将EnviromentalReverb和PresetReverb添加到mediaPlayer (wav和m4a格式)，但混响不适用

在 Android 开发中，使用 MediaPlayer 播放音频时，可以通过 EnvironmentalReverb 和 PresetReverb 来添加混响效果。然而，混响效果可能不会直接应用于 MediaPlayer，因为 MediaPlayer 的音频输出路径可能不支持这些效果。为了确保混响效果能够应用于音频播放，您可以尝试以下步骤：

1. 使用 `AudioTrack` 代替 `MediaPlayer`

AudioTrack 提供了更低级别的音频播放控制，允许您更灵活地应用音频效果。以下是一个示例，展示如何使用 AudioTrack 和 EnvironmentalReverb 来播放音频并应用混响效果。

示例代码

import android.media.AudioAttributes;
import android.media.AudioFormat;
import android.media.AudioManager;
import android.media.AudioTrack;
import android.media.MediaExtractor;
import android.media.MediaFormat;
import android.media.audiofx.EnvironmentalReverb;
import android.media.audiofx.PresetReverb;
import android.os.Build;
import android.util.Log;

import java.io.IOException;
import java.nio.ByteBuffer;

public class AudioPlayer {
    private static final String TAG = "AudioPlayer";
    private static final int BUFFER_SIZE = 1024 * 1024;

    private AudioTrack audioTrack;
    private EnvironmentalReverb environmentalReverb;
    private PresetReverb presetReverb;

    public void playAudio(String filePath) {
        MediaExtractor extractor = new MediaExtractor();
        try {
            extractor.setDataSource(filePath);
        } catch (IOException e) {
            e.printStackTrace();
            return;
        }

        MediaFormat format = null;
        for (int i = 0; i < extractor.getTrackCount(); i++) {
            format = extractor.getTrackFormat(i);
            String mime = format.getString(MediaFormat.KEY_MIME);
            if (mime.startsWith("audio/")) {
                extractor.selectTrack(i);
                break;
            }
        }

        if (format == null) {
            Log.e(TAG, "No audio track found in file");
            return;
        }

        int sampleRate = format.getInteger(MediaFormat.KEY_SAMPLE_RATE);
        int channelConfig = format.getInteger(MediaFormat.KEY_CHANNEL_COUNT) == 1 ?
                AudioFormat.CHANNEL_OUT_MONO : AudioFormat.CHANNEL_OUT_STEREO;
        int audioFormat = AudioFormat.ENCODING_PCM_16BIT;

        int minBufferSize = AudioTrack.getMinBufferSize(sampleRate, channelConfig, audioFormat);
        audioTrack = new AudioTrack(
                new AudioAttributes.Builder()
                        .setUsage(AudioAttributes.USAGE_MEDIA)
                        .setContentType(AudioAttributes.CONTENT_TYPE_MUSIC)
                        .build(),
                new AudioFormat.Builder()
                        .setSampleRate(sampleRate)
                        .setChannelMask(channelConfig)
                        .setEncoding(audioFormat)
                        .build(),
                Math.max(minBufferSize, BUFFER_SIZE),
                AudioTrack.MODE_STREAM,
                AudioManager.AUDIO_SESSION_ID_GENERATE
        );

        // Initialize EnvironmentalReverb
        environmentalReverb = new EnvironmentalReverb(0, audioTrack.getAudioSessionId());
        environmentalReverb.setDecayTime(5000);
        environmentalReverb.setDensity((short) 1000);
        environmentalReverb.setEnabled(true);

        // Initialize PresetReverb
        presetReverb = new PresetReverb(0, audioTrack.getAudioSessionId());
        presetReverb.setPreset(PresetReverb.PRESET_LARGEHALL);
        presetReverb.setEnabled(true);

        audioTrack.play();

        ByteBuffer inputBuffer = ByteBuffer.allocate(BUFFER_SIZE);
        while (true) {
            int sampleSize = extractor.readSampleData(inputBuffer, 0);
            if (sampleSize < 0) {
                break;
            }
            byte[] buffer = new byte[sampleSize];
            inputBuffer.get(buffer);
            inputBuffer.clear();
            audioTrack.write(buffer, 0, sampleSize);
            extractor.advance();
        }

        audioTrack.stop();
        audioTrack.release();
        environmentalReverb.release();
        presetReverb.release();
    }
}

2. 使用 `MediaPlayer` 和 `AuxEffect`

如果您仍然希望使用 MediaPlayer，可以尝试将混响效果作为辅助效果（AuxEffect）应用到 MediaPlayer。以下是一个示例，展示如何将 EnvironmentalReverb 和 PresetReverb 应用于 MediaPlayer。

示例代码

import android.media.MediaPlayer;
import android.media.audiofx.EnvironmentalReverb;
import android.media.audiofx.PresetReverb;
import android.os.Bundle;
import androidx.appcompat.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity {
    private MediaPlayer mediaPlayer;
    private EnvironmentalReverb environmentalReverb;
    private PresetReverb presetReverb;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mediaPlayer = MediaPlayer.create(this, R.raw.your_audio_file); // Replace with your audio file

        // Initialize EnvironmentalReverb
        environmentalReverb = new EnvironmentalReverb(0, mediaPlayer.getAudioSessionId());
        environmentalReverb.setDecayTime(5000);
        environmentalReverb.setDensity((short) 1000);
        environmentalReverb.setEnabled(true);

        // Initialize PresetReverb
        presetReverb = new PresetReverb(0, mediaPlayer.getAudioSessionId());
        presetReverb.setPreset(PresetReverb.PRESET_LARGEHALL);
        presetReverb.setEnabled(true);

        // Attach the effects to the MediaPlayer
        mediaPlayer.attachAuxEffect(environmentalReverb.getId());
        mediaPlayer.setAuxEffectSendLevel(1.0f);

        mediaPlayer.attachAuxEffect(presetReverb.getId());
        mediaPlayer.setAuxEffectSendLevel(1.0f);

        mediaPlayer.start();
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        if (mediaPlayer != null) {
            mediaPlayer.release();
        }
        if (environmentalReverb != null) {
            environmentalReverb.release();
        }
        if (presetReverb != null) {
            presetReverb.release();
        }
    }
}