb * row1[1] + a_mb * row3[1] + ma_b * row2[1] + a_b * row4[1] + 0.5f;
+                       byte_output[2] = ma_mb * row1[2] + a_mb * row3[2] + ma_b * row2[2] + a_b * row4[2] + 0.5f;
                }
                else {
-                       byte_output[0] = ma_mb * row1[0] + a_mb * row3[0] + ma_b * row2[0] + a_b * row4[0];
-                       byte_output[1] = ma_mb * row1[1] + a_mb * row3[1] + ma_b * row2[1] + a_b * row4[1];
-                       byte_output[2] = ma_mb * row1[2] + a_mb * row3[2] + ma_b * row2[2] + a_b * row4[2];
-                       byte_output[3] = ma_mb * row1[3] + a_mb * row3[3] + ma_b * row2[3] + a_b * row4[3];
+                       byte_output[0] = ma_mb * row1[0] + a_mb * row3[0] + ma_b * row2[0] + a_b * row4[0] + 0.5f;
+                       byte_output[1] = ma_mb * row1[1] + a_mb * row3[1] + ma_b * row2[1] + a_b * row4[1] + 0.5f;
+                       byte_output[2] = ma_mb * row1[2] + a_mb * row3[2] + ma_b * row2[2] + a_b * row4[2] + 0.5f;
+                       byte_output[3] = ma_mb * row1[3] + a_mb * row3[3] + ma_b * row2[3] + a_b * row4[3] + 0.5f;
                }
        }
 }