summaryrefslogtreecommitdiffstats
path: root/src/3rdparty/libjpeg/src/jcdiffct.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/3rdparty/libjpeg/src/jcdiffct.c')
-rw-r--r--src/3rdparty/libjpeg/src/jcdiffct.c411
1 files changed, 411 insertions, 0 deletions
diff --git a/src/3rdparty/libjpeg/src/jcdiffct.c b/src/3rdparty/libjpeg/src/jcdiffct.c
new file mode 100644
index 0000000000..0bae068919
--- /dev/null
+++ b/src/3rdparty/libjpeg/src/jcdiffct.c
@@ -0,0 +1,411 @@
+/*
+ * jcdiffct.c
+ *
+ * This file was part of the Independent JPEG Group's software:
+ * Copyright (C) 1994-1997, Thomas G. Lane.
+ * Lossless JPEG Modifications:
+ * Copyright (C) 1999, Ken Murchison.
+ * libjpeg-turbo Modifications:
+ * Copyright (C) 2022, D. R. Commander.
+ * For conditions of distribution and use, see the accompanying README.ijg
+ * 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 the prediction/differencing and entropy
+ * encoding steps.
+ */
+
+#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 {
+ 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 */
+
+ _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];
+} my_diff_controller;
+
+typedef my_diff_controller *my_diff_ptr;
+
+
+/* Forward declarations */
+METHODDEF(boolean) compress_data(j_compress_ptr cinfo, _JSAMPIMAGE input_buf);
+#ifdef FULL_SAMP_BUFFER_SUPPORTED
+METHODDEF(boolean) compress_first_pass(j_compress_ptr cinfo,
+ _JSAMPIMAGE input_buf);
+METHODDEF(boolean) compress_output(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 */
+{
+ my_diff_ptr diff = (my_diff_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) {
+ 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)
+{
+ my_diff_ptr diff = (my_diff_ptr)cinfo->coef;
+
+ /* Because it is hitching a ride on the jpeg_forward_dct struct,
+ * start_pass_lossless() will be called at the start of the initial pass.
+ * This ensures that it will be called at the start of the Huffman
+ * optimization and output passes as well.
+ */
+ if (pass_mode == JBUF_CRANK_DEST)
+ (*cinfo->fdct->start_pass) (cinfo);
+
+ 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);
+ diff->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);
+ diff->pub._compress_data = compress_first_pass;
+ break;
+ case JBUF_CRANK_DEST:
+ if (diff->whole_image[0] == NULL)
+ ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
+ diff->pub._compress_data = compress_output;
+ break;
+#endif
+ default:
+ ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
+ break;
+ }
+}
+
+
+#define SWAP_ROWS(rowa, rowb) { \
+ _JSAMPROW 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)
+{
+ my_diff_ptr diff = (my_diff_ptr)cinfo->coef;
+ lossless_comp_ptr losslessc = (lossless_comp_ptr)cinfo->fdct;
+ JDIMENSION MCU_col_num; /* index of current MCU within row */
+ JDIMENSION MCU_count; /* number of MCUs encoded */
+ JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
+ int ci, compi, 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 an MCU row, ie,
+ * we don't want to reprocess a row suspended by the output.
+ */
+ if (MCU_col_num == 0) {
+ for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
+ compptr = cinfo->cur_comp_info[ci];
+ compi = 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_blocks % 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++)
+ memset(diff->diff_buf[compi][samp_row], 0,
+ jround_up((long)compptr->width_in_blocks,
+ (long)compptr->h_samp_factor) * sizeof(JDIFF));
+ }
+ }
+ samps_across = compptr->width_in_blocks;
+
+ for (samp_row = 0; samp_row < samp_rows; samp_row++) {
+ (*losslessc->scaler_scale) (cinfo,
+ input_buf[compi][samp_row],
+ diff->cur_row[compi],
+ samps_across);
+ (*losslessc->predict_difference[compi])
+ (cinfo, compi, diff->cur_row[compi], diff->prev_row[compi],
+ diff->diff_buf[compi][samp_row], samps_across);
+ SWAP_ROWS(diff->cur_row[compi], diff->prev_row[compi]);
+ }
+ }
+ }
+ /* Try to write the MCU row (or remaining portion of suspended MCU row). */
+ MCU_count =
+ (*cinfo->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)
+{
+ my_diff_ptr diff = (my_diff_ptr)cinfo->coef;
+ JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
+ JDIMENSION samps_across;
+ int ci, samp_row, samp_rows;
+ _JSAMPARRAY buffer;
+ jpeg_component_info *compptr;
+
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ /* Align the virtual buffer for this component. */
+ buffer = (_JSAMPARRAY)(*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_blocks % compptr->v_samp_factor);
+ if (samp_rows == 0) samp_rows = compptr->v_samp_factor;
+ }
+ samps_across = compptr->width_in_blocks;
+
+ /* Perform point transform scaling and prediction/differencing for all
+ * non-dummy rows in this iMCU row. Each call on these functions
+ * processes a complete row of samples.
+ */
+ for (samp_row = 0; samp_row < samp_rows; samp_row++) {
+ memcpy(buffer[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)
+{
+ my_diff_ptr diff = (my_diff_ptr)cinfo->coef;
+ int ci, compi;
+ _JSAMPARRAY buffer[MAX_COMPS_IN_SCAN];
+ jpeg_component_info *compptr;
+
+ /* 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 (ci = 0; ci < cinfo->comps_in_scan; ci++) {
+ compptr = cinfo->cur_comp_info[ci];
+ compi = compptr->component_index;
+ buffer[compi] = (_JSAMPARRAY)(*cinfo->mem->access_virt_sarray)
+ ((j_common_ptr)cinfo, diff->whole_image[compi],
+ 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)
+{
+ my_diff_ptr diff;
+ int ci, row;
+ jpeg_component_info *compptr;
+
+ diff = (my_diff_ptr)
+ (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
+ sizeof(my_diff_controller));
+ cinfo->coef = (struct jpeg_c_coef_controller *)diff;
+ diff->pub.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] = *(_JSAMPARRAY)(*cinfo->mem->alloc_sarray)
+ ((j_common_ptr)cinfo, JPOOL_IMAGE,
+ (JDIMENSION)jround_up((long)compptr->width_in_blocks,
+ (long)compptr->h_samp_factor),
+ (JDIMENSION)1);
+ diff->prev_row[ci] = *(_JSAMPARRAY)(*cinfo->mem->alloc_sarray)
+ ((j_common_ptr)cinfo, JPOOL_IMAGE,
+ (JDIMENSION)jround_up((long)compptr->width_in_blocks,
+ (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] =
+ ALLOC_DARRAY(JPOOL_IMAGE,
+ (JDIMENSION)jround_up((long)compptr->width_in_blocks,
+ (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++)
+ memset(diff->diff_buf[ci][row], 0,
+ jround_up((long)compptr->width_in_blocks,
+ (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. */
+ 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_blocks,
+ (long)compptr->h_samp_factor),
+ (JDIMENSION)jround_up((long)compptr->height_in_blocks,
+ (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 */