NV21转jpeg 实现方法---使用libjpeg库

// N21ToJpg.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include "stdio.h"
#include "stdlib.h"
#include "string.h"

extern "C" {
#include "libjpeg/jpeglib.h"
}

#pragma comment(lib, "libjpeg/jpeg-static.lib")
#define JPEG_QUALITY 90

unsigned int GetTextFileSize(char *filename)
{
	unsigned int  size = 0;
	FILE  *fp = NULL;
	fp = fopen(filename, "rb");
	if (fp)
	{
		fseek(fp, 0, SEEK_END);
		size = ftell(fp);
		fclose(fp);
	}
	return size;
}

bool readFile(char *path, unsigned char *buf, unsigned int &size)
{
	FILE *infile;
	infile = fopen(path, "rb");
	if (!infile)
	{
		return false;
	}
	unsigned int  nActSize = (unsigned int)fread(buf, sizeof(unsigned char), size, infile);
	if (nActSize > size)
	{
		return false;
	}

	size = nActSize;
	fclose(infile);
	return true;
}

//函数参数：pFileName :jpeg 文件名
int Nv21ToJpgFile(const char *pFileName,const char* pYUVBuffer, const int nWidth, const int nHeight)
{
	struct jpeg_compress_struct cinfo;
	struct jpeg_error_mgr jerr;
	JSAMPROW row_pointer[1];
	FILE * pJpegFile = NULL;
	unsigned char *yuvbuf = NULL;
	unsigned char *ybase = NULL, *ubase = NULL;
	int i = 0, j = 0;
	int idx = 0;

	cinfo.err = jpeg_std_error(&jerr);
	jpeg_create_compress(&cinfo);

	if ((pJpegFile = fopen(pFileName, "wb")) == NULL)
	{
		return -1;
	}

	jpeg_stdio_dest(&cinfo, pJpegFile);

	// image width and height, in pixels
	cinfo.image_width = nWidth;
	cinfo.image_height = nHeight;
	cinfo.input_components = 3;    // # of color components per pixel
	cinfo.in_color_space = JCS_YCbCr;  //colorspace of input image
	jpeg_set_defaults(&cinfo);
	jpeg_set_quality(&cinfo, JPEG_QUALITY, TRUE);

	cinfo.jpeg_color_space = JCS_YCbCr;
	cinfo.comp_info[0].h_samp_factor = 2;
	cinfo.comp_info[0].v_samp_factor = 2;

	jpeg_start_compress(&cinfo, TRUE);

	if (!(yuvbuf = (unsigned char *)malloc(nWidth * 3)) != NULL)
	{
		return -1;
	}

	memset(yuvbuf, 0, nWidth * 3);

	ybase = (unsigned char *)pYUVBuffer;
	ubase = (unsigned char *)pYUVBuffer + nWidth*nHeight;

	while (cinfo.next_scanline < cinfo.image_height)
	{
		idx = 0;
		for (i = 0; i