Camera预览时需要对yuv帧做水平翻转处理，直接在onPreviewFrame(byte[] data, Camera camera)里调用Mirror函数，处理完后的图片和预览效果成水平翻转关系。
nv21的镜像算法：
private void Mirror(byte[] src, int w, int h) { //src是原始yuv数组
int i;
int index;
byte temp;
int a, b;
//mirror y
for (i = 0; i < h; i++) {
a = i * w;
b = (i + 1) * w - 1;
while (a < b) {
temp = src[a];
src[a] = src[b];
src[b] = temp;
a++;
b--;
}
}
// mirror u and v
index = w * h;
for (i = 0; i < h / 2; i++) {
a = i * w;
b = (i + 1) * w - 2;
while (a < b) {
temp = src[a + index];
src[a + index] = src[b + index];
src[b + index] = temp;
temp = src[a + index + 1];
src[a + index + 1] = src[b + index + 1];
src[b + index + 1] = temp;
a+=2;
b-=2;
}
}
}
i420的镜像算法：
private void Mirror(byte[] src, int w, int h) { //src是原始yuv数组
int i;
int index;
byte temp;
int a, b;
//mirror y
for (i = 0; i < h; i++) {
a = i * w;
b = (i + 1) * w - 1;
while (a < b) {
temp = src[a];
src[a] = src[b];
src[b] = temp;
a++;
b--;
}
}
//mirror u
index = w * h;//U起始位置
for (i = 0; i < h / 2; i++) {
a = i * w / 2;
b = (i + 1) * w / 2 - 1;
while (a < b) {
temp = src[a + index];
src[a + index] = src[b + index];
src[b + index] = temp;
a++;
b--;
}
}
//mirror v
index = w * h / 4 * 5;//V起始位置
for (i = 0; i < h / 2; i++) {
a = i * w / 2;
b = (i + 1) * w / 2 - 1;
while (a < b) {
temp = src[a + index];
src[a + index] = src[b + index];
src[b + index] = temp;
a++;
b--;
}
}
I420，YV12，NV12，NV21均属于YUV420，以下为四种格式的排列顺序：
I420: YYYYYYYY UUVV =>YUV420P
YV12: YYYYYYYY VVUU =>YUV420P
NV12: YYYYYYYY UVUV =>YUV420SP
NV21: YYYYYYYY VUVU =>YUV420SP
以上这篇android camera yuv帧水平翻转实例就是小编分享给大家的全部内容了，希望能给大家一个参考，也希望大家多多支持找一找教程网。
