Allocate the threadData array directly

The threadData array (formerly named tdArray) has a fixed size (i.e.,
the array does not grow or shrink while in use), so we can allocate the
array directly. It is not necessary to define the array as avifArray.

(cherry picked from commit c74189f)

Author: wantehchang

src/reformat.c

@@ -1544,11 +1544,12 @@ avifResult avifImageYUVToRGB(const avifImage * image, avifRGBImage * rgb)
         return avifImageYUVToRGBImpl(image, rgb, &state, alphaMultiplyMode);
     }
 
-    AVIF_ARRAY_DECLARE(YUVToRGBThreadDataArray, YUVToRGBThreadData, threadData);
-    YUVToRGBThreadDataArray tdArray;
-    if (!avifArrayCreate(&tdArray, sizeof(YUVToRGBThreadData), jobs)) {
+    const size_t byteCount = sizeof(YUVToRGBThreadData) * jobs;
+    YUVToRGBThreadData * threadData = avifAlloc(byteCount);
+    if (!threadData) {
         return AVIF_RESULT_OUT_OF_MEMORY;
     }
+    memset(threadData, 0, byteCount);
     int rowsPerJob = image->height / jobs;
     if (rowsPerJob % 2) {
         ++rowsPerJob;
@@ -1557,7 +1558,7 @@ avifResult avifImageYUVToRGB(const avifImage * image, avifRGBImage * rgb)
     int startRow = 0;
     uint32_t i;
     for (i = 0; i < jobs; ++i, startRow += rowsPerJob) {
-        YUVToRGBThreadData * tdata = &tdArray.threadData[i];
+        YUVToRGBThreadData * tdata = &threadData[i];
         const avifCropRect rect = { .x = 0, .y = startRow, .width = image->width, .height = (i == jobs - 1) ? rowsForLastJob : rowsPerJob };
         if (avifImageSetViewRect(&tdata->image, image, &rect) != AVIF_RESULT_OK) {
             tdata->result = AVIF_RESULT_REFORMAT_FAILED;
@@ -1581,19 +1582,19 @@ avifResult avifImageYUVToRGB(const avifImage * image, avifRGBImage * rgb)
     }
     // If above loop ran successfully, Run the first job in the current thread.
     if (i == jobs) {
-        avifImageYUVToRGBThreadWorker(&tdArray.threadData[0]);
+        avifImageYUVToRGBThreadWorker(&threadData[0]);
     }
     avifResult result = AVIF_RESULT_OK;
     for (i = 0; i < jobs; ++i) {
-        YUVToRGBThreadData * tdata = &tdArray.threadData[i];
+        YUVToRGBThreadData * tdata = &threadData[i];
         if (tdata->threadCreated && !avifJoinYUVToRGBThread(tdata)) {
             result = AVIF_RESULT_REFORMAT_FAILED;
         }
         if (tdata->result != AVIF_RESULT_OK) {
             result = tdata->result;
         }
     }
-    avifArrayDestroy(&tdArray);
+    avifFree(threadData);
     return result;
 }