Add support of separte delta Qs for chroma channels

Change-Id: Iae7c054def0c0d5b5af52263f0c4d2e1e346282d

av1/common/onyxc_int.h

@@ -325,6 +325,10 @@ typedef struct AV1Common {
   int v_dc_delta_q;
   int u_ac_delta_q;
   int v_ac_delta_q;
+
+#if CONFIG_EXT_QM
+  int separate_uv_delta_q;
+#endif
   // The dequantizers below are true dequntizers used only in the
   // dequantization process.  They have the same coefficient
   // shift/scale as TX.

av1/decoder/decodeframe.c

@@ -1242,10 +1242,19 @@ static void setup_quantization(AV1_COMMON *const cm,
                                struct aom_read_bit_buffer *rb) {
   cm->base_qindex = aom_rb_read_literal(rb, QINDEX_BITS);
   cm->y_dc_delta_q = read_delta_q(rb);
+  int diff_uv_delta = 0;
+#if CONFIG_EXT_QM
+  if (cm->separate_uv_delta_q) diff_uv_delta = aom_rb_read_bit(rb);
+#endif
   cm->u_dc_delta_q = read_delta_q(rb);
   cm->u_ac_delta_q = read_delta_q(rb);
-  cm->v_dc_delta_q = cm->u_dc_delta_q;
-  cm->v_ac_delta_q = cm->u_ac_delta_q;
+  if (diff_uv_delta) {
+    cm->v_dc_delta_q = read_delta_q(rb);
+    cm->v_ac_delta_q = read_delta_q(rb);
+  } else {
+    cm->v_dc_delta_q = cm->u_dc_delta_q;
+    cm->v_ac_delta_q = cm->u_ac_delta_q;
+  }
   cm->dequant_bit_depth = cm->bit_depth;
 #if CONFIG_AOM_QM
   cm->using_qmatrix = aom_rb_read_bit(rb);
@@ -2423,6 +2432,9 @@ static void read_bitdepth_colorspace_sampling(AV1_COMMON *cm,
                          "4:4:4 color not supported in profile 0 or 2");
     }
   }
+#if CONFIG_EXT_QM
+  cm->separate_uv_delta_q = aom_rb_read_bit(rb);
+#endif
 }
 
 #if CONFIG_REFERENCE_BUFFER || CONFIG_OBU

av1/encoder/bitstream.c

@@ -2661,10 +2661,19 @@ static void encode_quantization(const AV1_COMMON *const cm,
                                 struct aom_write_bit_buffer *wb) {
   aom_wb_write_literal(wb, cm->base_qindex, QINDEX_BITS);
   write_delta_q(wb, cm->y_dc_delta_q);
-  assert(cm->u_dc_delta_q == cm->v_dc_delta_q);
+  int diff_uv_delta = (cm->u_dc_delta_q != cm->v_dc_delta_q) ||
+                      (cm->u_ac_delta_q != cm->v_ac_delta_q);
+#if CONFIG_EXT_QM
+  if (cm->separate_uv_delta_q) aom_wb_write_bit(wb, diff_uv_delta);
+#else
+  assert(!diff_uv_delta);
+#endif
   write_delta_q(wb, cm->u_dc_delta_q);
-  assert(cm->u_ac_delta_q == cm->v_ac_delta_q);
   write_delta_q(wb, cm->u_ac_delta_q);
+  if (diff_uv_delta) {
+    write_delta_q(wb, cm->v_dc_delta_q);
+    write_delta_q(wb, cm->v_ac_delta_q);
+  }
 #if CONFIG_AOM_QM
   aom_wb_write_bit(wb, cm->using_qmatrix);
   if (cm->using_qmatrix) {
@@ -3497,6 +3506,9 @@ static void write_bitdepth_colorspace_sampling(
     assert(cm->profile == PROFILE_1 || cm->profile == PROFILE_3);
     aom_wb_write_bit(wb, 0);  // unused
   }
+#if CONFIG_EXT_QM
+  aom_wb_write_bit(wb, cm->separate_uv_delta_q);
+#endif
 }
 
 #if CONFIG_REFERENCE_BUFFER || CONFIG_OBU