Android中如何通过surfaceview获取texture
时间: 2023-03-03 19:47:54 浏览: 256
SurfaceView是一种视图,可以用来从texture获取图像,可以通过使用SurfaceHolder.Callback接口来捕获texture,也可以使用SurfaceTexture.OnFrameAvailableListener接口来捕获texture。
相关问题
使用surface texture和surfaceview实现相机预览
好的,我会给您讲解使用 SurfaceTexture 和 SurfaceView 实现相机预览的方法。
首先,在布局文件中添加一个 SurfaceView:
```xml
<SurfaceView
android:id="@+id/surfaceView"
android:layout_width="match_parent"
android:layout_height="match_parent" />
```
然后在 Activity 或 Fragment 中获取 SurfaceView,并设置相机预览:
```java
// 获取 SurfaceView
SurfaceView surfaceView = findViewById(R.id.surfaceView);
// 获取相机实例
Camera camera = Camera.open();
try {
// 设置相机预览显示的 Surface
camera.setPreviewDisplay(surfaceView.getHolder());
// 开始预览
camera.startPreview();
} catch (IOException e) {
e.printStackTrace();
}
```
接下来,我们来使用 SurfaceTexture 来实现相机预览。
首先,在布局文件中添加一个 TextureView:
```xml
<TextureView
android:id="@+id/textureView"
android:layout_width="match_parent"
android:layout_height="match_parent" />
```
然后在 Activity 或 Fragment 中获取 TextureView,并设置相机预览:
```java
// 获取 TextureView
TextureView textureView = findViewById(R.id.textureView);
// 获取相机实例
Camera camera = Camera.open();
try {
// 创建 SurfaceTexture
SurfaceTexture surfaceTexture = new SurfaceTexture(0);
// 设置相机预览显示的 Surface
camera.setPreviewTexture(surfaceTexture);
// 开始预览
camera.startPreview();
} catch (IOException e) {
e.printStackTrace();
}
```
使用 SurfaceTexture 来实现相机预览的好处在于,可以通过 TextureView 的 setSurfaceTextureListener() 方法来监听 SurfaceTexture 的状态,例如当 SurfaceTexture 准备好后,可以获取它的宽高等信息,从而进行一些额外的操作。
希望这些代码可以帮助到您。
android camera 录制15秒视频
你可以使用Android的Camera2 API来录制15秒的视频。以下是一个简单的示例代码,可以帮助你开始录制视频:
1. 在你的AndroidManifest.xml文件中添加以下权限:
```xml
<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.RECORD_AUDIO" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
```
2. 在你的布局文件中添加一个SurfaceView元素用于预览视频:
```xml
<SurfaceView
android:id="@+id/surfaceView"
android:layout_width="match_parent"
android:layout_height="match_parent" />
```
3. 在你的Activity或Fragment中,获取SurfaceView并设置它的回调:
```java
private SurfaceView surfaceView;
private SurfaceHolder surfaceHolder;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
surfaceView = findViewById(R.id.surfaceView);
surfaceHolder = surfaceView.getHolder();
surfaceHolder.addCallback(surfaceHolderCallback);
}
private SurfaceHolder.Callback surfaceHolderCallback = new SurfaceHolder.Callback() {
@Override
public void surfaceCreated(SurfaceHolder holder) {
// 初始化Camera
initializeCamera();
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
// 当SurfaceView尺寸发生变化时,更新Camera参数
updateCameraParameters();
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
// 释放Camera资源
releaseCamera();
}
};
```
4. 初始化Camera并设置参数:
```java
private CameraDevice camera;
private CameraCaptureSession captureSession;
private CaptureRequest.Builder previewRequestBuilder;
private Size previewSize;
private void initializeCamera() {
CameraManager cameraManager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
try {
// 获取后置摄像头
String cameraId = cameraManager.getCameraIdList()[0];
CameraCharacteristics characteristics = cameraManager.getCameraCharacteristics(cameraId);
StreamConfigurationMap map = characteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP);
previewSize = map.getOutputSizes(SurfaceTexture.class)[0];
// 打开Camera
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.CAMERA) == PackageManager.PERMISSION_GRANTED) {
cameraManager.openCamera(cameraId, cameraStateCallback, null);
}
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
private CameraDevice.StateCallback cameraStateCallback = new CameraDevice.StateCallback() {
@Override
public void onOpened(CameraDevice camera) {
MainActivity.this.camera = camera;
// 开始预览
startPreview();
}
@Override
public void onDisconnected(CameraDevice camera) {
camera.close();
MainActivity.this.camera = null;
}
@Override
public void onError(CameraDevice camera, int error) {
camera.close();
MainActivity.this.camera = null;
}
};
private void startPreview() {
try {
SurfaceTexture texture = surfaceHolder.getSurfaceTexture();
texture.setDefaultBufferSize(previewSize.getWidth(), previewSize.getHeight());
Surface surface = new Surface(texture);
previewRequestBuilder = camera.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
previewRequestBuilder.addTarget(surface);
List<Surface> surfaces = new ArrayList<>();
surfaces.add(surface);
camera.createCaptureSession(surfaces, captureSessionStateCallback, null);
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
private CameraCaptureSession.StateCallback captureSessionStateCallback = new CameraCaptureSession.StateCallback() {
@Override
public void onConfigured(CameraCaptureSession session) {
captureSession = session;
try {
previewRequestBuilder.set(CaptureRequest.CONTROL_AF_MODE, CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE);
previewRequestBuilder.set(CaptureRequest.CONTROL_AE_MODE, CaptureRequest.CONTROL_AE_MODE_ON_AUTO_FLASH);
CaptureRequest previewRequest = previewRequestBuilder.build();
captureSession.setRepeatingRequest(previewRequest, null, null);
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
@Override
public void onConfigureFailed(CameraCaptureSession session) {
session.close();
captureSession = null;
}
};
private void updateCameraParameters() {
if (camera == null) {
return;
}
try {
// 获取最佳预览尺寸
CameraCharacteristics characteristics = camera.getCameraCharacteristics(camera.getId());
StreamConfigurationMap map = characteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP);
Size[] supportedSizes = map.getOutputSizes(SurfaceTexture.class);
Size optimalSize = getOptimalPreviewSize(supportedSizes, surfaceView.getWidth(), surfaceView.getHeight());
// 更新预览尺寸
if (!previewSize.equals(optimalSize)) {
previewSize = optimalSize;
updatePreview();
}
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
private void updatePreview() {
if (camera == null) {
return;
}
try {
// 停止当前预览
captureSession.stopRepeating();
captureSession.abortCaptures();
// 更新预览大小
SurfaceTexture texture = surfaceHolder.getSurfaceTexture();
texture.setDefaultBufferSize(previewSize.getWidth(), previewSize.getHeight());
// 创建新的预览请求
Surface surface = new Surface(texture);
previewRequestBuilder = camera.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
previewRequestBuilder.addTarget(surface);
List<Surface> surfaces = new ArrayList<>();
surfaces.add(surface);
camera.createCaptureSession(surfaces, captureSessionStateCallback, null);
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
private Size getOptimalPreviewSize(Size[] sizes, int width, int height) {
final double ASPECT_TOLERANCE = 0.1;
double targetRatio = (double) height / width;
if (sizes == null) {
return null;
}
Size optimalSize = null;
double minDiff = Double.MAX_VALUE;
int targetHeight = height;
for (Size size : sizes) {
double ratio = (double) size.getWidth() / size.getHeight();
if (Math.abs(ratio - targetRatio) > ASPECT_TOLERANCE) {
continue;
}
if (Math.abs(size.getHeight() - targetHeight) < minDiff) {
optimalSize = size;
minDiff = Math.abs(size.getHeight() - targetHeight);
}
}
if (optimalSize == null) {
minDiff = Double.MAX_VALUE;
for (Size size : sizes) {
if (Math.abs(size.getHeight() - targetHeight) < minDiff) {
optimalSize = size;
minDiff = Math.abs(size.getHeight() - targetHeight);
}
}
}
return optimalSize;
}
```
5. 在你的Activity或Fragment中实现录制视频的逻辑:
```java
private MediaRecorder mediaRecorder;
private File outputFile;
private void startRecording() {
try {
// 创建输出文件
outputFile = new File(getExternalFilesDir(null), "video.mp4");
// 创建MediaRecorder
mediaRecorder = new MediaRecorder();
mediaRecorder.setVideoSource(MediaRecorder.VideoSource.SURFACE);
mediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);
mediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.H264);
mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AAC);
mediaRecorder.setVideoSize(previewSize.getWidth(), previewSize.getHeight());
mediaRecorder.setVideoFrameRate(30);
mediaRecorder.setOutputFile(outputFile.getAbsolutePath());
// 配置MediaRecorder
mediaRecorder.prepare();
mediaRecorder.start();
// 录制15秒后停止
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
stopRecording();
}
}, 15000);
} catch (IOException e) {
e.printStackTrace();
}
}
private void stopRecording() {
if (mediaRecorder != null) {
mediaRecorder.stop();
mediaRecorder.release();
mediaRecorder = null;
// 停止预览
if (camera != null) {
captureSession.close();
captureSession = null;
camera.close();
camera = null;
}
// 播放录制的视频
Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(outputFile.getAbsolutePath()));
intent.setDataAndType(Uri.parse(outputFile.getAbsolutePath()), "video/*");
startActivity(intent);
}
}
```
6. 最后,在你的Activity或Fragment中添加一个按钮来启动录制:
```java
public void onRecordButtonClicked(View view) {
startRecording();
}
```