Fix incorrect alpha step used for RGBA64 sources.

diff --git a/src/lib/image.cc b/src/lib/image.cc
index 4042d5886df28ccd3386e98e3acb237918a97216..98c52c8e0452bd4255df4f20c227d763ee2cdcbe 100644 (file)
--- a/src/lib/image.cc
+++ b/src/lib/image.cc
@@ -673,6 +673,7 @@ struct OtherYUVParams
 
        uint8_t* const* alpha_data;
        int const* alpha_stride;
+       int alpha_bpp;
 };
 
 
@@ -816,7 +817,7 @@ alpha_blend_onto_yuv420p(TargetParams const& target, OtherYUVParams const& other
                uint8_t* oY = other.data[0] + (oy * other.stride[0]) + other.start_x;
                uint8_t* oU = other.data[1] + (hoy * other.stride[1]) + other.start_x / 2;
                uint8_t* oV = other.data[2] + (hoy * other.stride[2]) + other.start_x / 2;
-               uint8_t* alpha = other.alpha_data[0] + (oy * other.alpha_stride[0]) + other.start_x * 4;
+               uint8_t* alpha = other.alpha_data[0] + (oy * other.alpha_stride[0]) + other.start_x * other.alpha_bpp;
                for (int tx = target.start_x, ox = other.start_x; tx < ts.width && ox < os.width; ++tx, ++ox) {
                        float const a = float(alpha[3]) / 255;
                        *tY = *oY * a + *tY * (1 - a);
@@ -832,7 +833,7 @@ alpha_blend_onto_yuv420p(TargetParams const& target, OtherYUVParams const& other
                                ++oU;
                                ++oV;
                        }
-                       alpha += 4;
+                       alpha += other.alpha_bpp;
                }
        }
 }
@@ -853,7 +854,7 @@ alpha_blend_onto_yuv420p10(TargetParams const& target, OtherYUVParams const& oth
                uint16_t* oY = reinterpret_cast<uint16_t*>(other.data[0] + (oy * other.stride[0])) + other.start_x;
                uint16_t* oU = reinterpret_cast<uint16_t*>(other.data[1] + (hoy * other.stride[1])) + other.start_x / 2;
                uint16_t* oV = reinterpret_cast<uint16_t*>(other.data[2] + (hoy * other.stride[2])) + other.start_x / 2;
-               uint8_t* alpha = other.alpha_data[0] + (oy * other.alpha_stride[0]) + other.start_x * 4;
+               uint8_t* alpha = other.alpha_data[0] + (oy * other.alpha_stride[0]) + other.start_x * other.alpha_bpp;
                for (int tx = target.start_x, ox = other.start_x; tx < ts.width && ox < os.width; ++tx, ++ox) {
                        float const a = float(alpha[3]) / 255;
                        *tY = *oY * a + *tY * (1 - a);
@@ -869,7 +870,7 @@ alpha_blend_onto_yuv420p10(TargetParams const& target, OtherYUVParams const& oth
                                ++oU;
                                ++oV;
                        }
-                       alpha += 4;
+                       alpha += other.alpha_bpp;
                }
        }
 }
@@ -888,7 +889,7 @@ alpha_blend_onto_yuv422p9or10le(TargetParams const& target, OtherYUVParams const
                uint16_t* oY = reinterpret_cast<uint16_t*>(other.data[0] + (oy * other.stride[0])) + other.start_x;
                uint16_t* oU = reinterpret_cast<uint16_t*>(other.data[1] + (oy * other.stride[1])) + other.start_x / 2;
                uint16_t* oV = reinterpret_cast<uint16_t*>(other.data[2] + (oy * other.stride[2])) + other.start_x / 2;
-               uint8_t* alpha = other.alpha_data[0] + (oy * other.alpha_stride[0]) + other.start_x * 4;
+               uint8_t* alpha = other.alpha_data[0] + (oy * other.alpha_stride[0]) + other.start_x * other.alpha_bpp;
                for (int tx = target.start_x, ox = other.start_x; tx < ts.width && ox < os.width; ++tx, ++ox) {
                        float const a = float(alpha[3]) / 255;
                        *tY = *oY * a + *tY * (1 - a);
@@ -904,7 +905,7 @@ alpha_blend_onto_yuv422p9or10le(TargetParams const& target, OtherYUVParams const
                                ++oU;
                                ++oV;
                        }
-                       alpha += 4;
+                       alpha += other.alpha_bpp;
                }
        }
 }
@@ -963,7 +964,8 @@ Image::alpha_blend (shared_ptr<const Image> other, Position<int> position)
                other->data(),
                other->stride(),
                nullptr,
-               nullptr
+               nullptr,
+               other->pixel_format() == AV_PIX_FMT_RGBA64BE ? 8 : 4
        };
 
        auto byteswap = [](uint16_t* p) {