decode jpeg to YV12, using libjpeg

#include <stdio.h>
#include <stdlib.h>
#include <setjmp.h>
#include <string.h>

#include <jpeglib.h>
#include <jerror.h>
 
struct my_error_mgr  
{
    struct jpeg_error_mgr pub;    /* "public" fields */
 
    jmp_buf setjmp_buffer;    /* for return to caller */
};
 
typedef struct my_error_mgr * my_error_ptr;
 
 
void my_error_exit (j_common_ptr cinfo)
{
    my_error_ptr myerr = (my_error_ptr) cinfo->err;
    
    (*cinfo->err->output_message) (cinfo);
    
    longjmp(myerr->setjmp_buffer, 1);
}
 
 
 
/* shamelessly ripped from jpegutils.c in mjpegtools */
static void add_huff_table (j_decompress_ptr dinfo,
    JHUFF_TBL ** htblptr, const UINT8 * bits, const UINT8 * val)
/* Define a Huffman table */
{
  int nsymbols, len;

  if (*htblptr == NULL)
    *htblptr = jpeg_alloc_huff_table ((j_common_ptr) dinfo);

  /* Copy the number-of-symbols-of-each-code-length counts */
  memcpy ((*htblptr)->bits, bits, sizeof ((*htblptr)->bits));

  /* Validate the counts.  We do this here mainly so we can copy the right
   * number of symbols from the val[] array, without risking marching off
   * the end of memory.  jchuff.c will do a more thorough test later.
   */
  nsymbols = 0;
  for (len = 1; len <= 16; len++)
    nsymbols += bits[len];
  if (nsymbols < 1 || nsymbols > 256)
    printf ("jpegutils.c:  add_huff_table failed badly. ");

  memcpy ((*htblptr)->huffval, val, nsymbols * sizeof (UINT8));
}



static void std_huff_tables (j_decompress_ptr dinfo)
/* Set up the standard Huffman tables (cf. JPEG standard section K.3) */
/* IMPORTANT: these are only valid for 8-bit data precision! */
{
  static const UINT8 bits_dc_luminance[17] =
      { /* 0-base */ 0, 0, 1, 5, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0 };
  static const UINT8 val_dc_luminance[] =
      { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 };

  static const UINT8 bits_dc_chrominance[17] =
      { /* 0-base */ 0, 0, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0 };
  static const UINT8 val_dc_chrominance[] =
      { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 };

  static const UINT8 bits_ac_luminance[17] =
      { /* 0-base */ 0, 0, 2, 1, 3, 3, 2, 4, 3, 5, 5, 4, 4, 0, 0, 1, 0x7d };
  static const UINT8 val_ac_luminance[] =
      { 0x01, 0x02, 0x03, 0x00, 0x04, 0x11, 0x05, 0x12,
    0x21, 0x31, 0x41, 0x06, 0x13, 0x51, 0x61, 0x07,
    0x22, 0x71, 0x14, 0x32, 0x81, 0x91, 0xa1, 0x08,
    0x23, 0x42, 0xb1, 0xc1, 0x15, 0x52, 0xd1, 0xf0,
    0x24, 0x33, 0x62, 0x72, 0x82, 0x09, 0x0a, 0x16,
    0x17, 0x18, 0x19, 0x1a, 0x25, 0x26, 0x27, 0x28,
    0x29, 0x2a, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39,
    0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49,
    0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
    0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69,
    0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79,
    0x7a, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89,
    0x8a, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98,
    0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
    0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6,
    0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3, 0xc4, 0xc5,
    0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2, 0xd3, 0xd4,
    0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xe1, 0xe2,
    0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea,
    0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8,
    0xf9, 0xfa
  };

  static const UINT8 bits_ac_chrominance[17] =
      { /* 0-base */ 0, 0, 2, 1, 2, 4, 4, 3, 4, 7, 5, 4, 4, 0, 1, 2, 0x77 };
  static const UINT8 val_ac_chrominance[] =
      { 0x00, 0x01, 0x02, 0x03, 0x11, 0x04, 0x05, 0x21,
    0x31, 0x06, 0x12, 0x41, 0x51, 0x07, 0x61, 0x71,
    0x13, 0x22, 0x32, 0x81, 0x08, 0x14, 0x42, 0x91,
    0xa1, 0xb1, 0xc1, 0x09, 0x23, 0x33, 0x52, 0xf0,
    0x15, 0x62, 0x72, 0xd1, 0x0a, 0x16, 0x24, 0x34,
    0xe1, 0x25, 0xf1, 0x17, 0x18, 0x19, 0x1a, 0x26,
    0x27, 0x28, 0x29, 0x2a, 0x35, 0x36, 0x37, 0x38,
    0x39, 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48,
    0x49, 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58,
    0x59, 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
    0x69, 0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78,
    0x79, 0x7a, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
    0x88, 0x89, 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96,
    0x97, 0x98, 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5,
    0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4,
    0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3,
    0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2,
    0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda,
    0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9,
    0xea, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8,
    0xf9, 0xfa
  };

  add_huff_table (dinfo, &dinfo->dc_huff_tbl_ptrs[0],
      bits_dc_luminance, val_dc_luminance);
  add_huff_table (dinfo, &dinfo->ac_huff_tbl_ptrs[0],
      bits_ac_luminance, val_ac_luminance);
  add_huff_table (dinfo, &dinfo->dc_huff_tbl_ptrs[1],
      bits_dc_chrominance, val_dc_chrominance);
  add_huff_table (dinfo, &dinfo->ac_huff_tbl_ptrs[1],
      bits_ac_chrominance, val_ac_chrominance);
}

static void guarantee_huff_tables (j_decompress_ptr dinfo)
{
  if ((dinfo->dc_huff_tbl_ptrs[0] == NULL) &&
      (dinfo->dc_huff_tbl_ptrs[1] == NULL) &&
      (dinfo->ac_huff_tbl_ptrs[0] == NULL) &&
      (dinfo->ac_huff_tbl_ptrs[1] == NULL))
      {
    printf ("Generating standard Huffman tables for this frame.");
    std_huff_tables (dinfo);
  }
}


static int gst_jpeg_dec_decode_direct (struct jpeg_decompress_struct *cinfo, unsigned char * base[3],
    unsigned char * last[3], unsigned int width, unsigned int height)
{
  unsigned char **line[3];             /* the jpeg line buffer         */
  unsigned char *y[4 * DCTSIZE] = { NULL, };   /* alloc enough for the lines   */
  unsigned char *u[4 * DCTSIZE] = { NULL, };   /* r_v will be <4               */
  unsigned char *v[4 * DCTSIZE] = { NULL, };
  int i, j;
  int lines, v_samp[3];

  line[0] = y;
  line[1] = u;
  line[2] = v;

  v_samp[0] = cinfo->comp_info[0].v_samp_factor;
  v_samp[1] = cinfo->comp_info[1].v_samp_factor;
  v_samp[2] = cinfo->comp_info[2].v_samp_factor;


  for (i = 0; i < height; i += v_samp[0] * DCTSIZE)
   {
    for (j = 0; j < (v_samp[0] * DCTSIZE); ++j)
    {
      /* Y */
      line[0][j] = base[0] + (i + j) * (width);
      if ((line[0][j] > last[0]))
        line[0][j] = last[0];
      /* U */
      if (v_samp[1] == v_samp[0]) {
        line[1][j] = base[1] + ((i + j) / 2) * (width)/2;
      } else if (j < (v_samp[1] * DCTSIZE)) {
        line[1][j] = base[1] + ((i / 2) + j) * (width)/2;
      }
      if ((line[1][j] > last[1]))
        line[1][j] = last[1];
      /* V */
      if (v_samp[2] == v_samp[0]) {
        line[2][j] = base[2] + ((i + j) / 2) * (width)/2;
      } else if (j < (v_samp[2] * DCTSIZE)) {
        line[2][j] = base[2] + ((i / 2) + j) * (width)/2;
      }
      if ((line[2][j] > last[2]))
        line[2][j] = last[2];
    }

    /* dump_lines (base, line, v_samp[0], width); */

    lines = jpeg_read_raw_data (cinfo, line, v_samp[0] * DCTSIZE);
 
  }
  return 0;
 
}


int read_JPEG_file (char * filename, char *outfilename)
{
    struct jpeg_decompress_struct cinfo;
    struct my_error_mgr jerr;
    FILE * infile;        /* source file */
    FILE * outfile;
    JSAMPARRAY buffer;        /* Output row buffer */
    int row_stride;        /* physical row width in output buffer */
    int width =0;
    int height=0;
       unsigned char *base[3], *last[3];
       unsigned char *outdata = NULL;
       
    if ((infile = fopen(filename, "rb")) == NULL)
    {
        fprintf(stderr, "can't open %s\n", filename);
        return 0;
    }
    if ((outfile = fopen(outfilename, "wb")) == NULL)
    {
        fprintf(stderr, "can't open %s\n", outfilename);
        return 0;
    }
 
    cinfo.err = jpeg_std_error(&jerr.pub);
    jerr.pub.error_exit = my_error_exit;
 
    if (setjmp(jerr.setjmp_buffer))  
    {
        printf("Eror\n");
        jpeg_destroy_decompress(&cinfo);
        fclose(infile);
        return 0;
    }
 
    jpeg_create_decompress(&cinfo);
 
    jpeg_stdio_src(&cinfo, infile);
 
    jpeg_read_header(&cinfo, TRUE);
 
   
    cinfo.do_fancy_upsampling = FALSE;
    cinfo.do_block_smoothing = FALSE;
    cinfo.out_color_space = JCS_YCbCr;
    cinfo.dct_method = JDCT_FASTEST;
    cinfo.raw_data_out = TRUE;

      guarantee_huff_tables (&cinfo);
      
    jpeg_start_decompress(&cinfo);
    
    width = cinfo.image_width;
    height= cinfo.image_height;
    
    printf("image width is %d\n", cinfo.output_width);    /* nominal image width (from SOF marker) */
    printf("image height is %d\n", cinfo.output_height);    /* nominal image width (from SOF marker) */
    printf("numcom is %d\n", cinfo.output_components);    /* nominal image width (from SOF marker) */
   
    outdata = malloc(width*height*3/2);
   
       base[0] = outdata;
      base[1] = outdata + width*height;
      base[2] = outdata + width*height*5/4;

    last[0] = base[0] + (width) * (height - 1);
    last[1] =  base[1] + (width/2) * ((height/ 2) - 1);
    last[2] =  base[2] + (width/2) * ((height/ 2) - 1);
    
    gst_jpeg_dec_decode_direct (&cinfo, base, last, width, height);
    
    fwrite(outdata, 1, width*height*3/2, outfile);
    
    jpeg_finish_decompress(&cinfo);
 
    jpeg_destroy_decompress(&cinfo);
     free(outdata);
    fclose(infile);
    fclose(outfile);
 
    return 1;
}
 
int main(int argc, char **argv)
{
    if(argc<3)
    {
        printf("Input Error\n");
        return 0;
    }
    read_JPEG_file(argv[1], argv[2]);
    return 0;
}