image: basic per-song album covers

Without any good caching support, so this will immediately break down.

app/src/main/java/org/oxycblt/auxio/image/extractor/Cover.kt

@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2023 Auxio Project
- * CoverUri.kt is part of Auxio.
+ * Cover.kt is part of Auxio.
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -24,9 +24,9 @@ import android.net.Uri
  * Bundle of [Uri] information used in [CoverExtractor] to ensure consistent [Uri] use when loading
  * images.
  *
- * @param mediaStore The album cover [Uri] obtained from MediaStore.
+ * @param mediaStoreUri The album cover [Uri] obtained from MediaStore.
  * @param song The [Uri] of the first song (by track) of the album, which can also be used to obtain
  *   an album cover.
  * @author Alexander Capehart (OxygenCobalt)
  */
-data class CoverUri(val mediaStore: Uri, val song: Uri)
+data class Cover(val perceptualHash: String?, val mediaStoreUri: Uri, val songUri: Uri)

app/src/main/java/org/oxycblt/auxio/image/extractor/CoverExtractor.kt

@@ -77,10 +77,10 @@ constructor(
      *   [computeCoverOrdering]. Otherwise, a [SourceResult] of one album cover will be returned.
      */
     suspend fun extract(songs: Collection<Song>, size: Size): FetchResult? {
-        val albums = computeCoverOrdering(songs)
+        val covers = computeCoverOrdering(songs)
         val streams = mutableListOf<InputStream>()
-        for (album in albums) {
-            openCoverInputStream(album)?.let(streams::add)
+        for (cover in covers) {
+            openCoverInputStream(cover)?.let(streams::add)
             // We don't immediately check for mosaic feasibility from album count alone, as that
             // does not factor in InputStreams failing to load. Instead, only check once we
             // definitely have image data to use.
@@ -116,40 +116,33 @@ constructor(
      *   by their names. "Representation" is defined by how many [Song]s were found to be linked to
      *   the given [Album] in the given [Song] list.
      */
-    fun computeCoverOrdering(songs: Collection<Song>): List<Album> {
-        // TODO: Start short-circuiting in more places
-        if (songs.isEmpty()) return listOf()
-        if (songs.size == 1) return listOf(songs.first().album)
+    fun computeCoverOrdering(songs: Collection<Song>) =
+        Sort(Sort.Mode.ByAlbum, Sort.Direction.ASCENDING)
+            .songs(songs)
+            .distinctBy { (it.cover.perceptualHash ?: it.uri).toString() }
+            .map { it.cover }
 
-        val sortedMap =
-            sortedMapOf<Album, Int>(Sort.Mode.ByName.getAlbumComparator(Sort.Direction.ASCENDING))
-        for (song in songs) {
-            sortedMap[song.album] = (sortedMap[song.album] ?: 0) + 1
-        }
-        return sortedMap.keys.sortedByDescending { sortedMap[it] }
-    }
-
-    private suspend fun openCoverInputStream(album: Album) =
+    private suspend fun openCoverInputStream(cover: Cover) =
         try {
             when (imageSettings.coverMode) {
                 CoverMode.OFF -> null
-                CoverMode.MEDIA_STORE -> extractMediaStoreCover(album)
-                CoverMode.QUALITY -> extractQualityCover(album)
+                CoverMode.MEDIA_STORE -> extractMediaStoreCover(cover)
+                CoverMode.QUALITY -> extractQualityCover(cover)
             }
         } catch (e: Exception) {
             logE("Unable to extract album cover due to an error: $e")
             null
         }
 
-    private suspend fun extractQualityCover(album: Album) =
-        extractAospMetadataCover(album)
-            ?: extractExoplayerCover(album) ?: extractMediaStoreCover(album)
+    private suspend fun extractQualityCover(cover: Cover) =
+        extractAospMetadataCover(cover)
+            ?: extractExoplayerCover(cover) ?: extractMediaStoreCover(cover)
 
-    private fun extractAospMetadataCover(album: Album): InputStream? =
+    private fun extractAospMetadataCover(cover: Cover): InputStream? =
         MediaMetadataRetriever().run {
             // This call is time-consuming but it also doesn't seem to hold up the main thread,
             // so it's probably fine not to wrap it.rmt
-            setDataSource(context, album.coverUri.song)
+            setDataSource(context, cover.songUri)
 
             // Get the embedded picture from MediaMetadataRetriever, which will return a full
             // ByteArray of the cover without any compression artifacts.
@@ -157,10 +150,9 @@ constructor(
             embeddedPicture?.let { ByteArrayInputStream(it) }.also { release() }
         }
 
-    private suspend fun extractExoplayerCover(album: Album): InputStream? {
+    private suspend fun extractExoplayerCover(cover: Cover): InputStream? {
         val tracks =
-            MetadataRetriever.retrieveMetadata(
-                    mediaSourceFactory, MediaItem.fromUri(album.coverUri.song))
+            MetadataRetriever.retrieveMetadata(mediaSourceFactory, MediaItem.fromUri(cover.songUri))
                 .asDeferred()
                 .await()
 
@@ -204,11 +196,9 @@ constructor(
         return stream
     }
 
-    private suspend fun extractMediaStoreCover(album: Album) =
+    private suspend fun extractMediaStoreCover(cover: Cover) =
         // Eliminate any chance that this blocking call might mess up the loading process
-        withContext(Dispatchers.IO) {
-            context.contentResolver.openInputStream(album.coverUri.mediaStore)
-        }
+        withContext(Dispatchers.IO) { context.contentResolver.openInputStream(cover.mediaStoreUri) }
 
     /** Derived from phonograph: https://github.com/kabouzeid/Phonograph */
     private suspend fun createMosaic(streams: List<InputStream>, size: Size): FetchResult {

app/src/main/java/org/oxycblt/auxio/music/Music.kt

@@ -27,7 +27,7 @@ import java.util.UUID
 import kotlin.math.max
 import kotlinx.parcelize.IgnoredOnParcel
 import kotlinx.parcelize.Parcelize
-import org.oxycblt.auxio.image.extractor.CoverUri
+import org.oxycblt.auxio.image.extractor.Cover
 import org.oxycblt.auxio.list.Item
 import org.oxycblt.auxio.music.fs.MimeType
 import org.oxycblt.auxio.music.fs.Path
@@ -246,6 +246,8 @@ interface Song : Music {
      * audio file in a way that is scoped-storage-safe.
      */
     val uri: Uri
+    /** Useful information to quickly obtain the album cover. */
+    val cover: Cover
     /**
      * The [Path] to this audio file. This is only intended for display, [uri] should be favored
      * instead for accessing the audio file.
@@ -293,11 +295,8 @@ interface Album : MusicParent {
      * [ReleaseType.Album].
      */
     val releaseType: ReleaseType
-    /**
-     * The URI to a MediaStore-provided album cover. These images will be fast to load, but at the
-     * cost of image quality.
-     */
-    val coverUri: CoverUri
+    /** Cover information from the template song used for the album. */
+    val cover: Cover
     /** The duration of all songs in the album, in milliseconds. */
     val durationMs: Long
     /** The earliest date a song in this album was added, as a unix epoch timestamp. */
@@ -326,6 +325,8 @@ interface Artist : MusicParent {
      * songs.
      */
     val durationMs: Long?
+    /** Useful information to quickly obtain a (single) cover for a Genre. */
+    val cover: Cover
     /** The [Genre]s of this artist. */
     val genres: List<Genre>
 }
@@ -340,6 +341,8 @@ interface Genre : MusicParent {
     val artists: Collection<Artist>
     /** The total duration of the songs in this genre, in milliseconds. */
     val durationMs: Long
+    /** Useful information to quickly obtain a (single) cover for a Genre. */
+    val cover: Cover
 }
 
 /**
@@ -352,6 +355,8 @@ interface Playlist : MusicParent {
     override val songs: List<Song>
     /** The total duration of the songs in this genre, in milliseconds. */
     val durationMs: Long
+    /** Useful information to quickly obtain a (single) cover for a Genre. */
+    val cover: Cover?
 }
 
 /**

app/src/main/java/org/oxycblt/auxio/music/device/DeviceMusicImpl.kt

@@ -19,7 +19,7 @@
 package org.oxycblt.auxio.music.device
 
 import org.oxycblt.auxio.R
-import org.oxycblt.auxio.image.extractor.CoverUri
+import org.oxycblt.auxio.image.extractor.Cover
 import org.oxycblt.auxio.list.sort.Sort
 import org.oxycblt.auxio.music.Album
 import org.oxycblt.auxio.music.Artist
@@ -112,6 +112,8 @@ class SongImpl(
     override val genres: List<Genre>
         get() = _genres
 
+    override val cover = Cover("", requireNotNull(rawSong.mediaStoreId).toCoverUri(), uri)
+
     /**
      * The [RawAlbum] instances collated by the [Song]. This can be used to group [Song]s into an
      * [Album].
@@ -291,9 +293,9 @@ class AlbumImpl(
     override val name = nameFactory.parse(rawAlbum.name, rawAlbum.sortName)
     override val dates: Date.Range?
     override val releaseType = rawAlbum.releaseType ?: ReleaseType.Album(null)
-    override val coverUri = CoverUri(rawAlbum.mediaStoreId.toCoverUri(), grouping.raw.src.uri)
     override val durationMs: Long
     override val dateAdded: Long
+    override val cover = grouping.raw.src.cover
 
     private val _artists = mutableListOf<ArtistImpl>()
     override val artists: List<Artist>
@@ -419,6 +421,12 @@ class ArtistImpl(
     override val explicitAlbums: Set<Album>
     override val implicitAlbums: Set<Album>
     override val durationMs: Long?
+    override val cover =
+        when (val src = grouping.raw.src) {
+            is AlbumImpl -> src.cover
+            is SongImpl -> src.cover
+            else -> error("Unexpected input music $src in $name ${src::class.simpleName}")
+        }
 
     override lateinit var genres: List<Genre>
 
@@ -528,6 +536,7 @@ class GenreImpl(
     override val songs: Set<Song>
     override val artists: Set<Artist>
     override val durationMs: Long
+    override val cover = grouping.raw.src.cover
 
     private var hashCode = uid.hashCode()
 

app/src/main/java/org/oxycblt/auxio/music/fs/StorageUtil.kt

@@ -102,7 +102,12 @@ fun Long.toAudioUri() =
  * @return An external storage image [Uri]. May not exist.
  * @see ContentUris.withAppendedId
  */
-fun Long.toCoverUri() = ContentUris.withAppendedId(externalCoversUri, this)
+fun Long.toCoverUri(): Uri =
+    MediaStore.Audio.Media.EXTERNAL_CONTENT_URI.buildUpon().run {
+        appendPath(this@toCoverUri.toString())
+        appendPath("albumart")
+        build()
+    }
 
 // --- STORAGEMANAGER UTILITIES ---
 // Largely derived from Material Files: https://github.com/zhanghai/MaterialFiles

app/src/main/java/org/oxycblt/auxio/music/service/MediaItemTranslation.kt

@@ -74,7 +74,7 @@ fun Song.toMediaItem(context: Context, parent: MusicParent?): MediaItem {
             .setMediaType(MediaMetadata.MEDIA_TYPE_MUSIC)
             .setIsPlayable(true)
             .setIsBrowsable(false)
-            .setArtworkUri(album.coverUri.mediaStore)
+            .setArtworkUri(album.cover.mediaStoreUri)
             .setExtras(
                 Bundle().apply {
                     putString("uid", mediaSessionUID.toString())
@@ -105,7 +105,7 @@ fun Album.toMediaItem(context: Context): MediaItem {
             .setMediaType(MediaMetadata.MEDIA_TYPE_ALBUM)
             .setIsPlayable(true)
             .setIsBrowsable(true)
-            .setArtworkUri(coverUri.mediaStore)
+            .setArtworkUri(cover.mediaStoreUri)
             .setExtras(Bundle().apply { putString("uid", mediaSessionUID.toString()) })
             .build()
     return MediaItem.Builder()
@@ -136,7 +136,7 @@ fun Artist.toMediaItem(context: Context): MediaItem {
             .setIsPlayable(true)
             .setIsBrowsable(true)
             .setGenre(genres.resolveNames(context))
-            .setArtworkUri(songs.firstOrNull()?.album?.coverUri?.mediaStore)
+            .setArtworkUri(cover.mediaStoreUri)
             .setExtras(Bundle().apply { putString("uid", mediaSessionUID.toString()) })
             .build()
     return MediaItem.Builder()
@@ -159,7 +159,7 @@ fun Genre.toMediaItem(context: Context): MediaItem {
             .setMediaType(MediaMetadata.MEDIA_TYPE_GENRE)
             .setIsPlayable(true)
             .setIsBrowsable(true)
-            .setArtworkUri(songs.firstOrNull()?.album?.coverUri?.mediaStore)
+            .setArtworkUri(cover.mediaStoreUri)
             .setExtras(Bundle().apply { putString("uid", mediaSessionUID.toString()) })
             .build()
     return MediaItem.Builder()
@@ -182,7 +182,7 @@ fun Playlist.toMediaItem(context: Context): MediaItem {
             .setMediaType(MediaMetadata.MEDIA_TYPE_PLAYLIST)
             .setIsPlayable(true)
             .setIsBrowsable(true)
-            .setArtworkUri(songs.firstOrNull()?.album?.coverUri?.mediaStore)
+            .setArtworkUri(cover?.mediaStoreUri)
             .setExtras(Bundle().apply { putString("uid", mediaSessionUID.toString()) })
             .build()
     return MediaItem.Builder()

app/src/main/java/org/oxycblt/auxio/music/user/PlaylistImpl.kt

@@ -46,6 +46,8 @@ private constructor(
 
     override fun toString() = "Playlist(uid=$uid, name=$name)"
 
+    override val cover = songs.firstOrNull()?.cover
+
     /**
      * Clone the data in this instance to a new [PlaylistImpl] with the given [name].
      *