Clean up stray monochrome flags.

The monochrome flags have been removed
from both the encoder and decoder, as this
is now an option in the colour space.

Change-Id: Iccd0f051f35811174ba286c6ee454443fd5268be
diff --git a/examples/aom_cx_set_ref.c b/examples/aom_cx_set_ref.c
index e6ec4c5..456e813 100644
--- a/examples/aom_cx_set_ref.c
+++ b/examples/aom_cx_set_ref.c
@@ -69,8 +69,7 @@
 }
 
 static void testing_decode(aom_codec_ctx_t *encoder, aom_codec_ctx_t *decoder,
-                           unsigned int frame_out, int *mismatch_seen,
-                           int is_mono) {
+                           unsigned int frame_out, int *mismatch_seen) {
   aom_image_t enc_img, dec_img;
   struct av1_ref_frame ref_enc, ref_dec;
 
@@ -85,7 +84,7 @@
     die_codec(decoder, "Failed to get decoder reference frame");
   dec_img = ref_dec.img;
 
-  if (!aom_compare_img(&enc_img, &dec_img, is_mono ? 1 : 3)) {
+  if (!aom_compare_img(&enc_img, &dec_img)) {
     int y[4], u[4], v[4];
 
     *mismatch_seen = 1;
@@ -107,8 +106,7 @@
 static int encode_frame(aom_codec_ctx_t *ecodec, aom_image_t *img,
                         unsigned int frame_in, AvxVideoWriter *writer,
                         int test_decode, aom_codec_ctx_t *dcodec,
-                        unsigned int *frame_out, int *mismatch_seen,
-                        int is_mono) {
+                        unsigned int *frame_out, int *mismatch_seen) {
   int got_pkts = 0;
   aom_codec_iter_t iter = NULL;
   const aom_codec_cx_pkt_t *pkt = NULL;
@@ -149,7 +147,7 @@
 
   // Mismatch checking
   if (got_data && test_decode) {
-    testing_decode(ecodec, dcodec, *frame_out, mismatch_seen, is_mono);
+    testing_decode(ecodec, dcodec, *frame_out, mismatch_seen);
   }
 
   return got_pkts;
@@ -289,7 +287,7 @@
     }
 
     encode_frame(&ecodec, &raw, frame_in, writer, test_decode, &dcodec,
-                 &frame_out, &mismatch_seen, cfg.monochrome);
+                 &frame_out, &mismatch_seen);
     frame_in++;
     if (mismatch_seen) break;
   }
@@ -297,7 +295,7 @@
   // Flush encoder.
   if (!mismatch_seen)
     while (encode_frame(&ecodec, NULL, frame_in, writer, test_decode, &dcodec,
-                        &frame_out, &mismatch_seen, cfg.monochrome)) {
+                        &frame_out, &mismatch_seen)) {
     }
 
   printf("\n");
diff --git a/examples/encoder_util.c b/examples/encoder_util.c
index 474690d..32acf0a 100644
--- a/examples/encoder_util.c
+++ b/examples/encoder_util.c
@@ -102,7 +102,10 @@
 }
 
 int aom_compare_img(const aom_image_t *const img1,
-                    const aom_image_t *const img2, int num_planes) {
+                    const aom_image_t *const img2) {
+  assert(img1->cs == img2->cs);
+  int num_planes = img1->cs == AOM_CS_MONOCHROME ? 1 : 3;
+
   uint32_t l_w = img1->d_w;
   uint32_t c_w = (img1->d_w + img1->x_chroma_shift) >> img1->x_chroma_shift;
   const uint32_t c_h =
diff --git a/examples/encoder_util.h b/examples/encoder_util.h
index 72057a9..38deef0 100644
--- a/examples/encoder_util.h
+++ b/examples/encoder_util.h
@@ -31,6 +31,6 @@
 
 // Returns 1 if the two images match.
 int aom_compare_img(const aom_image_t *const img1,
-                    const aom_image_t *const img2, int num_planes);
+                    const aom_image_t *const img2);
 
 #endif  // EXAMPLES_ENCODER_UTIL_H_