一、需要閱讀的文章
https://blog.csdn.net/feifeiwendao/article/details/52527824
####MediaCodec類相關的文章:########
https://www.cnblogs.com/renhui/p/7478527.html
https://blog.csdn.net/junzia/article/details/54018671 (思路很清晰的一篇文章)
https://www.cnblogs.com/roger-yu/p/5635494.html
https://www.cnblogs.com/Sharley/p/5964490.html
https://blog.csdn.net/leif_/article/details/50971616
MediaCodec實際上就是一個編解碼的容器,将byte[]放進去,取出來就得到自己想要的編碼格式的byte[],然後
寫入檔案即可。
#########AudioRecorder錄音:###################
https://blog.csdn.net/qq_36982160/article/details/79383046
https://www.cnblogs.com/whoislcj/p/5477216.html
錄音的流程:
1)初始化AudioRecorder
2)調用AudioRecorder的startRecording方法
3)調用AudioRecorder的read方法,讀出byte[]資料。你可以選擇将資料存儲到檔案,最終得到的是.pcm檔案。
這種檔案一般播放器不支援,需要用andorid的AudioTrack去播放。
AudioTrack,播放PCM音頻檔案。
https://www.cnblogs.com/stnlcd/p/7151438.html
注意:AudioTrack的構造參數,要與錄制時的參數保持一緻 。如channelConfig如果不對應
則人說話的聲音就超級奇怪了。
以下是PCM錄音和播放的源碼:
package com.xinyi.czsuperrecorder;
import android.media.AudioFormat;
import android.media.AudioManager;
import android.media.AudioRecord;
import android.media.AudioTrack;
import android.media.MediaCodec;
import android.media.MediaCodecInfo;
import android.media.MediaFormat;
import android.media.MediaRecorder;
import android.util.Log;
import com.xinyi.baselib.io.tf.TFileHelper;
import java.io.BufferedInputStream;
import java.io.DataInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
/**
* Created by XinYi on 2018/7/5.
* (錄音API)
*/
public class AudioRecorder {
private static final String TAG = "AudioRecorder";
private int sampleRate=44100; //采樣率,預設44.1k
private int channelConfig= AudioFormat.CHANNEL_IN_STEREO; //通道設定,預設立體聲
private int audioFormat=AudioFormat.ENCODING_PCM_16BIT; //設定采樣資料格式,預設16比特PCM
private AudioRecord mRecorder;
private int bufferSize;
private File recordingFile = new File(TFileHelper.getInstance().getRoot() + "/test/a.pcm");
public void prepare(){
bufferSize = AudioRecord.getMinBufferSize(sampleRate, channelConfig, audioFormat)*2;
// buffer=new byte[bufferSize];
mRecorder=new AudioRecord(MediaRecorder.AudioSource.MIC,sampleRate,channelConfig,
audioFormat,bufferSize);
}
public void start() throws IOException {
byte[] tempBuffer = new byte[bufferSize];
if (mRecorder.getState() != AudioRecord.STATE_INITIALIZED) {
stop();
return;
}
//開始錄制
mRecorder.startRecording();
//循環讀取資料到buffer中,并儲存buffer中的資料到檔案中
Log.e(TAG, "start: 錄音中。。。");
TFileHelper.getInstance().deleteFile(recordingFile.getAbsolutePath());
TFileHelper.getInstance().createFile(recordingFile.getAbsolutePath());
FileOutputStream fileOutputStream = null;
try {
fileOutputStream = new FileOutputStream(recordingFile);
int length;
while ((length = mRecorder.read(tempBuffer, 0, bufferSize)) != -1) {
fileOutputStream.write(tempBuffer, 0, length);
fileOutputStream.flush();
}
} catch (IOException e) {
e.printStackTrace();
} finally {
if (fileOutputStream != null) {
try {
fileOutputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
public void stop(){
//中止循環并結束錄制
mRecorder.stop();
Log.e(TAG, "start: 錄音結束。。。");
}
//播放音頻(PCM)
public void play()
{
DataInputStream dis=null;
try {
//從音頻檔案中讀取聲音
dis=new DataInputStream(new BufferedInputStream(new FileInputStream(recordingFile)));
} catch (FileNotFoundException e) {
e.printStackTrace();
}
//最小緩存區
int bufferSizeInBytes= AudioTrack.getMinBufferSize(sampleRate,AudioFormat.CHANNEL_OUT_MONO,AudioFormat.ENCODING_PCM_16BIT);
//建立AudioTrack對象 依次傳入 :流類型、采樣率(與采集的要一緻)、音頻通道(采集是IN 播放時OUT)、量化位數、最小緩沖區、模式
/**
* !!注意,音頻通道與錄制時的音頻通道要保持一緻。
*/
AudioTrack player=new AudioTrack(AudioManager.STREAM_MUSIC,sampleRate,AudioFormat.CHANNEL_OUT_STEREO,AudioFormat.ENCODING_PCM_16BIT, bufferSizeInBytes, AudioTrack.MODE_STREAM);
byte[] data =new byte [bufferSizeInBytes];
player.play();//開始播放
while(true)
{
int i=0;
try {
while(dis.available()>0&&i<data.length)
{
data[i]=dis.readByte();
i++;
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
player.write(data,0,data.length);
if(i!=bufferSizeInBytes) //表示讀取完了
{
player.stop();//停止播放
player.release();//釋放資源
break;
}
}
}
public AudioRecord getmRecorder() {
return mRecorder;
}
public int getBufferSize() {
return bufferSize;
}
}
二、緩沖區
https://blog.csdn.net/bzlj2912009596/article/details/75581675
三、音頻AAC編碼
關于AAC編碼的文章:
https://blog.csdn.net/jay100500/article/details/52955232/ (AAC的頭檔案,介紹了一款工具可以檢視aac檔案的頭檔案)
音頻AAC編碼實作過程
1)開啟音頻錄制
2)通過MediaCodec,将音頻編碼,得到AAC裸流,加上AAC頭,然後再寫入檔案。
代碼如下:
package com.xinyi.czsuperrecorder.code.audio;
import android.media.AudioRecord;
import android.media.MediaCodec;
import android.media.MediaCodecInfo;
import android.media.MediaFormat;
import android.util.Log;
import com.xinyi.baselib.io.tf.TFileHelper;
import com.xinyi.czsuperrecorder.Config;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.ByteBuffer;
/**
* Created by XinYi on 2018/7/5.
* AAC編碼
*/
public class AACEncoder {
private static final String TAG = "AACEncoder";
private String mime = "audio/mp4a-latm"; //錄音編碼的mime
private int rate=256000; //編碼的key bit rate
private MediaCodec mEnc;
private AudioRecorder audioRecorder;
private File recordingFile = new File(TFileHelper.getInstance().getRoot() + "/test/a.m4a");
private boolean isStopped = true;
private int bufferSize;
public AACEncoder(AudioRecorder audioRecorder) {
this.audioRecorder = audioRecorder;
isStopped = true;
}
public void prepare(){
audioRecorder.prepare();
try {
bufferSize = 0;
//相對于上面的音頻錄制,我們需要一個編碼器的執行個體
MediaFormat format=MediaFormat.createAudioFormat(mime, Config.sampleRate,Config.channelCount);
format.setInteger(MediaFormat.KEY_AAC_PROFILE, MediaCodecInfo.CodecProfileLevel.AACObjectLC);
format.setInteger(MediaFormat.KEY_BIT_RATE, rate);
mEnc= MediaCodec.createEncoderByType(mime);
mEnc.configure(format,null,null,MediaCodec.CONFIGURE_FLAG_ENCODE); //設定為編碼器
} catch (IOException e) {
e.printStackTrace();
}
}
public void start() throws IOException {
//同樣,在設定錄音開始的時候,也要設定編碼開始
mEnc.start();
//之前的音頻錄制是直接循環讀取,然後寫入檔案,這裡需要做編碼處理再寫入檔案
//這裡的處理就是和之前傳送帶取盒子放原料的流程一樣了,注意一般在子線程中循環處理
isStopped = false;
MediaCodec.BufferInfo mInfo=new MediaCodec.BufferInfo();
FileOutputStream fos = null;
TFileHelper.getInstance().deleteFile(recordingFile.getAbsolutePath());
TFileHelper.getInstance().createFile(recordingFile.getAbsolutePath());
try {
fos = new FileOutputStream(recordingFile);
audioRecorder.start();
while (!isStopped){ //循環讀取AudioRecorder的資料流
int index=mEnc.dequeueInputBuffer(-1);
Log.e(TAG, "start: index1 = " + index);
if(index>=0){
final ByteBuffer buffer=mEnc.getInputBuffer(index);
buffer.clear();
int length=audioRecorder.getmRecorder().read(buffer,audioRecorder.getBufferSize());
Log.e(TAG, "start length = : " + length);
if(length>0){
mEnc.queueInputBuffer(index,0,length,System.nanoTime()/1000,0);
}
}
int outIndex;
//每次取出的時候,把所有加工好的都循環取出來
do{
outIndex=mEnc.dequeueOutputBuffer(mInfo,0);
Log.e(TAG, "start: index2 = " + outIndex);
if(outIndex>=0){
ByteBuffer buffer=mEnc.getOutputBuffer(outIndex);
buffer.position(mInfo.offset);
//AAC編碼,需要加資料頭,AAC編碼資料頭固定為7個位元組
byte[] temp=new byte[mInfo.size+7];
buffer.get(temp,7,mInfo.size);
addADTStoPacket(temp,temp.length);
fos.write(temp);
mEnc.releaseOutputBuffer(outIndex,false);
}else if(outIndex ==MediaCodec.INFO_TRY_AGAIN_LATER){
//TODO something
}else if(outIndex==MediaCodec.INFO_OUTPUT_FORMAT_CHANGED){
//TODO something
}
}while (outIndex>=0);
}
//編碼停止,發送編碼結束的标志,循環結束後,停止并釋放編碼器
mEnc.stop();
mEnc.release();
} catch (IOException e) {
e.printStackTrace();
} catch (MediaCodec.CryptoException e) {
e.printStackTrace();
} finally {
if(fos != null){
fos.close();
}
}
}
/**
* 給編碼出的aac裸流添加adts頭字段
* @param packet 要空出前7個位元組,否則會搞亂資料
* @param packetLen
*/
private void addADTStoPacket(byte[] packet, int packetLen) {
int profile = 2; //AAC LC
int freqIdx = 4; //44.1KHz
int chanCfg = 2; //CPE
packet[0] = (byte)0xFF;
packet[1] = (byte)0xF9;
packet[2] = (byte)(((profile-1)<<6) + (freqIdx<<2) +(chanCfg>>2));
packet[3] = (byte)(((chanCfg&3)<<6) + (packetLen>>11));
packet[4] = (byte)((packetLen&0x7FF) >> 3);
packet[5] = (byte)(((packetLen&7)<<5) + 0x1F);
packet[6] = (byte)0xFC;
}
public void stop(){
audioRecorder.stop();
isStopped = true;
}
}
四、視訊編碼
https://www.jianshu.com/p/f3a55d3d1f5d/ (攝像頭采集的資料格式YUV)
五、MP4檔案裁剪
1)mp4parser
https://github.com/sannies/mp4parser
https://blog.csdn.net/u012027644/article/details/53885837
https://blog.csdn.net/u014691453/article/details/53256605
https://blog.csdn.net/foryou96/article/details/64132636 (詳細 )
此開源庫的缺點就是由開源庫裁剪或者合并出來的視訊檔案,不能再由此開源庫進行二次操作,否則會抛出異常。
2)FFmepg
https://www.jianshu.com/p/2cf527f2129f
六、視訊壓縮
- https://github.com/zerochl/FFMPEG-AAC-264-Android-32-64
- https://blog.csdn.net/w690333243/article/details/88591807
- https://www.cnblogs.com/wainiwann/p/4633208.html (MediaMetadataRetriever視訊資訊擷取)
- https://blog.csdn.net/chen930724/article/details/50267669 (MediaMetadataRetriever視訊資訊擷取)
- https://blog.csdn.net/u014653815/article/details/81084161 (MediaCodec解碼)
-
https://github.com/mabeijianxi/small-video-record
https://www.jianshu.com/p/cdae476087d4
8.https://www.cnblogs.com/wzqnxd/p/10038881.html (SiliCompressor,親測可用,缺點是沒有進度監聽)
9.https://blog.csdn.net/dzzzheng95/article/details/60142379 (系統相機錄制視訊無效)
- https://www.jianshu.com/p/3f4ad878f6c8
- https://blog.csdn.net/nature_day/article/details/36889815 (音視訊Uri轉真實位址)
- 音頻格式:https://blog.csdn.net/love_xsq/article/details/51254777
- 播放音頻的幾種方式:https://www.cnblogs.com/HDK2016/p/8043247.html
-
暫停其他應用的音頻:https://blog.csdn.net/franksunny/article/details/12224551
https://blog.csdn.net/oLevin/article/details/51476122
https://bbs.csdn.net/topics/391930743?page=1
- https://www.cnblogs.com/senior-engineer/p/7867626.html (mediaplayer詳解)
- https://blog.csdn.net/weixin_34015860/article/details/87948255 (音視訊播放器架構)