From 083a7c8f0a71076d4f2f5130d70abaedb2f8c8a5 Mon Sep 17 00:00:00 2001
From: Alexander Smorkalov <alexander.smorkalov@xperience.ai>
Date: Wed, 28 Apr 2021 10:41:59 +0300
Subject: [PATCH] Fix OpenCV build with OpenEXR before 2.2.0.

---
 modules/imgcodecs/include/opencv2/imgcodecs.hpp | 4 ++--
 modules/imgcodecs/src/grfmt_exr.cpp             | 3 +++
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/modules/imgcodecs/include/opencv2/imgcodecs.hpp b/modules/imgcodecs/include/opencv2/imgcodecs.hpp
index 42227f3788..101a944146 100644
--- a/modules/imgcodecs/include/opencv2/imgcodecs.hpp
+++ b/modules/imgcodecs/include/opencv2/imgcodecs.hpp
@@ -120,8 +120,8 @@ enum ImwriteEXRCompressionFlags {
        IMWRITE_EXR_COMPRESSION_PXR24 = 5, //!< lossy 24-bit float compression
        IMWRITE_EXR_COMPRESSION_B44   = 6, //!< lossy 4-by-4 pixel block compression, fixed compression rate
        IMWRITE_EXR_COMPRESSION_B44A  = 7, //!< lossy 4-by-4 pixel block compression, flat fields are compressed more
-       IMWRITE_EXR_COMPRESSION_DWAA  = 8, //!< lossy DCT based compression, in blocks of 32 scanlines. More efficient for partial buffer access.
-       IMWRITE_EXR_COMPRESSION_DWAB  = 9, //!< lossy DCT based compression, in blocks of 256 scanlines. More efficient space wise and faster to decode full frames than DWAA_COMPRESSION.
+       IMWRITE_EXR_COMPRESSION_DWAA  = 8, //!< lossy DCT based compression, in blocks of 32 scanlines. More efficient for partial buffer access. Supported since OpenEXR 2.2.0.
+       IMWRITE_EXR_COMPRESSION_DWAB  = 9, //!< lossy DCT based compression, in blocks of 256 scanlines. More efficient space wise and faster to decode full frames than DWAA_COMPRESSION. Supported since OpenEXR 2.2.0.
      };
 
 //! Imwrite PNG specific flags used to tune the compression algorithm.
diff --git a/modules/imgcodecs/src/grfmt_exr.cpp b/modules/imgcodecs/src/grfmt_exr.cpp
index aaf28eead6..7acaf434c6 100644
--- a/modules/imgcodecs/src/grfmt_exr.cpp
+++ b/modules/imgcodecs/src/grfmt_exr.cpp
@@ -64,6 +64,7 @@
 #include <ImfStandardAttributes.h>
 #include <half.h>
 #include "grfmt_exr.hpp"
+#include "OpenEXRConfig.h"
 
 #if defined _WIN32
 
@@ -649,12 +650,14 @@ bool  ExrEncoder::write( const Mat& img, const std::vector<int>& params )
             case IMWRITE_EXR_COMPRESSION_B44A:
                 header.compression() = B44A_COMPRESSION;
                 break;
+#if ((OPENEXR_VERSION_MAJOR * 1000 + OPENEXR_VERSION_MINOR) >= (2 * 1000 + 2)) // available since version 2.2.0
             case IMWRITE_EXR_COMPRESSION_DWAA:
                 header.compression() = DWAA_COMPRESSION;
                 break;
             case IMWRITE_EXR_COMPRESSION_DWAB:
                 header.compression() = DWAB_COMPRESSION;
                 break;
+#endif
             default:
                 CV_Error(Error::StsBadArg, "IMWRITE_EXR_COMPRESSION is invalid or not supported");
             }
-- 
2.29.2.windows.2