jrdjfif.c

EVM板JPEG实现,Texas Instruments TMS320C54x EVM JPEG

/*
 * jrdjfif.c
 *
 * Copyright (C) 1991, 1992, Thomas G. Lane.
 * This file is part of the Independent JPEG Group's software.
 * For conditions of distribution and use, see the accompanying README file.
 *
 * This file contains routines to decode standard JPEG file headers/markers.
 * This code will handle "raw JPEG" and JFIF-convention JPEG files.
 *
 * You can also use this module to decode a raw-JPEG or JFIF-standard data
 * stream that is embedded within a larger file.  To do that, you must
 * position the file to the JPEG SOI marker (0xFF/0xD8) that begins the
 * data sequence to be decoded.  If nothing better is possible, you can scan
 * the file until you see the SOI marker, then use JUNGETC to push it back.
 *
 * This module relies on the JGETC macro and the read_jpeg_data method (which
 * is provided by the user interface) to read from the JPEG data stream.
 * Therefore, this module is not dependent on any particular assumption about
 * the data source; it need not be a stdio stream at all.  (This fact does
 * NOT carry over to more complex JPEG file formats such as JPEG-in-TIFF;
 * those format control modules may well need to assume stdio input.)
 *
 * These routines are invoked via the methods read_file_header,
 * read_scan_header, read_jpeg_data, read_scan_trailer, and read_file_trailer.
 */

#include "jinclude.h"

#ifdef JFIF_SUPPORTED


typedef enum {			/* JPEG marker codes */
  M_SOF0  = 0xc0,
  M_SOF1  = 0xc1,
  M_SOF2  = 0xc2,
  M_SOF3  = 0xc3,
  
  M_SOF5  = 0xc5,
  M_SOF6  = 0xc6,
  M_SOF7  = 0xc7,
  
  M_JPG   = 0xc8,
  M_SOF9  = 0xc9,
  M_SOF10 = 0xca,
  M_SOF11 = 0xcb,
  
  M_SOF13 = 0xcd,
  M_SOF14 = 0xce,
  M_SOF15 = 0xcf,
  
  M_DHT   = 0xc4,
  
  M_DAC   = 0xcc,
  
  M_RST0  = 0xd0,
  M_RST1  = 0xd1,
  M_RST2  = 0xd2,
  M_RST3  = 0xd3,
  M_RST4  = 0xd4,
  M_RST5  = 0xd5,
  M_RST6  = 0xd6,
  M_RST7  = 0xd7,
  
  M_SOI   = 0xd8,
  M_EOI   = 0xd9,
  M_SOS   = 0xda,
  M_DQT   = 0xdb,
  M_DNL   = 0xdc,
  M_DRI   = 0xdd,
  M_DHP   = 0xde,
  M_EXP   = 0xdf,
  
  M_APP0  = 0xe0,
  M_APP15 = 0xef,
  
  M_JPG0  = 0xf0,
  M_JPG13 = 0xfd,
  M_COM   = 0xfe,
  
  M_TEM   = 0x01,
  
  M_ERROR = 0x100
} JPEG_MARKER;


/*
 * Reload the input buffer after it's been emptied, and return the next byte.
 * This is exported for direct use by the entropy decoder.
 * See the JGETC macro for calling conditions.  Note in particular that
 * read_jpeg_data may NOT return EOF.  If no more data is available, it must
 * exit via ERREXIT, or perhaps synthesize fake data (such as an RST marker).
 * For error recovery purposes, synthesizing an EOI marker is probably best.
 *
 * For this header control module, read_jpeg_data is supplied by the
 * user interface.  However, header formats that require random access
 * to the input file would need to supply their own code.  This code is
 * left here to indicate what is required.
 */

#if 0				/* not needed in this module */

METHODDEF int
read_jpeg_data (decompress_info_ptr cinfo)
{
  cinfo->next_input_byte = cinfo->input_buffer + MIN_UNGET;

  cinfo->bytes_in_buffer = (int) JFREAD(cinfo->input_file,
					cinfo->next_input_byte,
					JPEG_BUF_SIZE);
  
  if (cinfo->bytes_in_buffer <= 0) {
/*    WARNMS(cinfo->emethods, "Premature EOF in JPEG file"); */
   send_command(ERR13);
    cinfo->next_input_byte[0] = (char) 0xFF;
    cinfo->next_input_byte[1] = (char) M_EOI;
    cinfo->bytes_in_buffer = 2;
  }

  return JGETC(cinfo);
}

#endif


/*
 * Routines to parse JPEG markers & save away the useful info.
 */


LOCAL INT32
get_2bytes (decompress_info_ptr cinfo)
/* Get a 2-byte unsigned integer (e.g., a marker parameter length field) */
{
  INT32 a;
  
  a = JGETC(cinfo);
  return (a << 8) + JGETC(cinfo);
}


LOCAL void
skip_variable (decompress_info_ptr cinfo, int code)
/* Skip over an unknown or uninteresting variable-length marker */
{
  INT32 length;
  
  length = get_2bytes(cinfo);
  
/*  TRACEMS2(cinfo->emethods, 1,
      "Skipping marker 0x%02x, length %u", code, (int) length); */

  for (length -= 2; length > 0; length--)
    (void) JGETC(cinfo);
}


LOCAL void
get_dht (decompress_info_ptr cinfo)
/* Process a DHT marker */
{
  INT32 length;
  UINT8 bits[17];
  UINT8 huffval[256];
  int i, index, count;
  HUFF_TBL **htblptr;
  
  length = get_2bytes(cinfo)-2;
  
  while (length > 0) {
    index = JGETC(cinfo);

/*    TRACEMS1(cinfo->emethods, 1, "Define Huffman Table 0x%02x", index); */
      
    bits[0] = 0;
    count = 0;
    for (i = 1; i <= 16; i++) {
      bits[i] = (UINT8) JGETC(cinfo);
      count += bits[i];
    }

/*    TRACEMS8(cinfo->emethods, 2, "        %3d %3d %3d %3d %3d %3d %3d %3d",
	     bits[1], bits[2], bits[3], bits[4],
        bits[5], bits[6], bits[7], bits[8]); */
/*    TRACEMS8(cinfo->emethods, 2, "        %3d %3d %3d %3d %3d %3d %3d %3d",
	     bits[9], bits[10], bits[11], bits[12],
        bits[13], bits[14], bits[15], bits[16]); */

    if (count > 256)
    {
/*      ERREXIT(cinfo->emethods, "Bogus DHT counts"); */
      send_command(ERR12);
      receive_command();
      exit();
    }

    for (i = 0; i < count; i++)
      huffval[i] = (UINT8) JGETC(cinfo);

    length -= 1 + 16 + count;

    if (index & 0x10) {		/* AC table definition */
      index -= 0x10;
      htblptr = &cinfo->ac_huff_tbl_ptrs[index];
    } else {			/* DC table definition */
      htblptr = &cinfo->dc_huff_tbl_ptrs[index];
    }

    if (index < 0 || index >= NUM_HUFF_TBLS)
   {
/*      ERREXIT1(cinfo->emethods, "Bogus DHT index %d", index); */
      send_command(ERR12);
      receive_command();
      exit();
    }

    if (*htblptr == NULL)
      *htblptr = (HUFF_TBL *) (*cinfo->emethods->alloc_small) (SIZEOF(HUFF_TBL));
  
    MEMCOPY((*htblptr)->bits, bits, SIZEOF((*htblptr)->bits));
    MEMCOPY((*htblptr)->huffval, huffval, SIZEOF((*htblptr)->huffval));
    }
}


LOCAL void
get_dac (decompress_info_ptr cinfo)
/* Process a DAC marker */
{
  INT32 length;
  int index, val;

  length = get_2bytes(cinfo)-2;
  
  while (length > 0) {
    index = JGETC(cinfo);
    val = JGETC(cinfo);

/*    TRACEMS2(cinfo->emethods, 1,
        "Define Arithmetic Table 0x%02x: 0x%02x", index, val); */
   
    if (index < 0 || index >= (2*NUM_ARITH_TBLS))
    {
/*      ERREXIT1(cinfo->emethods, "Bogus DAC index %d", index); */
      send_command(ERR12);
      receive_command();
      exit();
    }

    if (index >= NUM_ARITH_TBLS) { /* define AC table */
      cinfo->arith_ac_K[index-NUM_ARITH_TBLS] = (UINT8) val;
    } else {			/* define DC table */
      cinfo->arith_dc_L[index] = (UINT8) (val & 0x0F);
      cinfo->arith_dc_U[index] = (UINT8) (val >> 4);
      if (cinfo->arith_dc_L[index] > cinfo->arith_dc_U[index])
      {
/*   ERREXIT1(cinfo->emethods, "Bogus DAC value 0x%x", val); */
        send_command(ERR12);
        receive_command();
        exit();
      }
    }

    length -= 2;
  }
}


LOCAL void
get_dqt (decompress_info_ptr cinfo)
/* Process a DQT marker */
{
  INT32 length;
  int n, i, prec;
  UINT16 tmp;
  QUANT_TBL_PTR quant_ptr;
  
  length = get_2bytes(cinfo) - 2;
  
  while (length > 0) {
    n = JGETC(cinfo);
    prec = n >> 4;
    n &= 0x0F;

/*    TRACEMS2(cinfo->emethods, 1,
        "Define Quantization Table %d  precision %d", n, prec); */

    if (n >= NUM_QUANT_TBLS)
    {
/*      ERREXIT1(cinfo->emethods, "Bogus table number %d", n); */
      send_command(ERR12);
      receive_command();
      exit();
    }
      
    if (cinfo->quant_tbl_ptrs[n] == NULL)
      cinfo->quant_tbl_ptrs[n] = (QUANT_TBL_PTR)
	(*cinfo->emethods->alloc_small) (SIZEOF(QUANT_TBL));
    quant_ptr = cinfo->quant_tbl_ptrs[n];

    for (i = 0; i < DCTSIZE2; i++) {
      tmp = JGETC(cinfo);
      if (prec)
	tmp = (tmp<<8) + JGETC(cinfo);
      quant_ptr[i] = tmp;
    }

    for (i = 0; i < DCTSIZE2; i += 8) {
/*      TRACEMS8(cinfo->emethods, 2, "        %4u %4u %4u %4u %4u %4u %4u %4u",
	       quant_ptr[i  ], quant_ptr[i+1], quant_ptr[i+2], quant_ptr[i+3],
          quant_ptr[i+4], quant_ptr[i+5], quant_ptr[i+6], quant_ptr[i+7]); */
    }

    length -= DCTSIZE2+1;
    if (prec) length -= DCTSIZE2;
  }
}


LOCAL void
get_dri (decompress_info_ptr cinfo)
/* Process a DRI marker */
{
  if (get_2bytes(cinfo) != 4)
  {
/*    ERREXIT(cinfo->emethods, "Bogus length in DRI"); */
      send_command(ERR12);
      receive_command();
      exit();
  }

  cinfo->restart_interval = (UINT16) get_2bytes(cinfo);

/*  TRACEMS1(cinfo->emethods, 1,
      "Define Restart Interval %u", cinfo->restart_interval); */
}


LOCAL void
get_app0 (decompress_info_ptr cinfo)
/* Process an APP0 marker */
{
#define JFIF_LEN 14
  INT32 length;
  UINT8 b[JFIF_LEN];
  int buffp;

  length = get_2bytes(cinfo) - 2;

  /* See if a JFIF APP0 marker is present */

  if (length >= JFIF_LEN) {
    for (buffp = 0; buffp < JFIF_LEN; buffp++)
      b[buffp] = (UINT8) JGETC(cinfo);
    length -= JFIF_LEN;

    if (b[0]==0x4A && b[1]==0x46 && b[2]==0x49 && b[3]==0x46 && b[4]==0) {
      /* Found JFIF APP0 marker: check version */
      /* Major version must be 1 */
      if (b[5] != 1)
      {
/*     ERREXIT2(cinfo->emethods, "Unsupported JFIF revision number %d.%02d",
		 b[5], b[6]); */
        send_command(ERR12);
        receive_command();
        exit();
      }

      /* Minor version should be 0..2, but try to process anyway if newer */
/*      if (b[6] > 2)
   TRACEMS2(cinfo->emethods, 1, "Warning: unknown JFIF revision number %d.%02d",
       b[5], b[6]); */
      /* Save info */
      cinfo->density_unit = b[7];
      cinfo->X_density = (b[8] << 8) + b[9];
      cinfo->Y_density = (b[10] << 8) + b[11];
		/* Assume colorspace is YCbCr, unless UI has overridden me */
/*      if (cinfo->jpeg_color_space == CS_UNKNOWN)
	cinfo->jpeg_color_space = CS_YCbCr;
      TRACEMS3(cinfo->emethods, 1, "JFIF APP0 marker, density %dx%d  %d",
          cinfo->X_density, cinfo->Y_density, cinfo->density_unit); */

/*      if (b[12] | b[13])
   TRACEMS2(cinfo->emethods, 1, "    with %d x %d thumbnail image",
       b[12], b[13]); */
/*      if (length != ((INT32) b[12] * (INT32) b[13] * (INT32) 3))
   TRACEMS1(cinfo->emethods, 1,
		 "Warning: thumbnail image size does not match data length %u",
       (int) length); */
  } else {
/*      TRACEMS1(cinfo->emethods, 1, "Unknown APP0 marker (not JFIF), length %u",
          (int) length + JFIF_LEN); */
    }
  } else {
/*    TRACEMS1(cinfo->emethods, 1, "Short APP0 marker, length %u", (int) length); */
  }

  while (length-- > 0)		/* skip any remaining data */
    (void) JGETC(cinfo);
}


LOCAL void
get_sof (decompress_info_ptr cinfo, int code)
/* Process a SOFn marker */
{
  INT32 length;
  short ci;
  int c;
  jpeg_component_info * compptr;
  
  length = get_2bytes(cinfo);
  
  cinfo->data_precision = JGETC(cinfo);
  cinfo->image_height   = get_2bytes(cinfo);
  cinfo->image_width    = get_2bytes(cinfo);
  cinfo->num_components = JGETC(cinfo);

/*  TRACEMS4(cinfo->emethods, 1,
	   "Start Of Frame 0x%02x: width=%u, height=%u, components=%d",
	   code, (int) cinfo->image_width, (int) cinfo->image_height,
      cinfo->num_components); */

  /* We don't support files in which the image height is initially specified */
  /* as 0 and is later redefined by DNL.  As long as we have to check that,  */
  /* might as well have a general sanity check. */
  if (cinfo->image_height <= 0 || cinfo->image_width <= 0
      || cinfo->num_components <= 0)
    {
/*    ERREXIT(cinfo->emethods, "Empty JPEG image (DNL not supported)"); */
      send_command(ERR12);
      receive_command();
      exit();
    }

#ifdef EIGHT_BIT_SAMPLES
  if (cinfo->data_precision != 8)
  {
/*    ERREXIT(cinfo->emethods, "Unsupported JPEG data precision"); */
      send_command(ERR12);
      receive_command();
      exit();
  }

#endif
#ifdef TWELVE_BIT_SAMPLES
  if (cinfo->data_precision != 12) /* this needs more thought?? */
   {
/*    ERREXIT(cinfo->emethods, "Unsupported JPEG data precision"); */
      send_command(ERR12);
      receive_command();
      exit();
    }
#endif
#ifdef SIXTEEN_BIT_SAMPLES
  if (cinfo->data_precision != 16) /* this needs more thought?? */
   {
/*    ERREXIT(cinfo->emethods, "Unsupported JPEG data precision"); */
      send_command(ERR12);
      receive_command();
      exit();
   }

#endif

  if (length != (cinfo->num_components * 3 + 8))