Prefer first embedded image that contains the 'front' keyword

src/libs/av/impl/AudioFile.cpp

@@ -281,9 +281,7 @@ namespace lms::av
 
             const AVPacket& pkt{ avstream->attached_pic };
 
-            picture.data = reinterpret_cast<const std::byte*>(pkt.data);
-            picture.dataSize = pkt.size;
-
+            picture.data = std::span{ reinterpret_cast<const std::byte*>(pkt.data), static_cast<std::size_t>(pkt.size) };
             func(picture, metadata);
         }
     }

src/libs/av/include/av/IAudioFile.hpp

@@ -23,6 +23,7 @@
 #include <filesystem>
 #include <functional>
 #include <optional>
+#include <span>
 #include <string>
 #include <string_view>
 #include <unordered_map>
@@ -60,8 +61,7 @@ namespace lms::av
     struct Picture
     {
         std::string mimeType;
-        const std::byte* data{}; // valid as long as IAudioFile exists
-        std::size_t dataSize{};
+        std::span<const std::byte> data; // valid as long as IAudioFile exists
     };
 
     struct ContainerInfo

src/libs/core/impl/String.cpp

@@ -321,6 +321,18 @@ namespace lms::core::stringUtils
         return true;
     }
 
+    std::string_view::size_type stringCaseInsensitiveContains(std::string_view str, std::string_view strtoFind)
+    {
+        if (str.empty() && strtoFind.empty())
+            return true; // same as std
+
+        const auto it{ std::search(
+            std::cbegin(str), std::cend(str),
+            std::cbegin(strtoFind), std::cend(strtoFind),
+            [](char chA, char chB) { return std::tolower(chA) == std::tolower(chB); }) };
+        return (it != std::cend(str));
+    }
+
     void capitalize(std::string& str)
     {
         for (auto it{ std::begin(str) }; it != std::end(str); ++it)

src/libs/core/include/core/String.hpp

@@ -62,6 +62,7 @@ namespace lms::core::stringUtils
     [[nodiscard]] std::string bufferToString(std::span<const unsigned char> data);
 
     [[nodiscard]] bool stringCaseInsensitiveEqual(std::string_view strA, std::string_view strB);
+    [[nodiscard]] std::string_view::size_type stringCaseInsensitiveContains(std::string_view str, std::string_view strtoFind);
 
     void capitalize(std::string& str);
 

src/libs/core/test/String.cpp

@@ -322,4 +322,16 @@ namespace lms::core::stringUtils::tests
         EXPECT_FALSE(stringEndsWith("FooBar", "1FooBar"));
         EXPECT_FALSE(stringEndsWith("FooBar", "R"));
     }
+
+    TEST(StringUtils, stringCaseInsensitiveContains)
+    {
+        EXPECT_TRUE(stringCaseInsensitiveContains("FooBar", "Bar"));
+        EXPECT_TRUE(stringCaseInsensitiveContains("FooBar", "bar"));
+        EXPECT_TRUE(stringCaseInsensitiveContains("FooBar", "Foo"));
+        EXPECT_TRUE(stringCaseInsensitiveContains("FooBar", "foo"));
+        EXPECT_FALSE(stringCaseInsensitiveContains("something", "foo"));
+        EXPECT_TRUE(stringCaseInsensitiveContains("FooBar", ""));
+        EXPECT_TRUE(stringCaseInsensitiveContains("", ""));
+        EXPECT_FALSE(stringCaseInsensitiveContains("", "Foo"));
+    }
 } // namespace lms::core::stringUtils::tests

src/libs/services/artwork/impl/ArtworkService.cpp

@@ -19,12 +19,15 @@
 
 #include "ArtworkService.hpp"
 
+#include <algorithm>
+#include <functional>
 #include <span>
 
 #include "av/IAudioFile.hpp"
 #include "av/Types.hpp"
 #include "core/IConfig.hpp"
 #include "core/ILogger.hpp"
+#include "core/String.hpp"
 #include "core/Utils.hpp"
 #include "database/Artist.hpp"
 #include "database/Db.hpp"
@@ -68,21 +71,47 @@ namespace lms::cover
 
     std::unique_ptr<image::IEncodedImage> ArtworkService::getFromAvMediaFile(const av::IAudioFile& input, std::optional<image::ImageSize> width) const
     {
+        struct CandidatePicture
+        {
+            av::Picture picture;
+            bool isFront{};
+            std::size_t index;
+
+            // > means is better candidate
+            bool operator>(const CandidatePicture& other) const
+            {
+                if (!isFront && other.isFront)
+                    return false;
+                if (isFront && !other.isFront)
+                    return true;
+
+                return index < other.index;
+            }
+        };
+
+        auto metadataHasFrontKeyword{ [](const av::IAudioFile::MetadataMap& metadata) {
+            return std::any_of(std::cbegin(metadata), std::cend(metadata), [](const auto& keyValue) { return core::stringUtils::stringCaseInsensitiveContains(keyValue.second, "front"); });
+        } };
+
+        std::vector<CandidatePicture> candidatePictures;
+        std::size_t pictureIndex{};
+        input.visitAttachedPictures([&](const av::Picture& picture, const av::IAudioFile::MetadataMap& metadata) {
+            candidatePictures.emplace_back(picture, metadataHasFrontKeyword(metadata), pictureIndex++);
+        });
+        std::stable_sort(std::begin(candidatePictures), std::end(candidatePictures), std::greater<>());
+
         std::unique_ptr<image::IEncodedImage> image;
-
-        input.visitAttachedPictures([&](const av::Picture& picture, const av::IAudioFile::MetadataMap& /* metadata */) {
-            if (image)
-                return;
-
+        for (const CandidatePicture& candidatePicture : candidatePictures)
+        {
             try
             {
                 if (!width)
                 {
-                    image = image::readImage(std::span{ picture.data, picture.dataSize }, picture.mimeType);
+                    image = image::readImage(candidatePicture.picture.data, candidatePicture.picture.mimeType);
                 }
                 else
                 {
-                    auto rawImage{ image::decodeImage(std::span{ picture.data, picture.dataSize }) };
+                    auto rawImage{ image::decodeImage(candidatePicture.picture.data) };
                     rawImage->resize(*width);
                     image = image::encodeToJPEG(*rawImage, _jpegQuality);
                 }
@@ -91,7 +120,7 @@ namespace lms::cover
             {
                 LMS_LOG(COVER, ERROR, "Cannot read embedded cover: " << e.what());
             }
-        });
+        }
 
         return image;
     }