Fix compilation with 1755 ≤ LIBYUV_VERSION < 1774

ScalePlane_12 only provide optimization for 2x scale up using
linear/bilinear filter (when scaling up, box and bilinear are the same),
and for the rest cases, it simply calls ScalePlane_16, which handles 2x
scale up just fine (slower though).

This optimization is thus optional and compilation can be allowed for
libyuv versions not providing it.

Fixes GH-781 (the function was introduced in libavif
https://github.com/AOMediaCodec/libavif/commit/46104d6db42ec2a94a7da6fc0693f24fa90a1b98).

CMakeLists.txt

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 3fc76df..e18156d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -233,12 +233,16 @@
 find_package(libyuv QUIET) # not required
 if(libyuv_FOUND)
     # libyuv 1755 exposed all of the I*Matrix() functions, which libavif relies on.
+    # libyuv 1774 exposed ScalePlane_12 function, which libavif can use for some additional optimizations.
     if(NOT LIBYUV_VERSION)
         message(STATUS "libavif: libyuv found, but version unknown; libyuv-based fast paths disabled.")
     elseif(LIBYUV_VERSION LESS 1755)
         message(STATUS "libavif: libyuv (${LIBYUV_VERSION}) found, but is too old; libyuv-based fast paths disabled.")
     else()
         message(STATUS "libavif: libyuv (${LIBYUV_VERSION}) found; libyuv-based fast paths enabled.")
+        if(LIBYUV_VERSION LESS 1774)
+            message(STATUS "libavif: some libyuv optimizations require at least version 1774 to work.")
+        endif()
         set(AVIF_PLATFORM_DEFINITIONS ${AVIF_PLATFORM_DEFINITIONS} -DAVIF_LIBYUV_ENABLED=1)
         set(AVIF_PLATFORM_INCLUDES ${AVIF_PLATFORM_INCLUDES} ${LIBYUV_INCLUDE_DIR})
         set(AVIF_PLATFORM_LIBRARIES ${AVIF_PLATFORM_LIBRARIES} ${LIBYUV_LIBRARY})

src/scale.c

diff --git a/src/scale.c b/src/scale.c
index 6ca651b..1bbbdd8 100644
--- a/src/scale.c
+++ b/src/scale.c
@@ -107,7 +107,11 @@
                 const uint32_t srcStride = srcYUVRowBytes[i] / 2;
                 uint16_t * const dstPlane = (uint16_t *)image->yuvPlanes[i];
                 const uint32_t dstStride = image->yuvRowBytes[i] / 2;
+#if LIBYUV_VERSION >= 1774
                 ScalePlane_12(srcPlane, srcStride, srcW, srcH, dstPlane, dstStride, dstW, dstH, AVIF_LIBYUV_FILTER_MODE);
+#else
+                ScalePlane_16(srcPlane, srcStride, srcW, srcH, dstPlane, dstStride, dstW, dstH, AVIF_LIBYUV_FILTER_MODE);
+#endif
             } else {
                 uint8_t * const srcPlane = srcYUVPlanes[i];
                 const uint32_t srcStride = srcYUVRowBytes[i];
@@ -130,7 +134,11 @@
             const uint32_t srcStride = srcAlphaRowBytes / 2;
             uint16_t * const dstPlane = (uint16_t *)image->alphaPlane;
             const uint32_t dstStride = image->alphaRowBytes / 2;
+#if LIBYUV_VERSION >= 1774
             ScalePlane_12(srcPlane, srcStride, srcWidth, srcHeight, dstPlane, dstStride, dstWidth, dstHeight, AVIF_LIBYUV_FILTER_MODE);
+#else
+            ScalePlane_16(srcPlane, srcStride, srcWidth, srcHeight, dstPlane, dstStride, dstWidth, dstHeight, AVIF_LIBYUV_FILTER_MODE);
+#endif
         } else {
             uint8_t * const srcPlane = srcAlphaPlane;
             const uint32_t srcStride = srcAlphaRowBytes;