MediaCodec 音视频编解码

package com.example.knowledgemanagement.helper; import android.app.Application; import android.content.Context; import android.graphics.Bitmap; import android.graphics.ImageFormat; import android.graphics.SurfaceTexture; import android.hardware.Camera; import android.renderscript.Allocation; import android.renderscript.Element; import android.renderscript.RenderScript; import android.renderscript.ScriptIntrinsicYuvToRGB; import android.renderscript.Type; import java.util.List; public class CameraHelper implements Camera.PreviewCallback { public static final String TAG="CameraHelper"; private int width; private int height; private int mCameraId; private Camera mCamera; private byte[] buffer; private Camera.PreviewCallback mPreviewCallback; private SurfaceTexture mSurfaceTexture; private Context mContext; public CameraHelper(Context context,int width,int height){ this.mContext = context; this.width=width; this.height=height; mCameraId= Camera.CameraInfo.CAMERA_FACING_BACK; } public void switchCamera(){ if(mCameraId == Camera.CameraInfo.CAMERA_FACING_BACK){ mCameraId=Camera.CameraInfo.CAMERA_FACING_FRONT; }else{ mCameraId=Camera.CameraInfo.CAMERA_FACING_BACK; } stopPreview(); startPreview(mSurfaceTexture); } public int getmCameraId(){ return mCameraId; } public void stopPreview(){ if(mCamera!=null){ //预览数据回调接口 mCamera.setPreviewCallback(null); //停止预览 mCamera.stopPreview(); //释放摄像头 mCamera.release(); mCamera=null; } } public void startPreview(SurfaceTexture surfaceTexture){ stopPreview(); try { mSurfaceTexture = surfaceTexture; //获取camera属性 mCamera = Camera.open(mCameraId); //配置cammera的属性 Camera.Parameters parameters = mCamera.getParameters(); //设置预览数据格式为nv21 parameters.setPreviewFormat(ImageFormat.NV21); boolean isSupportSize = false; List<Camera.Size> supportedPreviewSizes = parameters.getSupportedPreviewSizes(); for (Camera.Size supportedPreviewSize : supportedPreviewSizes) { if (supportedPreviewSize.width == width && supportedPreviewSize.height == height) { isSupportSize = true; break; } } if (!isSupportSize) { Camera.Size size=supportedPreviewSizes.get(0); width=size.width; height=size.height; } //这里是摄像头的宽高 parameters.setPreviewSize(width,height); parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_VIDEO); mCamera.setDisplayOrientation(90); //设置摄像头 图像传感器的角度、方向 mCamera.setParameters(parameters); buffer=new byte[width*height*3/2]; i420=new byte[width*height*3/2]; //数据缓存区 mCamera.addCallbackBuffer(buffer); mCamera.setPreviewCallbackWithBuffer(this); //设置预览画面 mCamera.setPreviewTexture(surfaceTexture); mCamera.startPreview(); }catch (Exception ex){ ex.printStackTrace(); } } public int getWidth(){return width;} public int getHeight(){return height;} public void setPreviewCallback(Camera.PreviewCallback previewCallback){ mPreviewCallback=previewCallback; } byte[] i420; private void nv21ToI420(byte[] data){ //y数据 System.arraycopy(data,0,i420,0,width*height); int index=width*height; for(int i=width*height;i<data.length;i+=2){ i420[index++]=data[i+1]; } for(int i=width*height;i<data.length;i+=2){ i420[index++]=data[i]; } } @Override public void onPreviewFrame(byte[] data, Camera camera) { if(null!=mPreviewCallback) { Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888); Allocation bmData = renderScriptNV21ToRGBA888(mContext, width, height, data); bmData.copyTo(bitmap); mPreviewCallback.onPreviewFrame(data,camera); } camera.addCallbackBuffer(buffer); } public Allocation renderScriptNV21ToRGBA888(Context context, int width, int height, byte[] nv21) { RenderScript rs = RenderScript.create(context); ScriptIntrinsicYuvToRGB yuvToRgbIntrinsic = ScriptIntrinsicYuvToRGB.create(rs, Element.U8_4(rs)); Type.Builder yuvType = new Type.Builder(rs, Element.U8(rs)).setX(nv21.length); Allocation in = Allocation.createTyped(rs, yuvType.create(), Allocation.USAGE_SCRIPT); Type.Builder rgbaType = new Type.Builder(rs, Element.RGBA_8888(rs)).setX(width).setY(height); Allocation out = Allocation.createTyped(rs, rgbaType.create(), Allocation.USAGE_SCRIPT); in.copyFrom(nv21); yuvToRgbIntrinsic.setInput(in); yuvToRgbIntrinsic.forEach(out); return out; } }