Disable chroma delta q in lossless mode

BUG=b/430090587

Change-Id: I6610ef37aa1b9fc866fdbaec1cc94b1a53570b06

av1/encoder/av1_quantize.c

diff --git a/av1/encoder/av1_quantize.c b/av1/encoder/av1_quantize.c
index 610b703..1673d53 100644
--- a/av1/encoder/av1_quantize.c
+++ b/av1/encoder/av1_quantize.c
@@ -883,7 +883,8 @@
   quant_params->base_qindex = AOMMAX(cm->delta_q_info.delta_q_present_flag, q);
   quant_params->y_dc_delta_q = 0;
 
-  if (enable_chroma_deltaq) {
+  // Disable deltaq in lossless mode.
+  if (enable_chroma_deltaq && q) {
     if (is_allintra &&
         (tuning == AOM_TUNE_IQ || tuning == AOM_TUNE_SSIMULACRA2)) {
       int chroma_dc_delta_q = 0;
@@ -964,7 +965,7 @@
 
   // following section 8.3.2 in T-REC-H.Sup15 document
   // to apply to AV1 qindex in the range of [0, 255]
-  if (enable_hdr_deltaq) {
+  if (enable_hdr_deltaq && q) {
     int dqpCb = adjust_hdr_cb_deltaq(quant_params->base_qindex);
     int dqpCr = adjust_hdr_cr_deltaq(quant_params->base_qindex);
     quant_params->u_dc_delta_q = quant_params->u_ac_delta_q = dqpCb;

test/lossless_test.cc

diff --git a/test/lossless_test.cc b/test/lossless_test.cc
index 5e126b6..db09b9b 100644
--- a/test/lossless_test.cc
+++ b/test/lossless_test.cc
@@ -47,6 +47,9 @@
       // alone will activate lossless
       if (cfg_.rc_max_quantizer > 0 || cfg_.rc_min_quantizer > 0) {
         encoder->Control(AV1E_SET_LOSSLESS, 1);
+
+        if (mode_ == libaom_test::kRealTime)
+          encoder->Control(AV1E_SET_ENABLE_CHROMA_DELTAQ, 1);
       }
       encoder->Control(AOME_SET_CPUUSED, cpu_used_);
     }