libyuv是Google開源庫,可用作圖像數據格式的轉換,比如視頻流編解碼時格式的轉換,YUV數據轉化RGB等 libyuv靜態庫 為了方便使用,已經將libyuv源代碼打包成了iOS靜態庫, "libyuv靜態庫" libyuv使用 下麵以nv12(yuv420sp)轉化為I420(yuv420 ...
libyuv是Google開源庫,可用作圖像數據格式的轉換,比如視頻流編解碼時格式的轉換,YUV數據轉化RGB等
libyuv靜態庫
為了方便使用,已經將libyuv源代碼打包成了iOS靜態庫,libyuv靜態庫
libyuv使用
下麵以nv12(yuv420sp)轉化為I420(yuv420p)為例:
void nv12_to_yuv420p(unsigned char* nv12, unsigned char* yuv420p, int width, int height) {
int y_size = width * height;
int u_size = y_size / 4;
int v_size = u_size;
int uv_size = u_size + v_size;
unsigned char *src_y = malloc(y_size);
unsigned char *src_uv = malloc(uv_size);
memcpy(src_y, nv12, y_size);
memcpy(src_uv, nv12 + y_size, uv_size);
unsigned char *dst_y = malloc(y_size);
unsigned char *dst_u = malloc(u_size);
unsigned char *dst_v = malloc(v_size);
int src_stride_y = width;
int src_stride_uv = width;
int dst_stride_y = width;
int dst_stride_u = width >> 1;
int dst_stride_v = dst_stride_u;
NV12ToI420(src_y, src_stride_y, src_uv, src_stride_uv, dst_y, dst_stride_y, dst_u, dst_stride_u, dst_v, dst_stride_v, width, height);
memcpy(yuv420p, dst_y, y_size);
memcpy(yuv420p + y_size, dst_u, u_size);
memcpy(yuv420p + y_size + u_size, dst_v, v_size);
free(src_y);
free(src_uv);
free(dst_y);
free(dst_u);
free(dst_v);
}
nv12轉化yuv420p實現方法有多種,比如利用libyuv,ffmpeg,除了利用第三方庫實現轉化,也可以自己實現,代碼如下:
void yuv420sp_to_yuv420p(unsigned char* yuv420sp, unsigned char* yuv420p, int width, int height)
{
int i, j;
int y_size = width * height;
unsigned char* y = yuv420sp;
unsigned char* uv = yuv420sp + y_size;
unsigned char* y_tmp = yuv420p;
unsigned char* u_tmp = yuv420p + y_size;
unsigned char* v_tmp = yuv420p + y_size * 5 / 4;
memcpy(y_tmp, y, y_size);
for (j = 0, i = 0; j < y_size/2; j+=2, i++)
{
u_tmp[i] = uv[j];
v_tmp[i] = uv[j+1];
}
}