Move toRGBAlphaMode out of avifReformatState
The toRGBAlphaMode member of the avifReformatState struct is only used
by avifImageYUVToRGB(). Move toRGBAlphaMode out of avifReformatState and
replace it with the existing local variable alphaMultiplyMode in
avifImageYUVToRGB(). alphaMultiplyMode also needs to be passed to
avifImageYUVAnyToRGBAnySlow() as an input parameter.
diff --git a/include/avif/internal.h b/include/avif/internal.h
index db163ca..6ee9212 100644
--- a/include/avif/internal.h
+++ b/include/avif/internal.h
@@ -136,8 +136,6 @@
avifPixelFormatInfo formatInfo;
avifReformatMode mode;
- // Used by avifImageYUVToRGB() only. avifImageRGBToYUV() uses a local variable (alphaMode) instead.
- avifAlphaMultiplyMode toRGBAlphaMode;
} avifReformatState;
// Returns:
diff --git a/src/reformat.c b/src/reformat.c
index 42afbd0..f6d3136 100644
--- a/src/reformat.c
+++ b/src/reformat.c
@@ -135,23 +135,6 @@
state->rangeY = (float)((state->yuvRange == AVIF_RANGE_LIMITED) ? (219 << (state->yuvDepth - 8)) : state->yuvMaxChannel);
state->rangeUV = (float)((state->yuvRange == AVIF_RANGE_LIMITED) ? (224 << (state->yuvDepth - 8)) : state->yuvMaxChannel);
- state->toRGBAlphaMode = AVIF_ALPHA_MULTIPLY_MODE_NO_OP;
- if (image->alphaPlane) {
- if (!avifRGBFormatHasAlpha(rgb->format) || rgb->ignoreAlpha) {
- // if we are converting some image with alpha into a format without alpha, we should do 'premultiply alpha' before
- // discarding alpha plane. This has the same effect of rendering this image on a black background, which makes sense.
- if (!image->alphaPremultiplied) {
- state->toRGBAlphaMode = AVIF_ALPHA_MULTIPLY_MODE_MULTIPLY;
- }
- } else {
- if (!image->alphaPremultiplied && rgb->alphaPremultiplied) {
- state->toRGBAlphaMode = AVIF_ALPHA_MULTIPLY_MODE_MULTIPLY;
- } else if (image->alphaPremultiplied && !rgb->alphaPremultiplied) {
- state->toRGBAlphaMode = AVIF_ALPHA_MULTIPLY_MODE_UNMULTIPLY;
- }
- }
- }
-
return AVIF_TRUE;
}
@@ -510,7 +493,10 @@
}
// Note: This function handles alpha (un)multiply.
-static avifResult avifImageYUVAnyToRGBAnySlow(const avifImage * image, avifRGBImage * rgb, avifReformatState * state)
+static avifResult avifImageYUVAnyToRGBAnySlow(const avifImage * image,
+ avifRGBImage * rgb,
+ const avifReformatState * state,
+ avifAlphaMultiplyMode alphaMultiplyMode)
{
// Aliases for some state
const float kr = state->kr;
@@ -540,7 +526,7 @@
// If toRGBAlphaMode is active (not no-op), assert that the alpha plane is present. The end of
// the avifPrepareReformatState() function should ensure this, but this assert makes it clear
// to clang's analyzer.
- assert((state->toRGBAlphaMode == AVIF_ALPHA_MULTIPLY_MODE_NO_OP) || aPlane);
+ assert((alphaMultiplyMode == AVIF_ALPHA_MULTIPLY_MODE_NO_OP) || aPlane);
for (uint32_t j = 0; j < image->height; ++j) {
const uint32_t uvJ = j >> state->formatInfo.chromaShiftY;
@@ -724,7 +710,7 @@
float Gc = AVIF_CLAMP(G, 0.0f, 1.0f);
float Bc = AVIF_CLAMP(B, 0.0f, 1.0f);
- if (state->toRGBAlphaMode != AVIF_ALPHA_MULTIPLY_MODE_NO_OP) {
+ if (alphaMultiplyMode != AVIF_ALPHA_MULTIPLY_MODE_NO_OP) {
// Calculate A
uint16_t unormA;
if (image->depth == 8) {
@@ -735,7 +721,7 @@
const float A = unormA / ((float)state->yuvMaxChannel);
const float Ac = AVIF_CLAMP(A, 0.0f, 1.0f);
- if (state->toRGBAlphaMode == AVIF_ALPHA_MULTIPLY_MODE_MULTIPLY) {
+ if (alphaMultiplyMode == AVIF_ALPHA_MULTIPLY_MODE_MULTIPLY) {
if (Ac == 0.0f) {
Rc = 0.0f;
Gc = 0.0f;
@@ -746,7 +732,7 @@
Bc *= Ac;
}
} else {
- // state->toRGBAlphaMode == AVIF_ALPHA_MULTIPLY_MODE_UNMULTIPLY
+ // alphaMultiplyMode == AVIF_ALPHA_MULTIPLY_MODE_UNMULTIPLY
if (Ac == 0.0f) {
Rc = 0.0f;
Gc = 0.0f;
@@ -1256,7 +1242,23 @@
return AVIF_RESULT_REFORMAT_FAILED;
}
- avifAlphaMultiplyMode alphaMultiplyMode = state.toRGBAlphaMode;
+ avifAlphaMultiplyMode alphaMultiplyMode = AVIF_ALPHA_MULTIPLY_MODE_NO_OP;
+ if (image->alphaPlane) {
+ if (!avifRGBFormatHasAlpha(rgb->format) || rgb->ignoreAlpha) {
+ // if we are converting some image with alpha into a format without alpha, we should do 'premultiply alpha' before
+ // discarding alpha plane. This has the same effect of rendering this image on a black background, which makes sense.
+ if (!image->alphaPremultiplied) {
+ alphaMultiplyMode = AVIF_ALPHA_MULTIPLY_MODE_MULTIPLY;
+ }
+ } else {
+ if (!image->alphaPremultiplied && rgb->alphaPremultiplied) {
+ alphaMultiplyMode = AVIF_ALPHA_MULTIPLY_MODE_MULTIPLY;
+ } else if (image->alphaPremultiplied && !rgb->alphaPremultiplied) {
+ alphaMultiplyMode = AVIF_ALPHA_MULTIPLY_MODE_UNMULTIPLY;
+ }
+ }
+ }
+
avifBool convertedWithLibYUV = AVIF_FALSE;
if (!rgb->avoidLibYUV && ((alphaMultiplyMode == AVIF_ALPHA_MULTIPLY_MODE_NO_OP) || avifRGBFormatHasAlpha(rgb->format))) {
avifResult libyuvResult = avifImageYUVToRGBLibYUV(image, rgb);
@@ -1370,7 +1372,7 @@
if (convertResult == AVIF_RESULT_NOT_IMPLEMENTED) {
// If we get here, there is no fast path for this combination. Time to be slow!
- convertResult = avifImageYUVAnyToRGBAnySlow(image, rgb, &state);
+ convertResult = avifImageYUVAnyToRGBAnySlow(image, rgb, &state, alphaMultiplyMode);
// The slow path also handles alpha (un)multiply, so forget the operation here.
alphaMultiplyMode = AVIF_ALPHA_MULTIPLY_MODE_NO_OP;
