直接对nv21的数据进行resize。

这是之前项目组遗留的一段代码改过来的。结果不太好。

void Scaler::Resize_NV(const Buffer *src,

Buffer *dst){

// this function have some problem

if (src->width == dst->width && src->height == dst->height) {

memcpy(dst->data[0], src->data[0], (dst->width * dst->height * 3 / 2) * sizeof(uint8_t));

return;

}

int srcy, srcx, src_index;

int xrIntFloat_16 = (src->width << 16) / dst->width + 1;

int yrIntFloat_16 = (src->height << 16) / dst->height + 1;

uint8_t* dst_uv = dst->data[0] + dst->height * dst->width;

dst->data[1] = dst_uv;

uint8_t* src_uv = src->data[0] + src->height * src->width;

uint8_t* dst_uv_yScanline = nullptr;

uint8_t* src_uv_yScanline = nullptr;

uint8_t* dst_y_slice = dst->data[0];

uint8_t* src_y_slice = nullptr;

uint8_t* sp = nullptr;

uint8_t* dp = nullptr;

for (uint32_t y = 0; y < (dst->height & -7); ++y) {

srcy = (y * yrIntFloat_16) >> 16;

src_y_slice = src->data[0] + srcy * src->width;

if (0 == (y & 1)) {

dst_uv_yScanline = dst_uv + (y / 2) * dst->width;

src_uv_yScanline = src_uv + (srcy / 2) * src->width;

}

for (uint32_t x = 0; x < (dst->width & -7); ++x) {

srcx = (x * xrIntFloat_16) >> 16;

dst_y_slice[x] = src_y_slice[srcx];

if ((y & 1) == 0) { // y is even

if ((x & 1) == 0) { // x is even

src_index = (srcx / 2) * 2;

sp = dst_uv_yScanline + x;

dp = src_uv_yScanline + src_index;

*sp = *dp;

++sp;

++dp;

*sp = *dp;

}

}

}

dst_y_slice += dst->width;

}

dst->stride[0] = dst->width;

dst->stride[1] = dst->width;

dst->stride[2] = 0;

dst->color = src->color;

}

结果

原图

结果

这结果明显有黑色的线条，不对啊。

后面我用libyuv实现了下nv的resize。

libyuv实现nv resize

标签：src,nv21,dst,uv,uint8,height,width,nv12,resize

来源： https://www.cnblogs.com/cyssmile/p/13725506.html