直播我想要做現場直播在潛望鏡是做它的方式。我在網上做了一個快速搜索，發現了一堆類似ffmpeg的庫，它們使用本地庫，但根據MediaCodec編碼，應該直接支持Android SDK嗎？如何從Android
https://developer.android.com/reference/android/media/MediaCodec.html
所以我想知道需要編碼外部本地庫，爲什麼？
另外我嘗試了一些庫，但他們似乎太慢，特別是對於高比特率（我在Nexus 5X上以每秒2500Kbps的速度在1280x720下獲得16 fps，我希望達到1080），那麼流行的廣播應用如何做到這一點？
有這麼多的處理涉及好像它不可能達到良好的質量與普通電話（不是該行的頂部）流。
的MediaCodec API往往會以高分辨率流緩慢。我建議你應該使用FFmpeg，有一個叫做JavaCV的好的java包裝器（它也適用於android）。下面是應該讓你去
public class MainActivity extends Activity implements OnClickListener {
private PowerManager.WakeLock mWakeLock;
private String ffmpeg_link = "rtmp://live:[email protected]:1935/live/test.flv";
private volatile FFmpegFrameRecorder recorder;
boolean recording = false;
long startTime = 0;
private int sampleAudioRateInHz = 44100;
private int imageWidth = 320;
private int imageHeight = 240;
private int frameRate = 30;
private Thread audioThread;
volatile boolean runAudioThread = true;
private AudioRecord audioRecord;
private AudioRecordRunnable audioRecordRunnable;
private CameraView cameraView;
private IplImage yuvIplimage = null;
private Button recordButton;
private LinearLayout mainLayout;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
setContentView(R.layout.activity_main);
initLayout();
initRecorder();
}
@Override
protected void onResume() {
super.onResume();
if (mWakeLock == null) {
PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
mWakeLock = pm.newWakeLock(PowerManager.SCREEN_BRIGHT_WAKE_LOCK, LOG_TAG);
mWakeLock.acquire();
}
}
@Override
protected void onPause() {
super.onPause();
if (mWakeLock != null) {
mWakeLock.release();
mWakeLock = null;
}
}
@Override
protected void onDestroy() {
super.onDestroy();
recording = false;
}
private void initLayout() {
mainLayout = (LinearLayout) this.findViewById(R.id.record_layout);
recordButton = (Button) findViewById(R.id.recorder_control);
recordButton.setText("Start");
recordButton.setOnClickListener(this);
cameraView = new CameraView(this);
LinearLayout.LayoutParams layoutParam = new LinearLayout.LayoutParams(imageWidth, imageHeight);
mainLayout.addView(cameraView, layoutParam);
Log.v(LOG_TAG, "added cameraView to mainLayout");
}
private void initRecorder() {
Log.w(LOG_TAG,"initRecorder");
if (yuvIplimage == null) {
// Recreated after frame size is set in surface change method
yuvIplimage = IplImage.create(imageWidth, imageHeight, IPL_DEPTH_8U, 2);
//yuvIplimage = IplImage.create(imageWidth, imageHeight, IPL_DEPTH_32S, 2);
Log.v(LOG_TAG, "IplImage.create");
}
recorder = new FFmpegFrameRecorder(ffmpeg_link, imageWidth, imageHeight, 1);
Log.v(LOG_TAG, "FFmpegFrameRecorder: " + ffmpeg_link + " imageWidth: " + imageWidth + " imageHeight " + imageHeight);
recorder.setFormat("flv");
Log.v(LOG_TAG, "recorder.setFormat(\"flv\")");
recorder.setSampleRate(sampleAudioRateInHz);
Log.v(LOG_TAG, "recorder.setSampleRate(sampleAudioRateInHz)");
// re-set in the surface changed method as well
recorder.setFrameRate(frameRate);
Log.v(LOG_TAG, "recorder.setFrameRate(frameRate)");
// Create audio recording thread
audioRecordRunnable = new AudioRecordRunnable();
audioThread = new Thread(audioRecordRunnable);
}
// Start the capture
public void startRecording() {
try {
recorder.start();
startTime = System.currentTimeMillis();
recording = true;
audioThread.start();
} catch (FFmpegFrameRecorder.Exception e) {
e.printStackTrace();
}
}
public void stopRecording() {
// This should stop the audio thread from running
runAudioThread = false;
if (recorder != null && recording) {
recording = false;
Log.v(LOG_TAG,"Finishing recording, calling stop and release on recorder");
try {
recorder.stop();
recorder.release();
} catch (FFmpegFrameRecorder.Exception e) {
e.printStackTrace();
}
recorder = null;
}
}
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
// Quit when back button is pushed
if (keyCode == KeyEvent.KEYCODE_BACK) {
if (recording) {
stopRecording();
}
finish();
return true;
}
return super.onKeyDown(keyCode, event);
}
@Override
public void onClick(View v) {
if (!recording) {
startRecording();
Log.w(LOG_TAG, "Start Button Pushed");
recordButton.setText("Stop");
} else {
stopRecording();
Log.w(LOG_TAG, "Stop Button Pushed");
recordButton.setText("Start");
}
}
//---------------------------------------------
// audio thread, gets and encodes audio data
//---------------------------------------------
class AudioRecordRunnable implements Runnable {
@Override
public void run() {
// Set the thread priority
android.os.Process.setThreadPriority(android.os.Process.THREAD_PRIORITY_URGENT_AUDIO);
// Audio
int bufferSize;
short[] audioData;
int bufferReadResult;
bufferSize = AudioRecord.getMinBufferSize(sampleAudioRateInHz,
AudioFormat.CHANNEL_CONFIGURATION_MONO, AudioFormat.ENCODING_PCM_16BIT);
audioRecord = new AudioRecord(MediaRecorder.AudioSource.MIC, sampleAudioRateInHz,
AudioFormat.CHANNEL_CONFIGURATION_MONO, AudioFormat.ENCODING_PCM_16BIT, bufferSize);
audioData = new short[bufferSize];
Log.d(LOG_TAG, "audioRecord.startRecording()");
audioRecord.startRecording();
// Audio Capture/Encoding Loop
while (runAudioThread) {
// Read from audioRecord
bufferReadResult = audioRecord.read(audioData, 0, audioData.length);
if (bufferReadResult > 0) {
//Log.v(LOG_TAG,"audioRecord bufferReadResult: " + bufferReadResult);
// Changes in this variable may not be picked up despite it being "volatile"
if (recording) {
try {
// Write to FFmpegFrameRecorder
recorder.record(ShortBuffer.wrap(audioData, 0, bufferReadResult));
} catch (FFmpegFrameRecorder.Exception e) {
Log.v(LOG_TAG,e.getMessage());
e.printStackTrace();
}
}
}
}
Log.v(LOG_TAG,"AudioThread Finished");
/* Capture/Encoding finished, release recorder */
if (audioRecord != null) {
audioRecord.stop();
audioRecord.release();
audioRecord = null;
Log.v(LOG_TAG,"audioRecord released");
}
}
}
class CameraView extends SurfaceView implements SurfaceHolder.Callback, PreviewCallback {
private boolean previewRunning = false;
private SurfaceHolder holder;
private Camera camera;
private byte[] previewBuffer;
long videoTimestamp = 0;
Bitmap bitmap;
Canvas canvas;
public CameraView(Context _context) {
super(_context);
holder = this.getHolder();
holder.addCallback(this);
holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
camera = Camera.open();
try {
camera.setPreviewDisplay(holder);
camera.setPreviewCallback(this);
Camera.Parameters currentParams = camera.getParameters();
Log.v(LOG_TAG,"Preview Framerate: " + currentParams.getPreviewFrameRate());
Log.v(LOG_TAG,"Preview imageWidth: " + currentParams.getPreviewSize().width + " imageHeight: " + currentParams.getPreviewSize().height);
// Use these values
imageWidth = currentParams.getPreviewSize().width;
imageHeight = currentParams.getPreviewSize().height;
frameRate = currentParams.getPreviewFrameRate();
bitmap = Bitmap.createBitmap(imageWidth, imageHeight, Bitmap.Config.ALPHA_8);
/*
Log.v(LOG_TAG,"Creating previewBuffer size: " + imageWidth * imageHeight * ImageFormat.getBitsPerPixel(currentParams.getPreviewFormat())/8);
previewBuffer = new byte[imageWidth * imageHeight * ImageFormat.getBitsPerPixel(currentParams.getPreviewFormat())/8];
camera.addCallbackBuffer(previewBuffer);
camera.setPreviewCallbackWithBuffer(this);
*/
camera.startPreview();
previewRunning = true;
}
catch (IOException e) {
Log.v(LOG_TAG,e.getMessage());
e.printStackTrace();
}
}
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
Log.v(LOG_TAG,"Surface Changed: width " + width + " height: " + height);
// We would do this if we want to reset the camera parameters
/*
if (!recording) {
if (previewRunning){
camera.stopPreview();
}
try {
//Camera.Parameters cameraParameters = camera.getParameters();
//p.setPreviewSize(imageWidth, imageHeight);
//p.setPreviewFrameRate(frameRate);
//camera.setParameters(cameraParameters);
camera.setPreviewDisplay(holder);
camera.startPreview();
previewRunning = true;
}
catch (IOException e) {
Log.e(LOG_TAG,e.getMessage());
e.printStackTrace();
}
}
*/
// Get the current parameters
Camera.Parameters currentParams = camera.getParameters();
Log.v(LOG_TAG,"Preview Framerate: " + currentParams.getPreviewFrameRate());
Log.v(LOG_TAG,"Preview imageWidth: " + currentParams.getPreviewSize().width + " imageHeight: " + currentParams.getPreviewSize().height);
// Use these values
imageWidth = currentParams.getPreviewSize().width;
imageHeight = currentParams.getPreviewSize().height;
frameRate = currentParams.getPreviewFrameRate();
// Create the yuvIplimage if needed
yuvIplimage = IplImage.create(imageWidth, imageHeight, IPL_DEPTH_8U, 2);
//yuvIplimage = IplImage.create(imageWidth, imageHeight, IPL_DEPTH_32S, 2);
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
try {
camera.setPreviewCallback(null);
previewRunning = false;
camera.release();
} catch (RuntimeException e) {
Log.v(LOG_TAG,e.getMessage());
e.printStackTrace();
}
}
@Override
public void onPreviewFrame(byte[] data, Camera camera) {
if (yuvIplimage != null && recording) {
videoTimestamp = 1000 * (System.currentTimeMillis() - startTime);
// Put the camera preview frame right into the yuvIplimage object
yuvIplimage.getByteBuffer().put(data);
// FAQ about IplImage:
// - For custom raw processing of data, getByteBuffer() returns an NIO direct
// buffer wrapped around the memory pointed by imageData, and under Android we can
// also use that Buffer with Bitmap.copyPixelsFromBuffer() and copyPixelsToBuffer().
// - To get a BufferedImage from an IplImage, we may call getBufferedImage().
// - The createFrom() factory method can construct an IplImage from a BufferedImage.
// - There are also a few copy*() methods for BufferedImage<->IplImage data transfers.
// Let's try it..
// This works but only on transparency
// Need to find the right Bitmap and IplImage matching types
/*
bitmap.copyPixelsFromBuffer(yuvIplimage.getByteBuffer());
//bitmap.setPixel(10,10,Color.MAGENTA);
canvas = new Canvas(bitmap);
Paint paint = new Paint();
paint.setColor(Color.GREEN);
float leftx = 20;
float topy = 20;
float rightx = 50;
float bottomy = 100;
RectF rectangle = new RectF(leftx,topy,rightx,bottomy);
canvas.drawRect(rectangle, paint);
bitmap.copyPixelsToBuffer(yuvIplimage.getByteBuffer());
*/
//Log.v(LOG_TAG,"Writing Frame");
try {
// Get the correct time
recorder.setTimestamp(videoTimestamp);
// Record the image into FFmpegFrameRecorder
recorder.record(yuvIplimage);
} catch (FFmpegFrameRecorder.Exception e) {
Log.v(LOG_TAG,e.getMessage());
e.printStackTrace();
}
}
}
}
}
「MediaCodec API往往會因高分辨率流而變慢。」這是正確的嗎？我會驚訝地聽到這一點，因爲這是用於在光盤上錄製視頻的API，因此可以將1080p視頻保存在設備上。 – MichelReap
這似乎是這種情況，這就是爲什麼libstream引發異常。你可以閱讀這個問題http://stackoverflow.com/questions/19256953/buffering-surface-input-to-mediacodec還是看H264Stream類128線https://github.com/Ziggeo/android-libstreaming/blob /master/src/net/majorkernelpanic/streaming/video/H264Stream.java –
你是對的短樣本。你必須考慮Android ndk處理密集的東西。
研究和建設這個yt watchme，這minicap。也 穿行webrtc
不需要編碼另一個rticonnextdds videodemo android
外部庫，但你需要一種方法來一個原始的H.264碼流轉換爲適合廣播的東西。有關MediaCodec編碼示例，請參閱Grafika（https://github.com/google/grafika）。 – fadden
@fadden究竟是什麼意思？就像將它製作爲RTMP的FLV一樣？你也不需要一個本地庫（即NDK），對吧？那些本地庫的好處是什麼？ – MichelReap
我會推薦Google的https://github.com/google/ExoPlayer。 –