我尝试构建一个自定义视频录制应用程序并按照互联网上的教程进行操作。但是我得到的问题是按下开始按钮后屏幕变黑并且没有其他任何事情发生。按下停止按钮后，我检查了放置输出视频的目录。它在那里，但大小为 0 KB。
我使用了surfaceview，这是xml布局：
<?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"
>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/hello"
/>
<Button
android:id="@+id/start"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="- Start Camera Preview -"
/>
<Button
android:id="@+id/stop"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="- Stop Camera Preview -"
/>
<SurfaceView
android:id="@+id/surfaceview"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
</LinearLayout>
这是录制视频的简短代码：
public class CamTestActivity extends Activity implements SurfaceHolder.Callback{
private static final String TAG = "Camera-Tutorial";
private SurfaceView surfaceView;
private SurfaceHolder surfaceHolder;
private Camera camera;
private boolean previewRunning;
private int VIDEO_TYPE = 3;
private int intVideoIndex = 1;
private MediaRecorder mediaRecorder;
private final int maxDurationInMs = 20000;
private final int videoFramesPerSecond = 20;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.videopreview);
// setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
surfaceView = (SurfaceView) findViewById(R.id.surfaceview);
surfaceHolder = surfaceView.getHolder();
surfaceHolder.addCallback(this);
Button start_video = (Button) findViewById(R.id.start);
Button stop_video = (Button) findViewById(R.id.stop);
stop_video.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
mediaRecorder.stop();
camera.lock();
}
});
start_video.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
try {
camera.unlock();
mediaRecorder = new MediaRecorder();
mediaRecorder.setCamera(camera);
mediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
mediaRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);
mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);
mediaRecorder.setOutputFile(GetOutputMediaFileDir(VIDEO_TYPE,intVideoIndex));
mediaRecorder.setVideoFrameRate(1);
mediaRecorder.setVideoEncoder(MediaRecorder.AudioEncoder.AAC);
mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AAC);
mediaRecorder.prepare();
mediaRecorder.start();
} catch (IllegalStateException e) {
Toast.makeText(getApplicationContext(), e.getMessage(), Toast.LENGTH_LONG).show();
// Log.e(TAG,e.getMessage());
// e.printStackTrace();
} catch (IOException e) {
Log.e(TAG,e.getMessage());
// e.printStackTrace();
}
}
});
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
camera = Camera.open();
if (camera != null){
Camera.Parameters params = camera.getParameters();
camera.setParameters(params);
}
else {
Toast.makeText(getApplicationContext(), "Camera not available!", Toast.LENGTH_LONG).show();
finish();
}
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
if (previewRunning){
camera.stopPreview();
}
Camera.Parameters p = camera.getParameters();
p.setPreviewSize(width, height);
camera.setParameters(p);
try {
camera.setPreviewDisplay(holder);
camera.startPreview();
previewRunning = true;
}
catch (IOException e) {
Log.e(TAG,e.getMessage());
e.printStackTrace();
}
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
camera.stopPreview();
previewRunning = false;
camera.release();
}
public static String GetOutputMediaFileDir(int fileType, int index){
String fileDir=null;
String strIndex = Integer.toString(index);
if(fileType == 1)
{
File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
Environment.DIRECTORY_MUSIC), "Audio");
if (! mediaStorageDir.exists()){
if (! mediaStorageDir.mkdirs()){
return null;
}
}
fileDir = mediaStorageDir.getPath() + File.separator +
"AUDIO_"+ strIndex + ".mp4";
}
if(fileType == 2)
{
File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
Environment.DIRECTORY_PICTURES), "Image");
if (! mediaStorageDir.exists()){
if (! mediaStorageDir.mkdirs()){
return null;
}
}
fileDir = mediaStorageDir.getPath() + File.separator +
"IMAGE_"+ strIndex + ".jpeg";
}
if(fileType == 3)
{
File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
Environment.DIRECTORY_MOVIES), "Video");
if (! mediaStorageDir.exists()){
if (! mediaStorageDir.mkdirs()){
return null;
}
}
fileDir = mediaStorageDir.getPath() + File.separator +
"VIDEO_"+ strIndex + ".mp4";
}
return fileDir;
}
}
关于如何解决问题的任何想法？提前非常感谢。
解决问题的更改：
首先我将视频编码器设置为音频编码器，这应该改变；
其次mediaRecorder.setPreviewDisplay(surfaceView.getHolder().getSurface());应该在之前添加mediaRecorder.prepare()
然后它可以正常工作。