Android MP3录音实现

    给APP做语音功能，必须考虑到IOS和Android平台的通用性。wav录音质量高，文件太大，AAC和AMR格式在IOS平台却不支持，所以采用libmp3lame把AudioRecord音频流直接转换成MP3格式。

       声明一下，代码参考了http://blog.csdn.net/cboy017/article/details/8455629，这里只是借花献佛，把整个流程写得更详细。

       这里采用的是最新的lame-3.99.5.tar。

       可以去Lame官网下载，博文最后也有CSDN下载地址。官网地址：http://lame.sourceforge.net/

       如果你对JNI和NDK完全不熟悉的话，请看前一篇博文 Android NDK开发之入门教程

      先看一下项目文件目录：

       

       开始Coding吧！

 

1  新建项目AndroidLameMP3。

2  创建JNI目录。

3 下载lame-3.99.5.tar。

       解压，把子文件夹libmp3lame中的非.h和.c格式的文件删除后的剩余的所有文件和include下的lame.h放进一个新建的lame-3.99.5_libmp3lame文件夹中，最后把整个lame-3.99.5_libmp3lame文件夹拷贝到JNI目录下。

4  在com.example.lamemp3下创建MP3Recorder.class：

MP3Recorder.class

public class MP3Recorder {

    private String mFilePath = null;
    private int sampleRate = 0;
    private boolean isRecording = false;
    private boolean isPause = false;
    private Handler handler = null;

    /**
     * 开始录音
     */
    public static final int MSG_REC_STARTED = 1;

    /**
     * 结束录音
     */
    public static final int MSG_REC_STOPPED = 2;

    /**
     * 暂停录音
     */
    public static final int MSG_REC_PAUSE = 3;

    /**
     * 继续录音
     */
    public static final int MSG_REC_RESTORE = 4;

    /**
     * 缓冲区挂了,采样率手机不支持
     */
    public static final int MSG_ERROR_GET_MIN_BUFFERSIZE = -1;

    /**
     * 创建文件时扑街了
     */
    public static final int MSG_ERROR_CREATE_FILE = -2;

    /**
     * 初始化录音器时扑街了
     */
    public static final int MSG_ERROR_REC_START = -3;

    /**
     * 录音的时候出错
     */
    public static final int MSG_ERROR_AUDIO_RECORD = -4;

    /**
     * 编码时挂了
     */
    public static final int MSG_ERROR_AUDIO_ENCODE = -5;

    /**
     * 写文件时挂了
     */
    public static final int MSG_ERROR_WRITE_FILE = -6;

    /**
     * 没法关闭文件流
     */
    public static final int MSG_ERROR_CLOSE_FILE = -7;

    public MP3Recorder() {
        this.sampleRate = 8000;
    }

    /**
     * 开片
     */
    public void start() {
        if (isRecording) {
            return;
        }

        new Thread() {
            @Override
            public void run() {
                String fileDir = StorageUtil.getSDPath() + "LameMP3/Voice/";

                File dir = new File(fileDir);
                if (!dir.exists()) {
                    dir.mkdirs();
                }

                mFilePath = StorageUtil.getSDPath() + "LameMP3/Voice/"
                        + System.currentTimeMillis() + ".mp3";

                System.out.println(mFilePath);
                android.os.Process
                        .setThreadPriority(android.os.Process.THREAD_PRIORITY_URGENT_AUDIO);
                // 根据定义好的几个配置，来获取合适的缓冲大小
                final int minBufferSize = AudioRecord.getMinBufferSize(
                        sampleRate, AudioFormat.CHANNEL_IN_MONO,
                        AudioFormat.ENCODING_PCM_16BIT);
                if (minBufferSize < 0) {
                    if (handler != null) {
                        handler.sendEmptyMessage(MSG_ERROR_GET_MIN_BUFFERSIZE);
                    }
                    return;
                }
                AudioRecord audioRecord = new AudioRecord(
                        MediaRecorder.AudioSource.MIC, sampleRate,
                        AudioFormat.CHANNEL_IN_MONO,
                        AudioFormat.ENCODING_PCM_16BIT, minBufferSize * 2);

                // 5秒的缓冲
                short[] buffer = new short[sampleRate * (16 / 8) * 1 * 5];
                byte[] mp3buffer = new byte[(int) (7200 + buffer.length * 2 * 1.25)];

                FileOutputStream output = null;
                try {
                    output = new FileOutputStream(new File(mFilePath));
                } catch (FileNotFoundException e) {
                    if (handler != null) {
                        handler.sendEmptyMessage(MSG_ERROR_CREATE_FILE);
                    }
                    return;
                }
                MP3Recorder.init(sampleRate, 1, sampleRate, 32);
                isRecording = true; // 录音状态
                isPause = false; // 录音状态
                try {
                    try {
                        audioRecord.startRecording(); // 开启录音获取音频数据
                    } catch (IllegalStateException e) {
                        // 不给录音...
                        if (handler != null) {
                            handler.sendEmptyMessage(MSG_ERROR_REC_START);
                        }
                        return;
                    }

                    try {
                        // 开始录音
                        if (handler != null) {
                            handler.sendEmptyMessage(MSG_REC_STARTED);
                        }

                        int readSize = 0;
                        boolean pause = false;
                        while (isRecording) {
                            /*--暂停--*/
                            if (isPause) {
                                if (!pause) {
                                    handler.sendEmptyMessage(MSG_REC_PAUSE);
                                    pause = true;
                                }
                                continue;
                            }
                            if (pause) {
                                handler.sendEmptyMessage(MSG_REC_RESTORE);
                                pause = false;
                            }
                            /*--End--*/
                            /*--实时录音写数据--*/
                            readSize = audioRecord.read(buffer, 0,
                                    minBufferSize);
                            if (readSize < 0) {
                                if (handler != null) {
                                    handler.sendEmptyMessage(MSG_ERROR_AUDIO_RECORD);
                                }
                                break;
                            } else if (readSize == 0) {
                                ;
                            } else {
                                int encResult = MP3Recorder.encode(buffer,
                                        buffer, readSize, mp3buffer);
                                if (encResult < 0) {
                                    if (handler != null) {
                                        handler.sendEmptyMessage(MSG_ERROR_AUDIO_ENCODE);
                                    }
                                    break;
                                }
                                if (encResult != 0) {
                                    try {
                                        output.write(mp3buffer, 0, encResult);
                                    } catch (IOException e) {
                                        if (handler != null) {
                                            handler.sendEmptyMessage(MSG_ERROR_WRITE_FILE);
                                        }
                                        break;
                                    }
                                }
                            }
                            /*--End--*/
                        }
                        /*--录音完--*/
                        int flushResult = MP3Recorder.flush(mp3buffer);
                        if (flushResult < 0) {
                            if (handler != null) {
                                handler.sendEmptyMessage(MSG_ERROR_AUDIO_ENCODE);
                            }
                        }
                        if (flushResult != 0) {
                            try {
                                output.write(mp3buffer, 0, flushResult);
                            } catch (IOException e) {
                                if (handler != null) {
                                    handler.sendEmptyMessage(MSG_ERROR_WRITE_FILE);
                                }
                            }
                        }
                        try {
                            output.close();
                        } catch (IOException e) {
                            if (handler != null) {
                                handler.sendEmptyMessage(MSG_ERROR_CLOSE_FILE);
                            }
                        }
                        /*--End--*/
                    } finally {
                        audioRecord.stop();
                        audioRecord.release();
                    }
                } finally {
                    MP3Recorder.close();
                    isRecording = false;
                }
                if (handler != null) {
                    handler.sendEmptyMessage(MSG_REC_STOPPED);
                }
            }
        }.start();
    }

    public void stop() {
        isRecording = false;
    }

    public void pause() {
        isPause = true;
    }

    public void restore() {
        isPause = false;
    }

    public boolean isRecording() {
        return isRecording;
    }

    public boolean isPaus() {
        if (!isRecording) {
            return false;
        }
        return isPause;
    }

    public String getFilePath() {
        return mFilePath;
    }

    /**
     * 录音状态管理
     *
     * @see RecMicToMp3#MSG_REC_STARTED
     * @see RecMicToMp3#MSG_REC_STOPPED
     * @see RecMicToMp3#MSG_REC_PAUSE
     * @see RecMicToMp3#MSG_REC_RESTORE
     * @see RecMicToMp3#MSG_ERROR_GET_MIN_BUFFERSIZE
     * @see RecMicToMp3#MSG_ERROR_CREATE_FILE
     * @see RecMicToMp3#MSG_ERROR_REC_START
     * @see RecMicToMp3#MSG_ERROR_AUDIO_RECORD
     * @see RecMicToMp3#MSG_ERROR_AUDIO_ENCODE
     * @see RecMicToMp3#MSG_ERROR_WRITE_FILE
     * @see RecMicToMp3#MSG_ERROR_CLOSE_FILE
     */
    public void setHandle(Handler handler) {
        this.handler = handler;
    }

    /*--以下为Native部分--*/
    static {
        System.loadLibrary("mp3lame");
    }

    /**
     * 初始化录制参数
     */
    public static void init(int inSamplerate, int outChannel,
            int outSamplerate, int outBitrate) {
        init(inSamplerate, outChannel, outSamplerate, outBitrate, 7);
    }

    /**
     * 初始化录制参数 quality:0=很好很慢 9=很差很快
     */
    public native static void init(int inSamplerate, int outChannel,
            int outSamplerate, int outBitrate, int quality);

    /**
     * 音频数据编码(PCM左进,PCM右进,MP3输出)
     */
    public native static int encode(short[] buffer_l, short[] buffer_r,
            int samples, byte[] mp3buf);

    /**
     * 刷干净缓冲区
     */
    public native static int flush(byte[] mp3buf);

    /**
     * 结束编码
     */
    public native static void close();
}

5  在JNI文件夹下创建com_example_lamemp3_MP3Recorder.h头文件，在里面定义几个方法，然后在
com_example_lamemp3_MP3Recorder.c中实现。

com_example_lamemp3_MP3Recorder.h：

/* DO NOT EDIT THIS FILE - it is machine generated */
#include <jni.h>
/* Header for class com_kubility_demo_MP3Recorder */

#ifndef _Included_com_example_lamemp3_MP3Recorder
#define _Included_com_example_lamemp3_MP3Recorder
#ifdef __cplusplus
extern "C" {
#endif
/*
 * Class:     com_kubility_demo_MP3Recorder
 * Method:    init
 * Signature: (IIIII)V
 */
JNIEXPORT void JNICALL Java_com_example_lamemp3_MP3Recorder_init
  (JNIEnv *, jclass, jint, jint, jint, jint, jint);

/*
 * Class:     com_kubility_demo_MP3Recorder
 * Method:    encode
 * Signature: ([S[SI[B)I
 */
JNIEXPORT jint JNICALL Java_com_example_lamemp3_MP3Recorder_encode
  (JNIEnv *, jclass, jshortArray, jshortArray, jint, jbyteArray);

/*
 * Class:     com_kubility_demo_MP3Recorder
 * Method:    flush
 * Signature: ([B)I
 */
JNIEXPORT jint JNICALL Java_com_example_lamemp3_MP3Recorder_flush
  (JNIEnv *, jclass, jbyteArray);

/*
 * Class:     com_kubility_demo_MP3Recorder
 * Method:    close
 * Signature: ()V
 */
JNIEXPORT void JNICALL Java_com_example_lamemp3_MP3Recorder_close
  (JNIEnv *, jclass);

#ifdef __cplusplus
}
#endif
#endif

com_example_lamemp3_MP3Recorder.c：

#include "lame-3.99.5_libmp3lame/lame.h"
#include "com_example_lamemp3_MP3Recorder.h"

static lame_global_flags *glf = NULL;

JNIEXPORT void JNICALL Java_com_example_lamemp3_MP3Recorder_init(
        JNIEnv *env, jclass cls, jint inSamplerate, jint outChannel,
        jint outSamplerate, jint outBitrate, jint quality) {
    if (glf != NULL) {
        lame_close(glf);
        glf = NULL;
    }
    glf = lame_init();
    lame_set_in_samplerate(glf, inSamplerate);
    lame_set_num_channels(glf, outChannel);
    lame_set_out_samplerate(glf, outSamplerate);
    lame_set_brate(glf, outBitrate);
    lame_set_quality(glf, quality);
    lame_init_params(glf);
}

JNIEXPORT jint JNICALL Java_com_example_lamemp3_MP3Recorder_encode(
        JNIEnv *env, jclass cls, jshortArray buffer_l, jshortArray buffer_r,
        jint samples, jbyteArray mp3buf) {
    jshort* j_buffer_l = (*env)->GetShortArrayElements(env, buffer_l, NULL);

    jshort* j_buffer_r = (*env)->GetShortArrayElements(env, buffer_r, NULL);

    const jsize mp3buf_size = (*env)->GetArrayLength(env, mp3buf);
    jbyte* j_mp3buf = (*env)->GetByteArrayElements(env, mp3buf, NULL);

    int result = lame_encode_buffer(glf, j_buffer_l, j_buffer_r,
            samples, j_mp3buf, mp3buf_size);

    (*env)->ReleaseShortArrayElements(env, buffer_l, j_buffer_l, 0);
    (*env)->ReleaseShortArrayElements(env, buffer_r, j_buffer_r, 0);
    (*env)->ReleaseByteArrayElements(env, mp3buf, j_mp3buf, 0);

    return result;
}

JNIEXPORT jint JNICALL Java_com_example_lamemp3_MP3Recorder_flush(
        JNIEnv *env, jclass cls, jbyteArray mp3buf) {
    const jsize mp3buf_size = (*env)->GetArrayLength(env, mp3buf);
    jbyte* j_mp3buf = (*env)->GetByteArrayElements(env, mp3buf, NULL);

    int result = lame_encode_flush(glf, j_mp3buf, mp3buf_size);

    (*env)->ReleaseByteArrayElements(env, mp3buf, j_mp3buf, 0);

    return result;
}

JNIEXPORT void JNICALL Java_com_example_lamemp3_MP3Recorder_close(
        JNIEnv *env, jclass cls) {
    lame_close(glf);
    glf = NULL;
}

6  创建Android.mk，注意把com_example_lamemp3_MP3Recorder.c添加进去。

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)

LAME_LIBMP3_DIR := lame-3.99.5_libmp3lame

LOCAL_MODULE    := mp3lame
LOCAL_SRC_FILES := $(LAME_LIBMP3_DIR)/bitstream.c $(LAME_LIBMP3_DIR)/fft.c $(LAME_LIBMP3_DIR)/id3tag.c $(LAME_LIBMP3_DIR)/mpglib_interface.c $(LAME_LIBMP3_DIR)/presets.c $(LAME_LIBMP3_DIR)/quantize.c $(LAME_LIBMP3_DIR)/reservoir.c $(LAME_LIBMP3_DIR)/tables.c $(LAME_LIBMP3_DIR)/util.c $(LAME_LIBMP3_DIR)/VbrTag.c $(LAME_LIBMP3_DIR)/encoder.c $(LAME_LIBMP3_DIR)/gain_analysis.c $(LAME_LIBMP3_DIR)/lame.c $(LAME_LIBMP3_DIR)/newmdct.c $(LAME_LIBMP3_DIR)/psymodel.c $(LAME_LIBMP3_DIR)/quantize_pvt.c $(LAME_LIBMP3_DIR)/set_get.c $(LAME_LIBMP3_DIR)/takehiro.c $(LAME_LIBMP3_DIR)/vbrquantize.c $(LAME_LIBMP3_DIR)/version.c com_example_lamemp3_MP3Recorder.c

include $(BUILD_SHARED_LIBRARY)

7  AndroidManifest.xml添加权限。

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
 <uses-permission android:name="android.permission.RECORD_AUDIO" />

8  创建Builder后（上篇中有详细介绍，这里不赘述），Clean，报错：

In file included from jni/lame-3.99.5_libmp3lame/bitstream.c:36:0:
jni/lame-3.99.5_libmp3lame/util.h:574:5: error: unknown type name 'ieee754_float32_t'
jni/lame-3.99.5_libmp3lame/util.h:574:40: error: unknown type name 'ieee754_float32_t'
make.exe: *** [obj/local/armeabi/objs/mp3lame/lame-3.99.5_libmp3lame/bitstream.o] Error 1

打开util.h
把 574行的 extern ieee754_float32_t fast_log2(ieee754_float32_t x);替换成extern float fast_log2(float x);

再次Clean，又报错：

jni/lame-3.99.5_libmp3lame/fft.c:47:32: fatal error: vector/lame_intrin.h: No such file or directory
compilation terminated.
make.exe: *** [obj/local/armeabi/objs/mp3lame/lame-3.99.5_libmp3lame/fft.o] Error 1

打开fft.c删除47行#include "vector/lame_intrin.h"

Clean还报错：

In file included from jni/lame-3.99.5_libmp3lame/presets.c:29:0:
jni/lame-3.99.5_libmp3lame/set_get.h:24:18: fatal error: lame.h: No such file or directory
compilation terminated.
make.exe: *** [obj/local/armeabi/objs/mp3lame/lame-3.99.5_libmp3lame/presets.o] Error 1

打开set_get.h，删除24行，#include <lame.h>

再次Clean，成功：

[armeabi] Compile thumb  : mp3lame <= version.c
[armeabi] Compile thumb  : mp3lame <= com_example_lamemp3_MP3Recorder.c
[armeabi] SharedLibrary  : libmp3lame.so
[armeabi] Install        : libmp3lame.so => libs/armeabi/libmp3lame.so