if (++(cinfo->output_iMCU_row) < cinfo->total_iMCU_rows)    return JPEG_ROW_COMPLETED;  return JPEG_SCAN_COMPLETED;}#endif /* D_MULTISCAN_FILES_SUPPORTED */#ifdef BLOCK_SMOOTHING_SUPPORTED/* * This code applies interblock smoothing as described by section K.8 * of the JPEG standard: the first 5 AC coefficients are estimated from * the DC values of a DCT block and its 8 neighboring blocks. * We apply smoothing only for progressive JPEG decoding, and only if * the coefficients it can estimate are not yet known to full precision. *//* Natural-order array positions of the first 5 zigzag-order coefficients */#define Q01_POS  1#define Q10_POS  8#define Q20_POS  16#define Q11_POS  9#define Q02_POS  2/* * Determine whether block smoothing is applicable and safe. * We also latch the current states of the coef_bits[] entries for the * AC coefficients; otherwise, if the input side of the decompressor * advances into a new scan, we might think the coefficients are known * more accurately than they really are. */LOCAL(boolean)smoothing_ok (j_decompress_ptr cinfo){  my_coef_ptr coef = (my_coef_ptr) cinfo->coef;  boolean smoothing_useful = FALSE;  int ci, coefi;  jpeg_component_info *compptr;  JQUANT_TBL * qtable;  int * coef_bits;  int * coef_bits_latch;  if (! cinfo->progressive_mode || cinfo->coef_bits == NULL)    return FALSE;  /* Allocate latch area if not already done */  if (coef->coef_bits_latch == NULL)    coef->coef_bits_latch = (int *)      (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,				  cinfo->num_components *				  (SAVED_COEFS * SIZEOF(int)));  coef_bits_latch = coef->coef_bits_latch;  for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;       ci++, compptr++) {    /* All components' quantization values must already be latched. */    if ((qtable = compptr->quant_table) == NULL)      return FALSE;    /* Verify DC & first 5 AC quantizers are nonzero to avoid zero-divide. */    if (qtable->quantval[0] == 0 ||	qtable->quantval[Q01_POS] == 0 ||	qtable->quantval[Q10_POS] == 0 ||	qtable->quantval[Q20_POS] == 0 ||	qtable->quantval[Q11_POS] == 0 ||	qtable->quantval[Q02_POS] == 0)      return FALSE;    /* DC values must be at least partly known for all components. */    coef_bits = cinfo->coef_bits[ci];    if (coef_bits[0] < 0)      return FALSE;    /* Block smoothing is helpful if some AC coefficients remain inaccurate. */    for (coefi = 1; coefi <= 5; coefi++) {      coef_bits_latch[coefi] = coef_bits[coefi];      if (coef_bits[coefi] != 0)	smoothing_useful = TRUE;    }    coef_bits_latch += SAVED_COEFS;  }  return smoothing_useful;}/* * Variant of decompress_data for use when doing block smoothing. */METHODDEF(int)decompress_smooth_data (j_decompress_ptr cinfo, JSAMPIMAGE output_buf){  my_coef_ptr coef = (my_coef_ptr) cinfo->coef;  JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;  JDIMENSION block_num, last_block_column;  int ci, block_row, block_rows, access_rows;  JBLOCKARRAY buffer;  JBLOCKROW buffer_ptr, prev_block_row, next_block_row;  JSAMPARRAY output_ptr;  JDIMENSION output_col;  jpeg_component_info *compptr;  inverse_DCT_method_ptr inverse_DCT;  boolean first_row, last_row;  JBLOCK workspace;  int *coef_bits;  JQUANT_TBL *quanttbl;  INT32 Q00,Q01,Q02,Q10,Q11,Q20, num;  int DC1,DC2,DC3,DC4,DC5,DC6,DC7,DC8,DC9;  int Al, pred;  /* Force some input to be done if we are getting ahead of the input. */  while (cinfo->input_scan_number <= cinfo->output_scan_number &&	 ! cinfo->inputctl->eoi_reached) {    if (cinfo->input_scan_number == cinfo->output_scan_number) {      /* If input is working on current scan, we ordinarily want it to       * have completed the current row.  But if input scan is DC,       * we want it to keep one row ahead so that next block row's DC       * values are up to date.       */      JDIMENSION delta = (cinfo->Ss == 0) ? 1 : 0;      if (cinfo->input_iMCU_row > cinfo->output_iMCU_row+delta)	break;    }    if ((*cinfo->inputctl->consume_input)(cinfo) == JPEG_SUSPENDED)      return JPEG_SUSPENDED;  }  /* OK, output from the virtual arrays. */  for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;       ci++, compptr++) {    /* Don't bother to IDCT an uninteresting component. */    if (! compptr->component_needed)      continue;    /* Count non-dummy DCT block rows in this iMCU row. */    if (cinfo->output_iMCU_row < last_iMCU_row) {      block_rows = compptr->v_samp_factor;      access_rows = block_rows * 2; /* this and next iMCU row */      last_row = FALSE;    } else {      /* NB: can't use last_row_height here; it is input-side-dependent! */      block_rows = (int) (compptr->height_in_blocks % compptr->v_samp_factor);      if (block_rows == 0) block_rows = compptr->v_samp_factor;      access_rows = block_rows; /* this iMCU row only */      last_row = TRUE;    }    /* Align the virtual buffer for this component. */    if (cinfo->output_iMCU_row > 0) {      access_rows += compptr->v_samp_factor; /* prior iMCU row too */      buffer = (*cinfo->mem->access_virt_barray)	((j_common_ptr) cinfo, coef->whole_image[ci],	 (cinfo->output_iMCU_row - 1) * compptr->v_samp_factor,	 (JDIMENSION) access_rows, FALSE);      buffer += compptr->v_samp_factor;	/* point to current iMCU row */      first_row = FALSE;    } else {      buffer = (*cinfo->mem->access_virt_barray)	((j_common_ptr) cinfo, coef->whole_image[ci],	 (JDIMENSION) 0, (JDIMENSION) access_rows, FALSE);      first_row = TRUE;    }    /* Fetch component-dependent info */    coef_bits = coef->coef_bits_latch + (ci * SAVED_COEFS);    quanttbl = compptr->quant_table;    Q00 = quanttbl->quantval[0];    Q01 = quanttbl->quantval[Q01_POS];    Q10 = quanttbl->quantval[Q10_POS];    Q20 = quanttbl->quantval[Q20_POS];    Q11 = quanttbl->quantval[Q11_POS];    Q02 = quanttbl->quantval[Q02_POS];    inverse_DCT = cinfo->idct->inverse_DCT[ci];    output_ptr = output_buf[ci];    /* Loop over all DCT blocks to be processed. */    for (block_row = 0; block_row < block_rows; block_row++) {      buffer_ptr = buffer[block_row];      if (first_row && block_row == 0)	prev_block_row = buffer_ptr;      else	prev_block_row = buffer[block_row-1];      if (last_row && block_row == block_rows-1)	next_block_row = buffer_ptr;      else	next_block_row = buffer[block_row+1];      /* We fetch the surrounding DC values using a sliding-register approach.       * Initialize all nine here so as to do the right thing on narrow pics.       */      DC1 = DC2 = DC3 = (int) prev_block_row[0][0];      DC4 = DC5 = DC6 = (int) buffer_ptr[0][0];      DC7 = DC8 = DC9 = (int) next_block_row[0][0];      output_col = 0;      last_block_column = compptr->width_in_blocks - 1;      for (block_num = 0; block_num <= last_block_column; block_num++) {	/* Fetch current DCT block into workspace so we can modify it. */	jcopy_block_row(buffer_ptr, (JBLOCKROW) workspace, (JDIMENSION) 1);	/* Update DC values */	if (block_num < last_block_column) {	  DC3 = (int) prev_block_row[1][0];	  DC6 = (int) buffer_ptr[1][0];	  DC9 = (int) next_block_row[1][0];	}	/* Compute coefficient estimates per K.8.	 * An estimate is applied only if coefficient is still zero,	 * and is not known to be fully accurate.	 */	/* AC01 */	if ((Al=coef_bits[1]) != 0 && workspace[1] == 0) {	  num = 36 * Q00 * (DC4 - DC6);	  if (num >= 0) {	    pred = (int) (((Q01<<7) + num) / (Q01<<8));	    if (Al > 0 && pred >= (1<<Al))	      pred = (1<<Al)-1;	  } else {	    pred = (int) (((Q01<<7) - num) / (Q01<<8));	    if (Al > 0 && pred >= (1<<Al))	      pred = (1<<Al)-1;	    pred = -pred;	  }	  workspace[1] = (JCOEF) pred;	}	/* AC10 */	if ((Al=coef_bits[2]) != 0 && workspace[8] == 0) {	  num = 36 * Q00 * (DC2 - DC8);	  if (num >= 0) {	    pred = (int) (((Q10<<7) + num) / (Q10<<8));	    if (Al > 0 && pred >= (1<<Al))	      pred = (1<<Al)-1;	  } else {	    pred = (int) (((Q10<<7) - num) / (Q10<<8));	    if (Al > 0 && pred >= (1<<Al))	      pred = (1<<Al)-1;	    pred = -pred;	  }	  workspace[8] = (JCOEF) pred;	}	/* AC20 */	if ((Al=coef_bits[3]) != 0 && workspace[16] == 0) {	  num = 9 * Q00 * (DC2 + DC8 - 2*DC5);	  if (num >= 0) {	    pred = (int) (((Q20<<7) + num) / (Q20<<8));	    if (Al > 0 && pred >= (1<<Al))	      pred = (1<<Al)-1;	  } else {	    pred = (int) (((Q20<<7) - num) / (Q20<<8));	    if (Al > 0 && pred >= (1<<Al))	      pred = (1<<Al)-1;	    pred = -pred;	  }	  workspace[16] = (JCOEF) pred;	}	/* AC11 */	if ((Al=coef_bits[4]) != 0 && workspace[9] == 0) {	  num = 5 * Q00 * (DC1 - DC3 - DC7 + DC9);	  if (num >= 0) {	    pred = (int) (((Q11<<7) + num) / (Q11<<8));	    if (Al > 0 && pred >= (1<<Al))	      pred = (1<<Al)-1;	  } else {	    pred = (int) (((Q11<<7) - num) / (Q11<<8));	    if (Al > 0 && pred >= (1<<Al))	      pred = (1<<Al)-1;	    pred = -pred;	  }	  workspace[9] = (JCOEF) pred;	}	/* AC02 */	if ((Al=coef_bits[5]) != 0 && workspace[2] == 0) {	  num = 9 * Q00 * (DC4 + DC6 - 2*DC5);	  if (num >= 0) {	    pred = (int) (((Q02<<7) + num) / (Q02<<8));	    if (Al > 0 && pred >= (1<<Al))	      pred = (1<<Al)-1;	  } else {	    pred = (int) (((Q02<<7) - num) / (Q02<<8));	    if (Al > 0 && pred >= (1<<Al))	      pred = (1<<Al)-1;	    pred = -pred;	  }	  workspace[2] = (JCOEF) pred;	}	/* OK, do the IDCT */	(*inverse_DCT) (cinfo, compptr, (JCOEFPTR) workspace,			output_ptr, output_col);	/* Advance for next column */	DC1 = DC2; DC2 = DC3;	DC4 = DC5; DC5 = DC6;	DC7 = DC8; DC8 = DC9;	buffer_ptr++, prev_block_row++, next_block_row++;	output_col += compptr->DCT_scaled_size;      }      output_ptr += compptr->DCT_scaled_size;    }  }  if (++(cinfo->output_iMCU_row) < cinfo->total_iMCU_rows)    return JPEG_ROW_COMPLETED;  return JPEG_SCAN_COMPLETED;}#endif /* BLOCK_SMOOTHING_SUPPORTED *//* * Initialize coefficient buffer controller. */GLOBAL(void)jinit_d_coef_controller (j_decompress_ptr cinfo, boolean need_full_buffer){  my_coef_ptr coef;  coef = (my_coef_ptr)    (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,				SIZEOF(my_coef_controller));  cinfo->coef = (struct jpeg_d_coef_controller *) coef;  coef->pub.start_input_pass = start_input_pass;  coef->pub.start_output_pass = start_output_pass;#ifdef BLOCK_SMOOTHING_SUPPORTED  coef->coef_bits_latch = NULL;#endif  /* Create the coefficient buffer. */  if (need_full_buffer) {#ifdef D_MULTISCAN_FILES_SUPPORTED    /* Allocate a full-image virtual array for each component, */    /* padded to a multiple of samp_factor DCT blocks in each direction. */    /* Note we ask for a pre-zeroed array. */    int ci, access_rows;    jpeg_component_info *compptr;    for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;	 ci++, compptr++) {      access_rows = compptr->v_samp_factor;#ifdef BLOCK_SMOOTHING_SUPPORTED      /* If block smoothing could be used, need a bigger window */      if (cinfo->progressive_mode)	access_rows *= 3;#endif      coef->whole_image[ci] = (*cinfo->mem->request_virt_barray)	((j_common_ptr) cinfo, JPOOL_IMAGE, TRUE,	 (JDIMENSION) jround_up((long) compptr->width_in_blocks,				(long) compptr->h_samp_factor),	 (JDIMENSION) jround_up((long) compptr->height_in_blocks,				(long) compptr->v_samp_factor),	 (JDIMENSION) access_rows);    }    coef->pub.consume_data = consume_data;    coef->pub.decompress_data = decompress_data;    coef->pub.coef_arrays = coef->whole_image; /* link to virtual arrays */#else    ERREXIT(cinfo, JERR_NOT_COMPILED);#endif  } else {    /* We only need a single-MCU buffer. */    JBLOCKROW buffer;    int i;    buffer = (JBLOCKROW)      (*cinfo->mem->alloc_large) ((j_common_ptr) cinfo, JPOOL_IMAGE,				  D_MAX_BLOCKS_IN_MCU * SIZEOF(JBLOCK));    for (i = 0; i < D_MAX_BLOCKS_IN_MCU; i++) {      coef->MCU_buffer[i] = buffer + i;    }    coef->pub.consume_data = dummy_consume_data;    coef->pub.decompress_data = decompress_onepass;    coef->pub.coef_arrays = NULL; /* flag for no virtual arrays */  }}