IJG's JPEG software v6b with lossless JPEG support

Patch obtained from:
https://sourceforge.net/projects/jpeg/files/ftp.oceana.com

Author date taken from original announcement and timestamp of patch
tarball:
https://groups.google.com/g/comp.protocols.dicom/c/rrkP8BxoMRk/m/Ij4dfprggp8J

jclossls.c

@@ -0,0 +1,78 @@
+/*
+ * jclossls.c
+ *
+ * Copyright (C) 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 control logic for the lossless JPEG compressor.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+#include "jlossls.h"
+
+
+#ifdef C_LOSSLESS_SUPPORTED
+
+/*
+ * Initialize for a processing pass.
+ */
+
+METHODDEF(void)
+start_pass (j_compress_ptr cinfo, J_BUF_MODE pass_mode)
+{
+  j_lossless_c_ptr losslsc = (j_lossless_c_ptr) cinfo->codec;
+
+  (*losslsc->scaler_start_pass) (cinfo);
+  (*losslsc->predict_start_pass) (cinfo);
+  (*losslsc->diff_start_pass) (cinfo, pass_mode);
+}
+
+
+/*
+ * Initialize the lossless compression codec.
+ * This is called only once, during master selection.
+ */
+
+GLOBAL(void) 
+jinit_lossless_c_codec(j_compress_ptr cinfo)
+{
+  j_lossless_c_ptr losslsc;
+
+  /* Create subobject in permanent pool */
+  losslsc = (j_lossless_c_ptr)
+    (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
+				SIZEOF(jpeg_lossless_c_codec));
+  cinfo->codec = (struct jpeg_c_codec *) losslsc;
+
+  /* Initialize sub-modules */
+
+  /* Scaler */
+  jinit_c_scaler(cinfo);
+
+  /* Differencer */
+  jinit_differencer(cinfo);
+
+  /* Entropy encoding: either Huffman or arithmetic coding. */
+  if (cinfo->arith_code) {
+    ERREXIT(cinfo, JERR_ARITH_NOTIMPL);
+  } else {
+    jinit_lhuff_encoder(cinfo);
+  }
+
+  /* Need a full-image difference buffer in any multi-pass mode. */
+  jinit_c_diff_controller(cinfo,
+			  (boolean) (cinfo->num_scans > 1 ||
+				     cinfo->optimize_coding));
+
+  /* Initialize method pointers.
+   *
+   * Note: entropy_start_pass and entropy_finish_pass are assigned in
+   * jclhuff.c and compress_data is assigned in jcdiffct.c.
+   */
+  losslsc->pub.start_pass = start_pass;
+}
+
+#endif /* C_LOSSLESS_SUPPORTED */