使用前置摄像头录制视频时分别获取视频和音频缓冲区
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【中文标题】使用前置摄像头录制视频时分别获取视频和音频缓冲区【英文标题】：Get Video and Audio buffer separately while recording video using front camera 【发布时间】：2019-05-31 15:15:10 【问题描述】：我在 SO 和一些不错的博客文章上挖掘了很多东西，但似乎我有独特的要求，即分别读取视频和音频缓冲区，以便在录制时对其进行进一步处理。
我的用例就像当用户开始录制视频时，我需要使用ML-Face-Detection-Kit 持续处理视频帧，并持续处理音频帧以确保用户说出某些内容并检测噪音水平.为此，我认为我需要将视频和音频都放在一个单独的缓冲区中，处理后，我会将其合并并保存到 MP4 文件中作为录音。
我尝试过由好人Mattia Iavarone 开发的CameraView，但它只提供视频帧。
我愿意接受其他有用的建议/反馈来处理这种情况。
【问题讨论】：
检查bigflake.com/mediacodec例子 是的，一直在解决这个问题，但无法找到如何使用 ML-Kit 处理视频编码器缓冲区并继续录制。 我也在使用该库，但无法获取音频流。我会看这个问题，希望在这里看到正确的答案。 【参考方案1】：这是一个引用 javaCV 库的 RecordActivity.java 示例的 answer。
它使用单独的音频和视频线程来实时获取帧。
编辑 1：我已按照建议包含了 Bytedeco 的 RecordActivity.java 的代码示例。
package org.bytedeco.javacv.recordactivity;
import android.app.Activity;
import android.content.Context;
import android.content.pm.ActivityInfo;
import android.hardware.Camera;
import android.hardware.Camera.PreviewCallback;
import android.media.AudioFormat;
import android.media.AudioRecord;
import android.media.MediaRecorder;
import android.os.Bundle;
import android.os.PowerManager;
import android.util.Log;
import android.view.Display;
import android.view.KeyEvent;
import android.view.LayoutInflater;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.WindowManager;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.RelativeLayout;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.ShortBuffer;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import org.bytedeco.javacpp.avutil;
import org.bytedeco.javacv.FFmpegFrameFilter;
import org.bytedeco.javacv.FFmpegFrameRecorder;
import org.bytedeco.javacv.Frame;
import org.bytedeco.javacv.FrameFilter;
public class RecordActivity extends Activity implements OnClickListener
private final static String CLASS_LABEL = "RecordActivity";
private final static String LOG_TAG = CLASS_LABEL;
private String ffmpeg_link = "/mnt/sdcard/stream.flv";
long startTime = 0;
boolean recording = false;
private FFmpegFrameRecorder recorder;
private boolean isPreviewOn = false;
/*Filter information, change boolean to true if adding a fitler*/
private boolean addFilter = true;
private String filterString = "";
FFmpegFrameFilter filter;
private int sampleAudioRateInHz = 44100;
private int imageWidth = 320;
private int imageHeight = 240;
private int frameRate = 30;
/* audio data getting thread */
private AudioRecord audioRecord;
private AudioRecordRunnable audioRecordRunnable;
private Thread audioThread;
volatile boolean runAudioThread = true;
/* video data getting thread */
private Camera cameraDevice;
private CameraView cameraView;
private Frame yuvImage = null;
/* layout setting */
private final int bg_screen_bx = 232;
private final int bg_screen_by = 128;
private final int bg_screen_width = 700;
private final int bg_screen_height = 500;
private final int bg_width = 1123;
private final int bg_height = 715;
private final int live_width = 640;
private final int live_height = 480;
private int screenWidth, screenHeight;
private Button btnRecorderControl;
/* The number of seconds in the continuous record loop (or 0 to disable loop). */
final int RECORD_LENGTH = 0;
Frame[] images;
long[] timestamps;
ShortBuffer[] samples;
int imagesIndex, samplesIndex;
@Override
public void onCreate(Bundle savedInstanceState)
super.onCreate(savedInstanceState);
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
setContentView(R.layout.main);
initLayout();
@Override
protected void onDestroy()
super.onDestroy();
recording = false;
if (cameraView != null)
cameraView.stopPreview();
if(cameraDevice != null)
cameraDevice.stopPreview();
cameraDevice.release();
cameraDevice = null;
private void initLayout()
/* get size of screen */
Display display = ((WindowManager) getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay();
screenWidth = display.getWidth();
screenHeight = display.getHeight();
RelativeLayout.LayoutParams layoutParam = null;
LayoutInflater myInflate = null;
myInflate = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
RelativeLayout topLayout = new RelativeLayout(this);
setContentView(topLayout);
LinearLayout preViewLayout = (LinearLayout) myInflate.inflate(R.layout.main, null);
layoutParam = new RelativeLayout.LayoutParams(screenWidth, screenHeight);
topLayout.addView(preViewLayout, layoutParam);
/* add control button: start and stop */
btnRecorderControl = (Button) findViewById(R.id.recorder_control);
btnRecorderControl.setText("Start");
btnRecorderControl.setOnClickListener(this);
/* add camera view */
int display_width_d = (int) (1.0 * bg_screen_width * screenWidth / bg_width);
int display_height_d = (int) (1.0 * bg_screen_height * screenHeight / bg_height);
int prev_rw, prev_rh;
if (1.0 * display_width_d / display_height_d > 1.0 * live_width / live_height)
prev_rh = display_height_d;
prev_rw = (int) (1.0 * display_height_d * live_width / live_height);
else
prev_rw = display_width_d;
prev_rh = (int) (1.0 * display_width_d * live_height / live_width);
layoutParam = new RelativeLayout.LayoutParams(prev_rw, prev_rh);
layoutParam.topMargin = (int) (1.0 * bg_screen_by * screenHeight / bg_height);
layoutParam.leftMargin = (int) (1.0 * bg_screen_bx * screenWidth / bg_width);
cameraDevice = Camera.open();
Log.i(LOG_TAG, "cameara open");
cameraView = new CameraView(this, cameraDevice);
topLayout.addView(cameraView, layoutParam);
Log.i(LOG_TAG, "cameara preview start: OK");
//---------------------------------------
// initialize ffmpeg_recorder
//---------------------------------------
private void initRecorder()
Log.w(LOG_TAG,"init recorder");
if (RECORD_LENGTH > 0)
imagesIndex = 0;
images = new Frame[RECORD_LENGTH * frameRate];
timestamps = new long[images.length];
for (int i = 0; i < images.length; i++)
images[i] = new Frame(imageWidth, imageHeight, Frame.DEPTH_UBYTE, 2);
timestamps[i] = -1;
else if (yuvImage == null)
yuvImage = new Frame(imageWidth, imageHeight, Frame.DEPTH_UBYTE, 2);
Log.i(LOG_TAG, "create yuvImage");
Log.i(LOG_TAG, "ffmpeg_url: " + ffmpeg_link);
recorder = new FFmpegFrameRecorder(ffmpeg_link, imageWidth, imageHeight, 1);
recorder.setFormat("flv");
recorder.setSampleRate(sampleAudioRateInHz);
// Set in the surface changed method
recorder.setFrameRate(frameRate);
// The filterString is any ffmpeg filter.
// Here is the link for a list: https://ffmpeg.org/ffmpeg-filters.html
filterString = "transpose=0";
filter = new FFmpegFrameFilter(filterString, imageWidth, imageHeight);
//default format on android
filter.setPixelFormat(avutil.AV_PIX_FMT_NV21);
Log.i(LOG_TAG, "recorder initialize success");
audioRecordRunnable = new AudioRecordRunnable();
audioThread = new Thread(audioRecordRunnable);
runAudioThread = true;
public void startRecording()
initRecorder();
try
recorder.start();
startTime = System.currentTimeMillis();
recording = true;
audioThread.start();
if(addFilter)
filter.start();
catch (FFmpegFrameRecorder.Exception | FrameFilter.Exception e)
e.printStackTrace();
public void stopRecording()
runAudioThread = false;
try
audioThread.join();
catch (InterruptedException e)
// reset interrupt to be nice
Thread.currentThread().interrupt();
return;
audioRecordRunnable = null;
audioThread = null;
if (recorder != null && recording)
if (RECORD_LENGTH > 0)
Log.v(LOG_TAG,"Writing frames");
try
int firstIndex = imagesIndex % samples.length;
int lastIndex = (imagesIndex - 1) % images.length;
if (imagesIndex <= images.length)
firstIndex = 0;
lastIndex = imagesIndex - 1;
if ((startTime = timestamps[lastIndex] - RECORD_LENGTH * 1000000L) < 0)
startTime = 0;
if (lastIndex < firstIndex)
lastIndex += images.length;
for (int i = firstIndex; i <= lastIndex; i++)
long t = timestamps[i % timestamps.length] - startTime;
if (t >= 0)
if (t > recorder.getTimestamp())
recorder.setTimestamp(t);
recorder.record(images[i % images.length]);
firstIndex = samplesIndex % samples.length;
lastIndex = (samplesIndex - 1) % samples.length;
if (samplesIndex <= samples.length)
firstIndex = 0;
lastIndex = samplesIndex - 1;
if (lastIndex < firstIndex)
lastIndex += samples.length;
for (int i = firstIndex; i <= lastIndex; i++)
recorder.recordSamples(samples[i % samples.length]);
catch (FFmpegFrameRecorder.Exception e)
Log.v(LOG_TAG,e.getMessage());
e.printStackTrace();
recording = false;
Log.v(LOG_TAG,"Finishing recording, calling stop and release on recorder");
try
recorder.stop();
recorder.release();
filter.stop();
filter.release();
catch (FFmpegFrameRecorder.Exception | FrameFilter.Exception e)
e.printStackTrace();
recorder = null;
@Override
public boolean onKeyDown(int keyCode, KeyEvent event)
if (keyCode == KeyEvent.KEYCODE_BACK)
if (recording)
stopRecording();
finish();
return true;
return super.onKeyDown(keyCode, event);
//---------------------------------------------
// audio thread, gets and encodes audio data
//---------------------------------------------
class AudioRecordRunnable implements Runnable
@Override
public void run()
android.os.Process.setThreadPriority(android.os.Process.THREAD_PRIORITY_URGENT_AUDIO);
// Audio
int bufferSize;
ShortBuffer audioData;
int bufferReadResult;
bufferSize = AudioRecord.getMinBufferSize(sampleAudioRateInHz,
AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT);
audioRecord = new AudioRecord(MediaRecorder.Audiosource.MIC, sampleAudioRateInHz,
AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT, bufferSize);
if (RECORD_LENGTH > 0)
samplesIndex = 0;
samples = new ShortBuffer[RECORD_LENGTH * sampleAudioRateInHz * 2 / bufferSize + 1];
for (int i = 0; i < samples.length; i++)
samples[i] = ShortBuffer.allocate(bufferSize);
else
audioData = ShortBuffer.allocate(bufferSize);
Log.d(LOG_TAG, "audioRecord.startRecording()");
audioRecord.startRecording();
/* ffmpeg_audio encoding loop */
while (runAudioThread)
if (RECORD_LENGTH > 0)
audioData = samples[samplesIndex++ % samples.length];
audioData.position(0).limit(0);
//Log.v(LOG_TAG,"recording? " + recording);
bufferReadResult = audioRecord.read(audioData.array(), 0, audioData.capacity());
audioData.limit(bufferReadResult);
if (bufferReadResult > 0)
Log.v(LOG_TAG,"bufferReadResult: " + bufferReadResult);
// If "recording" isn't true when start this thread, it never get's set according to this if statement...!!!
// Why? Good question...
if (recording)
if (RECORD_LENGTH <= 0) try
recorder.recordSamples(audioData);
//Log.v(LOG_TAG,"recording " + 1024*i + " to " + 1024*i+1024);
catch (FFmpegFrameRecorder.Exception e)
Log.v(LOG_TAG,e.getMessage());
e.printStackTrace();
Log.v(LOG_TAG,"AudioThread Finished, release audioRecord");
/* encoding finish, release recorder */
if (audioRecord != null)
audioRecord.stop();
audioRecord.release();
audioRecord = null;
Log.v(LOG_TAG,"audioRecord released");
//---------------------------------------------
// camera thread, gets and encodes video data
//---------------------------------------------
class CameraView extends SurfaceView implements SurfaceHolder.Callback, PreviewCallback
private SurfaceHolder mHolder;
private Camera mCamera;
public CameraView(Context context, Camera camera)
super(context);
Log.w("camera","camera view");
mCamera = camera;
mHolder = getHolder();
mHolder.addCallback(CameraView.this);
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
mCamera.setPreviewCallback(CameraView.this);
@Override
public void surfaceCreated(SurfaceHolder holder)
try
stopPreview();
mCamera.setPreviewDisplay(holder);
catch (IOException exception)
mCamera.release();
mCamera = null;
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height)
stopPreview();
Camera.Parameters camParams = mCamera.getParameters();
List<Camera.Size> sizes = camParams.getSupportedPreviewSizes();
// Sort the list in ascending order
Collections.sort(sizes, new Comparator<Camera.Size>()
public int compare(final Camera.Size a, final Camera.Size b)
return a.width * a.height - b.width * b.height;
);
// Pick the first preview size that is equal or bigger, or pick the last (biggest) option if we cannot
// reach the initial settings of imageWidth/imageHeight.
for (int i = 0; i < sizes.size(); i++)
if ((sizes.get(i).width >= imageWidth && sizes.get(i).height >= imageHeight) || i == sizes.size() - 1)
imageWidth = sizes.get(i).width;
imageHeight = sizes.get(i).height;
Log.v(LOG_TAG, "Changed to supported resolution: " + imageWidth + "x" + imageHeight);
break;
camParams.setPreviewSize(imageWidth, imageHeight);
Log.v(LOG_TAG,"Setting imageWidth: " + imageWidth + " imageHeight: " + imageHeight + " frameRate: " + frameRate);
camParams.setPreviewFrameRate(frameRate);
Log.v(LOG_TAG,"Preview Framerate: " + camParams.getPreviewFrameRate());
mCamera.setParameters(camParams);
// Set the holder (which might have changed) again
try
mCamera.setPreviewDisplay(holder);
mCamera.setPreviewCallback(CameraView.this);
startPreview();
catch (Exception e)
Log.e(LOG_TAG, "Could not set preview display in surfaceChanged");
@Override
public void surfaceDestroyed(SurfaceHolder holder)
try
mHolder.addCallback(null);
mCamera.setPreviewCallback(null);
catch (RuntimeException e)
// The camera has probably just been released, ignore.
public void startPreview()
if (!isPreviewOn && mCamera != null)
isPreviewOn = true;
mCamera.startPreview();
public void stopPreview()
if (isPreviewOn && mCamera != null)
isPreviewOn = false;
mCamera.stopPreview();
@Override
public void onPreviewFrame(byte[] data, Camera camera)
if (audioRecord == null || audioRecord.getRecordingState() != AudioRecord.RECORDSTATE_RECORDING)
startTime = System.currentTimeMillis();
return;
if (RECORD_LENGTH > 0)
int i = imagesIndex++ % images.length;
yuvImage = images[i];
timestamps[i] = 1000 * (System.currentTimeMillis() - startTime);
/* get video data */
if (yuvImage != null && recording)
((ByteBuffer)yuvImage.image[0].position(0)).put(data);
if (RECORD_LENGTH <= 0) try
Log.v(LOG_TAG,"Writing Frame");
long t = 1000 * (System.currentTimeMillis() - startTime);
if (t > recorder.getTimestamp())
recorder.setTimestamp(t);
if(addFilter)
filter.push(yuvImage);
Frame frame2;
while ((frame2 = filter.pull()) != null)
recorder.record(frame2, filter.getPixelFormat());
else
recorder.record(yuvImage);
catch (FFmpegFrameRecorder.Exception | FrameFilter.Exception e)
Log.v(LOG_TAG,e.getMessage());
e.printStackTrace();
@Override
public void onClick(View v)
if (!recording)
startRecording();
Log.w(LOG_TAG, "Start Button Pushed");
btnRecorderControl.setText("Stop");
else
// This will trigger the audio recording loop to stop and then set isRecorderStart = false;
stopRecording();
Log.w(LOG_TAG, "Stop Button Pushed");
btnRecorderControl.setText("Start");
【讨论】：
虽然此链接可能会回答问题，但最好在此处包含答案的基本部分并提供链接以供参考。如果链接页面发生更改，仅链接答案可能会失效。 - From Review @Sociopath 抱歉，我刚开始回答 SO。这样抄别人的答案可以吗？ 这并没有什么坏处，但这里不鼓励只提供链接。当您有足够的声誉时，您需要解释答案或简单地使用评论部分提供链接。以上是关于使用前置摄像头录制视频时分别获取视频和音频缓冲区的主要内容，如果未能解决你的问题，请参考以下文章