/*

 * jdmarker.c

 *

 * Copyright (C) 1991-1998, 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 JPEG datastream markers.

 * Most of the complexity arises from our desire to support input

 * suspension: if not all of the data for a marker is available,

 * we must exit back to the application.  On resumption, we reprocess

 * the marker.

 */

#define JPEG_INTERNALS

#include "jinclude.h"

#include "jpeglib.h"

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_APP1  = 0xe1,

  M_APP2  = 0xe2,

  M_APP3  = 0xe3,

  M_APP4  = 0xe4,

  M_APP5  = 0xe5,

  M_APP6  = 0xe6,

  M_APP7  = 0xe7,

  M_APP8  = 0xe8,

  M_APP9  = 0xe9,

  M_APP10 = 0xea,

  M_APP11 = 0xeb,

  M_APP12 = 0xec,

  M_APP13 = 0xed,

  M_APP14 = 0xee,

  M_APP15 = 0xef,

  M_JPG0  = 0xf0,

  M_JPG13 = 0xfd,

  M_COM   = 0xfe,

  M_TEM   = 0x01,

  M_ERROR = 0x100

} JPEG_MARKER;

/* Private state */

typedef struct {

  struct jpeg_marker_reader pub; /* public fields */

  /* Application-overridable marker processing methods */

  jpeg_marker_parser_method process_COM;

  jpeg_marker_parser_method process_APPn[16];

  /* Limit on marker data length to save for each marker type */

  unsigned int length_limit_COM;

  unsigned int length_limit_APPn[16];

  /* Status of COM/APPn marker saving */

  jpeg_saved_marker_ptr cur_marker;	/* NULL if not processing a marker */

  unsigned int bytes_read;		/* data bytes read so far in marker */

  /* Note: cur_marker is not linked into marker_list until it's all read. */

} my_marker_reader;

typedef my_marker_reader * my_marker_ptr;

/*

 * Macros for fetching data from the data source module.

 *

 * At all times, cinfo->src->next_input_byte and ->bytes_in_buffer reflect

 * the current restart point; we update them only when we have reached a

 * suitable place to restart if a suspension occurs.

 */

/* Declare and initialize local copies of input pointer/count */

#define INPUT_VARS(cinfo)  \

	struct jpeg_source_mgr * datasrc = (cinfo)->src;  \

	const JOCTET * next_input_byte = datasrc->next_input_byte;  \

	size_t bytes_in_buffer = datasrc->bytes_in_buffer

/* Unload the local copies --- do this only at a restart boundary */

#define INPUT_SYNC(cinfo)  \

	( datasrc->next_input_byte = next_input_byte,  \

	  datasrc->bytes_in_buffer = bytes_in_buffer )

/* Reload the local copies --- used only in MAKE_BYTE_AVAIL */

#define INPUT_RELOAD(cinfo)  \

	( next_input_byte = datasrc->next_input_byte,  \

	  bytes_in_buffer = datasrc->bytes_in_buffer )

/* Internal macro for INPUT_BYTE and INPUT_2BYTES: make a byte available.

 * Note we do *not* do INPUT_SYNC before calling fill_input_buffer,

 * but we must reload the local copies after a successful fill.

 */

#define MAKE_BYTE_AVAIL(cinfo,action)  \

	if (bytes_in_buffer == 0) {  \

	  if (! (*datasrc->fill_input_buffer) (cinfo))  \

	    { action; }  \

	  INPUT_RELOAD(cinfo);  \

	}

/* Read a byte into variable V.

 * If must suspend, take the specified action (typically "return FALSE").

 */

#define INPUT_BYTE(cinfo,V,action)  \

	MAKESTMT( MAKE_BYTE_AVAIL(cinfo,action); \

		  bytes_in_buffer--; \

		  V = GETJOCTET(*next_input_byte++); )

/* As above, but read two bytes interpreted as an unsigned 16-bit integer.

 * V should be declared unsigned int or perhaps INT32.

 */

#define INPUT_2BYTES(cinfo,V,action)  \

	MAKESTMT( MAKE_BYTE_AVAIL(cinfo,action); \

		  bytes_in_buffer--; \

		  V = ((unsigned int) GETJOCTET(*next_input_byte++)) << 8; \

		  MAKE_BYTE_AVAIL(cinfo,action); \

		  bytes_in_buffer--; \

		  V += GETJOCTET(*next_input_byte++); )

/*

 * Routines to process JPEG markers.

 *

 * Entry condition: JPEG marker itself has been read and its code saved

 *   in cinfo->unread_marker; input restart point is just after the marker.

 *

 * Exit: if return TRUE, have read and processed any parameters, and have

 *   updated the restart point to point after the parameters.

 *   If return FALSE, was forced to suspend before reaching end of

 *   marker parameters; restart point has not been moved.  Same routine

 *   will be called again after application supplies more input data.

 *

 * This approach to suspension assumes that all of a marker's parameters

 * can fit into a single input bufferload.  This should hold for "normal"

 * markers.  Some COM/APPn markers might have large parameter segments

 * that might not fit.  If we are simply dropping such a marker, we use

 * skip_input_data to get past it, and thereby put the problem on the

 * source manager's shoulders.  If we are saving the marker's contents

 * into memory, we use a slightly different convention: when forced to

 * suspend, the marker processor updates the restart point to the end of

 * what it's consumed (ie, the end of the buffer) before returning FALSE.

 * On resumption, cinfo->unread_marker still contains the marker code,

 * but the data source will point to the next chunk of marker data.

 * The marker processor must retain internal state to deal with this.

 *

 * Note that we don't bother to avoid duplicate trace messages if a

 * suspension occurs within marker parameters.  Other side effects

 * require more care.

 */

LOCAL(boolean)

get_soi (j_decompress_ptr cinfo)

/* Process an SOI marker */

{

  int i;

  TRACEMS(cinfo, 1, JTRC_SOI);

  if (cinfo->marker->saw_SOI)

    ERREXIT(cinfo, JERR_SOI_DUPLICATE);

  /* Reset all parameters that are defined to be reset by SOI */

  for (i = 0; i < NUM_ARITH_TBLS; i++) {

    cinfo->arith_dc_L[i] = 0;

    cinfo->arith_dc_U[i] = 1;

    cinfo->arith_ac_K[i] = 5;

  }

  cinfo->restart_interval = 0;

  /* Set initial assumptions for colorspace etc */

  cinfo->jpeg_color_space = JCS_UNKNOWN;

  cinfo->CCIR601_sampling = FALSE; /* Assume non-CCIR sampling??? */

  cinfo->saw_JFIF_marker = FALSE;

  cinfo->JFIF_major_version = 1; /* set default JFIF APP0 values */

  cinfo->JFIF_minor_version = 1;

  cinfo->density_unit = 0;

  cinfo->X_density = 1;

  cinfo->Y_density = 1;

  cinfo->saw_Adobe_marker = FALSE;

  cinfo->Adobe_transform = 0;

  cinfo->marker->saw_SOI = TRUE;

  return TRUE;

}

LOCAL(boolean)

get_sof (j_decompress_ptr cinfo, boolean is_prog, boolean is_arith)

/* Process a SOFn marker */

{

  INT32 length;

  int c, ci;

  jpeg_component_info * compptr;

  INPUT_VARS(cinfo);

  cinfo->progressive_mode = is_prog;

  cinfo->arith_code = is_arith;

  INPUT_2BYTES(cinfo, length, return FALSE);

  INPUT_BYTE(cinfo, cinfo->data_precision, return FALSE);

  INPUT_2BYTES(cinfo, cinfo->image_height, return FALSE);

  INPUT_2BYTES(cinfo, cinfo->image_width, return FALSE);

  INPUT_BYTE(cinfo, cinfo->num_components, return FALSE);

  length -= 8;

  TRACEMS4(cinfo, 1, JTRC_SOF, cinfo->unread_marker,

	   (int) cinfo->image_width, (int) cinfo->image_height,

	   cinfo->num_components);

  if (cinfo->marker->saw_SOF)

    ERREXIT(cinfo, JERR_SOF_DUPLICATE);

  /* 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, JERR_EMPTY_IMAGE);

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

    ERREXIT(cinfo, JERR_BAD_LENGTH);

  if (cinfo->comp_info == NULL)	/* do only once, even if suspend */

    cinfo->comp_info = (jpeg_component_info *) (*cinfo->mem->alloc_small)

			((j_common_ptr) cinfo, JPOOL_IMAGE,

			 cinfo->num_components * SIZEOF(jpeg_component_info));

  for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;

       ci++, compptr++) {

    compptr->component_index = ci;

    INPUT_BYTE(cinfo, compptr->component_id, return FALSE);

    INPUT_BYTE(cinfo, c, return FALSE);

    compptr->h_samp_factor = (c >> 4) & 15;

    compptr->v_samp_factor = (c     ) & 15;

    INPUT_BYTE(cinfo, compptr->quant_tbl_no, return FALSE);

    TRACEMS4(cinfo, 1, JTRC_SOF_COMPONENT,

	     compptr->component_id, compptr->h_samp_factor,

	     compptr->v_samp_factor, compptr->quant_tbl_no);

  }

  cinfo->marker->saw_SOF = TRUE;

  INPUT_SYNC(cinfo);

  return TRUE;

}

LOCAL(boolean)

get_sos (j_decompress_ptr cinfo)

/* Process a SOS marker */

{

  INT32 length;

  int i, ci, n, c, cc;

  jpeg_component_info * compptr;

  INPUT_VARS(cinfo);

  if (! cinfo->marker->saw_SOF)

    ERREXIT(cinfo, JERR_SOS_NO_SOF);

  INPUT_2BYTES(cinfo, length, return FALSE);

  INPUT_BYTE(cinfo, n, return FALSE); /* Number of components */

  TRACEMS1(cinfo, 1, JTRC_SOS, n);

  if (length != (n * 2 + 6) || n < 1 || n > MAX_COMPS_IN_SCAN)

    ERREXIT(cinfo, JERR_BAD_LENGTH);

  cinfo->comps_in_scan = n;

  /* Collect the component-spec parameters */

  for (i = 0; i < n; i++) {

    INPUT_BYTE(cinfo, cc, return FALSE);

    INPUT_BYTE(cinfo, c, return FALSE);

    for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;

	 ci++, compptr++) {

      if (cc == compptr->component_id)

	goto id_found;

    }

    ERREXIT1(cinfo, JERR_BAD_COMPONENT_ID, cc);

  id_found:

    cinfo->cur_comp_info[i] = compptr;

    compptr->dc_tbl_no = (c >> 4) & 15;

    compptr->ac_tbl_no = (c     ) & 15;

    TRACEMS3(cinfo, 1, JTRC_SOS_COMPONENT, cc,

	     compptr->dc_tbl_no, compptr->ac_tbl_no);

  }

  /* Collect the additional scan parameters Ss, Se, Ah/Al. */

  INPUT_BYTE(cinfo, c, return FALSE);

  cinfo->Ss = c;

  INPUT_BYTE(cinfo, c, return FALSE);

  cinfo->Se = c;

  INPUT_BYTE(cinfo, c, return FALSE);

  cinfo->Ah = (c >> 4) & 15;

  cinfo->Al = (c     ) & 15;

  TRACEMS4(cinfo, 1, JTRC_SOS_PARAMS, cinfo->Ss, cinfo->Se,

	   cinfo->Ah, cinfo->Al);

  /* Prepare to scan data & restart markers */

  cinfo->marker->next_restart_num = 0;

  /* Count another SOS marker */

  cinfo->input_scan_number++;

  INPUT_SYNC(cinfo);

  return TRUE;

}

#ifdef D_ARITH_CODING_SUPPORTED

LOCAL(boolean)

get_dac (j_decompress_ptr cinfo)

/* Process a DAC marker */

{

  INT32 length;

  int index, val;

  INPUT_VARS(cinfo);

  INPUT_2BYTES(cinfo, length, return FALSE);

  length -= 2;

  while (length > 0) {

    INPUT_BYTE(cinfo, index, return FALSE);

    INPUT_BYTE(cinfo, val, return FALSE);

    length -= 2;

    TRACEMS2(cinfo, 1, JTRC_DAC, index, val);

    if (index < 0 || index >= (2*NUM_ARITH_TBLS))

      ERREXIT1(cinfo, JERR_DAC_INDEX, index);

    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, JERR_DAC_VALUE, val);

    }

  }

  if (length != 0)

    ERREXIT(cinfo, JERR_BAD_LENGTH);

  INPUT_SYNC(cinfo);

  return TRUE;

}

#else /* ! D_ARITH_CODING_SUPPORTED */

#define get_dac(cinfo)  skip_variable(cinfo)

#endif /* D_ARITH_CODING_SUPPORTED */

LOCAL(boolean)

get_dht (j_decompress_ptr cinfo)

/* Process a DHT marker */

{

  INT32 length;

  UINT8 bits[17];

  UINT8 huffval[256];

  int i, index, count;

  JHUFF_TBL **htblptr;

  INPUT_VARS(cinfo);

  INPUT_2BYTES(cinfo, length, return FALSE);

  length -= 2;

  while (length > 16) {

    INPUT_BYTE(cinfo, index, return FALSE);

    TRACEMS1(cinfo, 1, JTRC_DHT, index);

    bits[0] = 0;

    count = 0;

    for (i = 1; i <= 16; i++) {

      INPUT_BYTE(cinfo, bits[i], return FALSE);

      count += bits[i];

    }

    length -= 1 + 16;

    TRACEMS8(cinfo, 2, JTRC_HUFFBITS,

	     bits[1], bits[2], bits[3], bits[4],

	     bits[5], bits[6], bits[7], bits[8]);

    TRACEMS8(cinfo, 2, JTRC_HUFFBITS,

	     bits[9], bits[10], bits[11], bits[12],

	     bits[13], bits[14], bits[15], bits[16]);

    /* Here we just do minimal validation of the counts to avoid walking

     * off the end of our table space.  jdhuff.c will check more carefully.

     */

    if (count > 256 || ((INT32) count) > length)

      ERREXIT(cinfo, JERR_BAD_HUFF_TABLE);

    for (i = 0; i < count; i++)

      INPUT_BYTE(cinfo, huffval[i], return FALSE);

    length -= 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, JERR_DHT_INDEX, index);

    if (*htblptr == NULL)

      *htblptr = jpeg_alloc_huff_table((j_common_ptr) cinfo);

    MEMCOPY((*htblptr)->bits, bits, SIZEOF((*htblptr)->bits));

    MEMCOPY((*htblptr)->huffval, huffval, SIZEOF((*htblptr)->huffval));

  }

  if (length != 0)

    ERREXIT(cinfo, JERR_BAD_LENGTH);

  INPUT_SYNC(cinfo);

  return TRUE;

}

LOCAL(boolean)

get_dqt (j_decompress_ptr cinfo)

/* Process a DQT marker */

{

  INT32 length;

  int n, i, prec;

  unsigned int tmp;

  JQUANT_TBL *quant_ptr;

  INPUT_VARS(cinfo);

  INPUT_2BYTES(cinfo, length, return FALSE);

  length -= 2;

  while (length > 0) {

    INPUT_BYTE(cinfo, n, return FALSE);

    prec = n >> 4;

    n &= 0x0F;

    TRACEMS2(cinfo, 1, JTRC_DQT, n, prec);

    if (n >= NUM_QUANT_TBLS)

      ERREXIT1(cinfo, JERR_DQT_INDEX, n);

    if (cinfo->quant_tbl_ptrs[n] == NULL)

      cinfo->quant_tbl_ptrs[n] = jpeg_alloc_quant_table((j_common_ptr) cinfo);

    quant_ptr = cinfo->quant_tbl_ptrs[n];

    for (i = 0; i < DCTSIZE2; i++) {

      if (prec)

	INPUT_2BYTES(cinfo, tmp, return FALSE);

      else

	INPUT_BYTE(cinfo, tmp, return FALSE);

      /* We convert the zigzag-order table to natural array order. */

      quant_ptr->quantval[jpeg_natural_order[i]] = (UINT16) tmp;

    }

    if (cinfo->err->trace_level >= 2) {

      for (i = 0; i < DCTSIZE2; i += 8) {

	TRACEMS8(cinfo, 2, JTRC_QUANTVALS,

		 quant_ptr->quantval[i],   quant_ptr->quantval[i+1],