Android 中 HEVC(H.265) 的 Android Media Recorder 视频编码

Question

目前我正在使用 MediaRecorder.VideoEncoder Class用于在 Android 中创建 HEVC(H.265) 编码的视频。

我正在使用 Camera Class使用 SurfaceView 启动/停止相机预览，并检索用于编码视频(录制视频)的帧。

   Camera mCamera = Camera.open();
   mCamera.setDisplayOrientation(90);
   mCamera.unlock();

对于我正在使用的编码和录制视频 MediaRecorder 使用 HEVC VideoEncoder。

    MediaRecordermMediaRecorder = new MediaRecorder();
    mMediaRecorder.setPreviewDisplay(surface);
    mMediaRecorder.setCamera(mCamera);
    mMediaRecorder.setVideoSource(MediaRecorder.VideoSource.DEFAULT);
    //       mMediaRecorder.setOutputFormat(8);
    mMediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);
    mMediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.HEVC);
    mMediaRecorder.setVideoEncodingBitRate(5000 * 1000);
    mMediaRecorder.setVideoFrameRate(30);
    mMediaRecorder.setVideoSize(640, 480);
    String basePath = BasePath.getBasePath(getApplicationContext());
    String VIDEO_PATH = new File(basePath, "v_" + currentTime) + ".mp4";
    mMediaRecorder.setOutputFile(VIDEO_PATH);
    try {
        mMediaRecorder.prepare();
    } catch (IllegalStateException e) {
        e.printStackTrace();
    }

   //Used this **Start** function for recording start.

       mMediaRecorder.start();

   //When we stoped the Video recording Release MediaRecorder and especially the Camera as it's a shared
   // object that can be used by other applications

    mMediaRecorder.reset();
    mMediaRecorder.release();
    if (mCamera != null)
        mCamera.release();

但最后我在本地文件中遇到了Problem in saving Recorded video，我无法在我的代码中跟踪这个问题。

This is my full code class file used for Encoding .

Answer 1

下面的代码我已经测试过并且工作正常，它将视频保存在图片文件夹中:

MainActivity.java

import android.content.Context;
import android.content.pm.PackageManager;
import android.hardware.Camera;
import android.media.MediaRecorder;
import android.os.Bundle;
import android.os.Environment;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.FrameLayout;

import java.io.File;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;


public class MainActivity extends AppCompatActivity {

    private Camera mCamera;
    private CameraPreview mPreview;
    private MediaRecorder mMediaRecorder;
    private boolean isRecording = false;
    public static String TAG = "CAMERA RECORDING";


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        if(!checkCameraHardware(this)){
            Log.e(TAG, "No Camera Found on this device !");
            return;
        }


        // TODO: Important :
        // TODO: Need to ask for camera, audio and file storage
        // TODO: permissions at runtime, if using api level > 23.
        // TODO: For testing purposes, I gave permissions from
        // TODO: Settings app myself.


        // Create an instance of Camera
        mCamera = getCameraInstance();
        if(mCamera == null){
            Log.e(TAG, "Camera instance is null");
            return;
        }

        // Create our Preview view and set it as the content of our activity.
        mPreview = new CameraPreview(this, mCamera);
        FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);
        preview.addView(mPreview);

        // Add a listener to the Capture button
        final Button captureButton = (Button) findViewById(R.id.button_capture);
        captureButton.setOnClickListener(
                new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        if (isRecording) {
                            // stop recording and release camera
                            mMediaRecorder.stop();  // stop the recording
                            releaseMediaRecorder(); // release the MediaRecorder object
                            mCamera.lock();         // take camera access back from MediaRecorder

                            // inform the user that recording has stopped
                            captureButton.setText("Capture");
                            isRecording = false;
                        } else {
                            // initialize video camera
                            if (prepareVideoRecorder()) {
                                // Camera is available and unlocked, MediaRecorder is prepared,
                                // now you can start recording
                                mMediaRecorder.start();

                                // inform the user that recording has started
                                captureButton.setText("Stop");
                                isRecording = true;
                            } else {
                                // prepare didn't work, release the camera
                                releaseMediaRecorder();
                                // inform user
                            }
                        }
                    }
                }
        );
    }

    private boolean prepareVideoRecorder() {

        mMediaRecorder = new MediaRecorder();

        // Step 1: Unlock and set camera to MediaRecorder
        if(mCamera == null){
            mCamera = getCameraInstance();
        }
        mCamera.unlock();
        mMediaRecorder.setCamera(mCamera);

        // Step 2: Set sources
        mMediaRecorder.setAudioSource(MediaRecorder.AudioSource.CAMCORDER);
        mMediaRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);

        // Step 3: Set Formats :
        mMediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);
        mMediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
        mMediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.MPEG_4_SP);
        mMediaRecorder.setVideoEncodingBitRate(5000 * 1000);
        mMediaRecorder.setVideoFrameRate(30);
        mMediaRecorder.setVideoSize(640, 480);

        // Step 4: Set output file
        mMediaRecorder.setOutputFile(getOutputMediaFile().toString());

        // Step 5: Set the preview output
        mMediaRecorder.setPreviewDisplay(mPreview.getHolder().getSurface());

        // Step 6: Prepare configured MediaRecorder
        try {
            mMediaRecorder.prepare();
        } catch (IllegalStateException e) {
            Log.d(TAG, "IllegalStateException preparing MediaRecorder: " + e.getMessage());
            releaseMediaRecorder();
            return false;
        } catch (IOException e) {
            Log.d(TAG, "IOException preparing MediaRecorder: " + e.getMessage());
            releaseMediaRecorder();
            return false;
        }
        return true;
    }

    /** Check if this device has a camera */
    private boolean checkCameraHardware(Context context) {
        if (context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA)){
            // this device has a camera
            return true;
        } else {
            // no camera on this device
            return false;
        }
    }

    /** A safe way to get an instance of the Camera object. */
    public static Camera getCameraInstance(){
        Camera c = null;
        try {
            c = Camera.open(); // attempt to get a Camera instance
        }
        catch (Exception e){
            Log.d(TAG, "Can't get camera instance : " + e.toString());
            // Camera is not available (in use or does not exist)
        }
        return c; // returns null if camera is unavailable
    }

    /** Create a File for saving video */
    private static File getOutputMediaFile(){
        // To be safe, you should check that the SDCard is mounted
        // using Environment.getExternalStorageState() before doing this.

        File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
                Environment.DIRECTORY_PICTURES), "TestApp");
        // This location works best if you want the created videos to be shared
        // between applications and persist after your app has been uninstalled.

        // Create the storage directory if it does not exist
        if (! mediaStorageDir.exists()){
            if (! mediaStorageDir.mkdirs()){
                Log.d(TAG, "failed to create directory");
                return null;
            }
        }

        // Create a media file name
        String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
        File mediaFile = new File(mediaStorageDir.getPath() + File.separator + "VID_"+ timeStamp + ".mp4");
        return mediaFile;
    }

    @Override
    protected void onPause() {
        super.onPause();
        releaseMediaRecorder();       // if you are using MediaRecorder, release it first
        releaseCamera();              // release the camera immediately on pause event
    }

    private void releaseMediaRecorder(){
        if (mMediaRecorder != null) {
            mMediaRecorder.reset();   // clear recorder configuration
            mMediaRecorder.release(); // release the recorder object
            mMediaRecorder = null;
            mCamera.lock();           // lock camera for later use
        }
    }

    private void releaseCamera(){
        if (mCamera != null){
            mCamera.release();        // release the camera for other applications
            mCamera = null;
        }
    }
}

---

CameraPreview.java

import android.content.Context;
import android.hardware.Camera;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

import java.io.IOException;

public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback{

    private SurfaceHolder mHolder;
    private Camera mCamera;
    public static String TAG = "CAMERA RECORDING";

    public CameraPreview(Context context, Camera camera) {
        super(context);
        mCamera = camera;

        // Install a SurfaceHolder.Callback so we get notified when the
        // underlying surface is created and destroyed.
        mHolder = getHolder();
        mHolder.addCallback(this);
    }

    public void surfaceCreated(SurfaceHolder holder) {
        // The Surface has been created, now tell the camera where to draw the preview.
        try {
            mCamera.setPreviewDisplay(holder);
            mCamera.startPreview();
        } catch (IOException e) {
            Log.d(TAG, "Error setting camera preview: " + e.getMessage());
        }
    }

    public void surfaceDestroyed(SurfaceHolder holder) {
        // empty. Take care of releasing the Camera preview in your activity.
    }

    public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
        // If your preview can change or rotate, take care of those events here.
        // Make sure to stop the preview before resizing or reformatting it.

        if (mHolder.getSurface() == null){
            // preview surface does not exist
            return;
        }

        // stop preview before making changes
        try {
            mCamera.stopPreview();
        } catch (Exception e){
            // ignore: tried to stop a non-existent preview
        }

        // set preview size and make any resize, rotate or
        // reformatting changes here

        // start preview with new settings
        try {
            mCamera.setPreviewDisplay(mHolder);
            mCamera.startPreview();

        } catch (Exception e){
            Log.d(TAG, "Error starting camera preview: " + e.getMessage());
        }
    }
}

---

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
    <FrameLayout
        android:id="@+id/camera_preview"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        />

    <Button
        android:id="@+id/button_capture"
        android:text="Capture"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        />
</LinearLayout>

---

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest
    xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.pabhinav.testapp">

    <uses-feature android:name="android.hardware.camera" />
    <uses-permission android:name="android.permission.CAMERA" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.RECORD_AUDIO" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity
            android:name=".MainActivity"
            android:screenOrientation="portrait">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

---

希望对您有所帮助!