Question

我想在android上显示YUV视频但是，我的项目只能显示视频的第一帧我无法在当前状态下成功显示下一帧

以下是我的java代码：

public class SkiaView extends SurfaceView implements SurfaceHolder.Callback, Runnable
{
private SurfaceHolder holder=null;//******Version2******//
private static final String TAG = "skiademo";

private int mSampleId = 0;
// final Rect rect = new Rect(0, 0, 352, 288);  
final int width=352,height=288;

int FrameNum=0;

static 
{
    System.loadLibrary("SkiaDemo");
}

public native void renderHello(Canvas canvas, int FrameNum,Rect rect);
public native void renderText(Canvas canvas);
class Pixel
{
    byte Y,U,V;
};
private int[] YUV2RGB(byte [] YUV)
{
    Byte R,G,B;
    int y,x,i;
    int  [] argb = new int [width*height];
    byte [] Y= new byte[width*height];
    byte [] U= new byte[width*height];
    byte [] V= new byte[width*height];
    for(i=0;i<width*height;i++)
    {
        Y[i] =YUV[i];
        if(i==0)
        Log.d(TAG, "Y="+Y[i] +" YUV[i]=" +YUV[i]);
    }
    i=0;
    byte container;
    for(y=0;y<height/2;y++)
        for(x=0;x<width/2;x++)
    {
        container =YUV[i+width*height];
        U[y*2*width+x*2]=container;
        U[y*2*width+x*2+1]=container;
        U[(y*2+1)*width+x*2]=container;
        U[(y*2+1)*width+x*2+1]=container;
        i++;

    }

    i=0;
    for(y=0;y<height/2;y++)
        for(x=0;x<width/2;x++)
    {
        container =YUV[i+width*height+width*height/4];
        V[y*2*width+x*2]=container;
        V[y*2*width+x*2+1]=container;
        V[(y*2+1)*width+x*2]=container;
        V[(y*2+1)*width+x*2+1]=container;

    } 
    for(i=0;i<width*height;i++)
    {
        R=(byte) (Y[i]+128+1.4075*(V[i]+128-128));
        G=(byte) (Y[i]+128-0.3455*(U[i]+128-128)-0.7169*(V[i]+128-128));
        B=(byte) (Y[i]+128+1.7790*(U[i]-128+128));
        argb[i]=(0xff000000 + (B << 16) + (G << 8) + R);
        if(i==0)
        {
            Log.d(TAG, "Y="+Y[i]+" U="+U[i]+ " V= "+V[i]);
            Log.d(TAG, "R="+R+" G="+G+ "B= "+B+" argb="+argb[0]);
        }

    }

    //Bitmap bmp=Bitmap.createBitmap(width,height,Bitmap.Config.ARGB_8888);


    return argb;


   }
 private void readYUV(String src,byte[] YUV,int frame )
 {      
    int i;
    try {
        FileInputStream inFile = new FileInputStream(src);
        int filelength=inFile.available();
        Log.d(TAG, "frame="+frame+" start="+width*height*1.5*frame+" Length="+width*height*1.5 + "   Filelength="+filelength);
            //inFile.read(YUV, (int)(width*height*1.5*(frame-1)),(int)(width*height*1.5));      
        for(i=0;i<width*height*1.5;i++)
            YUV[i]=(byte) inFile.read();

        Log.d(TAG, " YUV[i]=" +YUV[0]);
            inFile.close();   
    } catch(FileNotFoundException fe) {
        System.out.println("There is no such file!");

    } catch(IOException ioe) {
        System.out.println("IO exception!");

    }

}

public SkiaView(Context context)//******Version2******//
{
       super(context);
       // TODO Auto-generated constructor stub
       holder=getHolder();
       holder.addCallback(this);
}

public void surfaceCreated(SurfaceHolder holder)//******Version2******//
{
       // TODO Auto-generated method stub
      new Thread(this).start();
}
private Bitmap Bytes2Bimap(byte[] b){
       if(b.length!=0){
       return BitmapFactory.decodeByteArray(b, 0, b.length);
       }
       else {
       return null;
       }
    }
private void render(Canvas canvas,int i) {


    canvas.drawColor(Color.BLACK);
    byte [] YUV = new byte[(int) (width*height*1.5)];
    int  [] rgb = new int [width*height];
    Bitmap bmp = Bitmap.createBitmap(width,height,Bitmap.Config.ARGB_8888);
    readYUV("/mnt/sdcard/out_352x288_P420_final.yuv",YUV,i);
    rgb=YUV2RGB(YUV);

    bmp.setPixels(rgb, 0, width, 0, 0, width, height);
    Log.d(TAG, "pixel="+bmp.getPixel(0, 0));
    canvas.drawBitmap(bmp, 0, 0, null);

}
@Override
public void run() {
    int i=0;
    while(true)
    {
        Canvas canvas = holder.lockCanvas();
        render(canvas,i);
        i++;
        if(i>=299)
        i=0;
        holder.unlockCanvasAndPost(canvas);
    }
}

public void surfaceChanged(SurfaceHolder holder, int format, int width,
        int height) {
    // TODO Auto-generated method stub

}
public void surfaceDestroyed(SurfaceHolder holder) {
    // TODO Auto-generated method stub

}


}

我也尝试打印每个帧的第一个像素所有内容都是一样的它应该不是那样的

希望任何人都可以给我答案

Answer 1

在readYUV（）方法中，您似乎一遍又一遍地读取第一帧。每次打开到源文件的流时，它都从偏移量0开始。您需要使用FileInputStream.skip（）方法来寻找每个帧的正确位置，或者将流指针保存在一个不变量的变量中。超出范围。你也应该在完成后关闭流。

Answer 2

你没有在readYUV中寻求。它总是读取第一帧。

PS，如果图像很大，yuv2rgb可能成为瓶颈，尝试使用somr NEON优化版本。

在Android上播放YUV视频

2 个答案: