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-rw-r--r--media/libjpeg/jcmainct.c162
1 files changed, 162 insertions, 0 deletions
diff --git a/media/libjpeg/jcmainct.c b/media/libjpeg/jcmainct.c
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+/*
+ * jcmainct.c
+ *
+ * This file was part of the Independent JPEG Group's software:
+ * Copyright (C) 1994-1996, Thomas G. Lane.
+ * It was modified by The libjpeg-turbo Project to include only code relevant
+ * to libjpeg-turbo.
+ * For conditions of distribution and use, see the accompanying README.ijg
+ * file.
+ *
+ * This file contains the main buffer controller for compression.
+ * The main buffer lies between the pre-processor and the JPEG
+ * compressor proper; it holds downsampled data in the JPEG colorspace.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+
+
+/* Private buffer controller object */
+
+typedef struct {
+ struct jpeg_c_main_controller pub; /* public fields */
+
+ JDIMENSION cur_iMCU_row; /* number of current iMCU row */
+ JDIMENSION rowgroup_ctr; /* counts row groups received in iMCU row */
+ boolean suspended; /* remember if we suspended output */
+ J_BUF_MODE pass_mode; /* current operating mode */
+
+ /* If using just a strip buffer, this points to the entire set of buffers
+ * (we allocate one for each component). In the full-image case, this
+ * points to the currently accessible strips of the virtual arrays.
+ */
+ JSAMPARRAY buffer[MAX_COMPONENTS];
+} my_main_controller;
+
+typedef my_main_controller *my_main_ptr;
+
+
+/* Forward declarations */
+METHODDEF(void) process_data_simple_main(j_compress_ptr cinfo,
+ JSAMPARRAY input_buf,
+ JDIMENSION *in_row_ctr,
+ JDIMENSION in_rows_avail);
+
+
+/*
+ * Initialize for a processing pass.
+ */
+
+METHODDEF(void)
+start_pass_main(j_compress_ptr cinfo, J_BUF_MODE pass_mode)
+{
+ my_main_ptr main_ptr = (my_main_ptr)cinfo->main;
+
+ /* Do nothing in raw-data mode. */
+ if (cinfo->raw_data_in)
+ return;
+
+ if (pass_mode != JBUF_PASS_THRU)
+ ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
+
+ main_ptr->cur_iMCU_row = 0; /* initialize counters */
+ main_ptr->rowgroup_ctr = 0;
+ main_ptr->suspended = FALSE;
+ main_ptr->pass_mode = pass_mode; /* save mode for use by process_data */
+ main_ptr->pub.process_data = process_data_simple_main;
+}
+
+
+/*
+ * Process some data.
+ * This routine handles the simple pass-through mode,
+ * where we have only a strip buffer.
+ */
+
+METHODDEF(void)
+process_data_simple_main(j_compress_ptr cinfo, JSAMPARRAY input_buf,
+ JDIMENSION *in_row_ctr, JDIMENSION in_rows_avail)
+{
+ my_main_ptr main_ptr = (my_main_ptr)cinfo->main;
+
+ while (main_ptr->cur_iMCU_row < cinfo->total_iMCU_rows) {
+ /* Read input data if we haven't filled the main buffer yet */
+ if (main_ptr->rowgroup_ctr < DCTSIZE)
+ (*cinfo->prep->pre_process_data) (cinfo, input_buf, in_row_ctr,
+ in_rows_avail, main_ptr->buffer,
+ &main_ptr->rowgroup_ctr,
+ (JDIMENSION)DCTSIZE);
+
+ /* If we don't have a full iMCU row buffered, return to application for
+ * more data. Note that preprocessor will always pad to fill the iMCU row
+ * at the bottom of the image.
+ */
+ if (main_ptr->rowgroup_ctr != DCTSIZE)
+ return;
+
+ /* Send the completed row to the compressor */
+ if (!(*cinfo->coef->compress_data) (cinfo, main_ptr->buffer)) {
+ /* If compressor did not consume the whole row, then we must need to
+ * suspend processing and return to the application. In this situation
+ * we pretend we didn't yet consume the last input row; otherwise, if
+ * it happened to be the last row of the image, the application would
+ * think we were done.
+ */
+ if (!main_ptr->suspended) {
+ (*in_row_ctr)--;
+ main_ptr->suspended = TRUE;
+ }
+ return;
+ }
+ /* We did finish the row. Undo our little suspension hack if a previous
+ * call suspended; then mark the main buffer empty.
+ */
+ if (main_ptr->suspended) {
+ (*in_row_ctr)++;
+ main_ptr->suspended = FALSE;
+ }
+ main_ptr->rowgroup_ctr = 0;
+ main_ptr->cur_iMCU_row++;
+ }
+}
+
+
+/*
+ * Initialize main buffer controller.
+ */
+
+GLOBAL(void)
+jinit_c_main_controller(j_compress_ptr cinfo, boolean need_full_buffer)
+{
+ my_main_ptr main_ptr;
+ int ci;
+ jpeg_component_info *compptr;
+
+ main_ptr = (my_main_ptr)
+ (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
+ sizeof(my_main_controller));
+ cinfo->main = (struct jpeg_c_main_controller *)main_ptr;
+ main_ptr->pub.start_pass = start_pass_main;
+
+ /* We don't need to create a buffer in raw-data mode. */
+ if (cinfo->raw_data_in)
+ return;
+
+ /* Create the buffer. It holds downsampled data, so each component
+ * may be of a different size.
+ */
+ if (need_full_buffer) {
+ ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
+ } else {
+ /* Allocate a strip buffer for each component */
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ main_ptr->buffer[ci] = (*cinfo->mem->alloc_sarray)
+ ((j_common_ptr)cinfo, JPOOL_IMAGE,
+ compptr->width_in_blocks * DCTSIZE,
+ (JDIMENSION)(compptr->v_samp_factor * DCTSIZE));
+ }
+ }
+}