From 643ca81c20b065bf9eac2e6d86eaef5da44d0699 Mon Sep 17 00:00:00 2001
From: Dirk Farin <dirk.farin@gmail.com>
Date: Tue, 20 Dec 2022 19:29:21 +0100
Subject: [PATCH] fix limited range scaling for chroma components in HDR RGB to
 YCbCr conversion

---
 libheif/heif_colorconversion.cc | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libheif/heif_colorconversion.cc b/libheif/heif_colorconversion.cc
index 7b8a41bee9..69b3852fba 100644
--- a/libheif/heif_colorconversion.cc
+++ b/libheif/heif_colorconversion.cc
@@ -2881,8 +2881,8 @@ Op_RRGGBBxx_HDR_to_YCbCr420::convert_colorspace(const std::shared_ptr<const Heif
       float cr = r * coeffs.c[2][0] + g * coeffs.c[2][1] + b * coeffs.c[2][2];
 
       if (!full_range_flag) {
-        cb = cb * 0.85547f;  // 0.85547 = 219/256
-        cr = cr * 0.85547f;  // 0.85547 = 219/256
+        cb = cb * 0.8750f;  // 0.8750 = 224/256
+        cr = cr * 0.8750f;  // 0.8750 = 224/256
       }
 
       out_cb[(y / 2) * out_cb_stride + (x / 2)] = clip_f_u16(halfRange + cb, fullRange);