多媒体——音频——利用MediaRecorder录制音频
布局：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical"> <LinearLayout android:layout_width="match_parent" android:layout_height="40dp" android:paddingLeft="5dp"> <TextView android:layout_width="wrap_content" android:layout_height="match_parent" android:gravity="center" android:text="音频编码：" android:textColor="@color/black" android:textSize="17sp" /> <Spinner android:id="@+id/sp_encoder" android:layout_width="0dp" android:layout_height="match_parent" android:layout_weight="1" android:gravity="left|center" android:spinnerMode="dialog" /> </LinearLayout> <LinearLayout android:layout_width="match_parent" android:layout_height="40dp" android:paddingLeft="5dp"> <TextView android:layout_width="wrap_content" android:layout_height="match_parent" android:gravity="center" android:text="输出格式：" android:textColor="@color/black" android:textSize="17sp" /> <Spinner android:id="@+id/sp_format" android:layout_width="0dp" android:layout_height="match_parent" android:layout_weight="1" android:gravity="left|center" android:spinnerMode="dialog" /> </LinearLayout> <LinearLayout android:layout_width="match_parent" android:layout_height="40dp" android:paddingLeft="5dp"> <TextView android:layout_width="wrap_content" android:layout_height="match_parent" android:gravity="center" android:text="录制时长：" android:textColor="@color/black" android:textSize="17sp" /> <Spinner android:id="@+id/sp_duration" android:layout_width="0dp" android:layout_height="match_parent" android:layout_weight="1" android:gravity="left|center" android:spinnerMode="dialog" /> </LinearLayout> <Button android:id="@+id/btn_record" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="开始录音" android:textColor="@color/black" android:textSize="17sp" /> <LinearLayout android:id="@+id/ll_progress" android:layout_width="match_parent" android:layout_height="30dp" android:paddingLeft="5dp" android:paddingRight="5dp" android:orientation="horizontal" android:visibility="gone"> <ProgressBar android:id="@+id/pb_record" style="?android:attr/progressBarStyleHorizontal" android:layout_width="0dp" android:layout_height="match_parent" android:layout_weight="4" /> <TextView android:id="@+id/tv_progress" android:layout_width="0dp" android:layout_height="match_parent" android:layout_weight="1" android:gravity="right|center" android:textColor="@color/black" android:textSize="15sp" /> </LinearLayout> <ImageView android:id="@+id/iv_audio" android:layout_width="match_parent" android:layout_height="50dp" android:scaleType="fitCenter" android:src="@drawable/play_audio" android:visibility="gone" /> </LinearLayout>
MediaUtil
package com.example.myapplication.util; import android.annotation.SuppressLint; import android.content.Context; import android.graphics.Bitmap; import android.media.MediaMetadataRetriever; import android.net.Uri; import android.os.Environment; import android.util.Log; import java.io.File; @SuppressLint("DefaultLocale") public class MediaUtil { private final static String TAG = "MediaUtil"; // 格式化播放时长（mm:ss） public static String formatDuration(int milliseconds) { int seconds = milliseconds / 1000; int hour = seconds / 3600; int minute = seconds / 60; int second = seconds % 60; String str; if (hour > 0) { str = String.format("%02d:%02d:%02d", hour, minute, second); } else { str = String.format("%02d:%02d", minute, second); } return str; } // 获得音视频文件的缓存路径 public static String getRecordFilePath(Context context, String dir_name, String extend_name) { String path = ""; File recordDir = new File(context.getExternalFilesDir(Environment.DIRECTORY_DOWNLOADS).toString() + "/" + dir_name + "/"); if (!recordDir.exists()) { recordDir.mkdirs(); } try { File recordFile = File.createTempFile(DateUtil.getNowDateTime(), extend_name, recordDir); path = recordFile.getAbsolutePath(); Log.d(TAG, "dir_name=" + dir_name + ", extend_name=" + extend_name + ", path=" + path); } catch (Exception e) { e.printStackTrace(); } return path; } // 获取视频文件中的某帧图片 public static Bitmap getOneFrame(Context ctx, Uri uri) { MediaMetadataRetriever retriever = new MediaMetadataRetriever(); retriever.setDataSource(ctx, uri); // 获得视频的播放时长，大于1秒的取第1秒处的帧图，不足1秒的取第0秒处的帧图 String duration = retriever.extractMetadata(MediaMetadataRetriever.METADATA_KEY_DURATION); Log.d(TAG, "duration="+duration); int pos = (Integer.parseInt(duration)/1000)>1 ? 1 : 0; // 获取指定时间的帧图，注意getFrameAtTime方法的时间单位是微秒 return retriever.getFrameAtTime(pos * 1000 * 1000); } }
item_select.xml
<TextView xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="50dp" android:singleLine="true" android:gravity="center" android:textSize="17sp" android:textColor="#0000ff" />
主代码：
package com.example.myapplication; import android.media.AudioManager; import android.media.MediaPlayer; import android.media.MediaRecorder; import android.os.Bundle; import android.text.TextUtils; import android.util.Log; import android.view.View; import android.widget.AdapterView; import android.widget.ArrayAdapter; import android.widget.Button; import android.widget.ImageView; import android.widget.LinearLayout; import android.widget.ProgressBar; import android.widget.Spinner; import android.widget.TextView; import android.widget.Toast; import com.example.myapplication.util.MediaUtil; import androidx.appcompat.app.AppCompatActivity; import java.util.Timer; import java.util.TimerTask; public class MainActivity extends AppCompatActivity implements View.OnClickListener, MediaRecorder.OnInfoListener { private static final String TAG = "MediaRecorderActivity"; private Button btn_record; private LinearLayout ll_progress; private ProgressBar pb_record; // 声明一个进度条对象 private TextView tv_progress; private ImageView iv_audio; // 该图标充当播放按钮 private MediaRecorder mMediaRecorder = new MediaRecorder(); // 媒体录制器 private boolean isRecording = false; // 是否正在录制 private int mAudioEncoder; // 音频编码 private int mOutputFormat; // 输出格式 private int mDuration; // 录制时长 private String mRecordFilePath; // 录制文件的保存路径 private Timer mTimer = new Timer(); // 计时器 private int mTimeCount; // 时间计数 private MediaPlayer mMediaPlayer = new MediaPlayer(); // 媒体播放器 @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); btn_record = findViewById(R.id.btn_record); ll_progress = findViewById(R.id.ll_progress); pb_record = findViewById(R.id.pb_record); tv_progress = findViewById(R.id.tv_progress); iv_audio = findViewById(R.id.iv_audio); btn_record.setOnClickListener(this); iv_audio.setOnClickListener(this); initEncoderSpinner(); // 初始化音频编码的下拉框 initFormatSpinner(); // 初始化输出格式的下拉框 initDurationSpinner(); // 初始化录制时长的下拉框 } // 初始化音频编码的下拉框 private void initEncoderSpinner() { ArrayAdapter<String> encoderAdapter = new ArrayAdapter<String>(this, R.layout.item_select, encoderDescArray); Spinner sp_encoder = findViewById(R.id.sp_encoder); sp_encoder.setPrompt("请选择音频编码"); // 设置下拉框的标题 sp_encoder.setAdapter(encoderAdapter); // 设置下拉框的数组适配器 // 给下拉框设置选择监听器，一旦用户选中某一项，就触发监听器的onItemSelected方法 sp_encoder.setOnItemSelectedListener(new EncoderSelectedListener()); sp_encoder.setSelection(0); // 设置下拉框默认显示第一项 } private String[] encoderDescArray = { "默认编码", "窄带编码", "宽带编码", "低复杂度的高级编码", "高效率的高级编码", "增强型低延时的高级编码" }; private int[] encoderArray = { MediaRecorder.AudioEncoder.DEFAULT, MediaRecorder.AudioEncoder.AMR_NB, MediaRecorder.AudioEncoder.AMR_WB, MediaRecorder.AudioEncoder.AAC, MediaRecorder.AudioEncoder.HE_AAC, MediaRecorder.AudioEncoder.AAC_ELD }; class EncoderSelectedListener implements AdapterView.OnItemSelectedListener { public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2, long arg3) { mAudioEncoder = encoderArray[arg2]; } public void onNothingSelected(AdapterView<?> arg0) {} } // 初始化输出格式的下拉框 private void initFormatSpinner() { ArrayAdapter<String> formatAdapter = new ArrayAdapter<String>(this, R.layout.item_select, formatDescArray); Spinner sp_format = findViewById(R.id.sp_format); sp_format.setPrompt("请选择输出格式"); // 设置下拉框的标题 sp_format.setAdapter(formatAdapter); // 设置下拉框的数组适配器 sp_format.setSelection(0); // 设置下拉框默认显示第一项 // 给下拉框设置选择监听器，一旦用户选中某一项，就触发监听器的onItemSelected方法 sp_format.setOnItemSelectedListener(new FormatSelectedListener()); } private String[] formatDescArray = { "默认格式", "窄带格式", "宽带格式", "高级的音频传输流格式" }; private int[] formatArray = { MediaRecorder.OutputFormat.DEFAULT, MediaRecorder.OutputFormat.AMR_NB, MediaRecorder.OutputFormat.AMR_WB, MediaRecorder.OutputFormat.AAC_ADTS }; class FormatSelectedListener implements AdapterView.OnItemSelectedListener { public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2, long arg3) { mOutputFormat = formatArray[arg2]; } public void onNothingSelected(AdapterView<?> arg0) {} } // 初始化录制时长的下拉框 private void initDurationSpinner() { ArrayAdapter<String> durationAdapter = new ArrayAdapter<String>(this, R.layout.item_select, durationDescArray); Spinner sp_duration = findViewById(R.id.sp_duration); sp_duration.setPrompt("请选择录制时长"); // 设置下拉框的标题 sp_duration.setAdapter(durationAdapter); // 设置下拉框的数组适配器 sp_duration.setSelection(0); // 设置下拉框默认显示第一项 // 给下拉框设置选择监听器，一旦用户选中某一项，就触发监听器的onItemSelected方法 sp_duration.setOnItemSelectedListener(new DurationSelectedListener()); } private String[] durationDescArray = {"5秒", "10秒", "20秒", "30秒", "60秒"}; private int[] durationArray = {5, 10, 20, 30, 60}; class DurationSelectedListener implements AdapterView.OnItemSelectedListener { public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2, long arg3) { mDuration = durationArray[arg2]; } public void onNothingSelected(AdapterView<?> arg0) {} } @Override public void onClick(View v) { if (v.getId() == R.id.btn_record) { if (!isRecording) { // 未在录音 startRecord(); // 开始录音 } else { // 正在录音 stopRecord(); // 停止录音 } } else if (v.getId() == R.id.iv_audio) { mMediaPlayer.reset(); // 重置媒体播放器 mMediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC); // 设置音频流的类型为音乐 try { mMediaPlayer.setDataSource(mRecordFilePath); // 设置媒体数据的文件路径 mMediaPlayer.prepare(); // 媒体播放器准备就绪 mMediaPlayer.start(); // 媒体播放器开始播放 } catch (Exception e) { e.printStackTrace(); } } } // 开始录音 private void startRecord() { Log.d(TAG, "startRecord mAudioEncoder="+mAudioEncoder+", mOutputFormat="+mOutputFormat+", mDuration="+mDuration); ll_progress.setVisibility(View.VISIBLE); isRecording = !isRecording; btn_record.setText("停止录制"); pb_record.setMax(mDuration); // 设置进度条的最大值 mTimeCount = 0; // 时间计数清零 mTimer = new Timer(); // 创建一个计时器 mTimer.schedule(new TimerTask() { @Override public void run() { pb_record.setProgress(mTimeCount); // 设置进度条的当前进度 tv_progress.setText(MediaUtil.formatDuration(mTimeCount*1000)); mTimeCount++; } }, 0, 1000); // 计时器每隔一秒就更新进度条上的录制进度 // 获取本次录制的媒体文件路径 mRecordFilePath = MediaUtil.getRecordFilePath(this, "RecordAudio", ".amr"); // 下面是媒体录制器的处理代码 mMediaRecorder.reset(); // 重置媒体录制器 mMediaRecorder.setOnInfoListener(this); // 设置媒体录制器的信息监听器 mMediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC); // 设置音频源为麦克风 mMediaRecorder.setOutputFormat(mOutputFormat); // 设置媒体的输出格式。该方法要先于setAudioEncoder调用 mMediaRecorder.setAudioEncoder(mAudioEncoder); // 设置媒体的音频编码器 // mMediaRecorder.setAudioSamplingRate(8); // 设置媒体的音频采样率。可选 // mMediaRecorder.setAudioChannels(2); // 设置媒体的音频声道数。可选 // mMediaRecorder.setAudioEncodingBitRate(1024); // 设置音频每秒录制的字节数。可选 mMediaRecorder.setMaxDuration(mDuration * 1000); // 设置媒体的最大录制时长 // mMediaRecorder.setMaxFileSize(1024*1024*10); // 设置媒体的最大文件大小 // setMaxFileSize与setMaxDuration设置其一即可 mMediaRecorder.setOutputFile(mRecordFilePath); // 设置媒体文件的保存路径 try { mMediaRecorder.prepare(); // 媒体录制器准备就绪 mMediaRecorder.start(); // 媒体录制器开始录制 } catch (Exception e) { e.printStackTrace(); } } // 停止录音 private void stopRecord() { isRecording = !isRecording; btn_record.setText("开始录制"); mTimer.cancel(); // 取消定时器 mMediaRecorder.stop(); // 媒体录制器停止录制 } @Override public void onInfo(MediaRecorder mr, int what, int extra) { // 录制达到最大时长，或者达到文件大小限制，都停止录制 if (what == MediaRecorder.MEDIA_RECORDER_INFO_MAX_DURATION_REACHED || what == MediaRecorder.MEDIA_RECORDER_INFO_MAX_FILESIZE_REACHED) { stopRecord(); // 停止录音 iv_audio.setVisibility(View.VISIBLE); Toast.makeText(this, "已结束录制，音频文件路径为"+mRecordFilePath, Toast.LENGTH_LONG).show(); } } @Override protected void onStop() { super.onStop(); if (!TextUtils.isEmpty(mRecordFilePath) && isRecording) { stopRecord(); // 停止录音 } if (mMediaPlayer.isPlaying()) { // 如果正在播放 mMediaPlayer.stop(); // 停止播放 } } @Override protected void onDestroy() { super.onDestroy(); mMediaRecorder.release(); // 释放媒体录制器 mMediaPlayer.release(); // 释放媒体播放器 } }
