X-Git-Url: https://git.creatis.insa-lyon.fr/pubgit/?a=blobdiff_plain;f=src%2Fgdcmjpeg%2Fjcdiffct.c;fp=src%2Fgdcmjpeg%2Fjcdiffct.c;h=d3953425c259f936c862c1205137d2c738d26b20;hb=e1830579102f036e9e558320a21990a9438ec9ef;hp=0000000000000000000000000000000000000000;hpb=82874940805320d00eecb834bfa8643822c49e45;p=gdcm.git

diff --git a/src/gdcmjpeg/jcdiffct.c b/src/gdcmjpeg/jcdiffct.c
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+/*
+ * jcdiffct.c
+ *
+ * Copyright (C) 1994-1998, 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 the difference buffer controller for compression.
+ * This controller is the top level of the lossless JPEG compressor proper.
+ * The difference buffer lies between prediction/differencing and entropy
+ * encoding.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+#include "jlossls.h"    /* Private declarations for lossless codec */
+
+
+#ifdef C_LOSSLESS_SUPPORTED
+
+/* We use a full-image sample buffer when doing Huffman optimization,
+ * and also for writing multiple-scan JPEG files.  In all cases, the
+ * full-image buffer is filled during the first pass, and the scaling,
+ * prediction and differencing steps are run during subsequent passes.
+ */
+#ifdef ENTROPY_OPT_SUPPORTED
+#define FULL_SAMP_BUFFER_SUPPORTED
+#else
+#ifdef C_MULTISCAN_FILES_SUPPORTED
+#define FULL_SAMP_BUFFER_SUPPORTED
+#endif
+#endif
+
+
+/* Private buffer controller object */
+
+typedef struct {
+  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 */
+
+  JSAMPROW cur_row[MAX_COMPONENTS];  /* row of point transformed samples */
+  JSAMPROW prev_row[MAX_COMPONENTS];  /* previous row of Pt'd samples */
+  JDIFFARRAY diff_buf[MAX_COMPONENTS];  /* iMCU row of differences */
+
+  /* In multi-pass modes, we need a virtual sample array for each component. */
+  jvirt_sarray_ptr whole_image[MAX_COMPONENTS];
+} c_diff_controller;
+
+typedef c_diff_controller * c_diff_ptr;
+
+
+/* Forward declarations */
+METHODDEF(boolean) compress_data
+    JPP((j_compress_ptr cinfo, JSAMPIMAGE input_buf));
+#ifdef FULL_SAMP_BUFFER_SUPPORTED
+METHODDEF(boolean) compress_first_pass
+    JPP((j_compress_ptr cinfo, JSAMPIMAGE input_buf));
+METHODDEF(boolean) compress_output
+    JPP((j_compress_ptr cinfo, JSAMPIMAGE input_buf));
+#endif
+
+
+LOCAL(void)
+start_iMCU_row (j_compress_ptr cinfo)
+/* Reset within-iMCU-row counters for a new row */
+{
+  j_lossless_c_ptr losslsc = (j_lossless_c_ptr) cinfo->codec;
+  c_diff_ptr diff = (c_diff_ptr) losslsc->diff_private;
+
+  /* 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) {
+    diff->MCU_rows_per_iMCU_row = 1;
+  } else {
+    if (diff->iMCU_row_num < (cinfo->total_iMCU_rows-1))
+      diff->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->v_samp_factor;
+    else
+      diff->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->last_row_height;
+  }
+
+  diff->mcu_ctr = 0;
+  diff->MCU_vert_offset = 0;
+}
+
+
+/*
+ * Initialize for a processing pass.
+ */
+
+METHODDEF(void)
+start_pass_diff (j_compress_ptr cinfo, J_BUF_MODE pass_mode)
+{
+  j_lossless_c_ptr losslsc = (j_lossless_c_ptr) cinfo->codec;
+  c_diff_ptr diff = (c_diff_ptr) losslsc->diff_private;
+
+  diff->iMCU_row_num = 0;
+  start_iMCU_row(cinfo);
+
+  switch (pass_mode) {
+  case JBUF_PASS_THRU:
+    if (diff->whole_image[0] != NULL)
+      ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
+    losslsc->pub.compress_data = compress_data;
+    break;
+#ifdef FULL_SAMP_BUFFER_SUPPORTED
+  case JBUF_SAVE_AND_PASS:
+    if (diff->whole_image[0] == NULL)
+      ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
+    losslsc->pub.compress_data = compress_first_pass;
+    break;
+  case JBUF_CRANK_DEST:
+    if (diff->whole_image[0] == NULL)
+      ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
+    losslsc->pub.compress_data = compress_output;
+    break;
+#endif
+  default:
+    ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
+    break;
+  }
+}
+
+
+#define SWAP_ROWS(rowa,rowb) {JSAMPROW temp; temp=rowa; rowa=rowb; rowb=temp;}
+
+/*
+ * Process some data in the single-pass case.
+ * We process the equivalent of one fully interleaved MCU row ("iMCU" row)
+ * per call, ie, v_samp_factor rows for each component in the image.
+ * Returns TRUE if the iMCU row is completed, FALSE if suspended.
+ *
+ * NB: input_buf contains a plane for each component in image,
+ * which we index according to the component's SOF position.
+ */
+
+METHODDEF(boolean)
+compress_data (j_compress_ptr cinfo, JSAMPIMAGE input_buf)
+{
+  j_lossless_c_ptr losslsc = (j_lossless_c_ptr) cinfo->codec;
+  c_diff_ptr diff = (c_diff_ptr) losslsc->diff_private;
+  JDIMENSION MCU_col_num;  /* index of current MCU within row */
+  JDIMENSION MCU_count;    /* number of MCUs encoded */
+  /* JDIMENSION last_MCU_col = cinfo->MCUs_per_row - 1; */
+  JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
+  int comp, ci, yoffset, samp_row, samp_rows, samps_across;
+  jpeg_component_info *compptr;
+
+  /* Loop to write as much as one whole iMCU row */
+  for (yoffset = diff->MCU_vert_offset; yoffset < diff->MCU_rows_per_iMCU_row;
+       yoffset++) {
+
+    MCU_col_num = diff->mcu_ctr;
+
+    /* Scale and predict each scanline of the MCU-row separately.
+     *
+     * Note: We only do this if we are at the start of a MCU-row, ie,
+     * we don't want to reprocess a row suspended by the output.
+     */
+    if (MCU_col_num == 0) {
+      for (comp = 0; comp < cinfo->comps_in_scan; comp++) {
+  compptr = cinfo->cur_comp_info[comp];
+  ci = compptr->component_index;
+  if (diff->iMCU_row_num < last_iMCU_row)
+    samp_rows = compptr->v_samp_factor;
+  else {
+    /* NB: can't use last_row_height here, since may not be set! */
+    samp_rows = (int) (compptr->height_in_data_units % compptr->v_samp_factor);
+    if (samp_rows == 0) samp_rows = compptr->v_samp_factor;
+    else {
+      /* Fill dummy difference rows at the bottom edge with zeros, which
+       * will encode to the smallest amount of data.
+       */
+      for (samp_row = samp_rows; samp_row < compptr->v_samp_factor;
+     samp_row++)
+        MEMZERO(diff->diff_buf[ci][samp_row],
+          jround_up((long) compptr->width_in_data_units,
+        (long) compptr->h_samp_factor) * SIZEOF(JDIFF));
+    }
+  }
+  samps_across = compptr->width_in_data_units;
+
+  for (samp_row = 0; samp_row < samp_rows; samp_row++) {
+    (*losslsc->scaler_scale) (cinfo,
+            input_buf[ci][samp_row],
+            diff->cur_row[ci], samps_across);
+    (*losslsc->predict_difference[ci]) (cinfo, ci,
+                diff->cur_row[ci],
+                diff->prev_row[ci],
+                diff->diff_buf[ci][samp_row],
+                samps_across);
+    SWAP_ROWS(diff->cur_row[ci], diff->prev_row[ci]);
+  }
+      }
+    }
+
+    /* Try to write the MCU-row (or remaining portion of suspended MCU-row). */
+    MCU_count =
+      (*losslsc->entropy_encode_mcus) (cinfo,
+               diff->diff_buf, yoffset, MCU_col_num,
+               cinfo->MCUs_per_row - MCU_col_num);
+    if (MCU_count != cinfo->MCUs_per_row - MCU_col_num) {
+      /* Suspension forced; update state counters and exit */
+      diff->MCU_vert_offset = yoffset;
+      diff->mcu_ctr += MCU_col_num;
+      return FALSE;
+    }
+
+    /* Completed an MCU row, but perhaps not an iMCU row */
+    diff->mcu_ctr = 0;
+  }
+
+  /* Completed the iMCU row, advance counters for next one */
+  diff->iMCU_row_num++;
+  start_iMCU_row(cinfo);
+  return TRUE;
+}
+
+
+#ifdef FULL_SAMP_BUFFER_SUPPORTED
+
+/*
+ * Process some data in the first pass of a multi-pass case.
+ * We process the equivalent of one fully interleaved MCU row ("iMCU" row)
+ * per call, ie, v_samp_factor rows for each component in the image.
+ * This amount of data is read from the source buffer and saved into the
+ * virtual arrays.
+ *
+ * We must also emit the data to the compressor.  This is conveniently
+ * done by calling compress_output() after we've loaded the current strip
+ * of the virtual arrays.
+ *
+ * NB: input_buf contains a plane for each component in image.  All components
+ * are loaded into the virtual arrays in this pass.  However, it may be that
+ * only a subset of the components are emitted to the compressor during
+ * this first pass; be careful about looking at the scan-dependent variables
+ * (MCU dimensions, etc).
+ */
+
+METHODDEF(boolean)
+compress_first_pass (j_compress_ptr cinfo, JSAMPIMAGE input_buf)
+{
+  j_lossless_c_ptr losslsc = (j_lossless_c_ptr) cinfo->codec;
+  c_diff_ptr diff = (c_diff_ptr) losslsc->diff_private;
+  JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
+  JDIMENSION samps_across;
+  int ci, samp_row, samp_rows;
+  JSAMPARRAY buffer[MAX_COMPONENTS];
+  jpeg_component_info *compptr;
+
+  for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+       ci++, compptr++) {
+    /* Align the virtual buffers for this component. */
+    buffer[ci] = (*cinfo->mem->access_virt_sarray)
+      ((j_common_ptr) cinfo, diff->whole_image[ci],
+       diff->iMCU_row_num * compptr->v_samp_factor,
+       (JDIMENSION) compptr->v_samp_factor, TRUE);
+
+    /* Count non-dummy sample rows in this iMCU row. */
+    if (diff->iMCU_row_num < last_iMCU_row)
+      samp_rows = compptr->v_samp_factor;
+    else {
+      /* NB: can't use last_row_height here, since may not be set! */
+      samp_rows = (int) (compptr->height_in_data_units % compptr->v_samp_factor);
+      if (samp_rows == 0) samp_rows = compptr->v_samp_factor;
+    }
+    samps_across = compptr->width_in_data_units;
+
+    /* Perform point transform scaling and prediction/differencing for all
+     * non-dummy rows in this iMCU row.  Each call on these functions
+     * process a complete row of samples.
+     */
+    for (samp_row = 0; samp_row < samp_rows; samp_row++) {
+      MEMCOPY(buffer[ci][samp_row], input_buf[ci][samp_row],
+        samps_across * SIZEOF(JSAMPLE));
+    }
+  }
+
+  /* NB: compress_output will increment iMCU_row_num if successful.
+   * A suspension return will result in redoing all the work above next time.
+   */
+
+  /* Emit data to the compressor, sharing code with subsequent passes */
+  return compress_output(cinfo, input_buf);
+}
+
+
+/*
+ * Process some data in subsequent passes of a multi-pass case.
+ * We process the equivalent of one fully interleaved MCU row ("iMCU" row)
+ * per call, ie, v_samp_factor rows for each component in the scan.
+ * The data is obtained from the virtual arrays and fed to the compressor.
+ * 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)
+{
+  j_lossless_c_ptr losslsc = (j_lossless_c_ptr) cinfo->codec;
+  c_diff_ptr diff = (c_diff_ptr) losslsc->diff_private;
+  /* JDIMENSION MCU_col_num; */  /* index of current MCU within row */
+  /* JDIMENSION MCU_count; */  /* number of MCUs encoded */
+  int comp, ci /* , yoffset */ ;
+  JSAMPARRAY buffer[MAX_COMPONENTS];
+  jpeg_component_info *compptr;
+  (void)input_buf;
+
+  /* Align the virtual buffers for the components used in this scan.
+   * NB: during first pass, this is safe only because the buffers will
+   * already be aligned properly, so jmemmgr.c won't need to do any I/O.
+   */
+  for (comp = 0; comp < cinfo->comps_in_scan; comp++) {
+    compptr = cinfo->cur_comp_info[comp];
+    ci = compptr->component_index;
+    buffer[ci] = (*cinfo->mem->access_virt_sarray)
+      ((j_common_ptr) cinfo, diff->whole_image[ci],
+       diff->iMCU_row_num * compptr->v_samp_factor,
+       (JDIMENSION) compptr->v_samp_factor, FALSE);
+  }
+
+  return compress_data(cinfo, buffer);
+}
+
+#endif /* FULL_SAMP_BUFFER_SUPPORTED */
+
+
+/*
+ * Initialize difference buffer controller.
+ */
+
+GLOBAL(void)
+jinit_c_diff_controller (j_compress_ptr cinfo, boolean need_full_buffer)
+{
+  j_lossless_c_ptr losslsc = (j_lossless_c_ptr) cinfo->codec;
+  c_diff_ptr diff;
+  int ci, row;
+  jpeg_component_info *compptr;
+
+  diff = (c_diff_ptr)
+    (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+        SIZEOF(c_diff_controller));
+  losslsc->diff_private = (void *) diff;
+  losslsc->diff_start_pass = start_pass_diff;
+
+  /* Create the prediction row buffers. */
+  for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+       ci++, compptr++) {
+    diff->cur_row[ci] = *(*cinfo->mem->alloc_sarray)
+      ((j_common_ptr) cinfo, JPOOL_IMAGE,
+       (JDIMENSION) jround_up((long) compptr->width_in_data_units,
+            (long) compptr->h_samp_factor),
+       (JDIMENSION) 1);
+    diff->prev_row[ci] = *(*cinfo->mem->alloc_sarray)
+      ((j_common_ptr) cinfo, JPOOL_IMAGE,
+       (JDIMENSION) jround_up((long) compptr->width_in_data_units,
+            (long) compptr->h_samp_factor),
+       (JDIMENSION) 1);
+  }
+
+  /* Create the difference buffer. */
+  for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+       ci++, compptr++) {
+    diff->diff_buf[ci] = (*cinfo->mem->alloc_darray)
+      ((j_common_ptr) cinfo, JPOOL_IMAGE,
+       (JDIMENSION) jround_up((long) compptr->width_in_data_units,
+            (long) compptr->h_samp_factor),
+       (JDIMENSION) compptr->v_samp_factor);
+    /* Prefill difference rows with zeros.  We do this because only actual
+     * data is placed in the buffers during prediction/differencing, leaving
+     * any dummy differences at the right edge as zeros, which will encode
+     * to the smallest amount of data.
+     */
+    for (row = 0; row < compptr->v_samp_factor; row++)
+      MEMZERO(diff->diff_buf[ci][row],
+        jround_up((long) compptr->width_in_data_units,
+      (long) compptr->h_samp_factor) * SIZEOF(JDIFF));
+  }
+
+  /* Create the sample buffer. */
+  if (need_full_buffer) {
+#ifdef FULL_SAMP_BUFFER_SUPPORTED
+    /* Allocate a full-image virtual array for each component, */
+    /* padded to a multiple of samp_factor differences in each direction. */
+    int ci;
+    jpeg_component_info *compptr;
+
+    for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+   ci++, compptr++) {
+      diff->whole_image[ci] = (*cinfo->mem->request_virt_sarray)
+  ((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,
+   (JDIMENSION) jround_up((long) compptr->width_in_data_units,
+        (long) compptr->h_samp_factor),
+   (JDIMENSION) jround_up((long) compptr->height_in_data_units,
+        (long) compptr->v_samp_factor),
+   (JDIMENSION) compptr->v_samp_factor);
+    }
+#else
+    ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
+#endif
+  } else
+    diff->whole_image[0] = NULL; /* flag for no virtual arrays */
+}
+
+#endif /* C_LOSSLESS_SUPPORTED */