Question

我正在尝试通过A2DP / AVRCP发送跟踪信息。现在，音乐完全流式传输，但在“接收器”（即：汽车音频）上，“音轨信息屏幕”是空白的（在那里使用流行的播放器不是这种情况）。有什么想法吗？

Answer 1

此代码对我有用：

private static final String AVRCP_PLAYSTATE_CHANGED = "com.android.music.playstatechanged";
private static final String AVRCP_META_CHANGED = "com.android.music.metachanged";

private void bluetoothNotifyChange(String what) {
    Intent i = new Intent(what);
    i.putExtra("id", Long.valueOf(getAudioId()));
    i.putExtra("artist", getArtistName());
    i.putExtra("album",getAlbumName());
    i.putExtra("track", getTrackName());
    i.putExtra("playing", isPlaying());        
    i.putExtra("ListSize", getQueue());
    i.putExtra("duration", duration());
    i.putExtra("position", position());
    sendBroadcast(i);
}

根据您的播放状态调用具有适当意图（如上所述）的bluetoothNotifyChange：暂停/播放/元数据已更改。

Answer 2

如果您只想将手机中的元数据信息发送到连接的AVRCP兼容音频蓝牙设备，并且 DON＆＃39; T 想要从蓝牙设备控制您的应用，您可能会发现以下代码有用。并且 NO 需要使用AudioManager实现和注册MediaButtonEventReceiver。

我还包括了API Version 21（LOLLIPOP，5.0）的代码。从API 21开始，不推荐使用RemoteControlClient，并鼓励使用MediaSession。

初始阶段：

    if (mAudioManager == null) {
        mAudioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
    }

    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
        if (mRemoteControlClient == null) {
            Log.d("init()", "API " + Build.VERSION.SDK_INT + " lower then " + Build.VERSION_CODES.LOLLIPOP);
            Log.d("init()", "Using RemoteControlClient API.");

            mRemoteControlClient = new RemoteControlClient(PendingIntent.getBroadcast(this, 0, new Intent(Intent.ACTION_MEDIA_BUTTON), 0));
            mAudioManager.registerRemoteControlClient(mRemoteControlClient);
        }
    } else {
        if (mMediaSession == null) {
            Log.d("init()", "API " + Build.VERSION.SDK_INT + " greater or equals " + Build.VERSION_CODES.LOLLIPOP);
            Log.d("init()", "Using MediaSession API.");

            mMediaSession = new MediaSession(this, "PlayerServiceMediaSession");
            mMediaSession.setFlags(MediaSession.FLAG_HANDLES_TRANSPORT_CONTROLS);
            mMediaSession.setActive(true);

        }
    }

将歌曲元数据信息发送到兼容AVRCP的蓝牙音频设备的方法：

private void onTrackChanged(String title, String artist, String album, long duration, long position, long trackNumber) {

    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {

        RemoteControlClient.MetadataEditor ed = mRemoteControlClient.editMetadata(true);
        ed.putString(MediaMetadataRetriever.METADATA_KEY_TITLE, title);
        ed.putString(MediaMetadataRetriever.METADATA_KEY_ARTIST, artist);
        ed.putString(MediaMetadataRetriever.METADATA_KEY_ALBUM, album);
        ed.putLong(MediaMetadataRetriever.METADATA_KEY_DURATION, duration);
        ed.putLong(MediaMetadataRetriever.METADATA_KEY_CD_TRACK_NUMBER, trackNumber);
        ed.apply();

        mRemoteControlClient.setPlaybackState(RemoteControlClient.PLAYSTATE_PLAYING, position, 1.0f);
    } else {

        MediaMetadata metadata = new MediaMetadata.Builder()
                .putString(MediaMetadata.METADATA_KEY_TITLE, title)
                .putString(MediaMetadata.METADATA_KEY_ARTIST, artist)
                .putString(MediaMetadata.METADATA_KEY_ALBUM, album)
                .putLong(MediaMetadata.METADATA_KEY_DURATION, duration)
                .putLong(MediaMetadata.METADATA_KEY_TRACK_NUMBER, trackNumber)
                .build();

        mMediaSession.setMetadata(metadata);

        PlaybackState state = new PlaybackState.Builder()
                .setActions(PlaybackState.ACTION_PLAY)
                .setState(PlaybackState.STATE_PLAYING, position, 1.0f, SystemClock.elapsedRealtime())
                .build();

        mMediaSession.setPlaybackState(state);
    }
}

如果元数据发生变化，请调用，但检查我们是否与音频蓝牙设备建立了A2DP连接。如果我们没有连接，则无需发送元数据信息：

if (mAudioManager.isBluetoothA2dpOn()) {
    Log.d("AudioManager", "isBluetoothA2dpOn() = true");
    onTrackChanged(getTitle(), getArtist(), getAlbum(), getDuration(), getCurrentPosition(), getId());
}

清理破坏：

@Override
public void onDestroy() {
    super.onDestroy();

[..]    

if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
        mAudioManager.unregisterRemoteControlClient(mRemoteControlClient);
    } else {
        mMediaSession.release();
    }
}

This就是我的汽车音响上的样子

Answer 3

这让我永远想通了。只是广播意图并没有奏效。我通过发送意图 AND 实施RemoteControlClient

来让AVRCP工作

这是我使用的代码：

public void onCreate(){
    super.onCreate();

    mAudioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
    ComponentName rec = new ComponentName(getPackageName(), MyReceiver.class.getName());
    mAudioManager.registerMediaButtonEventReceiver(rec);

    Intent i = new Intent(Intent.ACTION_MEDIA_BUTTON);
    i.setComponent(rec);
    PendingIntent pi = PendingIntent.getBroadcast(this, 0, i, 0);
    mRemoteControlClient = new RemoteControlClient(pi);
    mAudioManager.registerRemoteControlClient(mRemoteControlClient);

    int flags = RemoteControlClient.FLAG_KEY_MEDIA_PREVIOUS
            | RemoteControlClient.FLAG_KEY_MEDIA_NEXT
            | RemoteControlClient.FLAG_KEY_MEDIA_PLAY
            | RemoteControlClient.FLAG_KEY_MEDIA_PAUSE
            | RemoteControlClient.FLAG_KEY_MEDIA_PLAY_PAUSE
            | RemoteControlClient.FLAG_KEY_MEDIA_STOP
            | RemoteControlClient.FLAG_KEY_MEDIA_FAST_FORWARD
            | RemoteControlClient.FLAG_KEY_MEDIA_REWIND;
    mRemoteControlClient.setTransportControlFlags(flags);
}

private void onTrackChanged(...) {
    String title = ...;
    String artist = ...;
    String album = ...;
    long duration = ...;

    Intent i = new Intent("com.android.music.metachanged");
    i.putExtra("id", 1);
    i.putExtra("track", title);
    i.putExtra("artist", artist);
    i.putExtra("album", album);
    i.putExtra("playing", "true");
    sendStickyBroadcast(i);

    RemoteControlClient.MetadataEditor ed = mRemoteControlClient.editMetadata(true);
    ed.putString(MediaMetadataRetriever.METADATA_KEY_TITLE, title);
    ed.putString(MediaMetadataRetriever.METADATA_KEY_ALBUM, album);
    ed.putString(MediaMetadataRetriever.METADATA_KEY_ARTIST, artist);
    ed.putLong(MediaMetadataRetriever.METADATA_KEY_DURATION, track.getDuration());
    ed.apply();
}

public void onDestroy(){
    mAudioManager.unregisterRemoteControlClient(mRemoteControlClient);
    super.onDestroy();
}

Answer 4

要将轨道元数据发送到headunit，您需要发送一个意图。

Intent avrcp = new Intent("com.android.music.metachanged");
avrcp.putExtra("track", "song title");
avrcp.putExtra("artist", "artist name");
avrcp.putExtra("album", "album name");
Context.sendBroadcast(avrcp);

当完成歌曲播放时，使用空字符串为putExtra方法的第二个参数发送另一个意图。

Answer 5

如果您使用Compat版本的组件，则无需控制SDK_INT。下面的代码测试了许多汽车蓝牙设备和魅力的工作。有些设备不了解某些KEY，因此使用可能的KEY会更好。 Reference。不要在putBitmap之前忘记.build（）

之前

public static void sendTrackInfo() {
if(audioManager == null) {
    audioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
}

if (mMediaSession == null) {
    mMediaSession = new MediaSessionCompat(this, "PlayerServiceMediaSession");
    mMediaSession.setFlags(MediaSessionCompat.FLAG_HANDLES_TRANSPORT_CONTROLS);
    mMediaSession.setActive(true);
}

if (audioManager.isBluetoothA2dpOn()) {
    try {
        String songTitle = getTitle();
        String artistTitle = getArtist();
        String radioImageUri = getImagesArr().get(0);
        String songImageUri = getImagesArr().get(1);
        long duration = getDuration();

        final MediaMetadataCompat.Builder metadata = new MediaMetadataCompat.Builder();

        metadata.putString(MediaMetadataCompat.METADATA_KEY_TITLE, songTitle);
        metadata.putString(MediaMetadataCompat.METADATA_KEY_DISPLAY_TITLE, songTitle);
        metadata.putString(MediaMetadataCompat.METADATA_KEY_ARTIST, artistTitle);
        metadata.putString(MediaMetadataCompat.METADATA_KEY_ALBUM_ARTIST, artistTitle);
        metadata.putString(MediaMetadataCompat.METADATA_KEY_ART_URI, radioImageUri);
        metadata.putString(MediaMetadataCompat.METADATA_KEY_DISPLAY_ICON_URI, radioImageUri);
        metadata.putString(MediaMetadataCompat.METADATA_KEY_ALBUM_ART_URI, songImageUri);
        metadata.putLong(MediaMetadataCompat.METADATA_KEY_DURATION, duration);

        imageCounter = 0;

        Glide.with(act)
                .load(Uri.parse(radioImageUri))
                .asBitmap()
                .into(new SimpleTarget<Bitmap>(250, 250) {
                    @Override
                    public void onResourceReady(Bitmap bitmap, GlideAnimation anim) {
                        metadata.putBitmap(MediaMetadataCompat.METADATA_KEY_ART, bitmap);
                        metadata.putBitmap(MediaMetadataCompat.METADATA_KEY_DISPLAY_ICON, bitmap);

                        imageCounter = imageCounter + 1;

                        if(imageCounter == 2) {
                            mMediaSession.setMetadata(metadata.build());
                        }
                    }
                });

        Glide.with(act)
                .load(Uri.parse(songImageUri))
                .asBitmap()
                .into(new SimpleTarget<Bitmap>(250, 250) {
                    @Override
                    public void onResourceReady(Bitmap bitmap, GlideAnimation anim) {
                        metadata.putBitmap(MediaMetadataCompat.METADATA_KEY_ALBUM_ART, bitmap);

                        imageCounter = imageCounter + 1;

                        if(imageCounter == 2) {
                            mMediaSession.setMetadata(metadata.build());
                        }
                    }
                });
    }
    catch (JSONException e) {
        e.printStackTrace();
    }
}

}

通过A2DP / AVRCP发送跟踪信息

5 个答案: