android視訊採集YUV420旋轉角度演算法
阿新 • • 發佈:2019-02-03
常用的YUV420旋轉角度演算法,選擇90度的演算法已經優化過了。網上也很多,不過有一些不能用,這些是本人親測過的。有一點需要注意。如果你需要旋轉90度或者270度,那麼需要把寬和高對調。否則會花屏。因為比如你320 X 240,影象旋轉90°之後寬高變成了240 X 320。
//順時針旋轉270度 private void YUV420spRotate270(byte[] des, byte[] src, int width, int height) { int n = 0; int uvHeight = height >> 1; int wh = width * height; //copy y for (int j = width - 1; j >= 0; j--) { for (int i = 0; i < height; i++) { des[n++] = src[width * i + j]; } } for (int j = width - 1; j > 0; j -= 2) { for (int i = 0; i < uvHeight; i++) { des[n++] = src[wh + width * i + j - 1]; des[n++] = src[wh + width * i + j]; } } } //旋轉180度(順時逆時結果是一樣的) private void YUV420spRotate180(byte[] src, byte[] des, int width, int height) { int n = 0; int uh = height >> 1; int wh = width * height; //copy y for (int j = height - 1; j >= 0; j--) { for (int i = width - 1; i >= 0; i--) { des[n++] = src[width * j + i]; } } for (int j = uh - 1; j >= 0; j--) { for (int i = width - 1; i > 0; i -= 2) { des[n] = src[wh + width * j + i - 1]; des[n + 1] = src[wh + width * j + i]; n += 2; } } } //順時針旋轉90 private void YUV420spRotate90Clockwise(byte[] src, byte[] dst, int srcWidth, int srcHeight) { // int wh = width * height; // int k = 0; // for (int i = 0; i < width; i++) { // for (int j = height - 1; j >= 0; j--) { // des[k] = src[width * j + i]; // k++; // } // } // for (int i = 0; i < width; i += 2) { // for (int j = height / 2 - 1; j >= 0; j--) { // des[k] = src[wh + width * j + i]; // des[k + 1] = src[wh + width * j + i + 1]; // k += 2; // } // } int wh = srcWidth * srcHeight; int uvHeight = srcHeight >> 1; //旋轉Y int k = 0; for (int i = 0; i < srcWidth; i++) { int nPos = 0; for (int j = 0; j < srcHeight; j++) { dst[k] = src[nPos + i]; k++; nPos += srcWidth; } } for (int i = 0; i < srcWidth; i += 2) { int nPos = wh; for (int j = 0; j < uvHeight; j++) { dst[k] = src[nPos + i]; dst[k + 1] = src[nPos + i + 1]; k += 2; nPos += srcWidth; } } } //逆時針旋轉90 private void YUV420spRotate90Anticlockwise(byte[] src, byte[] dst, int width, int height) { int wh = width * height; int uvHeight = height >> 1; //旋轉Y int k = 0; for (int i = 0; i < width; i++) { int nPos = width - 1; for (int j = 0; j < height; j++) { dst[k] = src[nPos - i]; k++; nPos += width; } } for (int i = 0; i < width; i += 2) { int nPos = wh + width - 1; for (int j = 0; j < uvHeight; j++) { dst[k] = src[nPos - i - 1]; dst[k + 1] = src[nPos - i]; k += 2; nPos += width; } } //不進行映象翻轉 // for (int i = 0; i < width; i++) { // int nPos = width - 1; // for (int j = 0; j < height; j++) { // dst[k] = src[nPos - i]; // k++; // nPos += width; // } // } // for (int i = 0; i < width; i += 2) { // int nPos = wh + width - 2; // for (int j = 0; j < uvHeight; j++) { // dst[k] = src[nPos - i]; // dst[k + 1] = src[nPos - i + 1]; // k += 2; // nPos += width; // } // } } //映象 private void Mirror(byte[] yuv_temp, int w, int h) { int i, j; int a, b; byte temp; //mirror y for (i = 0; i < h; i++) { a = i * w; b = (i + 1) * w - 1; while (a < b) { temp = yuv_temp[a]; yuv_temp[a] = yuv_temp[b]; yuv_temp[b] = temp; a++; b--; } } //mirror u int uindex = w * h; for (i = 0; i < h / 2; i++) { a = i * w / 2; b = (i + 1) * w / 2 - 1; while (a < b) { temp = yuv_temp[a + uindex]; yuv_temp[a + uindex] = yuv_temp[b + uindex]; yuv_temp[b + uindex] = temp; a++; b--; } } //mirror v uindex = w * h / 4 * 5; for (i = 0; i < h / 2; i++) { a = i * w / 2; b = (i + 1) * w / 2 - 1; while (a < b) { temp = yuv_temp[a + uindex]; yuv_temp[a + uindex] = yuv_temp[b + uindex]; yuv_temp[b + uindex] = temp; a++; b--; } } }