ktaglib: implement metadata builder

ktaglib/src/main/cpp/CMakeLists.txt

@@ -48,6 +48,7 @@ add_library(${CMAKE_PROJECT_NAME} SHARED
         ktaglib.cpp
         JVMInputStream.cpp
         JVMTagMap.cpp
+        JVMMetadataBuilder.cpp
 )
 
 # Specifies libraries CMake should link to your target library. You

ktaglib/src/main/cpp/JVMMetadataBuilder.cpp

@@ -3,3 +3,122 @@
 //
 
 #include "JVMMetadataBuilder.h"
+
+#include <taglib/mp4tag.h>
+
+JVMMetadataBuilder::JVMMetadataBuilder(JNIEnv *env) : env(env), id3v2(env), xiph(env), mp4(env),
+                                                      cover(), properties(nullptr) {}
+
+void JVMMetadataBuilder::setMimeType(const std::string_view mimeType) {
+    this->mimeType = mimeType;
+}
+
+void JVMMetadataBuilder::setId3v2(const TagLib::ID3v2::Tag &tag) {
+    for (auto frame: tag.frameList()) {
+        auto frameId = TagLib::String(frame->frameID());
+        auto frameText = frame->toStringList();
+        id3v2.add(frameId, frameText);
+    }
+}
+
+void JVMMetadataBuilder::setXiph(const TagLib::Ogg::XiphComment &tag) {
+    for (auto field: tag.fieldListMap()) {
+        auto fieldName = TagLib::String(field.first);
+        auto fieldValue = field.second;
+        xiph.add(fieldName, fieldValue);
+    }
+}
+
+void JVMMetadataBuilder::setMp4(const TagLib::MP4::Tag &tag) {
+    for (auto item: tag.itemMap()) {
+        auto atomName = item.first;
+        // Strip out ID Padding
+        while (atomName.startsWith("\251")) {
+            atomName = atomName.substr(1);
+        }
+        auto itemName = TagLib::String(atomName);
+        auto itemValue = item.second;
+        auto type = itemValue.type();
+
+        // Only read out the atoms for the reasonable tags we are expecting.
+        // None of the crazy binary atoms.
+        if (type == TagLib::MP4::Item::Type::StringList) {
+            auto value = itemValue.toStringList();
+            mp4.add(itemName, value);
+            return;
+        }
+
+        // Assume that taggers will be unhinged and store track numbers
+        // as ints, uints, or longs.
+        if (type == TagLib::MP4::Item::Type::Int) {
+            auto value = std::to_string(itemValue.toInt());
+            id3v2.add(itemName, value);
+            return;
+        }
+        if (type == TagLib::MP4::Item::Type::UInt) {
+            auto value = std::to_string(itemValue.toUInt());
+            id3v2.add(itemName, value);
+            return;
+        }
+        if (type == TagLib::MP4::Item::Type::LongLong) {
+            auto value = std::to_string(itemValue.toLongLong());
+            id3v2.add(itemName, value);
+            return;
+        }
+        if (type == TagLib::MP4::Item::Type::IntPair) {
+            // It's inefficient going from the integer representation back into
+            // a string, but I fully expect taggers to just write "NN/TT" strings
+            // anyway.
+            auto value = std::to_string(itemValue.toIntPair().first) + "/" +
+                         std::to_string(itemValue.toIntPair().second);
+            id3v2.add(itemName, value);
+            return;
+        }
+        // Nothing else makes sense to handle as far as I can tell.
+    }
+}
+
+void JVMMetadataBuilder::setCover(const TagLib::List<TagLib::VariantMap> covers) {
+    if (covers.isEmpty()) {
+        return;
+    }
+    // Find the cover with a "front cover" type
+    for (auto cover: covers) {
+        auto type = cover["pictureType"].toString();
+        if (type == "Front Cover") {
+            this->cover = cover["data"].toByteVector();
+            return;
+        }
+    }
+    // No front cover, just pick first.
+    // TODO: Consider having cascading fallbacks to increasingly less
+    //  relevant covers perhaps
+    this->cover = covers.front()["data"].toByteVector();
+}
+
+void JVMMetadataBuilder::setProperties(TagLib::AudioProperties *properties) {
+    this->properties = properties;
+}
+
+jobject JVMMetadataBuilder::build() {
+    jclass propertiesClass = env->FindClass("org/oxycblt/ktaglib/Properties");
+    jmethodID propertiesInit = env->GetMethodID(propertiesClass, "<init>", "(Ljava/lang/String;JII)V");
+    jobject propertiesObj = env->NewObject(propertiesClass, propertiesInit,
+                                           env->NewStringUTF(mimeType.data()), (jlong) properties->lengthInMilliseconds(),
+                                           properties->bitrate(), properties->sampleRate());
+    env->DeleteLocalRef(propertiesClass);
+
+    jclass metadataClass = env->FindClass("org/oxycblt/ktaglib/Metadata");
+    jmethodID metadataInit = env->GetMethodID(metadataClass, "<init>", "(Ljava/util/Map;Ljava/util/Map;Ljava/util/Map;[BLorg/oxycblt/ktaglib/Properties;)V");
+    jobject id3v2Map = id3v2.getObject();
+    jobject xiphMap = xiph.getObject();
+    jobject mp4Map = mp4.getObject();
+    jbyteArray coverArray = nullptr;
+    if (cover.has_value()) {
+        coverArray = env->NewByteArray(cover->size());
+        env->SetByteArrayRegion(coverArray, 0, cover->size(), reinterpret_cast<const jbyte *>(cover->data()));
+    }
+    jobject metadataObj = env->NewObject(metadataClass, metadataInit, id3v2Map, xiphMap, mp4Map, coverArray, propertiesObj);
+    env->DeleteLocalRef(metadataClass);
+    return metadataObj;
+}

ktaglib/src/main/cpp/JVMMetadataBuilder.h

@@ -25,7 +25,7 @@ public:
     void setXiph(const TagLib::Ogg::XiphComment &tag);
     void setMp4(const TagLib::MP4::Tag &tag);
     void setCover(const TagLib::List<TagLib::VariantMap> covers);
-    void setProperties(const TagLib::AudioProperties &properties);
+    void setProperties(TagLib::AudioProperties *properties);
 
     jobject build();
 
@@ -34,8 +34,8 @@ private:
 
     std::string_view mimeType;
 
-    TagLib::ByteVector cover;
+    std::optional<TagLib::ByteVector> cover;
-    TagLib::AudioProperties &properties;
+    TagLib::AudioProperties *properties;
 
     JVMTagMap id3v2;
     JVMTagMap xiph;

ktaglib/src/main/cpp/JVMTagMap.cpp

@@ -22,9 +22,9 @@ JVMTagMap::~JVMTagMap() {
     env->DeleteLocalRef(hashMap);
 }
 
-void JVMTagMap::add(TagLib::String &key, TagLib::String &value) {
+void JVMTagMap::add(TagLib::String &key, std::string_view value) {
     jstring jKey = env->NewStringUTF(key.toCString(true));
-    jstring jValue = env->NewStringUTF(value.toCString(true));
+    jstring jValue = env->NewStringUTF(value.data());
 
     // check if theres already a value arraylist in the map
     jobject existingValue = env->CallObjectMethod(hashMap, hashMapGetMethod, jKey);

ktaglib/src/main/cpp/JVMTagMap.h

@@ -18,7 +18,7 @@ public:
     JVMTagMap(const JVMTagMap &) = delete;
     JVMTagMap &operator=(const JVMTagMap &) = delete;
 
-    void add(TagLib::String &key, TagLib::String &value);
+    void add(TagLib::String &key, std::string_view value);
     void add(TagLib::String &key, TagLib::StringList &value);
 
     jobject getObject();

ktaglib/src/main/cpp/ktaglib.cpp

@@ -49,5 +49,7 @@ Java_org_oxycblt_ktaglib_KTagLib_openNative(
         return nullptr;
     }
 
+    builder.setProperties(file->audioProperties());
+
     return builder.build();
 }

ktaglib/src/main/java/org/oxycblt/ktaglib/KTagLib.kt

@@ -14,14 +14,14 @@ object KTagLib {
      * Note: This method is blocking and should be handled as such if
      * calling from a coroutine.
      */
-    fun open(context: Context, ref: FileRef): Tag? {
+    fun open(context: Context, ref: FileRef): Metadata? {
         val inputStream = AndroidInputStream(context, ref)
         val tag = openNative(inputStream)
         inputStream.close()
         return tag
     }
 
-    private external fun openNative(ioStream: AndroidInputStream): Tag?
+    private external fun openNative(ioStream: AndroidInputStream): Metadata?
 }
 
 data class FileRef(
@@ -29,28 +29,44 @@ data class FileRef(
     val uri: Uri
 )
 
-data class Tag(
+data class Metadata(
     val id3v2: Map<String, String>,
-    val vorbis: Map<String, String>,
+    val xiph: Map<String, String>,
-    val coverData: ByteArray
+    val mp4: Map<String, String>,
+    val cover: ByteArray?,
+    val properties: Properties
 ) {
     override fun equals(other: Any?): Boolean {
         if (this === other) return true
         if (javaClass != other?.javaClass) return false
 
-        other as Tag
+        other as Metadata
 
         if (id3v2 != other.id3v2) return false
-        if (vorbis != other.vorbis) return false
+        if (xiph != other.xiph) return false
-        if (!coverData.contentEquals(other.coverData)) return false
+        if (mp4 != other.mp4) return false
+        if (cover != null) {
+            if (other.cover == null) return false
+            if (!cover.contentEquals(other.cover)) return false
+        } else if (other.cover != null) return false
+        if (properties != other.properties) return false
 
         return true
     }
 
     override fun hashCode(): Int {
         var result = id3v2.hashCode()
-        result = 31 * result + vorbis.hashCode()
+        result = 31 * result + xiph.hashCode()
-        result = 31 * result + coverData.contentHashCode()
+        result = 31 * result + mp4.hashCode()
+        result = 31 * result + (cover?.contentHashCode() ?: 0)
+        result = 31 * result + properties.hashCode()
         return result
     }
 }
+
+data class Properties(
+    val mimeType: String,
+    val durationMs: Long,
+    val bitrate: Int,
+    val sampleRate: Int,
+)