ENC: fix the low quality at the first GOP for AVC encoder on the platform previous SKL

RC logic initialize the big QP at the first GOP, this cause the low quality.

Fixes #147

Signed-off-by: Pengfei Qu <Pengfei.Qu@intel.com>

diff --git a/src/gen6_mfc_common.c b/src/gen6_mfc_common.c
index e4dbfe4..f5a68cb 100644 (file)
--- a/src/gen6_mfc_common.c
+++ b/src/gen6_mfc_common.c
@@ -105,6 +105,7 @@ static void intel_mfc_brc_init(struct encode_state *encode_state,
         bnum = encoder_context->brc.num_bframes_in_gop; /* Gop structure: number of I, P, B frames in the Gop. */
     int intra_period = encoder_context->brc.gop_size;
     int i;
+    int tmp_min_qp = 0;
 
     if (encoder_context->layer.num_layers > 1)
         qp1_size = 0.15 * frame_per_bits;
@@ -176,6 +177,10 @@ static void intel_mfc_brc_init(struct encode_state *encode_state,
             mfc_context->brc.qp_prime_y[i][SLICE_TYPE_I] = encoder_context->brc.initial_qp;
             mfc_context->brc.qp_prime_y[i][SLICE_TYPE_P] = encoder_context->brc.initial_qp;
             mfc_context->brc.qp_prime_y[i][SLICE_TYPE_B] = encoder_context->brc.initial_qp;
+
+            BRC_CLIP(mfc_context->brc.qp_prime_y[i][SLICE_TYPE_I], min_qp, 51);
+            BRC_CLIP(mfc_context->brc.qp_prime_y[i][SLICE_TYPE_P], min_qp, 51);
+            BRC_CLIP(mfc_context->brc.qp_prime_y[i][SLICE_TYPE_B], min_qp, 51);
         } else {
             if ((bpf > qp51_size) && (bpf < qp1_size)) {
                 mfc_context->brc.qp_prime_y[i][SLICE_TYPE_P] = 51 - 50 * (bpf - qp51_size) / (qp1_size - qp51_size);
@@ -186,11 +191,14 @@ static void intel_mfc_brc_init(struct encode_state *encode_state,
 
             mfc_context->brc.qp_prime_y[i][SLICE_TYPE_I] = mfc_context->brc.qp_prime_y[i][SLICE_TYPE_P];
             mfc_context->brc.qp_prime_y[i][SLICE_TYPE_B] = mfc_context->brc.qp_prime_y[i][SLICE_TYPE_I];
-        }
 
-        BRC_CLIP(mfc_context->brc.qp_prime_y[i][SLICE_TYPE_I], min_qp, 51);
-        BRC_CLIP(mfc_context->brc.qp_prime_y[i][SLICE_TYPE_P], min_qp, 51);
-        BRC_CLIP(mfc_context->brc.qp_prime_y[i][SLICE_TYPE_B], min_qp, 51);
+            tmp_min_qp = (min_qp < 36) ? min_qp : 36;
+            BRC_CLIP(mfc_context->brc.qp_prime_y[i][SLICE_TYPE_I], tmp_min_qp, 36);
+            tmp_min_qp = (min_qp < 40) ? min_qp : 40;
+            BRC_CLIP(mfc_context->brc.qp_prime_y[i][SLICE_TYPE_P], tmp_min_qp, 40);
+            tmp_min_qp = (min_qp < 45) ? min_qp : 45;
+            BRC_CLIP(mfc_context->brc.qp_prime_y[i][SLICE_TYPE_B], tmp_min_qp, 45);
+        }
     }
 }