From 79cb3a2fd32b56d5358c10dba8bd75b42c9d05fd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Arttu=20Yl=C3=A4-Outinen?= <arttu.yla-outinen@tut.fi>
Date: Mon, 24 Apr 2017 14:10:49 +0300
Subject: [PATCH] Permit negative QP deltas in ROI

Delta QPs should not be arbitrarily restricted to positive values.
---
 src/cfg.c          | 4 ++--
 src/kvazaar.h      | 2 +-
 src/rate_control.c | 2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/cfg.c b/src/cfg.c
index 85ea5420..f0135ec0 100644
--- a/src/cfg.c
+++ b/src/cfg.c
@@ -1021,7 +1021,7 @@ int kvz_config_parse(kvz_config *cfg, const char *name, const char *value)
     }
 
     const unsigned size = width * height;
-    uint8_t *dqp_array  = calloc((size_t)size, sizeof(cfg->roi.dqps[0]));
+    int8_t *dqp_array  = calloc((size_t)size, sizeof(cfg->roi.dqps[0]));
     if (!dqp_array) {
       fprintf(stderr, "Failed to allocate memory for ROI table.\n");
       fclose(f);
@@ -1040,7 +1040,7 @@ int kvz_config_parse(kvz_config *cfg, const char *name, const char *value)
         fclose(f);
         return 0;
       }
-      dqp_array[i] = (uint8_t)number;
+      dqp_array[i] = CLIP(-51, 51, number);
     }
 
     fclose(f);
diff --git a/src/kvazaar.h b/src/kvazaar.h
index 1eb8feaf..0b597e2e 100644
--- a/src/kvazaar.h
+++ b/src/kvazaar.h
@@ -335,7 +335,7 @@ typedef struct kvz_config
   struct {
     int32_t width;
     int32_t height;
-    uint8_t *dqps;
+    int8_t *dqps;
   } roi; /*!< \since 3.14.0 \brief Map of delta QPs for region of interest coding. */
 
   unsigned slices; /*!< \since 3.15.0 \brief How to map slices to frame. */
diff --git a/src/rate_control.c b/src/rate_control.c
index 3e6254df..a706ec80 100644
--- a/src/rate_control.c
+++ b/src/rate_control.c
@@ -291,7 +291,7 @@ void kvz_set_lcu_lambda_and_qp(encoder_state_t * const state,
     };
     int roi_index = roi.x + roi.y * ctrl->cfg.roi.width;
     int dqp = ctrl->cfg.roi.dqps[roi_index];
-    state->qp = state->frame->QP + dqp;
+    state->qp = CLIP(0, 51, state->frame->QP + dqp);
     state->lambda = qp_to_lamba(state, state->qp);
     state->lambda_sqrt = sqrt(state->frame->lambda);