对android录制的NV21视频数据进行旋转(90,180,270)与剪切
android默认的视频采集格式是NV21,(属于YUV420)
在onPreviewFrame中传进来的byte[] data即为NV21格式。
旋转算法
对NV21进行顺时针旋转90度,180度和270度算法。
旋转90度
privatebyte[] rotateYUV420Degree90(byte[] data, int imageWidth, int imageHeight){
byte[] yuv =newbyte[imageWidth*imageHeight*3/2];
// Rotate the Y luma
int i =0;
for(int x =0;x < imageWidth;x++){
for(int y = imageHeight-1;y >=0;y--){ yuv[i]= data[y*imageWidth+x]; i++;} }
// Rotate the U and V color components i = imageWidth*imageHeight*3/2-1;for(int x = imageWidth-1;x >0;x=x-2){for(int y =0;y < imageHeight/2;y++){ yuv[i]= data[(imageWidth*imageHeight)+(y*imageWidth)+x]; i--; yuv[i]= data[(imageWidth*imageHeight)+(y*imageWidth)+(x-1)]; i--;}}return yuv;}
用法:
//clockwise90:IplImage.create(480, 640) && new NewFFmpegFrameRecorder(480, 640)顺时针旋转90度, 将IplImage.create和new NewFFmpegFrameRecorder处源图像的宽高640x480对换成旋转后的真实宽高480x640 byte[] outdata; outdata = rotateYUV420Degree90(data, 640, 480);
旋转180度
privatebyte[] rotateYUV420Degree180(byte[] data, int imageWidth, int imageHeight){
byte[] yuv =newbyte[imageWidth*imageHeight*3/2];
int i =0;int count =0; for(i = imageWidth * imageHeight -1; i >=0; i--){ yuv[count]= data[i]; count++;} i = imageWidth * imageHeight *3/2-1;for(i = imageWidth * imageHeight *3/2-1; i >= imageWidth * imageHeight; i -=2){ yuv[count++]= data[i -1]; yuv[count++]= data[i];}return yuv;}
用法:
//clockwise180:IplImage.create(640, 480) && new NewFFmpegFrameRecorder(640, 480)上述2处无需改动 byte[] outdata; outdata = rotateYUV420Degree180(data, 640, 480);
旋转270度
private byte[] rotateYUV420Degree270(byte[] data, int imageWidth, int imageHeight){
byte[] yuv =new byte[imageWidth*imageHeight*3/2];
// Rotate the Y luma
int i =0;
for(int x = imageWidth-1;x >=0;x--){
for(int y =0;y < imageHeight;y++){
yuv[i]= data[y*imageWidth+x]; i++;
} }// Rotate the U and V color components i = imageWidth*imageHeight;
for(int x = imageWidth-1;x >0;x=x-2){
for(int y =0;y < imageHeight/2;y++){ yuv[i]= data[(imageWidth*imageHeight)+(y*imageWidth)+(x-1)]; i++; yuv[i]= data[(imageWidth*imageHeight)+(y*imageWidth)+x]; i++;
}
}
return yuv;
}
用法:
//clockwise270:IplImage.create(480, 640) && new NewFFmpegFrameRecorder(480, 640),设置与旋转90度相同 byte[] outdata; outdata = rotateYUV420Degree270(data, 640, 480);
裁剪NV21
publicbyte[] cropYUV420(byte[] data,int imageW,int imageH,int newImageH){int cropH;int i,j,count,tmp;byte[] yuv =newbyte[imageW*newImageH*3/2]; cropH =(imageH - newImageH)/2; count =0;for(j=cropH;j<cropH+newImageH;j++){for(i=0;i<imageW;i++){ yuv[count++]= data[j*imageW+i];}} //Cr Cb tmp = imageH+cropH/2;for(j=tmp;j<tmp + newImageH/2;j++){for(i=0;i<imageW;i++){ yuv[count++]= data[j*imageW+i];}} return yuv;}
用法:
将640x480裁剪成480x480时用法如下:
在onPreviewFrame(byte[] data, Camera camera)中调用
byte[] outdata2; byte[] outdata; outdata2 = rotateYUV420Degree90(data, 640, 480);//将640x480旋转成480x640 outdata = cropYUV420(outdata2, 480, 640,480);//将480x640裁剪成480x480
在initVideoRecorder中
videoRecorder = new NewFFmpegFrameRecorder(strVideoPath, 480, 480, 1);
在handleSurfaceChanged中
yuvIplImage = IplImage.create(480, 480, IPL_DEPTH_8U, 2);
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