介绍开源库
使用第三方开源库来简化开发，屏蔽一些底层的复杂度，节省大量编写代码的时间。
libyuv： Google 开源的实现各种 YUV 与 RGB 之间相互转换、旋转、缩放的库。
yuv2rgb：C library for fast image conversion between yuv420p and rgb24.
使用开源库
libyuv
FFmpeg 生成代码所需文件：
ffmpeg -i rainbow.bmp -video_size 700x700 -pix_fmt yuv444p rainbow-yuv444p.yuv
ffmpeg -i rainbow.bmp -video_size 700x700 -pix_fmt yuv420p rainbow-yuv420p.yuv
ffmpeg -i rainbow.bmp -video_size 700x700 -pix_fmt rgb24 rainbow-rgb24.rgb
YUV444P to RGB32
将 FFmpeg 生成的 YUV444P 格式转换成 RGB32 格式。
[rainbow-yuv444p.yuv] -> [rainbow-yuv444p-to-rgb32-libyuv.rgb]
#include <stdio.h>
#include "libyuv.h"
void libyuv_I444_to_Rgb(char *srcFileName, char *dstFileName, int width, int height) {
FILE *src_file = fopen(srcFileName, "rb");
FILE *dst_file = fopen(dstFileName, "wb");
int size_src = width * height * 3;
int size_dest = width * height * 4;
char *buffer_src = (char *)malloc(size_src);
char *buffer_dest = (char *)malloc(size_dest);
fread(buffer_src, 1, size_src, src_file);
I444ToARGB(
(const u_int8_t*)buffer_src, width,
(const u_int8_t*)(buffer_src + width * height), width,
(const u_int8_t*)(buffer_src + 2 * width * height), width,
(u_int8_t*)buffer_dest, width * 4,
width, height);
fwrite(buffer_dest, 1, size_dest, dst_file);
free(buffer_src);
free(buffer_dest);
fclose(dst_file);
fclose(src_file);
}
int main() {
int width = 700, height = 700;
libyuv_I444_to_Rgb("/Users/staff/Desktop/rainbow-yuv444p.yuv", "/Users/staff/Desktop/rainbow-yuv444p-to-rgb32-libyuv.yuv", width, height);
return 0;
}
FFplay 显示生成的 rainbow-yuv444p-to-rgb32-libyuv.rgb
ffplay -f rawvideo -pixel_format rgb32 -video_size 700x700 rainbow-yuv444p-to-rgb32-libyuv.rgb
yuv444p-to-rgb32-libyuv.jpg
RGB24 to YUV420p
将 FFmpeg 生成的 RGB24 格式转换成 YUV420p 格式。
[rainbow-rgb24.rgb] -> [rainbow-rgb24-to-yuv420p-libyuv.yuv]
#include <stdio.h>
#include "libyuv.h"
void libyuv_Rgb24_to_Yuv420p(char *rgbFileName, char *yuvFileName, int width, int height) {
FILE *rgb_file = fopen(rgbFileName, "rb");
FILE *yuv_file = fopen(yuvFileName, "wb");
int size_rgb = width * height * 3;
int size_yuv = width * height * 3 / 2;
uint8_t *buffer_rgb = (uint8_t *)malloc(size_rgb);
uint8_t *buffer_yuv = (uint8_t *)malloc(size_yuv);
fread(buffer_rgb, 1, size_rgb, rgb_file);
// RGB to BGR
// uint8_t temp;
// for(int i = 0; i < size_rgb; i+=3) {
// temp = buffer_rgb[i + 0];
// buffer_rgb[i + 0] = buffer_rgb[i + 2];
// buffer_rgb[i + 2] = temp;
// }
// RGB24ToI420(
RAWToI420(
buffer_rgb, width*3,
buffer_yuv, width,
buffer_yuv + width*height, (width+1)/2,
buffer_yuv + width*height + ((width+1)/2)*((height+1)/2), (width+1)/2,
width, height);
fwrite(buffer_yuv, 1, size_yuv, yuv_file);
free(buffer_rgb);
free(buffer_yuv);
fclose(yuv_file);
fclose(rgb_file);
}
int main() {
int width = 700, height = 700;
libyuv_Rgb24_to_Yuv420p("/Users/staff/Desktop/rainbow-rgb24.rgb", "/Users/staff/Desktop/rainbow-rgb24-to-yuv420p-libyuv.yuv", width, height);
return 0;
}
FFplay 显示生成的 rainbow-rgb24-to-yuv420p-libyuv.yuv
ffplay -f rawvideo -pixel_format yuv420p -video_size 700x700 rainbow-rgb24-to-yuv420p-libyuv.yuv
rgb24-to-yuv420p-libyuv.png
descampsa/yuv2rgb
YUV420p to RGB24
将 FFmpeg 生成的 YUV420P 格式转换成 RGB24 格式。
[rainbow-yuv420p.yuv] -> [rainbow-yuv420p-to-rgb24-descampsa.rgb]
#include <stdio.h>
#include "descampsa/yuv2rgb/yuv_rgb.h"
void yuv420pToRgb24(uint8_t *YUV, uint8_t *RGB, uint32_t width, uint32_t height) {
const YCbCrType yuv_format = YCBCR_601;
// const YCbCrType yuv_format = YCBCR_709;
// const YCbCrType yuv_format = YCBCR_JPEG;
yuv420_rgb24_std(
width,
height,
YUV,
YUV+width*height,
YUV+width*height+((width+1)/2)*((height+1)/2),
width,
(width+1)/2,
RGB,
width*3,
yuv_format);
}
int main() {
uint32_t width = 700, height = 700;
uint8_t RGB[width*height*3];
uint8_t YUV[width*height*3/2];
FILE *yuv420pFile = fopen("/Users/staff/Desktop/rainbow-yuv420p.yuv", "rb");
fread(YUV, sizeof(YUV), 1, yuv420pFile);
yuv420pToRgb24(YUV, RGB, width, height);
FILE *rgb24File = fopen("/Users/staff/Desktop/rainbow-yuv420p-to-rgb24-descampsa.rgb", "wb");
fwrite(RGB, sizeof(RGB), 1, rgb24File);
fclose(rgb24File);
fclose(yuv420pFile);
return 0;
}
FFplay 显示生成的 rainbow-yuv420p-to-rgb24-descampsa.rgb
ffplay -f rawvideo -pixel_format rgb24 -video_size 700x700 rainbow-yuv420p-to-rgb24-descampsa.rgb
yuv420p-to-rgb24-descampsa.jpg
RGB24 to YUV420p
将 FFmpeg 生成的 RGB24 格式转换成 YUV420p 格式。
[rainbow-rgb24.rgb] -> [rainbow-rgb24-to-yuv420p-descampsa.yuv]
#include <stdio.h>
#include "descampsa/yuv2rgb/yuv_rgb.h"
void rgb24ToYuv420p(uint8_t *RGB, uint8_t *YUV, uint32_t width, uint32_t height) {
const YCbCrType yuv_format = YCBCR_601;
// const YCbCrType yuv_format = YCBCR_709;
//const YCbCrType yuv_format = YCBCR_JPEG;
rgb24_yuv420_std(
width,
height,
RGB,
width*3,
YUV,
YUV+width*height,
YUV+width*height+((width+1)/2)*((height+1)/2),
width,
width/2,
yuv_format);
}
int main() {
uint32_t width = 700, height = 700;
uint8_t RGB[width*height*3];
uint8_t YUV[width*height*3/2];
FILE *rgb24File = fopen("/Users/staff/Desktop/rainbow-rgb24.rgb", "rb");
fread(RGB, sizeof(RGB), 1, rgb24File);
rgb24ToYuv420p(RGB, YUV, width, height);
FILE *yuvFile = fopen("/Users/staff/Desktop/rainbow-rgb24-to-yuv420p-descampsa.yuv", "wb");
fwrite(YUV, sizeof(YUV), 1, yuvFile);
fclose(rgb24File);
fclose(yuvFile);
return 0;
}
FFplay 显示生成的 rainbow-rgb24-to-yuv420p-descampsa.yuv
ffplay -f rawvideo -pixel_format yuv420p -video_size 700x700 rainbow-rgb24-to-yuv420p-descampsa.yuv
rgb24-to-yuv420p-descampsa.jpg
参考资料：
