将NV21字节数组转换为位图可读格式

嘿,我正在创build小型相机应用程序,我已经实现了每一件事情,但我有一个问题是将NV21字节数组转换为JPEG格式
我find了很多方法,但是他们中的所有人甚至不工作或者在某些设备上工作
首先我试过这个片段,它在Xperia z2 5.2上工作,但是在Galaxy S4.4 4.4.4上

bitmap = BitmapFactory.decodeByteArray(data, 0, data.length); 

也是这种方式在同一设备上工作,并在另一个失败

  int pich = camera.getParameters().getPreviewSize().height; int picw = camera.getParameters().getPreviewSize().width; int[] pix = new int[picw * pich]; bitmap.getPixels(pix, 0, picw, 0, 0, picw, pich); // int R, G, B, Y; for (int y = 0; y < pich; y++) { for (int x = 0; x < picw; x++) { int index = y * picw + x; int R = (pix[index] >> 16) & 0xff; int G = (pix[index] >> 8) & 0xff; int B = pix[index] & 0xff; pix[index] = 0xff000000 | (R << 16) | (G << 8) | B; } } 

其次,我尝试了很多解决scheme来转换解码NV21第一个renderscript代码

  public Bitmap convertYUV420_NV21toRGB8888_RenderScript(byte [] data,int W, int H, Fragment fragment) { // http://stackoverflow.com/questions/20358803/how-to-use-scriptintrinsicyuvtorgb-converting-byte-yuv-to-byte-rgba RenderScript rs; ScriptIntrinsicYuvToRGB yuvToRgbIntrinsic; rs = RenderScript.create(fragment.getActivity()); yuvToRgbIntrinsic = ScriptIntrinsicYuvToRGB.create(rs, Element.U8_4(rs)); //Create an intrinsic for converting YUV to RGB. Type.Builder yuvType = new Type.Builder(rs, Element.U8(rs)).setX(data.length); Allocation in = Allocation.createTyped(rs, yuvType.create(), Allocation.USAGE_SCRIPT); //an Allocation will be populated with empty data when it is first created Type.Builder rgbaType = new Type.Builder(rs, Element.RGBA_8888(rs)).setX(W).setY(H); Allocation out = Allocation.createTyped(rs, rgbaType.create(), Allocation.USAGE_SCRIPT); //an Allocation will be populated with empty data when it is first created in.copyFrom(data);//Populate Allocations with data. yuvToRgbIntrinsic.setInput(in); //Set the input yuv allocation, must be U8(RenderScript). yuvToRgbIntrinsic.forEach(out); //Launch the appropriate kernels,Convert the image to RGB. Bitmap bmpout = Bitmap.createBitmap(W, H, Bitmap.Config.ARGB_8888); out.copyTo(bmpout); //Copy data out of Allocation objects. return bmpout; } 

也是这个代码

  void decodeYUV420SP(int[] rgb, byte[] yuv420sp, int width, int height) { final int frameSize = width * height; for (int j = 0, yp = 0; j < height; j++) { int uvp = frameSize + (j >> 1) * width, u = 0, v = 0; for (int i = 0; i < width; i++, yp++) { int y = (0xff & ((int) yuv420sp[yp])) - 16; if (y < 0) y = 0; if ((i & 1) == 0) { v = (0xff & yuv420sp[uvp++]) - 128; u = (0xff & yuv420sp[uvp++]) - 128; } int y1192 = 1192 * y; int r = (y1192 + 1634 * v); int g = (y1192 - 833 * v - 400 * u); int b = (y1192 + 2066 * u); if (r < 0) r = 0; else if (r > 262143) r = 262143; if (g < 0) g = 0; else if (g > 262143) g = 262143; if (b < 0) b = 0; else if (b > 262143) b = 262143; rgb[yp] = 0xff000000 | ((r << 6) & 0xff0000) | ((g >> 2) & 0xff00) | ((b >> 10) & 0xff); } } } 

最后我试图保存在SD卡上的图像,然后重新打开,但也失败了

 File pictureFile = new File(filename); int pich = camera.getParameters().getPreviewSize().height; int picw = camera.getParameters().getPreviewSize().width; Rect rect = new Rect(0, 0,picw, pich); YuvImage img = new YuvImage(data, ImageFormat.NV21, picw, picw, null); try { FileOutputStream fos = new FileOutputStream(pictureFile); img.compressToJpeg(rect, 100, fos); fos.write(data); fos.close(); 

这是我跟随的最后3种方法的结果 在这里输入图像说明

Solutions Collecting From Web of "将NV21字节数组转换为位图可读格式"

有几种方法可以保存来自相机的NV21帧,最简单的方法是将其转换为YuvImage,然后将其保存为Jpeg文件:

 FileOutputStream fos = new FileOutputStream(Environment.getExternalStorageDirectory() + "/imagename.jpg"); YuvImage yuvImage = new YuvImage(nv21bytearray, ImageFormat.NV21, width, height, null); yuvImage.compressToJpeg(new Rect(0, 0, width, height), 100, fos); fos.close(); 

或者,您也可以将其转换为Android位图对象,并将其保存为PNG或其他格式:

 YuvImage yuvImage = new YuvImage(nv21bytearray, ImageFormat.NV21, width, height, null); ByteArrayOutputStream os = new ByteArrayOutputStream(); yuvImage.compressToJpeg(new Rect(0, 0, width, height), 100, os); byte[] jpegByteArray = os.toByteArray(); Bitmap bitmap = BitmapFactory.decodeByteArray(jpegByteArray, 0, jpegByteArray.length); FileOutputStream fos = new FileOutputStream(Environment.getExternalStorageDirectory() + "/imagename.png"); bitmap.compress(Bitmap.CompressFormat.PNG, 100, fos); fos.close(); 

请注意,最后一个选项是NV21 -> JPEG -> Bitmap Object -> PNG file处理,所以请记住,如果您需要高性能,这不是从相机保存预览图像的非常有效的方法。

更新:我厌倦了这个转换工作需要多长时间,于是我写了一个关于RenderScript的库( easyRS ),以便在一行代码中轻松完成这个工作:

 Bitmap outputBitmap = Nv21Image.nv21ToBitmap(rs, nv21ByteArray, width, height); 

在Moto G 2nd的2000×2000图像上,它的速度比JPEG处理快5倍左右。

你的第二次尝试(ScriptIntrinsicYuvToRGB)看起来很有希望。 使用JellyBean 4.3(API18)或更高版本,请执行以下操作(相机预览格式必须为NV21):

首先,不要在脚本执行的方法或循环中创buildrs,yuvToRgbIntrinsic和分配。 这将极大地降低您的应用程序的速度,并可能导致内存不足错误。 把这些放在onCreate()..方法中:

 rs = RenderScript.create(this); // create rs object only once and use it as long as possible yuvToRgbIntrinsic = ScriptIntrinsicYuvToRGB.create(rs, Element.U8_4(rs)); // ditto. 

使用Api18 +,分配会更容易创build(您不需要Type.Builder对象!)。 用你的cameraPreviewWidth和cameraPreviewHeight创build分配aIn:

 int yuvDatalength = cameraPreviewWidth*cameraPreviewHeight*3/2; // this is 12 bit per pixel aIn = Allocation.createSized(rs, Element.U8(rs), yuvDatalength); 

你需要一个位图输出:

 bmpout = Bitmap.createBitmap(cameraPreviewWidth, cameraPreviewHeight, Bitmap.Config.ARGB_8888); 

并从这个位图简单地创buildaOut分配:

 aOut = Allocation.createFromBitmap(rs, bmpout); 

设置脚本的分配(只在循环之外 ):

 yuvToRgbIntrinsic.setInput(aIn); //Set the input yuv allocation, must be U8(RenderScript). 

在“摄像机循环”中用byte []数据:

 aIn.copyFrom(data); // or aIn.copyFromUnchecked(data); // which is faster and safe with camera data yuvToRgbIntrinsic.forEach(aOut); //Launch the appropriate kernels,Convert the image to RGB. aOut.copyTo(bmpout); // copy data from Allocation aOut to Bitmap bmpout 

例如,在Nexus 7(2013,JellyBean 4.3)上,全高清(1920×1080像素)相机预览转换大约需要7 ms。