1 files changed, 385 insertions, 382 deletions
diff --git a/plugins/AdvaImg/src/LibJPEG/jctrans.c b/plugins/AdvaImg/src/LibJPEG/jctrans.c
index f7d7b81491..9dc9e5f3a7 100644
--- a/plugins/AdvaImg/src/LibJPEG/jctrans.c
+++ b/plugins/AdvaImg/src/LibJPEG/jctrans.c
@@ -1,382 +1,385 @@
-/*
- * jctrans.c
- *
- * Copyright (C) 1995-1998, Thomas G. Lane.
- * Modified 2000-2011 by Guido Vollbeding.
- * 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 library routines for transcoding compression,
- * that is, writing raw DCT coefficient arrays to an output JPEG file.
- * The routines in jcapimin.c will also be needed by a transcoder.
- */
-
-#define JPEG_INTERNALS
-#include "jinclude.h"
-#include "jpeglib.h"
-
-
-/* Forward declarations */
-LOCAL(void) transencode_master_selection
-	JPP((j_compress_ptr cinfo, jvirt_barray_ptr * coef_arrays));
-LOCAL(void) transencode_coef_controller
-	JPP((j_compress_ptr cinfo, jvirt_barray_ptr * coef_arrays));
-
-
-/*
- * Compression initialization for writing raw-coefficient data.
- * Before calling this, all parameters and a data destination must be set up.
- * Call jpeg_finish_compress() to actually write the data.
- *
- * The number of passed virtual arrays must match cinfo->num_components.
- * Note that the virtual arrays need not be filled or even realized at
- * the time write_coefficients is called; indeed, if the virtual arrays
- * were requested from this compression object's memory manager, they
- * typically will be realized during this routine and filled afterwards.
- */
-
-GLOBAL(void)
-jpeg_write_coefficients (j_compress_ptr cinfo, jvirt_barray_ptr * coef_arrays)
-{
-  if (cinfo->global_state != CSTATE_START)
-    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
-  /* Mark all tables to be written */
-  jpeg_suppress_tables(cinfo, FALSE);
-  /* (Re)initialize error mgr and destination modules */
-  (*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo);
-  (*cinfo->dest->init_destination) (cinfo);
-  /* Perform master selection of active modules */
-  transencode_master_selection(cinfo, coef_arrays);
-  /* Wait for jpeg_finish_compress() call */
-  cinfo->next_scanline = 0;	/* so jpeg_write_marker works */
-  cinfo->global_state = CSTATE_WRCOEFS;
-}
-
-
-/*
- * Initialize the compression object with default parameters,
- * then copy from the source object all parameters needed for lossless
- * transcoding.  Parameters that can be varied without loss (such as
- * scan script and Huffman optimization) are left in their default states.
- */
-
-GLOBAL(void)
-jpeg_copy_critical_parameters (j_decompress_ptr srcinfo,
-			       j_compress_ptr dstinfo)
-{
-  JQUANT_TBL ** qtblptr;
-  jpeg_component_info *incomp, *outcomp;
-  JQUANT_TBL *c_quant, *slot_quant;
-  int tblno, ci, coefi;
-
-  /* Safety check to ensure start_compress not called yet. */
-  if (dstinfo->global_state != CSTATE_START)
-    ERREXIT1(dstinfo, JERR_BAD_STATE, dstinfo->global_state);
-  /* Copy fundamental image dimensions */
-  dstinfo->image_width = srcinfo->image_width;
-  dstinfo->image_height = srcinfo->image_height;
-  dstinfo->input_components = srcinfo->num_components;
-  dstinfo->in_color_space = srcinfo->jpeg_color_space;
-  dstinfo->jpeg_width = srcinfo->output_width;
-  dstinfo->jpeg_height = srcinfo->output_height;
-  dstinfo->min_DCT_h_scaled_size = srcinfo->min_DCT_h_scaled_size;
-  dstinfo->min_DCT_v_scaled_size = srcinfo->min_DCT_v_scaled_size;
-  /* Initialize all parameters to default values */
-  jpeg_set_defaults(dstinfo);
-  /* jpeg_set_defaults may choose wrong colorspace, eg YCbCr if input is RGB.
-   * Fix it to get the right header markers for the image colorspace.
-   */
-  jpeg_set_colorspace(dstinfo, srcinfo->jpeg_color_space);
-  dstinfo->data_precision = srcinfo->data_precision;
-  dstinfo->CCIR601_sampling = srcinfo->CCIR601_sampling;
-  /* Copy the source's quantization tables. */
-  for (tblno = 0; tblno < NUM_QUANT_TBLS; tblno++) {
-    if (srcinfo->quant_tbl_ptrs[tblno] != NULL) {
-      qtblptr = & dstinfo->quant_tbl_ptrs[tblno];
-      if (*qtblptr == NULL)
-	*qtblptr = jpeg_alloc_quant_table((j_common_ptr) dstinfo);
-      MEMCOPY((*qtblptr)->quantval,
-	      srcinfo->quant_tbl_ptrs[tblno]->quantval,
-	      SIZEOF((*qtblptr)->quantval));
-      (*qtblptr)->sent_table = FALSE;
-    }
-  }
-  /* Copy the source's per-component info.
-   * Note we assume jpeg_set_defaults has allocated the dest comp_info array.
-   */
-  dstinfo->num_components = srcinfo->num_components;
-  if (dstinfo->num_components < 1 || dstinfo->num_components > MAX_COMPONENTS)
-    ERREXIT2(dstinfo, JERR_COMPONENT_COUNT, dstinfo->num_components,
-	     MAX_COMPONENTS);
-  for (ci = 0, incomp = srcinfo->comp_info, outcomp = dstinfo->comp_info;
-       ci < dstinfo->num_components; ci++, incomp++, outcomp++) {
-    outcomp->component_id = incomp->component_id;
-    outcomp->h_samp_factor = incomp->h_samp_factor;
-    outcomp->v_samp_factor = incomp->v_samp_factor;
-    outcomp->quant_tbl_no = incomp->quant_tbl_no;
-    /* Make sure saved quantization table for component matches the qtable
-     * slot.  If not, the input file re-used this qtable slot.
-     * IJG encoder currently cannot duplicate this.
-     */
-    tblno = outcomp->quant_tbl_no;
-    if (tblno < 0 || tblno >= NUM_QUANT_TBLS ||
-	srcinfo->quant_tbl_ptrs[tblno] == NULL)
-      ERREXIT1(dstinfo, JERR_NO_QUANT_TABLE, tblno);
-    slot_quant = srcinfo->quant_tbl_ptrs[tblno];
-    c_quant = incomp->quant_table;
-    if (c_quant != NULL) {
-      for (coefi = 0; coefi < DCTSIZE2; coefi++) {
-	if (c_quant->quantval[coefi] != slot_quant->quantval[coefi])
-	  ERREXIT1(dstinfo, JERR_MISMATCHED_QUANT_TABLE, tblno);
-      }
-    }
-    /* Note: we do not copy the source's Huffman table assignments;
-     * instead we rely on jpeg_set_colorspace to have made a suitable choice.
-     */
-  }
-  /* Also copy JFIF version and resolution information, if available.
-   * Strictly speaking this isn't "critical" info, but it's nearly
-   * always appropriate to copy it if available.  In particular,
-   * if the application chooses to copy JFIF 1.02 extension markers from
-   * the source file, we need to copy the version to make sure we don't
-   * emit a file that has 1.02 extensions but a claimed version of 1.01.
-   * We will *not*, however, copy version info from mislabeled "2.01" files.
-   */
-  if (srcinfo->saw_JFIF_marker) {
-    if (srcinfo->JFIF_major_version == 1) {
-      dstinfo->JFIF_major_version = srcinfo->JFIF_major_version;
-      dstinfo->JFIF_minor_version = srcinfo->JFIF_minor_version;
-    }
-    dstinfo->density_unit = srcinfo->density_unit;
-    dstinfo->X_density = srcinfo->X_density;
-    dstinfo->Y_density = srcinfo->Y_density;
-  }
-}
-
-
-/*
- * Master selection of compression modules for transcoding.
- * This substitutes for jcinit.c's initialization of the full compressor.
- */
-
-LOCAL(void)
-transencode_master_selection (j_compress_ptr cinfo,
-			      jvirt_barray_ptr * coef_arrays)
-{
-  /* Initialize master control (includes parameter checking/processing) */
-  jinit_c_master_control(cinfo, TRUE /* transcode only */);
-
-  /* Entropy encoding: either Huffman or arithmetic coding. */
-  if (cinfo->arith_code)
-    jinit_arith_encoder(cinfo);
-  else {
-    jinit_huff_encoder(cinfo);
-  }
-
-  /* We need a special coefficient buffer controller. */
-  transencode_coef_controller(cinfo, coef_arrays);
-
-  jinit_marker_writer(cinfo);
-
-  /* We can now tell the memory manager to allocate virtual arrays. */
-  (*cinfo->mem->realize_virt_arrays) ((j_common_ptr) cinfo);
-
-  /* Write the datastream header (SOI, JFIF) immediately.
-   * Frame and scan headers are postponed till later.
-   * This lets application insert special markers after the SOI.
-   */
-  (*cinfo->marker->write_file_header) (cinfo);
-}
-
-
-/*
- * The rest of this file is a special implementation of the coefficient
- * buffer controller.  This is similar to jccoefct.c, but it handles only
- * output from presupplied virtual arrays.  Furthermore, we generate any
- * dummy padding blocks on-the-fly rather than expecting them to be present
- * in the arrays.
- */
-
-/* Private buffer controller object */
-
-typedef struct {
-  struct jpeg_c_coef_controller pub; /* public fields */
-
-  JDIMENSION iMCU_row_num;	/* iMCU row # within image */
-  JDIMENSION mcu_ctr;		/* counts MCUs processed in current row */
-  int MCU_vert_offset;		/* counts MCU rows within iMCU row */
-  int MCU_rows_per_iMCU_row;	/* number of such rows needed */
-
-  /* Virtual block array for each component. */
-  jvirt_barray_ptr * whole_image;
-
-  /* Workspace for constructing dummy blocks at right/bottom edges. */
-  JBLOCKROW dummy_buffer[C_MAX_BLOCKS_IN_MCU];
-} my_coef_controller;
-
-typedef my_coef_controller * my_coef_ptr;
-
-
-LOCAL(void)
-start_iMCU_row (j_compress_ptr cinfo)
-/* Reset within-iMCU-row counters for a new row */
-{
-  my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
-
-  /* In an interleaved scan, an MCU row is the same as an iMCU row.
-   * In a noninterleaved scan, an iMCU row has v_samp_factor MCU rows.
-   * But at the bottom of the image, process only what's left.
-   */
-  if (cinfo->comps_in_scan > 1) {
-    coef->MCU_rows_per_iMCU_row = 1;
-  } else {
-    if (coef->iMCU_row_num < (cinfo->total_iMCU_rows-1))
-      coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->v_samp_factor;
-    else
-      coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->last_row_height;
-  }
-
-  coef->mcu_ctr = 0;
-  coef->MCU_vert_offset = 0;
-}
-
-
-/*
- * Initialize for a processing pass.
- */
-
-METHODDEF(void)
-start_pass_coef (j_compress_ptr cinfo, J_BUF_MODE pass_mode)
-{
-  my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
-
-  if (pass_mode != JBUF_CRANK_DEST)
-    ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
-
-  coef->iMCU_row_num = 0;
-  start_iMCU_row(cinfo);
-}
-
-
-/*
- * Process some data.
- * We process the equivalent of one fully interleaved MCU row ("iMCU" row)
- * per call, ie, v_samp_factor block rows for each component in the scan.
- * The data is obtained from the virtual arrays and fed to the entropy coder.
- * Returns TRUE if the iMCU row is completed, FALSE if suspended.
- *
- * NB: input_buf is ignored; it is likely to be a NULL pointer.
- */
-
-METHODDEF(boolean)
-compress_output (j_compress_ptr cinfo, JSAMPIMAGE input_buf)
-{
-  my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
-  JDIMENSION MCU_col_num;	/* index of current MCU within row */
-  JDIMENSION last_MCU_col = cinfo->MCUs_per_row - 1;
-  JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
-  int blkn, ci, xindex, yindex, yoffset, blockcnt;
-  JDIMENSION start_col;
-  JBLOCKARRAY buffer[MAX_COMPS_IN_SCAN];
-  JBLOCKROW MCU_buffer[C_MAX_BLOCKS_IN_MCU];
-  JBLOCKROW buffer_ptr;
-  jpeg_component_info *compptr;
-
-  /* Align the virtual buffers for the components used in this scan. */
-  for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
-    compptr = cinfo->cur_comp_info[ci];
-    buffer[ci] = (*cinfo->mem->access_virt_barray)
-      ((j_common_ptr) cinfo, coef->whole_image[compptr->component_index],
-       coef->iMCU_row_num * compptr->v_samp_factor,
-       (JDIMENSION) compptr->v_samp_factor, FALSE);
-  }
-
-  /* Loop to process one whole iMCU row */
-  for (yoffset = coef->MCU_vert_offset; yoffset < coef->MCU_rows_per_iMCU_row;
-       yoffset++) {
-    for (MCU_col_num = coef->mcu_ctr; MCU_col_num < cinfo->MCUs_per_row;
-	 MCU_col_num++) {
-      /* Construct list of pointers to DCT blocks belonging to this MCU */
-      blkn = 0;			/* index of current DCT block within MCU */
-      for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
-	compptr = cinfo->cur_comp_info[ci];
-	start_col = MCU_col_num * compptr->MCU_width;
-	blockcnt = (MCU_col_num < last_MCU_col) ? compptr->MCU_width
-						: compptr->last_col_width;
-	for (yindex = 0; yindex < compptr->MCU_height; yindex++) {
-	  if (coef->iMCU_row_num < last_iMCU_row ||
-	      yindex+yoffset < compptr->last_row_height) {
-	    /* Fill in pointers to real blocks in this row */
-	    buffer_ptr = buffer[ci][yindex+yoffset] + start_col;
-	    for (xindex = 0; xindex < blockcnt; xindex++)
-	      MCU_buffer[blkn++] = buffer_ptr++;
-	  } else {
-	    /* At bottom of image, need a whole row of dummy blocks */
-	    xindex = 0;
-	  }
-	  /* Fill in any dummy blocks needed in this row.
-	   * Dummy blocks are filled in the same way as in jccoefct.c:
-	   * all zeroes in the AC entries, DC entries equal to previous
-	   * block's DC value.  The init routine has already zeroed the
-	   * AC entries, so we need only set the DC entries correctly.
-	   */
-	  for (; xindex < compptr->MCU_width; xindex++) {
-	    MCU_buffer[blkn] = coef->dummy_buffer[blkn];
-	    MCU_buffer[blkn][0][0] = MCU_buffer[blkn-1][0][0];
-	    blkn++;
-	  }
-	}
-      }
-      /* Try to write the MCU. */
-      if (! (*cinfo->entropy->encode_mcu) (cinfo, MCU_buffer)) {
-	/* Suspension forced; update state counters and exit */
-	coef->MCU_vert_offset = yoffset;
-	coef->mcu_ctr = MCU_col_num;
-	return FALSE;
-      }
-    }
-    /* Completed an MCU row, but perhaps not an iMCU row */
-    coef->mcu_ctr = 0;
-  }
-  /* Completed the iMCU row, advance counters for next one */
-  coef->iMCU_row_num++;
-  start_iMCU_row(cinfo);
-  return TRUE;
-}
-
-
-/*
- * Initialize coefficient buffer controller.
- *
- * Each passed coefficient array must be the right size for that
- * coefficient: width_in_blocks wide and height_in_blocks high,
- * with unitheight at least v_samp_factor.
- */
-
-LOCAL(void)
-transencode_coef_controller (j_compress_ptr cinfo,
-			     jvirt_barray_ptr * coef_arrays)
-{
-  my_coef_ptr coef;
-  JBLOCKROW buffer;
-  int i;
-
-  coef = (my_coef_ptr)
-    (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
-				SIZEOF(my_coef_controller));
-  cinfo->coef = (struct jpeg_c_coef_controller *) coef;
-  coef->pub.start_pass = start_pass_coef;
-  coef->pub.compress_data = compress_output;
-
-  /* Save pointer to virtual arrays */
-  coef->whole_image = coef_arrays;
-
-  /* Allocate and pre-zero space for dummy DCT blocks. */
-  buffer = (JBLOCKROW)
-    (*cinfo->mem->alloc_large) ((j_common_ptr) cinfo, JPOOL_IMAGE,
-				C_MAX_BLOCKS_IN_MCU * SIZEOF(JBLOCK));
-  FMEMZERO((void FAR *) buffer, C_MAX_BLOCKS_IN_MCU * SIZEOF(JBLOCK));
-  for (i = 0; i < C_MAX_BLOCKS_IN_MCU; i++) {
-    coef->dummy_buffer[i] = buffer + i;
-  }
-}
+/*
+ * jctrans.c
+ *
+ * Copyright (C) 1995-1998, Thomas G. Lane.
+ * Modified 2000-2012 by Guido Vollbeding.
+ * 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 library routines for transcoding compression,
+ * that is, writing raw DCT coefficient arrays to an output JPEG file.
+ * The routines in jcapimin.c will also be needed by a transcoder.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+
+
+/* Forward declarations */
+LOCAL(void) transencode_master_selection
+	JPP((j_compress_ptr cinfo, jvirt_barray_ptr * coef_arrays));
+LOCAL(void) transencode_coef_controller
+	JPP((j_compress_ptr cinfo, jvirt_barray_ptr * coef_arrays));
+
+
+/*
+ * Compression initialization for writing raw-coefficient data.
+ * Before calling this, all parameters and a data destination must be set up.
+ * Call jpeg_finish_compress() to actually write the data.
+ *
+ * The number of passed virtual arrays must match cinfo->num_components.
+ * Note that the virtual arrays need not be filled or even realized at
+ * the time write_coefficients is called; indeed, if the virtual arrays
+ * were requested from this compression object's memory manager, they
+ * typically will be realized during this routine and filled afterwards.
+ */
+
+GLOBAL(void)
+jpeg_write_coefficients (j_compress_ptr cinfo, jvirt_barray_ptr * coef_arrays)
+{
+  if (cinfo->global_state != CSTATE_START)
+    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
+  /* Mark all tables to be written */
+  jpeg_suppress_tables(cinfo, FALSE);
+  /* (Re)initialize error mgr and destination modules */
+  (*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo);
+  (*cinfo->dest->init_destination) (cinfo);
+  /* Perform master selection of active modules */
+  transencode_master_selection(cinfo, coef_arrays);
+  /* Wait for jpeg_finish_compress() call */
+  cinfo->next_scanline = 0;	/* so jpeg_write_marker works */
+  cinfo->global_state = CSTATE_WRCOEFS;
+}
+
+
+/*
+ * Initialize the compression object with default parameters,
+ * then copy from the source object all parameters needed for lossless
+ * transcoding.  Parameters that can be varied without loss (such as
+ * scan script and Huffman optimization) are left in their default states.
+ */
+
+GLOBAL(void)
+jpeg_copy_critical_parameters (j_decompress_ptr srcinfo,
+			       j_compress_ptr dstinfo)
+{
+  JQUANT_TBL ** qtblptr;
+  jpeg_component_info *incomp, *outcomp;
+  JQUANT_TBL *c_quant, *slot_quant;
+  int tblno, ci, coefi;
+
+  /* Safety check to ensure start_compress not called yet. */
+  if (dstinfo->global_state != CSTATE_START)
+    ERREXIT1(dstinfo, JERR_BAD_STATE, dstinfo->global_state);
+  /* Copy fundamental image dimensions */
+  dstinfo->image_width = srcinfo->image_width;
+  dstinfo->image_height = srcinfo->image_height;
+  dstinfo->input_components = srcinfo->num_components;
+  dstinfo->in_color_space = srcinfo->jpeg_color_space;
+  dstinfo->jpeg_width = srcinfo->output_width;
+  dstinfo->jpeg_height = srcinfo->output_height;
+  dstinfo->min_DCT_h_scaled_size = srcinfo->min_DCT_h_scaled_size;
+  dstinfo->min_DCT_v_scaled_size = srcinfo->min_DCT_v_scaled_size;
+  /* Initialize all parameters to default values */
+  jpeg_set_defaults(dstinfo);
+  /* jpeg_set_defaults may choose wrong colorspace, eg YCbCr if input is RGB.
+   * Fix it to get the right header markers for the image colorspace.
+   * Note: Entropy table assignment in jpeg_set_colorspace depends
+   * on color_transform.
+   */
+  dstinfo->color_transform = srcinfo->color_transform;
+  jpeg_set_colorspace(dstinfo, srcinfo->jpeg_color_space);
+  dstinfo->data_precision = srcinfo->data_precision;
+  dstinfo->CCIR601_sampling = srcinfo->CCIR601_sampling;
+  /* Copy the source's quantization tables. */
+  for (tblno = 0; tblno < NUM_QUANT_TBLS; tblno++) {
+    if (srcinfo->quant_tbl_ptrs[tblno] != NULL) {
+      qtblptr = & dstinfo->quant_tbl_ptrs[tblno];
+      if (*qtblptr == NULL)
+	*qtblptr = jpeg_alloc_quant_table((j_common_ptr) dstinfo);
+      MEMCOPY((*qtblptr)->quantval,
+	      srcinfo->quant_tbl_ptrs[tblno]->quantval,
+	      SIZEOF((*qtblptr)->quantval));
+      (*qtblptr)->sent_table = FALSE;
+    }
+  }
+  /* Copy the source's per-component info.
+   * Note we assume jpeg_set_defaults has allocated the dest comp_info array.
+   */
+  dstinfo->num_components = srcinfo->num_components;
+  if (dstinfo->num_components < 1 || dstinfo->num_components > MAX_COMPONENTS)
+    ERREXIT2(dstinfo, JERR_COMPONENT_COUNT, dstinfo->num_components,
+	     MAX_COMPONENTS);
+  for (ci = 0, incomp = srcinfo->comp_info, outcomp = dstinfo->comp_info;
+       ci < dstinfo->num_components; ci++, incomp++, outcomp++) {
+    outcomp->component_id = incomp->component_id;
+    outcomp->h_samp_factor = incomp->h_samp_factor;
+    outcomp->v_samp_factor = incomp->v_samp_factor;
+    outcomp->quant_tbl_no = incomp->quant_tbl_no;
+    /* Make sure saved quantization table for component matches the qtable
+     * slot.  If not, the input file re-used this qtable slot.
+     * IJG encoder currently cannot duplicate this.
+     */
+    tblno = outcomp->quant_tbl_no;
+    if (tblno < 0 || tblno >= NUM_QUANT_TBLS ||
+	srcinfo->quant_tbl_ptrs[tblno] == NULL)
+      ERREXIT1(dstinfo, JERR_NO_QUANT_TABLE, tblno);
+    slot_quant = srcinfo->quant_tbl_ptrs[tblno];
+    c_quant = incomp->quant_table;
+    if (c_quant != NULL) {
+      for (coefi = 0; coefi < DCTSIZE2; coefi++) {
+	if (c_quant->quantval[coefi] != slot_quant->quantval[coefi])
+	  ERREXIT1(dstinfo, JERR_MISMATCHED_QUANT_TABLE, tblno);
+      }
+    }
+    /* Note: we do not copy the source's entropy table assignments;
+     * instead we rely on jpeg_set_colorspace to have made a suitable choice.
+     */
+  }
+  /* Also copy JFIF version and resolution information, if available.
+   * Strictly speaking this isn't "critical" info, but it's nearly
+   * always appropriate to copy it if available.  In particular,
+   * if the application chooses to copy JFIF 1.02 extension markers from
+   * the source file, we need to copy the version to make sure we don't
+   * emit a file that has 1.02 extensions but a claimed version of 1.01.
+   * We will *not*, however, copy version info from mislabeled "2.01" files.
+   */
+  if (srcinfo->saw_JFIF_marker) {
+    if (srcinfo->JFIF_major_version == 1) {
+      dstinfo->JFIF_major_version = srcinfo->JFIF_major_version;
+      dstinfo->JFIF_minor_version = srcinfo->JFIF_minor_version;
+    }
+    dstinfo->density_unit = srcinfo->density_unit;
+    dstinfo->X_density = srcinfo->X_density;
+    dstinfo->Y_density = srcinfo->Y_density;
+  }
+}
+
+
+/*
+ * Master selection of compression modules for transcoding.
+ * This substitutes for jcinit.c's initialization of the full compressor.
+ */
+
+LOCAL(void)
+transencode_master_selection (j_compress_ptr cinfo,
+			      jvirt_barray_ptr * coef_arrays)
+{
+  /* Initialize master control (includes parameter checking/processing) */
+  jinit_c_master_control(cinfo, TRUE /* transcode only */);
+
+  /* Entropy encoding: either Huffman or arithmetic coding. */
+  if (cinfo->arith_code)
+    jinit_arith_encoder(cinfo);
+  else {
+    jinit_huff_encoder(cinfo);
+  }
+
+  /* We need a special coefficient buffer controller. */
+  transencode_coef_controller(cinfo, coef_arrays);
+
+  jinit_marker_writer(cinfo);
+
+  /* We can now tell the memory manager to allocate virtual arrays. */
+  (*cinfo->mem->realize_virt_arrays) ((j_common_ptr) cinfo);
+
+  /* Write the datastream header (SOI, JFIF) immediately.
+   * Frame and scan headers are postponed till later.
+   * This lets application insert special markers after the SOI.
+   */
+  (*cinfo->marker->write_file_header) (cinfo);
+}
+
+
+/*
+ * The rest of this file is a special implementation of the coefficient
+ * buffer controller.  This is similar to jccoefct.c, but it handles only
+ * output from presupplied virtual arrays.  Furthermore, we generate any
+ * dummy padding blocks on-the-fly rather than expecting them to be present
+ * in the arrays.
+ */
+
+/* Private buffer controller object */
+
+typedef struct {
+  struct jpeg_c_coef_controller pub; /* public fields */
+
+  JDIMENSION iMCU_row_num;	/* iMCU row # within image */
+  JDIMENSION mcu_ctr;		/* counts MCUs processed in current row */
+  int MCU_vert_offset;		/* counts MCU rows within iMCU row */
+  int MCU_rows_per_iMCU_row;	/* number of such rows needed */
+
+  /* Virtual block array for each component. */
+  jvirt_barray_ptr * whole_image;
+
+  /* Workspace for constructing dummy blocks at right/bottom edges. */
+  JBLOCKROW dummy_buffer[C_MAX_BLOCKS_IN_MCU];
+} my_coef_controller;
+
+typedef my_coef_controller * my_coef_ptr;
+
+
+LOCAL(void)
+start_iMCU_row (j_compress_ptr cinfo)
+/* Reset within-iMCU-row counters for a new row */
+{
+  my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
+
+  /* In an interleaved scan, an MCU row is the same as an iMCU row.
+   * In a noninterleaved scan, an iMCU row has v_samp_factor MCU rows.
+   * But at the bottom of the image, process only what's left.
+   */
+  if (cinfo->comps_in_scan > 1) {
+    coef->MCU_rows_per_iMCU_row = 1;
+  } else {
+    if (coef->iMCU_row_num < (cinfo->total_iMCU_rows-1))
+      coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->v_samp_factor;
+    else
+      coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->last_row_height;
+  }
+
+  coef->mcu_ctr = 0;
+  coef->MCU_vert_offset = 0;
+}
+
+
+/*
+ * Initialize for a processing pass.
+ */
+
+METHODDEF(void)
+start_pass_coef (j_compress_ptr cinfo, J_BUF_MODE pass_mode)
+{
+  my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
+
+  if (pass_mode != JBUF_CRANK_DEST)
+    ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
+
+  coef->iMCU_row_num = 0;
+  start_iMCU_row(cinfo);
+}
+
+
+/*
+ * Process some data.
+ * We process the equivalent of one fully interleaved MCU row ("iMCU" row)
+ * per call, ie, v_samp_factor block rows for each component in the scan.
+ * The data is obtained from the virtual arrays and fed to the entropy coder.
+ * Returns TRUE if the iMCU row is completed, FALSE if suspended.
+ *
+ * NB: input_buf is ignored; it is likely to be a NULL pointer.
+ */
+
+METHODDEF(boolean)
+compress_output (j_compress_ptr cinfo, JSAMPIMAGE input_buf)
+{
+  my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
+  JDIMENSION MCU_col_num;	/* index of current MCU within row */
+  JDIMENSION last_MCU_col = cinfo->MCUs_per_row - 1;
+  JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
+  int blkn, ci, xindex, yindex, yoffset, blockcnt;
+  JDIMENSION start_col;
+  JBLOCKARRAY buffer[MAX_COMPS_IN_SCAN];
+  JBLOCKROW MCU_buffer[C_MAX_BLOCKS_IN_MCU];
+  JBLOCKROW buffer_ptr;
+  jpeg_component_info *compptr;
+
+  /* Align the virtual buffers for the components used in this scan. */
+  for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
+    compptr = cinfo->cur_comp_info[ci];
+    buffer[ci] = (*cinfo->mem->access_virt_barray)
+      ((j_common_ptr) cinfo, coef->whole_image[compptr->component_index],
+       coef->iMCU_row_num * compptr->v_samp_factor,
+       (JDIMENSION) compptr->v_samp_factor, FALSE);
+  }
+
+  /* Loop to process one whole iMCU row */
+  for (yoffset = coef->MCU_vert_offset; yoffset < coef->MCU_rows_per_iMCU_row;
+       yoffset++) {
+    for (MCU_col_num = coef->mcu_ctr; MCU_col_num < cinfo->MCUs_per_row;
+	 MCU_col_num++) {
+      /* Construct list of pointers to DCT blocks belonging to this MCU */
+      blkn = 0;			/* index of current DCT block within MCU */
+      for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
+	compptr = cinfo->cur_comp_info[ci];
+	start_col = MCU_col_num * compptr->MCU_width;
+	blockcnt = (MCU_col_num < last_MCU_col) ? compptr->MCU_width
+						: compptr->last_col_width;
+	for (yindex = 0; yindex < compptr->MCU_height; yindex++) {
+	  if (coef->iMCU_row_num < last_iMCU_row ||
+	      yindex+yoffset < compptr->last_row_height) {
+	    /* Fill in pointers to real blocks in this row */
+	    buffer_ptr = buffer[ci][yindex+yoffset] + start_col;
+	    for (xindex = 0; xindex < blockcnt; xindex++)
+	      MCU_buffer[blkn++] = buffer_ptr++;
+	  } else {
+	    /* At bottom of image, need a whole row of dummy blocks */
+	    xindex = 0;
+	  }
+	  /* Fill in any dummy blocks needed in this row.
+	   * Dummy blocks are filled in the same way as in jccoefct.c:
+	   * all zeroes in the AC entries, DC entries equal to previous
+	   * block's DC value.  The init routine has already zeroed the
+	   * AC entries, so we need only set the DC entries correctly.
+	   */
+	  for (; xindex < compptr->MCU_width; xindex++) {
+	    MCU_buffer[blkn] = coef->dummy_buffer[blkn];
+	    MCU_buffer[blkn][0][0] = MCU_buffer[blkn-1][0][0];
+	    blkn++;
+	  }
+	}
+      }
+      /* Try to write the MCU. */
+      if (! (*cinfo->entropy->encode_mcu) (cinfo, MCU_buffer)) {
+	/* Suspension forced; update state counters and exit */
+	coef->MCU_vert_offset = yoffset;
+	coef->mcu_ctr = MCU_col_num;
+	return FALSE;
+      }
+    }
+    /* Completed an MCU row, but perhaps not an iMCU row */
+    coef->mcu_ctr = 0;
+  }
+  /* Completed the iMCU row, advance counters for next one */
+  coef->iMCU_row_num++;
+  start_iMCU_row(cinfo);
+  return TRUE;
+}
+
+
+/*
+ * Initialize coefficient buffer controller.
+ *
+ * Each passed coefficient array must be the right size for that
+ * coefficient: width_in_blocks wide and height_in_blocks high,
+ * with unitheight at least v_samp_factor.
+ */
+
+LOCAL(void)
+transencode_coef_controller (j_compress_ptr cinfo,
+			     jvirt_barray_ptr * coef_arrays)
+{
+  my_coef_ptr coef;
+  JBLOCKROW buffer;
+  int i;
+
+  coef = (my_coef_ptr)
+    (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+				SIZEOF(my_coef_controller));
+  cinfo->coef = &coef->pub;
+  coef->pub.start_pass = start_pass_coef;
+  coef->pub.compress_data = compress_output;
+
+  /* Save pointer to virtual arrays */
+  coef->whole_image = coef_arrays;
+
+  /* Allocate and pre-zero space for dummy DCT blocks. */
+  buffer = (JBLOCKROW)
+    (*cinfo->mem->alloc_large) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+				C_MAX_BLOCKS_IN_MCU * SIZEOF(JBLOCK));
+  FMEMZERO((void FAR *) buffer, C_MAX_BLOCKS_IN_MCU * SIZEOF(JBLOCK));
+  for (i = 0; i < C_MAX_BLOCKS_IN_MCU; i++) {
+    coef->dummy_buffer[i] = buffer + i;
+  }
+}