YUV422转JPEG

#include "jpeglib.h"
int yuv422_to_jpeg(unsigned char *data, int image_width, int image_height, FILE *fp, int quality)
{
    struct jpeg_compress_struct cinfo;
    struct jpeg_error_mgr jerr;
    JSAMPROW row_pointer[1]; 
    int row_stride;   
    JSAMPIMAGE  buffer;
    int band,i,buf_width[3],buf_height[3], mem_size, max_line, counter;
    unsigned char *yuv[3];
    uint8_t *pSrc, *pDst;
    yuv[0] = data;
    yuv[1] = yuv[0] + (image_width * image_height);
    yuv[2] = yuv[1] + (image_width * image_height) /2;
    cinfo.err = jpeg_std_error(&jerr);
    jpeg_create_compress(&cinfo);
    jpeg_stdio_dest(&cinfo, fp);
    cinfo.image_width = image_width; 
    cinfo.image_height = image_height;
    cinfo.input_components = 3;   
    cinfo.in_color_space = JCS_RGB; 
    jpeg_set_defaults(&cinfo);
    jpeg_set_quality(&cinfo, quality, TRUE );
    cinfo.raw_data_in = TRUE;
    cinfo.jpeg_color_space = JCS_YCbCr;
    cinfo.comp_info[0].h_samp_factor = 2;
    cinfo.comp_info[0].v_samp_factor = 1;
    jpeg_start_compress(&cinfo, TRUE);
    buffer = (JSAMPIMAGE) (*cinfo.mem->alloc_small) ((j_common_ptr) &cinfo, JPOOL_IMAGE, 3 * sizeof(JSAMPARRAY));
    for(band=0; band <3; band++)
    {
        buf_width[band] = cinfo.comp_info[band].width_in_blocks * DCTSIZE;
        buf_height[band] = cinfo.comp_info[band].v_samp_factor * DCTSIZE;
        buffer[band] = (*cinfo.mem->alloc_sarray) ((j_common_ptr) &cinfo, JPOOL_IMAGE, buf_width[band], buf_height[band]);
    }
    max_line = cinfo.max_v_samp_factor*DCTSIZE;
    for(counter=0; cinfo.next_scanline < cinfo.image_height; counter++)
    {
        //buffer image copy.
        for(band=0; band <3; band++)
        {
            mem_size = buf_width[band];
            pDst = (uint8_t *) buffer[band][0];
            pSrc = (uint8_t *) yuv[band] + counter*buf_height[band] * buf_width[band];
            for(i=0; i             {
                memcpy(pDst, pSrc, mem_size);
                pSrc += buf_width[band];