void CVideoEncoder::RGB24ToYUV420(int Width,int Height,uint8_t* RgbBuffer,uint8_t*YuvBuffer)
{
uint8_t* yuvBuf=YuvBuffer;//YUV空间
int nWidth=Width;
int nHeight=Height;
/下面转换算法是网上查到的
int i, j;
uint8_t*bufY = yuvBuf;
uint8_t*bufU = yuvBuf + nWidth * nHeight;
uint8_t*bufV = bufU + (nWidth* nHeight* 1/4);
uint8_t*Y=bufY;
uint8_t*U=bufU;
uint8_t*V=bufV;
uint8_t*bufRGB;
unsigned char y, u, v, r, g, b,testu,testv;
if (NULL==pRGBBuffer)
{
return ;
}
for (j = 0; j>8) + 16;//16
v = (unsigned char)((-38 * r - 74 * g + 112 * b + 128) >>8) +128 ; //128
u = (unsigned char)((112 * r - 94 * g - 18 * b + 128) >> 8) + 128 ;
*(bufY++)=max(0,min(y, 255 ));
if (j%2==0&&i%2 ==0)
{
if (u>255)
{
u=255;
}
if (u<0)
{
u = 0;
}
*(bufU++) =u;
//存u分量
}
else
{
//存v分量
if (i%2==0)
{
if (v>255)
{
v = 255;
}
if (v<0)
{
v = 0;
}
*(bufV++) =v;
}
}
}
}
}
//YUV对应到data
pVideoEncoder->m_pYUVFrame->data[0]=pVideoEncoder->yuv_buff;
pVideoEncoder->m_pYUVFrame->data[1]=pVideoEncoder->yuv_buff+y_size;
pVideoEncoder->m_pYUVFrame->data[2]=pVideoEncoder->yuv_buff+(y_size*5)/4;
//第二种方法 用FFMPEG
uint8_t *rgb_src[3]= {rgb, NULL, NULL};
int rgb_stride[3]={3*biWidth, 0, 0};
AVFrame picture;
avpicture_alloc((AVPicture*)(&picture), AV_PIX_FMT_YUV420P,biWidth,biHeight);
SwsContext *yuvContext=sws_getContext(biWidth,biHeight,AV_PIX_FMT_BGR24,biWidth,
biHeight,AV_PIX_FMT_YUV420P,SWS_BICUBIC, NULL, NULL, NULL);
sws_scale(yuvContext,rgb_src, rgb_stride, 0, biHeight, picture.data, picture.linesize);
//注意 如果转换后出现倒立,请安下面方式更正
picture.data[0] += picture.linesize[0] * (biHeight - 1);
picture.linesize[0] *= -1;
picture.data[1] += picture.linesize[1] * (biHeight / 2 - 1);
picture.linesize[1] *= -1;
picture.data[2] += picture.linesize[2] * (biHeight/ 2 - 1);
picture.linesize[2] *= -1;