android_jni: Set alphaPremultiplied to true
Android platform always sees the Bitmaps as premultiplied with
alpha when it renders them. So set alphaPremultiplied to true
when computing the pixels to be copied into the Bitmap.
https://developer.android.com/reference/android/graphics/Bitmap#setPremultiplied(boolean)
Fixes Issue #1362
diff --git a/android_jni/avifandroidjni/src/main/jni/libavif_jni.cc b/android_jni/avifandroidjni/src/main/jni/libavif_jni.cc
index f68e3dc..0e1bf11 100644
--- a/android_jni/avifandroidjni/src/main/jni/libavif_jni.cc
+++ b/android_jni/avifandroidjni/src/main/jni/libavif_jni.cc
@@ -175,6 +175,10 @@
}
rgb_image.pixels = static_cast<uint8_t*>(bitmap_pixels);
rgb_image.rowBytes = bitmap_info.stride;
+ // Android always sees the Bitmaps as premultiplied with alpha when it renders
+ // them:
+ // https://developer.android.com/reference/android/graphics/Bitmap#setPremultiplied(boolean)
+ rgb_image.alphaPremultiplied = AVIF_TRUE;
res = avifImageYUVToRGB(decoder.decoder->image, &rgb_image);
AndroidBitmap_unlockPixels(env, bitmap);
if (res != AVIF_RESULT_OK) {
