Files
crossdesk/src/common/nv12_scaler.cpp
T

63 lines
2.4 KiB
C++

#include "nv12_scaler.h"
#include <cstddef>
#include <limits>
#include "libyuv/planar_functions.h"
namespace crossdesk {
int ScaleNv12ViaI420(const uint8_t* src_y, int src_stride_y,
const uint8_t* src_uv, int src_stride_uv, int src_width,
int src_height, uint8_t* dst_y, int dst_stride_y,
uint8_t* dst_uv, int dst_stride_uv, int dst_width,
int dst_height, libyuv::FilterMode filtering,
std::vector<uint8_t>* scratch_buffer) {
if (!src_y || !src_uv || !dst_y || !dst_uv || !scratch_buffer ||
src_width <= 0 || src_height <= 0 || dst_width <= 0 || dst_height <= 0 ||
(src_width & 1) != 0 || (src_height & 1) != 0 || (dst_width & 1) != 0 ||
(dst_height & 1) != 0) {
return -1;
}
const int src_chroma_width = src_width / 2;
const int src_chroma_height = src_height / 2;
const int dst_chroma_width = dst_width / 2;
const int dst_chroma_height = dst_height / 2;
const size_t src_chroma_size =
static_cast<size_t>(src_chroma_width) * src_chroma_height;
const size_t dst_chroma_size =
static_cast<size_t>(dst_chroma_width) * dst_chroma_height;
const size_t max_size = std::numeric_limits<size_t>::max();
if (src_chroma_size > max_size / 2 || dst_chroma_size > max_size / 2) {
return -1;
}
const size_t src_planes_size = 2 * src_chroma_size;
const size_t dst_planes_size = 2 * dst_chroma_size;
if (src_planes_size > max_size - dst_planes_size) {
return -1;
}
scratch_buffer->resize(src_planes_size + dst_planes_size);
uint8_t* src_u = scratch_buffer->data();
uint8_t* src_v = src_u + src_chroma_size;
uint8_t* dst_u = src_v + src_chroma_size;
uint8_t* dst_v = dst_u + dst_chroma_size;
libyuv::SplitUVPlane(src_uv, src_stride_uv, src_u, src_chroma_width, src_v,
src_chroma_width, src_chroma_width, src_chroma_height);
const int result = libyuv::I420Scale(
src_y, src_stride_y, src_u, src_chroma_width, src_v, src_chroma_width,
src_width, src_height, dst_y, dst_stride_y, dst_u, dst_chroma_width,
dst_v, dst_chroma_width, dst_width, dst_height, filtering);
if (result != 0) {
return result;
}
libyuv::MergeUVPlane(dst_u, dst_chroma_width, dst_v, dst_chroma_width, dst_uv,
dst_stride_uv, dst_chroma_width, dst_chroma_height);
return 0;
}
} // namespace crossdesk