Check against mode 1 instead of input mode for Chops.c

Author: wiredfool

src/_avif.c

@@ -503,7 +503,9 @@ _encoder_add(AvifEncoderObject *self, PyObject *args) {
 
     avifRGBImageSetDefaults(&rgb, frame);
 
-    if (strcmp(mode, "RGBA") == 0) {
+    const ModeID mode = findModeID(mode_name);
+
+    if (mode == IMAGING_MODE_RGBA) {
         rgb.format = AVIF_RGB_FORMAT_RGBA;
     } else {
         rgb.format = AVIF_RGB_FORMAT_RGB;

src/libImaging/Chops.c

@@ -64,7 +64,8 @@ create(Imaging im1, Imaging im2, const ModeID mode) {
     int xsize, ysize;
 
     if (!im1 || !im2 || im1->type != IMAGING_TYPE_UINT8 ||
-        (mode != IMAGING_MODE_UNKNOWN && (im1->mode != mode || im2->mode != mode))) {
+        (mode != IMAGING_MODE_UNKNOWN &&
+         (im1->mode != IMAGING_MODE_1 || im2->mode != IMAGING_MODE_1))) {
         return (Imaging)ImagingError_ModeError();
     }
     if (im1->type != im2->type || im1->bands != im2->bands) {