jpegutils.c

Go to the documentation of this file.

/*
 *  jpegutils.c: Some Utility programs for dealing with
 *               JPEG encoded images
 *
 *  Copyright (C) 1999 Rainer Johanni <Rainer@Johanni.de>
 *  Copyright (C) 2001 pHilipp Zabel  <pzabel@gmx.de>
 *  Copyright (C) 2008 Angel Carpintero <ack@telefonica.net>
 *
 *  based on jdatasrc.c and jdatadst.c from the Independent
 *  JPEG Group's software by Thomas G. Lane
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 *  as published by the Free Software Foundation; either version 2
 *  of the License, or (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */
 
#include "jpegutils.h"
 
#include <jpeglib.h>
#include <jerror.h>
 
#include <assert.h>
#include <setjmp.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
 
/*
* jpeg_data:       buffer with input / output jpeg
* len:             Length of jpeg buffer
* itype:           0: Not interlaced
*                  1: Interlaced, Top field first
*                  2: Interlaced, Bottom field first
* ctype            Chroma format for decompression.
*                  Currently only Y4M_CHROMA_{420JPEG,422}  are available
* raw0             buffer with input / output raw Y channel
* raw1             buffer with input / output raw U/Cb channel
* raw2             buffer with input / output raw V/Cr channel
* width            width of Y channel (width of U/V is width/2)
* height           height of Y channel (height of U/V is height/2)
*/
 
static void jpeg_buffer_src(j_decompress_ptr cinfo, unsigned char *buffer, long num);
static void jpeg_buffer_dest(j_compress_ptr cinfo, unsigned char *buffer, long len);
static void jpeg_skip_ff(j_decompress_ptr cinfo);
 
/*******************************************************************
 *                                                                 *
 *    The following routines define a JPEG Source manager which    *
 *    just reads from a given buffer (instead of a file as in      *
 *    the jpeg library)                                            *
 *                                                                 *
 *******************************************************************/
 
/*
 * Initialize source --- called by jpeg_read_header
 * before any data is actually read.
 */
 
static void init_source(j_decompress_ptr cinfo)
{
    (void)cinfo;
    /* no work necessary here */
}
 
/*
 * Fill the input buffer --- called whenever buffer is emptied.
 *
 * Should never be called since all data should be allready provided.
 * Is nevertheless sometimes called - sets the input buffer to data
 * which is the JPEG EOI marker;
 *
 */
 
static uint8_t EOI_data[2] = { 0xFF, 0xD9 };
 
static boolean fill_input_buffer(j_decompress_ptr cinfo)
{
    cinfo->src->next_input_byte = EOI_data;
    cinfo->src->bytes_in_buffer = 2;
    return TRUE;
}
 
/*
 * Skip data --- used to skip over a potentially large amount of
 * uninteresting data (such as an APPn marker).
 *
 */
 
static void skip_input_data(j_decompress_ptr cinfo, long num_bytes)
{
    if (num_bytes > 0)
    {
        if (num_bytes > (long)cinfo->src->bytes_in_buffer)
            num_bytes = (long)cinfo->src->bytes_in_buffer;
        cinfo->src->next_input_byte += (size_t)num_bytes;
        cinfo->src->bytes_in_buffer -= (size_t)num_bytes;
    }
}
 
/*
 * Terminate source --- called by jpeg_finish_decompress
 * after all data has been read.  Often a no-op.
 */
 
static void term_source(j_decompress_ptr cinfo)
{
    (void)cinfo;
    /* no work necessary here */
}
 
/*
 * Prepare for input from a data buffer.
 */
 
static void jpeg_buffer_src(j_decompress_ptr cinfo, unsigned char *buffer, long num)
{
    /* The source object and input buffer are made permanent so that a series
    * of JPEG images can be read from the same buffer by calling jpeg_buffer_src
    * only before the first one.  (If we discarded the buffer at the end of
    * one image, we'd likely lose the start of the next one.)
    * This makes it unsafe to use this manager and a different source
    * manager serially with the same JPEG object.  Caveat programmer.
    */
    if (cinfo->src == NULL) /* first time for this JPEG object? */
    {
        cinfo->src = (struct jpeg_source_mgr *)(*cinfo->mem->alloc_small)((j_common_ptr)cinfo, JPOOL_PERMANENT,
                                                                          sizeof(struct jpeg_source_mgr));
    }
 
    cinfo->src->init_source       = init_source;
    cinfo->src->fill_input_buffer = fill_input_buffer;
    cinfo->src->skip_input_data   = skip_input_data;
    cinfo->src->resync_to_restart = jpeg_resync_to_restart; /* use default method */
    cinfo->src->term_source       = term_source;
    cinfo->src->bytes_in_buffer   = num;
    cinfo->src->next_input_byte   = (JOCTET *)buffer;
}
 
/*
 * jpeg_skip_ff is not a part of the source manager but it is
 * particularly useful when reading several images from the same buffer:
 * It should be called to skip padding 0xff bytes beetween images.
 */
 
static void jpeg_skip_ff(j_decompress_ptr cinfo)
{
    while (cinfo->src->bytes_in_buffer > 1 && cinfo->src->next_input_byte[0] == 0xff &&
           cinfo->src->next_input_byte[1] == 0xff)
    {
        cinfo->src->bytes_in_buffer--;
        cinfo->src->next_input_byte++;
    }
}
 
/*******************************************************************
 *                                                                 *
 *    The following routines define a JPEG Destination manager     *
 *    which just reads from a given buffer (instead of a file      *
 *    as in the jpeg library)                                      *
 *                                                                 *
 *******************************************************************/
 
/*
 * Initialize destination --- called by jpeg_start_compress
 * before any data is actually written.
 */
 
static void init_destination(j_compress_ptr cinfo)
{
    (void)cinfo;
    /* No work necessary here */
}
 
/*
 * Empty the output buffer --- called whenever buffer fills up.
 *
 * Should never be called since all data should be written to the buffer.
 * If it gets called, the given jpeg buffer was too small.
 *
 */
 
static boolean empty_output_buffer(j_compress_ptr cinfo)
{
    (void)cinfo;
    return TRUE;
}
 
/*
 * Terminate destination --- called by jpeg_finish_compress
 * after all data has been written.  Usually needs to flush buffer.
 *
 * NB: *not* called by jpeg_abort or jpeg_destroy; surrounding
 * application must deal with any cleanup that should happen even
 * for error exit.
 */
 
static void term_destination(j_compress_ptr cinfo)
{
    (void)cinfo;
    /* no work necessary here */
}
 
/*
 * Prepare for output to a stdio stream.
 * The caller must have already opened the stream, and is responsible
 * for closing it after finishing compression.
 */
 
static void jpeg_buffer_dest(j_compress_ptr cinfo, unsigned char *buf, long len)
{
    /* The destination object is made permanent so that multiple JPEG images
     * can be written to the same file without re-executing jpeg_stdio_dest.
    * This makes it dangerous to use this manager and a different destination
    * manager serially with the same JPEG object, because their private object
    * sizes may be different.  Caveat programmer.
    */
    if (cinfo->dest == NULL) /* first time for this JPEG object? */
    {
        cinfo->dest = (struct jpeg_destination_mgr *)(*cinfo->mem->alloc_small)((j_common_ptr)cinfo, JPOOL_PERMANENT,
                                                                                sizeof(struct jpeg_destination_mgr));
    }
 
    cinfo->dest->init_destination    = init_destination;
    cinfo->dest->empty_output_buffer = empty_output_buffer;
    cinfo->dest->term_destination    = term_destination;
    cinfo->dest->free_in_buffer      = len;
    cinfo->dest->next_output_byte    = (JOCTET *)buf;
}
 
/*******************************************************************
 *                                                                 *
 *    decode_jpeg_data: Decode a (possibly interlaced) JPEG frame  *
 *                                                                 *
 *******************************************************************/
 
/*
 * ERROR HANDLING:
 *
 *    We want in all cases to return to the user.
 *    The following kind of error handling is from the
 *    example.c file in the Independent JPEG Group's JPEG software
 */
 
struct my_error_mgr
{
    struct jpeg_error_mgr pub; /* "public" fields */
    jmp_buf setjmp_buffer;     /* for return to caller */
 
    /* original emit_message method */
    JMETHOD(void, original_emit_message, (j_common_ptr cinfo, int msg_level));
    /* was a corrupt-data warning seen */
    int warning_seen;
};
 
static void my_error_exit(j_common_ptr cinfo)
{
    /* cinfo->err really points to a my_error_mgr struct, so coerce pointer */
    struct my_error_mgr *myerr = (struct my_error_mgr *)cinfo->err;
 
    /* Always display the message. */
    /* We could postpone this until after returning, if we chose. */
    (*cinfo->err->output_message)(cinfo);
 
    /* Return control to the setjmp point */
    longjmp(myerr->setjmp_buffer, 1);
}
 
static void my_emit_message(j_common_ptr cinfo, int msg_level)
{
    /* cinfo->err really points to a my_error_mgr struct, so coerce pointer */
    struct my_error_mgr *myerr = (struct my_error_mgr *)cinfo->err;
 
    if (msg_level < 0)
        myerr->warning_seen = 1;
 
    /* call original emit_message() */
    /* geehalel (myerr->original_emit_message)(cinfo, msg_level); */
}
 
#define MAX_LUMA_WIDTH   4096
#define MAX_CHROMA_WIDTH 2048
 
static unsigned char buf0[16][MAX_LUMA_WIDTH];
static unsigned char buf1[8][MAX_CHROMA_WIDTH];
static unsigned char buf2[8][MAX_CHROMA_WIDTH];
static unsigned char chr1[8][MAX_CHROMA_WIDTH];
static unsigned char chr2[8][MAX_CHROMA_WIDTH];
 
#if 1 /* generation of 'std' Huffman tables... */
 
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)
        fprintf(stderr, "%s: Given jpeg buffer was too small", __FUNCTION__);
 
    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))
    {
        std_huff_tables(dinfo);
    }
}
 
#endif /* ...'std' Huffman table generation */
 
/*
 * jpeg_data:       Buffer with jpeg data to decode
 * len:             Length of buffer
 * itype:           0: Not interlaced
 *                  1: Interlaced, Top field first
 *                  2: Interlaced, Bottom field first
 * ctype            Chroma format for decompression.
 *                  Currently only Y4M_CHROMA_{420JPEG,422} are available
 * returns:
 *      -1 on fatal error
 *      0 on success
 *      1 if jpeg lib threw a "corrupt jpeg data" warning.
 *              in this case, "a damaged output image is likely."
 *
 */
 
int decode_jpeg_raw(unsigned char *jpeg_data, int len, int itype, int ctype, unsigned int width, unsigned int height,
                    unsigned char *raw0, unsigned char *raw1, unsigned char *raw2)
{
    int numfields, hsf[3], field;
    unsigned int  yl, yc;
    int i, xsl, xsc, xs, hdown;
    unsigned int x, y = 0, vsf[3], xd;
 
    JSAMPROW row0[16] = { buf0[0], buf0[1], buf0[2],  buf0[3],  buf0[4],  buf0[5],  buf0[6],  buf0[7],
                          buf0[8], buf0[9], buf0[10], buf0[11], buf0[12], buf0[13], buf0[14], buf0[15] };
 
    JSAMPROW row1[8] = { buf1[0], buf1[1], buf1[2], buf1[3], buf1[4], buf1[5], buf1[6], buf1[7] };
 
    JSAMPROW row2[16] = { buf2[0], buf2[1], buf2[2], buf2[3], buf2[4], buf2[5], buf2[6], buf2[7] };
 
    JSAMPROW row1_444[16], row2_444[16];
 
    JSAMPARRAY scanarray[3] = { row0, row1, row2 };
 
    struct jpeg_decompress_struct dinfo;
    struct my_error_mgr jerr;
 
    /* We set up the normal JPEG error routines, then override error_exit. */
    dinfo.err           = jpeg_std_error(&jerr.pub);
    jerr.pub.error_exit = my_error_exit;
    /* also hook the emit_message routine to note corrupt-data warnings */
    jerr.original_emit_message = jerr.pub.emit_message;
    jerr.pub.emit_message      = my_emit_message;
    jerr.warning_seen          = 0;
 
    /* Establish the setjmp return context for my_error_exit to use. */
    if (setjmp(jerr.setjmp_buffer))
    {
        /* If we get here, the JPEG code has signaled an error. */
        jpeg_destroy_decompress(&dinfo);
        return -1;
    }
 
    jpeg_create_decompress(&dinfo);
 
    jpeg_buffer_src(&dinfo, jpeg_data, len);
 
    /* Read header, make some checks and try to figure out what the
       user really wants */
 
    jpeg_read_header(&dinfo, TRUE);
    dinfo.raw_data_out    = TRUE;
    dinfo.out_color_space = JCS_YCbCr;
    dinfo.dct_method      = JDCT_IFAST;
    guarantee_huff_tables(&dinfo);
    jpeg_start_decompress(&dinfo);
 
    if (dinfo.output_components != 3)
    {
        fprintf(stderr, "%s: Output components of JPEG image = %d, must be 3", __FUNCTION__, dinfo.output_components);
        goto ERR_EXIT;
    }
 
    for (i = 0; i < 3; i++)
    {
        hsf[i] = dinfo.comp_info[i].h_samp_factor;
        vsf[i] = dinfo.comp_info[i].v_samp_factor;
    }
 
    if ((hsf[0] != 2 && hsf[0] != 1) || hsf[1] != 1 || hsf[2] != 1 || (vsf[0] != 1 && vsf[0] != 2) || vsf[1] != 1 ||
        vsf[2] != 1)
    {
        fprintf(stderr,
                "%s: Unsupported sampling factors, hsf=(%d, %d, %d) "
                "vsf=(%d, %d, %d) !",
                __FUNCTION__, hsf[0], hsf[1], hsf[2], vsf[0], vsf[1], vsf[2]);
        goto ERR_EXIT;
    }
 
    if (hsf[0] == 1)
    {
        if (height % 8 != 0)
        {
            fprintf(stderr,
                    "%s: YUV 4:4:4 sampling, but image height %d "
                    "not dividable by 8 !",
                    __FUNCTION__, height);
            goto ERR_EXIT;
        }
 
        for (y = 0; y < 16; y++) // allocate a special buffer for the extra sampling depth
        {
            row1_444[y] = (unsigned char *)malloc(dinfo.output_width * sizeof(unsigned char));
            row2_444[y] = (unsigned char *)malloc(dinfo.output_width * sizeof(unsigned char));
        }
        scanarray[1] = row1_444;
        scanarray[2] = row2_444;
    }
 
    /* Height match image height or be exact twice the image height */
 
    if (dinfo.output_height == height)
    {
        numfields = 1;
    }
    else if (2 * dinfo.output_height == height)
    {
        numfields = 2;
    }
    else
    {
        fprintf(stderr,
                "%s: Read JPEG: requested height = %d, "
                "height of image = %d",
                __FUNCTION__, height, dinfo.output_height);
        goto ERR_EXIT;
    }
 
    /* Width is more flexible */
 
    if (dinfo.output_width > MAX_LUMA_WIDTH)
    {
        fprintf(stderr, "%s: Image width of %d exceeds max", __FUNCTION__, dinfo.output_width);
        goto ERR_EXIT;
    }
 
    if (width < 2 * dinfo.output_width / 3)
    {
        /* Downsample 2:1 */
        hdown = 1;
        if (2 * width < dinfo.output_width)
            xsl = (dinfo.output_width - 2 * width) / 2;
        else
            xsl = 0;
    }
    else if (width == 2 * dinfo.output_width / 3)
    {
        /* special case of 3:2 downsampling */
        hdown = 2;
        xsl   = 0;
    }
    else
    {
        /* No downsampling */
        hdown = 0;
        if (width < dinfo.output_width)
            xsl = (dinfo.output_width - width) / 2;
        else
            xsl = 0;
    }
 
    /* Make xsl even, calculate xsc */
 
    xsl = xsl & ~1;
    xsc = xsl / 2;
 
    yl = yc = 0;
 
    for (field = 0; field < numfields; field++)
    {
        if (field > 0)
        {
            jpeg_read_header(&dinfo, TRUE);
            dinfo.raw_data_out    = TRUE;
            dinfo.out_color_space = JCS_YCbCr;
            dinfo.dct_method      = JDCT_IFAST;
            jpeg_start_decompress(&dinfo);
        }
 
        if (numfields == 2)
        {
            switch (itype)
            {
                case Y4M_ILACE_TOP_FIRST:
                    yl = yc = field;
                    break;
                case Y4M_ILACE_BOTTOM_FIRST:
                    yl = yc = (1 - field);
                    break;
                default:
                    fprintf(stderr, "%s: Input is interlaced but no interlacing set", __FUNCTION__);
                    goto ERR_EXIT;
            }
        }
        else
        {
            yl = yc = 0;
        }
 
        while (dinfo.output_scanline < dinfo.output_height)
        {
            /* read raw data */
            jpeg_read_raw_data(&dinfo, scanarray, 8 * vsf[0]);
 
            for (y = 0; y < 8 * vsf[0] && yl < height; yl += numfields, y++)
            {
                xd = yl * width;
                xs = xsl;
 
                if (hdown == 0)
                {
                    for (x = 0; x < width; x++)
                        raw0[xd++] = row0[y][xs++];
                }
                else if (hdown == 1)
                {
                    for (x = 0; x < width; x++, xs += 2)
                        raw0[xd++] = (row0[y][xs] + row0[y][xs + 1]) >> 1;
                }
                else
                {
                    for (x = 0; x < width / 2; x++, xd += 2, xs += 3)
                    {
                        raw0[xd]     = (2 * row0[y][xs] + row0[y][xs + 1]) / 3;
                        raw0[xd + 1] = (2 * row0[y][xs + 2] + row0[y][xs + 1]) / 3;
                    }
                }
            }
 
            /* Horizontal downsampling of chroma */
 
            for (y = 0; y < 8; y++)
            {
                xs = xsc;
 
                if (hsf[0] == 1)
                    for (x = 0; x < width / 2; x++, xs++)
                    {
                        row1[y][xs] = (row1_444[y][2 * x] + row1_444[y][2 * x + 1]) >> 1;
                        row2[y][xs] = (row2_444[y][2 * x] + row2_444[y][2 * x + 1]) >> 1;
                    }
 
                xs = xsc;
                if (hdown == 0)
                {
                    for (x = 0; x < width / 2; x++, xs++)
                    {
                        chr1[y][x] = row1[y][xs];
                        chr2[y][x] = row2[y][xs];
                    }
                }
                else if (hdown == 1)
                {
                    for (x = 0; x < width / 2; x++, xs += 2)
                    {
                        chr1[y][x] = (row1[y][xs] + row1[y][xs + 1]) >> 1;
                        chr2[y][x] = (row2[y][xs] + row2[y][xs + 1]) >> 1;
                    }
                }
                else
                {
                    for (x = 0; x < width / 2; x += 2, xs += 3)
                    {
                        chr1[y][x]     = (2 * row1[y][xs] + row1[y][xs + 1]) / 3;
                        chr1[y][x + 1] = (2 * row1[y][xs + 2] + row1[y][xs + 1]) / 3;
                        chr2[y][x]     = (2 * row2[y][xs] + row2[y][xs + 1]) / 3;
                        chr2[y][x + 1] = (2 * row2[y][xs + 2] + row2[y][xs + 1]) / 3;
                    }
                }
            }
 
            /* Vertical resampling of chroma */
 
            switch (ctype)
            {
                case Y4M_CHROMA_422:
                    if (vsf[0] == 1)
                    {
                        /* Just copy */
                        for (y = 0; y < 8 && yc < height; y++, yc += numfields)
                        {
                            xd = yc * width / 2;
 
                            for (x = 0; x < width / 2; x++, xd++)
                            {
                                raw1[xd] = chr1[y][x];
                                raw2[xd] = chr2[y][x];
                            }
                        }
                    }
                    else
                    {
                        /* upsample */
                        for (y = 0; y < 8 && yc < height; y++)
                        {
                            xd = yc * width / 2;
 
                            for (x = 0; x < width / 2; x++, xd++)
                            {
                                raw1[xd] = chr1[y][x];
                                raw2[xd] = chr2[y][x];
                            }
 
                            yc += numfields;
                            xd = yc * width / 2;
 
                            for (x = 0; x < width / 2; x++, xd++)
                            {
                                raw1[xd] = chr1[y][x];
                                raw2[xd] = chr2[y][x];
                            }
 
                            yc += numfields;
                        }
                    }
                    break;
                default:
                    /*
                    * should be case Y4M_CHROMA_420JPEG: but use default: for compatibility. Some
                    * pass things like '420' in with the expectation that anything other than
                    * Y4M_CHROMA_422 will default to 420JPEG.
                    */
                    if (vsf[0] == 1)
                    {
                        /* Really downsample */
                        for (y = 0; y < 8 && yc < height/2; y += 2, yc += numfields)
                        {
                            xd = yc * width / 2;
 
                            for (x = 0; x < width / 2; x++, xd++)
                            {
                                assert(xd < (width * height / 4));
                                raw1[xd] = (chr1[y][x] + chr1[y + 1][x]) >> 1;
                                raw2[xd] = (chr2[y][x] + chr2[y + 1][x]) >> 1;
                            }
                        }
                    }
                    else
                    {
                        /* Just copy */
                        for (y = 0; y < 8 && yc < height/2; y++, yc += numfields)
                        {
                            xd = yc * width / 2;
 
                            for (x = 0; x < width / 2; x++, xd++)
                            {
                                raw1[xd] = chr1[y][x];
                                raw2[xd] = chr2[y][x];
                            }
                        }
                    }
                    break;
            }
        }
 
        (void)jpeg_finish_decompress(&dinfo);
        if (field == 0 && numfields > 1)
            jpeg_skip_ff(&dinfo);
    }
 
    if (hsf[0] == 1)
    {
        for (y = 0; y < 16; y++) // allocate a special buffer for the extra sampling depth
        {
            free(row1_444[y]);
            free(row2_444[y]);
        }
    }
 
    jpeg_destroy_decompress(&dinfo);
 
    if (jerr.warning_seen)
        return 1;
    else
        return 0;
 
ERR_EXIT:
    jpeg_destroy_decompress(&dinfo);
    return -1;
}
 
/*
 * jpeg_data:       Buffer with jpeg data to decode, must be grayscale mode
 * len:             Length of buffer
 * itype:           0: Not interlaced
 *                  1: Interlaced, Top field first
 *                  2: Interlaced, Bottom field first
 * ctype            Chroma format for decompression.
 *                  Currently only Y4M_CHROMA_{420JPEG,422} are available
 */
 
int decode_jpeg_gray_raw(unsigned char *jpeg_data, int len, int itype, int ctype, unsigned int width,
                         unsigned int height, unsigned char *raw0, unsigned char *raw1, unsigned char *raw2)
{
    int numfields, field, yl, yc, xsl, xsc, xs, xd, hdown;
    unsigned int x, y, vsf[3];
 
    JSAMPROW row0[16] = { buf0[0], buf0[1], buf0[2],  buf0[3],  buf0[4],  buf0[5],  buf0[6],  buf0[7],
                          buf0[8], buf0[9], buf0[10], buf0[11], buf0[12], buf0[13], buf0[14], buf0[15] };
 
    JSAMPARRAY scanarray[3] = { row0 };
    struct jpeg_decompress_struct dinfo;
    struct my_error_mgr jerr;
 
    /* We set up the normal JPEG error routines, then override error_exit. */
    dinfo.err           = jpeg_std_error(&jerr.pub);
    jerr.pub.error_exit = my_error_exit;
 
    /* Establish the setjmp return context for my_error_exit to use. */
    if (setjmp(jerr.setjmp_buffer))
    {
        /* If we get here, the JPEG code has signaled an error. */
        jpeg_destroy_decompress(&dinfo);
        return -1;
    }
 
    jpeg_create_decompress(&dinfo);
 
    jpeg_buffer_src(&dinfo, jpeg_data, len);
 
    /* Read header, make some checks and try to figure out what the
      user really wants */
 
    jpeg_read_header(&dinfo, TRUE);
    dinfo.raw_data_out    = TRUE;
    dinfo.out_color_space = JCS_GRAYSCALE;
    dinfo.dct_method      = JDCT_IFAST;
 
    if (dinfo.jpeg_color_space != JCS_GRAYSCALE)
    {
        fprintf(stderr, "%s: Expected grayscale colorspace for JPEG raw decoding", __FUNCTION__);
        goto ERR_EXIT;
    }
 
    guarantee_huff_tables(&dinfo);
    jpeg_start_decompress(&dinfo);
 
//    hsf[0] = 1;
//    hsf[1] = 1;
//    hsf[2] = 1;
    vsf[0] = 1;
    vsf[1] = 1;
    vsf[2] = 1;
 
    /* Height match image height or be exact twice the image height */
 
    if (dinfo.output_height == height)
    {
        numfields = 1;
    }
    else if (2 * dinfo.output_height == height)
    {
        numfields = 2;
    }
    else
    {
        fprintf(stderr,
                "%s: Read JPEG: requested height = %d, "
                "height of image = %d",
                __FUNCTION__, height, dinfo.output_height);
        goto ERR_EXIT;
    }
 
    /* Width is more flexible */
 
    if (dinfo.output_width > MAX_LUMA_WIDTH)
    {
        fprintf(stderr, "%s: Image width of %d exceeds max", __FUNCTION__, dinfo.output_width);
        goto ERR_EXIT;
    }
 
    if (width < 2 * dinfo.output_width / 3)
    {
        /* Downsample 2:1 */
        hdown = 1;
        if (2 * width < dinfo.output_width)
            xsl = (dinfo.output_width - 2 * width) / 2;
        else
            xsl = 0;
    }
    else if (width == 2 * dinfo.output_width / 3)
    {
        /* special case of 3:2 downsampling */
        hdown = 2;
        xsl   = 0;
    }
    else
    {
        /* No downsampling */
        hdown = 0;
        if (width < dinfo.output_width)
            xsl = (dinfo.output_width - width) / 2;
        else
            xsl = 0;
    }
 
    /* Make xsl even, calculate xsc */
 
    xsl = xsl & ~1;
    xsc = xsl / 2;
 
    yl = yc = 0;
 
    for (field = 0; field < numfields; field++)
    {
        if (field > 0)
        {
            jpeg_read_header(&dinfo, TRUE);
            dinfo.raw_data_out    = TRUE;
            dinfo.out_color_space = JCS_GRAYSCALE;
            dinfo.dct_method      = JDCT_IFAST;
            jpeg_start_decompress(&dinfo);
        }
 
        if (numfields == 2)
        {
            switch (itype)
            {
                case Y4M_ILACE_TOP_FIRST:
                    yl = yc = field;
                    break;
                case Y4M_ILACE_BOTTOM_FIRST:
                    yl = yc = (1 - field);
                    break;
                default:
                    fprintf(stderr, "%s: Input is interlaced but no interlacing set", __FUNCTION__);
                    goto ERR_EXIT;
            }
        }
        else
        {
            yl = yc = 0;
        }
 
        while (dinfo.output_scanline < dinfo.output_height)
        {
            jpeg_read_raw_data(&dinfo, scanarray, 16);
 
            for (y = 0; y < 8 * vsf[0]; yl += numfields, y++)
            {
                xd = yl * width;
                xs = xsl;
 
                if (hdown == 0) // no horiz downsampling
                {
                    for (x = 0; x < width; x++)
                        raw0[xd++] = row0[y][xs++];
                }
                else if (hdown == 1) // half the res
                {
                    for (x = 0; x < width; x++, xs += 2)
                        raw0[xd++] = (row0[y][xs] + row0[y][xs + 1]) >> 1;
                }
                else // 2:3 downsampling
                {
                    for (x = 0; x < width / 2; x++, xd += 2, xs += 3)
                    {
                        raw0[xd]     = (2 * row0[y][xs] + row0[y][xs + 1]) / 3;
                        raw0[xd + 1] = (2 * row0[y][xs + 2] + row0[y][xs + 1]) / 3;
                    }
                }
            }
 
            for (y = 0; y < 8; y++)
            {
                xs = xsc;
 
                if (hdown == 0)
                {
                    for (x = 0; x < width / 2; x++, xs++)
                    {
                        chr1[y][x] = 0; //row1[y][xs];
                        chr2[y][x] = 0; //row2[y][xs];
                    }
                }
                else if (hdown == 1)
                {
                    for (x = 0; x < width / 2; x++, xs += 2)
                    {
                        chr1[y][x] = 0; //(row1[y][xs] + row1[y][xs + 1]) >> 1;
                        chr2[y][x] = 0; //(row2[y][xs] + row2[y][xs + 1]) >> 1;
                    }
                }
                else
                {
                    for (x = 0; x < width / 2; x += 2, xs += 3)
                    {
                        chr1[y][x]     = 0; //(2 * row1[y][xs] + row1[y][xs + 1]) / 3;
                        chr1[y][x + 1] = 0;
                        //(2 * row1[y][xs + 2] + row1[y][xs + 1]) / 3;
                        chr2[y][x]     = 0; // (2 * row2[y][xs] + row2[y][xs + 1]) / 3;
                        chr2[y][x + 1] = 0;
                        //(2 * row2[y][xs + 2] + row2[y][xs + 1]) / 3;
                    }
                }
            }
 
            switch (ctype)
            {
                case Y4M_CHROMA_422:
                    if (vsf[0] == 1)
                    {
                        /* Just copy */
                        for (y = 0; y < 8 /*&& yc < height */; y++, yc += numfields)
                        {
                            xd = yc * width / 2;
 
                            for (x = 0; x < width / 2; x++, xd++)
                            {
                                raw1[xd] = 127; //chr1[y][x];
                                raw2[xd] = 127; //chr2[y][x];
                            }
                        }
                    }
                    else
                    {
                        /* upsample */
                        for (y = 0; y < 8 /*&& yc < height */; y++)
                        {
                            xd = yc * width / 2;
 
                            for (x = 0; x < width / 2; x++, xd++)
                            {
                                raw1[xd] = 127; //chr1[y][x];
                                raw2[xd] = 127; //chr2[y][x];
                            }
 
                            yc += numfields;
                            xd = yc * width / 2;
 
                            for (x = 0; x < width / 2; x++, xd++)
                            {
                                raw1[xd] = 127; //chr1[y][x];
                                raw2[xd] = 127; //chr2[y][x];
                            }
 
                            yc += numfields;
                        }
                    }
                    break;
                /*
                 * should be case Y4M_CHROMA_420JPEG: but use default: for compatibility. Some
                 * pass things like '420' in with the expectation that anything other than
                 * Y4M_CHROMA_422 will default to 420JPEG.
                 */
                default:
                    if (vsf[0] == 1)
                    {
                        /* Really downsample */
                        for (y = 0; y < 8; y += 2, yc += numfields)
                        {
                            xd = yc * width / 2;
 
                            for (x = 0; x < width / 2; x++, xd++)
                            {
                                raw1[xd] = 127; //(chr1[y][x] + chr1[y + 1][x]) >> 1;
                                raw2[xd] = 127; //(chr2[y][x] + chr2[y + 1][x]) >> 1;
                            }
                        }
                    }
                    else
                    {
                        /* Just copy */
 
                        for (y = 0; y < 8; y++, yc += numfields)
                        {
                            xd = yc * width / 2;
 
                            for (x = 0; x < width / 2; x++, xd++)
                            {
                                raw1[xd] = 127; //chr1[y][x];
                                raw2[xd] = 127; //chr2[y][x];
                            }
                        }
                    }
                    break;
            }
        }
 
        (void)jpeg_finish_decompress(&dinfo);
 
        if (field == 0 && numfields > 1)
            jpeg_skip_ff(&dinfo);
    }
 
    jpeg_destroy_decompress(&dinfo);
    return 0;
 
ERR_EXIT:
    jpeg_destroy_decompress(&dinfo);
    return -1;
}
 
/*******************************************************************
 *                                                                 *
 *    encode_jpeg_data: Compress raw YCbCr data (output JPEG       *
 *                      may be interlaced                          *
 *                                                                 *
 *******************************************************************/
 
/*
* jpeg_data:       Buffer to hold output jpeg
* len:             Length of buffer
* itype:           0: Not interlaced
*                  1: Interlaced, Top field first
*                  2: Interlaced, Bottom field first
* ctype            Chroma format for decompression.
*                  Currently only Y4M_CHROMA_{420JPEG,422} are available
*/
 
int encode_jpeg_raw(unsigned char *jpeg_data, int len, int quality, int itype, int ctype, unsigned int width,
                    unsigned int height, unsigned char *raw0, unsigned char *raw1, unsigned char *raw2)
{
    int numfields, field, yl, yc, y, i;
 
    JSAMPROW row0[16] = { buf0[0], buf0[1], buf0[2],  buf0[3],  buf0[4],  buf0[5],  buf0[6],  buf0[7],
                          buf0[8], buf0[9], buf0[10], buf0[11], buf0[12], buf0[13], buf0[14], buf0[15] };
 
    JSAMPROW row1[8] = { buf1[0], buf1[1], buf1[2], buf1[3], buf1[4], buf1[5], buf1[6], buf1[7] };
 
    JSAMPROW row2[8] = { buf2[0], buf2[1], buf2[2], buf2[3], buf2[4], buf2[5], buf2[6], buf2[7] };
 
    JSAMPARRAY scanarray[3] = { row0, row1, row2 };
 
    struct jpeg_compress_struct cinfo;
    struct my_error_mgr jerr;
 
    /* We set up the normal JPEG error routines, then override error_exit. */
    cinfo.err           = jpeg_std_error(&jerr.pub);
    jerr.pub.error_exit = my_error_exit;
 
    /* Establish the setjmp return context for my_error_exit to use. */
    if (setjmp(jerr.setjmp_buffer))
    {
        /* If we get here, the JPEG code has signaled an error. */
        jpeg_destroy_compress(&cinfo);
        return -1;
    }
 
    jpeg_create_compress(&cinfo);
 
    jpeg_buffer_dest(&cinfo, jpeg_data, len);
 
    /* Set some jpeg header fields */
 
    cinfo.input_components = 3;
    jpeg_set_defaults(&cinfo);
    jpeg_set_quality(&cinfo, quality, FALSE);
 
    cinfo.raw_data_in    = TRUE;
    cinfo.in_color_space = JCS_YCbCr;
    cinfo.dct_method     = JDCT_IFAST;
 
    cinfo.input_gamma = 1.0;
 
    cinfo.comp_info[0].h_samp_factor = 2;
    cinfo.comp_info[0].v_samp_factor = 1; /*1||2 */
    cinfo.comp_info[1].h_samp_factor = 1;
    cinfo.comp_info[1].v_samp_factor = 1;
    cinfo.comp_info[2].h_samp_factor = 1; /*1||2 */
    cinfo.comp_info[2].v_samp_factor = 1;
 
    if ((width > 4096) || (height > 4096))
    {
        fprintf(stderr,
                "%s: Image dimensions (%dx%d) exceed lavtools' max "
                "(4096x4096)",
                __FUNCTION__, width, height);
        goto ERR_EXIT;
    }
 
    if ((width % 16) || (height % 16))
    {
        fprintf(stderr, "%s: Image dimensions (%dx%d) not multiples of 16", __FUNCTION__, width, height);
        goto ERR_EXIT;
    }
 
    cinfo.image_width = width;
 
    switch (itype)
    {
        case Y4M_ILACE_TOP_FIRST:
        case Y4M_ILACE_BOTTOM_FIRST: /* interlaced */
            numfields = 2;
            break;
        default:
            numfields = 1;
            if (height > 2048)
            {
                fprintf(stderr,
                        "%s: Image height (%d) exceeds lavtools max "
                        "for non-interlaced frames",
                        __FUNCTION__, height);
                goto ERR_EXIT;
            }
    }
 
    cinfo.image_height = height / numfields;
 
    yl = yc = 0; /* y luma, chroma */
 
    for (field = 0; field < numfields; field++)
    {
        jpeg_start_compress(&cinfo, FALSE);
 
        if (numfields == 2)
        {
            static const JOCTET marker0[40];
 
            jpeg_write_marker(&cinfo, JPEG_APP0, marker0, 14);
            jpeg_write_marker(&cinfo, JPEG_APP0 + 1, marker0, 40);
 
            switch (itype)
            {
                case Y4M_ILACE_TOP_FIRST: /* top field first */
                    yl = yc = field;
                    break;
                case Y4M_ILACE_BOTTOM_FIRST: /* bottom field first */
                    yl = yc = (1 - field);
                    break;
                default:
                    fprintf(stderr, "%s: Input is interlaced but no interlacing set", __FUNCTION__);
                    goto ERR_EXIT;
            }
        }
        else
        {
            yl = yc = 0;
        }
 
        while (cinfo.next_scanline < cinfo.image_height)
        {
            for (y = 0; y < 8 * cinfo.comp_info[0].v_samp_factor; yl += numfields, y++)
            {
                row0[y] = &raw0[yl * width];
            }
 
            for (y = 0; y < 8; y++)
            {
                row1[y] = &raw1[yc * width / 2];
                row2[y] = &raw2[yc * width / 2];
 
                if ((ctype == Y4M_CHROMA_422) || (y % 2))
                    yc += numfields;
            }
 
            jpeg_write_raw_data(&cinfo, scanarray, 8 * cinfo.comp_info[0].v_samp_factor);
        }
 
        (void)jpeg_finish_compress(&cinfo);
    }
 
    /* FIXME */
    i = len - cinfo.dest->free_in_buffer;
 
    jpeg_destroy_compress(&cinfo);
    return i; /* size of jpeg */
 
ERR_EXIT:
    jpeg_destroy_compress(&cinfo);
    return -1;
}
 
int decode_jpeg_rgb(unsigned char *inBuffer, unsigned long inSize, uint8_t **memptr, size_t *memsize, int *naxis, int *w, int *h)
{
    /* these are standard libjpeg structures for reading(decompression) */
    struct jpeg_decompress_struct cinfo;
    struct jpeg_error_mgr jerr;
    /* libjpeg data structure for storing one row, that is, scanline of an image */
    JSAMPROW row_pointer[1] = { NULL };
 
    /* here we set up the standard libjpeg error handler */
    cinfo.err = jpeg_std_error(&jerr);
    /* setup decompression process and source, then read JPEG header */
    jpeg_create_decompress(&cinfo);
    /* this makes the library read from infile */
    jpeg_mem_src(&cinfo, inBuffer, inSize);
 
    /* reading the image header which contains image information */
    jpeg_read_header(&cinfo, (boolean)TRUE);
 
    /* Start decompression jpeg here */
    jpeg_start_decompress(&cinfo);
 
    *memsize = cinfo.output_width * cinfo.output_height * cinfo.num_components;
    *memptr  = (uint8_t *)realloc(*memptr, *memsize);
 
    uint8_t *destmem = *memptr;
 
    *naxis = cinfo.num_components;
    *w     = cinfo.output_width;
    *h     = cinfo.output_height;
 
    /* now actually read the jpeg into the raw buffer */
    row_pointer[0] = (unsigned char *)malloc(cinfo.output_width * cinfo.num_components);
 
    /* read one scan line at a time */
    for (unsigned int row = 0; row < cinfo.image_height; row++)
    {
        unsigned char *ppm8 = row_pointer[0];
        jpeg_read_scanlines(&cinfo, row_pointer, 1);
        memcpy(destmem, ppm8, cinfo.output_width * cinfo.num_components);
        destmem += cinfo.output_width * cinfo.num_components;
    }
 
    /* wrap up decompression, destroy objects, free pointers and close open files */
    jpeg_finish_decompress(&cinfo);
    jpeg_destroy_decompress(&cinfo);
 
    if (row_pointer[0])
        free(row_pointer[0]);
 
    return 0;
}