yuv编码简介
在YUV420中，一个像素点对应一个Y，一个2X2的小方块对应一个U和V。对于所有YUV420图像，它们的Y值排列是完全相同的，因为只有Y的图像就是灰度图像。YUV420sp与YUV420p的数据格式它们的UV排列在原理上是完全不同的。420p它是先把U存放完后，再存放V，也就是说UV它们是连续的。而420sp它是UV、UV这样交替存放的。
yuv流的各种操作。
代码：
public static byte[] flip(byte[] src, int width, int height) {
for (int i = 0; i < height; i++) {
int left = 0;
int right = width - 1;
while (left < right) {
byte b = src[i * width + right];
src[i * width + right] = src[i * width + left];
src[i * width + left] = b;
left++;
right--;
}
}
int uHeader = width * height;
int uHeight = height / 2;
for (int i = 0; i < uHeight; i++) {
int left = 0;
int right = width - 2;
while (left < right) {
byte b = src[uHeader + i * width + right];
src[uHeader + i * width + right] = src[uHeader + i * width + left];
src[uHeader + i * width + left] = b;
b = src[uHeader + i * width + right + 1];
src[uHeader + i * width + right + 1] = src[uHeader + i * width + left + 1];
src[uHeader + i * width + left + 1] = b;
left += 2;
right -= 2;
}
}
return src;
}
public static byte[] rotate270(byte[] src, int width, int height) {
byte[] dest = new byte[src.length];
int index = 0;
for (int i = width - 1; i >= 0; i--) {
for (int j = 0; j < height; j++) {
dest[index++] = src[j * width + i];
}
}
int uHeader = index;
int uHeight = height / 2;
for (int i = width - 2; i >= 0; i -= 2) {
for (int j = 0; j < uHeight; j++) {
dest[index++] = src[uHeader + j * width + i];
dest[index++] = src[uHeader + j * width + i + 1];
}
}
return dest;
}
public static byte[] rotate90(byte[] src, int width, int height) {
byte[] dest = new byte[src.length];
int index = 0;
for (int i = 0; i < width; i++) {
for (int j = height - 1; j >= 0; j--) {
dest[index++] = src[j * width + i];
}
}
int uHeader = index;
int uHeight = height / 2;
for (int i = 0; i < width; i += 2) {
for (int j = uHeight - 1; j >= 0; j--) {
dest[index++] = src[uHeader + j * width + i];
dest[index++] = src[uHeader + j * width + i + 1];
}
}
return dest;
}
public static byte[] rotate180(byte[] src, int width, int height) {
int top = 0;
int bottom = height - 1;
while (top < bottom) {
for (int i = 0; i < width; i++) {
byte b = src[bottom * width + width - 1 - i];
src[bottom * width + width - 1 - i] = src[top * width + i];
src[top * width + i] = b;
}
top++;
bottom--;
}
int uHeader = width * height;
top = 0;
bottom = height / 2 - 1;
while (top < bottom) {
for (int i = 0; i < width; i += 2) {
byte b = src[uHeader + bottom * width + width - 2 - i];
src[uHeader + bottom * width + width - 2 - i] = src[uHeader + top * width + i];
src[uHeader + top * width + i] = b;
b = src[uHeader + bottom * width + width - 1 - i];
src[uHeader + bottom * width + width - 1 - i] = src[uHeader + top * width + i + 1];
src[uHeader + top * width + i + 1] = b;
}
top++;
bottom--;
}
return src;
}
转载自：https://blog.csdn.net/weixin_33943347/article/details/87200308