Android音視頻開(kāi)發(fā)之——音頻非壓縮編碼和壓縮編碼
2021-09-24 14:45:43

public AudioRecord (int audioSource, 
                int sampleRateInHz, 
                int channelConfig, 
                int audioFormat, 
                int bufferSizeInBytes)

public static int getMinBufferSize (int sampleRateInHz, 
                int channelConfig, 
                int audioFormat)

if (null!=audioRecord && audioRecord?.state!=AudioRecord.STATE_UNINITIALIZED){
    audioRecord?.startRecording()
}

thread = Thread(Runnable {
   writeData2File()
})
thread?.start()

private fun writeData2File() {
    var ret = 0
    val byteArray = ByteArray(bufferSizeInBytes)
    val file = File(externalCacheDir?.absolutePath + File.separator + filename)

    if (file.exists()) {
        file.delete()
    } else {
        file.createNewFile()
    }
    val fos = FileOutputStream(file)
    while (status == Status.STARTING) {
        ret = audioRecord?.read(byteArray, 0, bufferSizeInBytes)!!
        if (ret!=AudioRecord.ERROR_BAD_VALUE || ret!=AudioRecord.ERROR_INVALID_OPERATION|| ret!=AudioRecord.ERROR_DEAD_OBJECT){
            fos.write(byteArray)
        }
    }
    fos.close()
}

if (null!=audioRecord && audioRecord?.state!=AudioRecord.STATE_UNINITIALIZED){
    audioRecord?.stop()
}

if (thread!=null){
    thread?.join()
    thread =null
}

if (audioRecord != null) {
    audioRecord?.release()
    audioRecord = null
}

public AudioTrack (int streamType, 
                int sampleRateInHz, 
                int channelConfig, 
                int audioFormat, 
                int bufferSizeInBytes, 
                int mode, 
                int sessionId)

public AudioTrack (AudioAttributes attributes, 
                AudioFormat format, 
                int bufferSizeInBytes, 
                int mode, 
                int sessionId)

var audioAttributes = AudioAttributes.Builder()
    .setLegacyStreamType(AudioManager.STREAM_MUSIC)
    .build()

var mAudioFormat = AudioFormat.Builder()
    .setChannelMask(channel)
    .setEncoding(audioFormat)
    .setSampleRate(sampleRate)
    .build()

if (null!=audioTrack && audioTrack?.state != AudioTrack.STATE_UNINITIALIZED){
    audioTrack?.play()
}

thread= Thread(Runnable {
    readDataFromFile()
})
thread?.start()

private fun readDataFromFile() {
    val byteArray = ByteArray(bufferSizeInBytes)

    val file = File(externalCacheDir?.absolutePath + File.separator + filename)
    if (!file.exists()) {
        Toast.makeText(this, "請(qǐng)先進(jìn)行錄制PCM音頻", Toast.LENGTH_SHORT).show()
        return
    }
    val fis = FileInputStream(file)
    var read: Int
    status = Status.STARTING

    while ({ read = fis.read(byteArray);read }() > 0) {
        var ret = audioTrack?.write(byteArray, 0, bufferSizeInBytes)!!
        if (ret == AudioTrack.ERROR_BAD_VALUE || ret == AudioTrack.ERROR_INVALID_OPERATION || ret == AudioManager.ERROR_DEAD_OBJECT) {
            break
        }
    }
    fis.close()
}

if (audioTrack != null && audioTrack?.state != AudioTrack.STATE_UNINITIALIZED) {
    audioTrack?.stop()
}

if (thread!=null){
    thread?.join()
    thread =null
}

if (audioTrack != null) {
    audioTrack?.release()
    audioTrack = null
}

mediaCodec = MediaCodec.createEncoderByType(MediaFormat.MIMETYPE_AUDIO_AAC)

// 配置采樣率和聲道數(shù)
mediaFormat = MediaFormat.createAudioFormat(MINE_TYPE,sampleRate,channel)
// 配置比特率
mediaFormat?.setInteger(MediaFormat.KEY_BIT_RATE,bitRate)
// 配置PROFILE，其中屬AAC-LC兼容性最好
mediaFormat?.setInteger(MediaFormat.KEY_AAC_PROFILE, MediaCodecInfo.CodecProfileLevel.AACObjectLC)
// 最大輸入大小
mediaFormat?.setInteger(MediaFormat.KEY_MAX_INPUT_SIZE, 10 * 1024)

mediaCodec!!.configure(mediaFormat,null,null,MediaCodec.CONFIGURE_FLAG_ENCODE)
mediaCodec?.start()

inputBuffers = mediaCodec?.inputBuffers
outputBuffers = mediaCodec?.outputBuffers

thread = Thread(Runnable {
    val fis = FileInputStream(pcmFile)
    fos = FileOutputStream(aacFile)
    var read: Int
    while ({ read = fis.read(byteArray);read }() > 0) {
        encode(byteArray)
    }
})
thread?.start()

private fun encode(byteArray: ByteArray){
    mediaCodec?.run {
        //返回要用有效數(shù)據(jù)填充的輸入緩沖區(qū)的索引， -1 無(wú)限期地等待輸入緩沖區(qū)的可用性
        val inputIndex = dequeueInputBuffer(-1)
        if (inputIndex > 0){
            // 根據(jù)索引獲取可用輸入緩存區(qū)
            val inputBuffer = this@AACEncoder.inputBuffers!![inputIndex]
            // 清空緩沖區(qū)
            inputBuffer.clear()
            // 將pcm數(shù)據(jù)放入緩沖區(qū)
            inputBuffer.put(byteArray)
            // 提交放入數(shù)據(jù)緩沖區(qū)索引以及大小
            queueInputBuffer(inputIndex,0,byteArray.size,System.nanoTime(),0)
        }
        // 指定編碼器緩沖區(qū)中有效數(shù)據(jù)范圍
        val bufferInfo = MediaCodec.BufferInfo()
        // 獲取輸出緩沖區(qū)索引
        var outputIndex = dequeueOutputBuffer(bufferInfo,0)

        while (outputIndex>0){
            // 根據(jù)索引獲取可用輸出緩存區(qū)
            val outputBuffer =this@AACEncoder.outputBuffers!![outputIndex]
            // 測(cè)量輸出緩沖區(qū)大小
            val bufferSize = bufferInfo.size
            // 輸出緩沖區(qū)實(shí)際大小，ADTS頭部長(zhǎng)度為7
            val bufferOutSize = bufferSize+7

            // 指定輸出緩存區(qū)偏移位置以及限制大小
            outputBuffer.position(bufferInfo.offset)
            outputBuffer.limit(bufferInfo.offset+bufferSize)
            // 創(chuàng)建輸出空數(shù)據(jù)
            val data = ByteArray(bufferOutSize)
            // 向空數(shù)據(jù)先增加ADTS頭部
            addADTStoPacket(data, bufferOutSize)
            // 將編碼輸出數(shù)據(jù)寫(xiě)入已加入ADTS頭部的數(shù)據(jù)中
            outputBuffer.get(data,7,bufferInfo.size)
            // 重新指定輸出緩存區(qū)偏移
            outputBuffer.position(bufferInfo.offset)
            // 將獲取的數(shù)據(jù)寫(xiě)入文件
            fos?.write(data)
            // 釋放輸出緩沖區(qū)
            releaseOutputBuffer(outputIndex,false)
            // 重新獲取輸出緩沖區(qū)索引
            outputIndex=dequeueOutputBuffer(bufferInfo,0)
        }
    }
}

fos?.close()
fis.close()

if (mediaCodec!=null){
     mediaCodec?.stop()
}

if (thread!=null){
    thread?.join()
    thread =null
}

if (mediaCodec!=null){
    mediaCodec?.release()
    mediaCodec = null

    mediaFormat = null
    inputBuffers = null
    outputBuffers = null
}

extern ieee754_float32_t fast_log2(ieee754_float32_t x)

extern float fast_log2(float x)

#ifdef STDC_HEADERS
# include <stddef.h>
# include <stdlib.h>
# include <string.h>
# include <ctype.h>
#else

/*# ifndef HAVE_STRCHR
#  define strchr index
#  define strrchr rindex
# endif
 */
char *strchr(), *strrchr();

/*# ifndef HAVE_MEMCPY
#  define memcpy(d, s, n) bcopy ((s), (d), (n))
# endif*/
#endif

//#include "vector/lame_intrin.h"

#include <lame.h>

#include "lame.h"

class Mp3Encoder {

    companion object {
        init {
            System.loadLibrary("mp3encoder")
        }
    }

    external fun init(
        pcmPath: String,
        channel: Int,
        bitRate: Int,
        sampleRate: Int,
        mp3Path: String
    ): Int

    external fun encode()

    external fun destroy()
}

FILE* pcmFile;
FILE* mp3File;
lame_t lameClient;

#include <jni.h>
#include <string>
#include "android/log.h"
#include "libmp3lame/lame.h"
#include "mp3-encoder.h"

#define LOGD(...) __android_log_print(ANDROID_LOG_DEBUG  , "mp3-encoder", __VA_ARGS__)

extern "C" JNIEXPORT jint JNICALL
Java_com_coder_media_Mp3Encoder_init(JNIEnv *env, jobject obj, jstring pcmPathParam, jint channels,
                                     jint bitRate, jint sampleRate, jstring mp3PathParam) {
    LOGD("encoder init");
    int ret = -1;
    const char* pcmPath = env->GetStringUTFChars(pcmPathParam, NULL);
    const char* mp3Path = env->GetStringUTFChars(mp3PathParam, NULL);
    pcmFile = fopen(pcmPath,"rb");
    if (pcmFile){
        mp3File = fopen(mp3Path,"wb");
        if (mp3File){
            lameClient = lame_init();
            lame_set_in_samplerate(lameClient, sampleRate);
            lame_set_out_samplerate(lameClient,sampleRate);
            lame_set_num_channels(lameClient,channels);
            lame_set_brate(lameClient,bitRate);
            lame_init_params(lameClient);
            ret = 0;
        }
    }
    env->ReleaseStringUTFChars(mp3PathParam, mp3Path);
    env->ReleaseStringUTFChars(pcmPathParam, pcmPath);
    return ret;
}

extern "C" JNIEXPORT void JNICALL
Java_com_coder_media_Mp3Encoder_encode(JNIEnv *env, jobject obj) {
    LOGD("encoder encode");
    int bufferSize = 1024 * 256;
    short* buffer = new short[bufferSize / 2];
    short* leftBuffer = new short[bufferSize / 4];
    short* rightBuffer = new short[bufferSize / 4];

    unsigned char* mp3_buffer = new unsigned char[bufferSize];
    size_t readBufferSize = 0;

    while ((readBufferSize = fread(buffer, 2, bufferSize / 2, pcmFile)) > 0) {
        for (int i = 0; i < readBufferSize; i++) {
            if (i % 2 == 0) {
                leftBuffer[i / 2] = buffer[i];
            } else {
                rightBuffer[i / 2] = buffer[i];
            }
        }
        size_t wroteSize = lame_encode_buffer(lameClient, (short int *) leftBuffer, (short int *) rightBuffer,
                                              (int)(readBufferSize / 2), mp3_buffer, bufferSize);
        fwrite(mp3_buffer, 1, wroteSize, mp3File);
    }
    delete[] buffer;
    delete[] leftBuffer;
    delete[] rightBuffer;
    delete[] mp3_buffer;
}

extern "C" JNIEXPORT void JNICALL
Java_com_coder_media_Mp3Encoder_destroy(JNIEnv *env, jobject obj) {
    LOGD("encoder destroy");
    if(pcmFile) {
        fclose(pcmFile);
    }
    if(mp3File) {
        fclose(mp3File);
        lame_close(lameClient);
    }
}

// 引入目錄
include_directories(libmp3lame)
// 將libmp3lame下所有文件路徑賦值給 SRC_LIST
aux_source_directory(libmp3lame SRC_LIST)

// 加入libmp3lame所有c文件
add_library(mp3encoder
        SHARED
        mp3-encoder.cpp ${SRC_LIST})

target_link_libraries( 
        mp3encoder
        native-lib
        ${log-lib})

private fun encodeAudio() {
    var pcmPath = File(externalCacheDir, "record.pcm").absolutePath
    var target = File(externalCacheDir, "target.mp3").absolutePath
    var encoder = Mp3Encoder()
    if (!File(pcmPath).exists()) {
        Toast.makeText(this, "請(qǐng)先進(jìn)行錄制PCM音頻", Toast.LENGTH_SHORT).show()
        return
    }
    var ret = encoder.init(pcmPath, 2, 128, 44100, target)
    if (ret == 0) {
        encoder.encode()
        encoder.destroy()
        Toast.makeText(this, "PCM->MP3編碼完成", Toast.LENGTH_SHORT).show()
    } else {
        Toast.makeText(this, "Lame初始化失敗", Toast.LENGTH_SHORT).show()
    }
}

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)
LOCAL_MODULE := mp3encoder

LOCAL_SRC_FILES := mp3-encoder.cpp 
                 libmp3lame/bitstream.c 
                 libmp3lame/psymodel.c 
                 libmp3lame/lame.c 
                 libmp3lame/takehiro.c 
                 libmp3lame/encoder.c 
                 libmp3lame/quantize.c 
                 libmp3lame/util.c 
                 libmp3lame/fft.c 
                 libmp3lame/quantize_pvt.c 
                 libmp3lame/vbrquantize.c 
                 libmp3lame/gain_analysis.c 
                 libmp3lame/reservoir.c 
                 libmp3lame/VbrTag.c 
                 libmp3lame/mpglib_interface.c 
                 libmp3lame/id3tag.c 
                 libmp3lame/newmdct.c 
                 libmp3lame/set_get.c 
                 libmp3lame/version.c 
                 libmp3lame/presets.c 
                 libmp3lame/tables.c 

LOCAL_LDLIBS := -llog -ljnigraphics -lz -landroid -lm -pthread -L$(SYSROOT)/usr/lib

include $(BUILD_SHARED_LIBRARY)

APP_ABI := all 
APP_PLATFORM := android-21
APP_OPTIM := release
APP_STL := c++_static

/home/relo/Android/Sdk/ndk-bundle/ndk-build