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-rw-r--r--media/java/android/media/MediaMetadataRetriever.java272
-rw-r--r--media/jni/android_media_MediaMetadataRetriever.cpp2
2 files changed, 272 insertions, 2 deletions
diff --git a/media/java/android/media/MediaMetadataRetriever.java b/media/java/android/media/MediaMetadataRetriever.java
index 4cd581b6628c..1617b875c6f7 100644
--- a/media/java/android/media/MediaMetadataRetriever.java
+++ b/media/java/android/media/MediaMetadataRetriever.java
@@ -28,6 +28,7 @@ import android.graphics.Bitmap;
import android.net.Uri;
import android.os.Build;
import android.os.IBinder;
+import android.text.TextUtils;
import java.io.FileDescriptor;
import java.io.FileInputStream;
@@ -44,6 +45,162 @@ import java.util.Map;
* frame and meta data from an input media file.
*/
public class MediaMetadataRetriever implements AutoCloseable {
+
+ // borrowed from ExoPlayer
+ private static final String[] STANDARD_GENRES = new String[] {
+ // These are the official ID3v1 genres.
+ "Blues",
+ "Classic Rock",
+ "Country",
+ "Dance",
+ "Disco",
+ "Funk",
+ "Grunge",
+ "Hip-Hop",
+ "Jazz",
+ "Metal",
+ "New Age",
+ "Oldies",
+ "Other",
+ "Pop",
+ "R&B",
+ "Rap",
+ "Reggae",
+ "Rock",
+ "Techno",
+ "Industrial",
+ "Alternative",
+ "Ska",
+ "Death Metal",
+ "Pranks",
+ "Soundtrack",
+ "Euro-Techno",
+ "Ambient",
+ "Trip-Hop",
+ "Vocal",
+ "Jazz+Funk",
+ "Fusion",
+ "Trance",
+ "Classical",
+ "Instrumental",
+ "Acid",
+ "House",
+ "Game",
+ "Sound Clip",
+ "Gospel",
+ "Noise",
+ "AlternRock",
+ "Bass",
+ "Soul",
+ "Punk",
+ "Space",
+ "Meditative",
+ "Instrumental Pop",
+ "Instrumental Rock",
+ "Ethnic",
+ "Gothic",
+ "Darkwave",
+ "Techno-Industrial",
+ "Electronic",
+ "Pop-Folk",
+ "Eurodance",
+ "Dream",
+ "Southern Rock",
+ "Comedy",
+ "Cult",
+ "Gangsta",
+ "Top 40",
+ "Christian Rap",
+ "Pop/Funk",
+ "Jungle",
+ "Native American",
+ "Cabaret",
+ "New Wave",
+ "Psychadelic",
+ "Rave",
+ "Showtunes",
+ "Trailer",
+ "Lo-Fi",
+ "Tribal",
+ "Acid Punk",
+ "Acid Jazz",
+ "Polka",
+ "Retro",
+ "Musical",
+ "Rock & Roll",
+ "Hard Rock",
+ // These were made up by the authors of Winamp and later added to the ID3 spec.
+ "Folk",
+ "Folk-Rock",
+ "National Folk",
+ "Swing",
+ "Fast Fusion",
+ "Bebob",
+ "Latin",
+ "Revival",
+ "Celtic",
+ "Bluegrass",
+ "Avantgarde",
+ "Gothic Rock",
+ "Progressive Rock",
+ "Psychedelic Rock",
+ "Symphonic Rock",
+ "Slow Rock",
+ "Big Band",
+ "Chorus",
+ "Easy Listening",
+ "Acoustic",
+ "Humour",
+ "Speech",
+ "Chanson",
+ "Opera",
+ "Chamber Music",
+ "Sonata",
+ "Symphony",
+ "Booty Bass",
+ "Primus",
+ "Porn Groove",
+ "Satire",
+ "Slow Jam",
+ "Club",
+ "Tango",
+ "Samba",
+ "Folklore",
+ "Ballad",
+ "Power Ballad",
+ "Rhythmic Soul",
+ "Freestyle",
+ "Duet",
+ "Punk Rock",
+ "Drum Solo",
+ "A capella",
+ "Euro-House",
+ "Dance Hall",
+ // These were made up by the authors of Winamp but have not been added to the ID3 spec.
+ "Goa",
+ "Drum & Bass",
+ "Club-House",
+ "Hardcore",
+ "Terror",
+ "Indie",
+ "BritPop",
+ "Afro-Punk",
+ "Polsk Punk",
+ "Beat",
+ "Christian Gangsta Rap",
+ "Heavy Metal",
+ "Black Metal",
+ "Crossover",
+ "Contemporary Christian",
+ "Christian Rock",
+ "Merengue",
+ "Salsa",
+ "Thrash Metal",
+ "Anime",
+ "Jpop",
+ "Synthpop"
+ };
+
static {
System.loadLibrary("media_jni");
native_init();
@@ -225,6 +382,8 @@ public class MediaMetadataRetriever implements AutoCloseable {
private native void _setDataSource(MediaDataSource dataSource)
throws IllegalArgumentException;
+ private native @Nullable String nativeExtractMetadata(int keyCode);
+
/**
* Call this method after setDataSource(). This method retrieves the
* meta data value associated with the keyCode.
@@ -236,7 +395,118 @@ public class MediaMetadataRetriever implements AutoCloseable {
* @return The meta data value associate with the given keyCode on success;
* null on failure.
*/
- public native @Nullable String extractMetadata(int keyCode);
+ public @Nullable String extractMetadata(int keyCode) {
+ String meta = nativeExtractMetadata(keyCode);
+ if (keyCode == METADATA_KEY_GENRE) {
+ // translate numeric genre code(s) to human readable
+ meta = convertGenreTag(meta);
+ }
+ return meta;
+ }
+
+ /*
+ * The id3v2 spec doesn't specify the syntax of the genre tag very precisely, so
+ * some assumptions are made. Using one possible interpretation of the id3v2
+ * spec, this method converts an id3 genre tag string to a human readable string,
+ * as follows:
+ * - if the first character of the tag is a digit, the entire tag is assumed to
+ * be an id3v1 numeric genre code. If the tag does not parse to a number, or
+ * the number is outside the range of defined standard genres, it is ignored.
+ * - if the tag does not start with a digit, it is assumed to be an id3v2 style
+ * tag consisting of one or more genres, with each genre being either a parenthesized
+ * integer referring to an id3v1 numeric genre code, the special indicators "(CR)" or
+ * "(RX)" (for "Cover" or "Remix", respectively), or a custom genre string. When
+ * a custom genre string is encountered, it is assumed to continue until the end
+ * of the tag, unless it starts with "((" in which case it is assumed to continue
+ * until the next close-parenthesis or the end of the tag. Any parse error in the tag
+ * causes it to be ignored.
+ * The human-readable genre string is not localized, and uses the English genre names
+ * from the spec.
+ */
+ private String convertGenreTag(String meta) {
+ if (TextUtils.isEmpty(meta)) {
+ return null;
+ }
+
+ if (Character.isDigit(meta.charAt(0))) {
+ // assume a single id3v1-style bare number without any extra characters
+ try {
+ int genreIndex = Integer.parseInt(meta);
+ if (genreIndex >= 0 && genreIndex < STANDARD_GENRES.length) {
+ return STANDARD_GENRES[genreIndex];
+ }
+ } catch (NumberFormatException e) {
+ // ignore and fall through
+ }
+ return null;
+ } else {
+ // assume id3v2-style genre tag, with parenthesized numeric genres
+ // and/or literal genre strings, possibly more than one per tag.
+ StringBuilder genres = null;
+ String nextGenre = null;
+ while (true) {
+ if (!TextUtils.isEmpty(nextGenre)) {
+ if (genres == null) {
+ genres = new StringBuilder();
+ }
+ if (genres.length() != 0) {
+ genres.append(", ");
+ }
+ genres.append(nextGenre);
+ nextGenre = null;
+ }
+ if (TextUtils.isEmpty(meta)) {
+ // entire tag has been processed.
+ break;
+ }
+ if (meta.startsWith("(RX)")) {
+ nextGenre = "Remix";
+ meta = meta.substring(4);
+ } else if (meta.startsWith("(CR)")) {
+ nextGenre = "Cover";
+ meta = meta.substring(4);
+ } else if (meta.startsWith("((")) {
+ // the id3v2 spec says that custom genres that start with a parenthesis
+ // should be "escaped" with another parenthesis, however the spec doesn't
+ // specify escaping parentheses inside the custom string. We'll parse any
+ // such strings until a closing parenthesis is found, or the end of
+ // the tag is reached.
+ int closeParenOffset = meta.indexOf(')');
+ if (closeParenOffset == -1) {
+ // string continues to end of tag
+ nextGenre = meta.substring(1);
+ meta = "";
+ } else {
+ nextGenre = meta.substring(1, closeParenOffset + 1);
+ meta = meta.substring(closeParenOffset + 1);
+ }
+ } else if (meta.startsWith("(")) {
+ // should be a parenthesized numeric genre
+ int closeParenOffset = meta.indexOf(')');
+ if (closeParenOffset == -1) {
+ return null;
+ }
+ String genreNumString = meta.substring(1, closeParenOffset);
+ try {
+ int genreIndex = Integer.parseInt(genreNumString.toString());
+ if (genreIndex >= 0 && genreIndex < STANDARD_GENRES.length) {
+ nextGenre = STANDARD_GENRES[genreIndex];
+ } else {
+ return null;
+ }
+ } catch (NumberFormatException e) {
+ return null;
+ }
+ meta = meta.substring(closeParenOffset + 1);
+ } else {
+ // custom genre
+ nextGenre = meta;
+ meta = "";
+ }
+ }
+ return genres == null || genres.length() == 0 ? null : genres.toString();
+ }
+ }
/**
* This method is similar to {@link #getFrameAtTime(long, int, BitmapParams)}
diff --git a/media/jni/android_media_MediaMetadataRetriever.cpp b/media/jni/android_media_MediaMetadataRetriever.cpp
index a5c62cb720cf..1c9b349a7eed 100644
--- a/media/jni/android_media_MediaMetadataRetriever.cpp
+++ b/media/jni/android_media_MediaMetadataRetriever.cpp
@@ -728,7 +728,7 @@ static const JNINativeMethod nativeMethods[] = {
(void *)android_media_MediaMetadataRetriever_getFrameAtIndex
},
- {"extractMetadata", "(I)Ljava/lang/String;",
+ {"nativeExtractMetadata", "(I)Ljava/lang/String;",
(void *)android_media_MediaMetadataRetriever_extractMetadata},
{"getEmbeddedPicture", "(I)[B",
(void *)android_media_MediaMetadataRetriever_getEmbeddedPicture},
generated by cgit v1.2.3-59-g8ed1b (git 2.39.0) at 2025-11-30 12:30:25 +0000