From 412e0da9ab53163072fdf88919d650e42767cd65 Mon Sep 17 00:00:00 2001
From: Oliver Schinagl <oliver@schinagl.nl>
Date: Wed, 18 May 2005 22:36:07 +0000
Subject: added init stuff, more research needed on what we need.

---
 src/c_huffman.c | 64 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 64 insertions(+)

diff --git a/src/c_huffman.c b/src/c_huffman.c
index acfcc92..22dda6e 100644
--- a/src/c_huffman.c
+++ b/src/c_huffman.c
@@ -20,6 +20,29 @@ typedef struct {
   int last_dc_val[MAX_COMPS_IN_SCAN]; /* last DC coef for each component */
 } savable_state;
 
+
+typedef struct {
+  struct jpeg_entropy_encoder pub; /* public fields */
+
+  savable_state saved;		/* Bit buffer & DC state at start of MCU */
+
+  /* These fields are NOT loaded into local working state. */
+  unsigned int restarts_to_go;	/* MCUs left in this restart interval */
+  int next_restart_num;		/* next restart number to write (0-7) */
+
+  /* Pointers to derived tables (these workspaces have image lifespan) */
+  c_derived_tbl * dc_derived_tbls[NUM_HUFF_TBLS];
+  c_derived_tbl * ac_derived_tbls[NUM_HUFF_TBLS];
+
+#ifdef ENTROPY_OPT_SUPPORTED	/* Statistics tables for optimization */
+  long * dc_count_ptrs[NUM_HUFF_TBLS];
+  long * ac_count_ptrs[NUM_HUFF_TBLS];
+#endif
+} huff_entropy_encoder;
+
+typedef huff_entropy_encoder * huff_entropy_ptr;
+
+
 /* Working state while writing an MCU.
  * This struct contains all the fields that are needed by subroutines.
  */
@@ -101,6 +124,25 @@ inline static boolean emit_bits(working_state * state, unsigned int code, int si
 	return TRUE;
 }
 
+/*
+ * Initialize for a Huffman-compressed scan.
+ */
+
+void start_pass_huff (j_compress_ptr cinfo) {
+  huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
+
+  entropy->pub.encode_mcu = encode_mcu_huff;
+  entropy->pub.finish_pass = finish_pass_huff;
+
+  /* Initialize bit buffer to empty */
+  entropy->saved.put_buffer = 0;
+  entropy->saved.put_bits = 0;
+
+  /* Initialize restart stuff */
+  entropy->restarts_to_go = cinfo->restart_interval;
+  entropy->next_restart_num = 0;
+}
+
 
 int encode_one_block(working_state *state, JCOEFPTR block, int last_dc_val, c_derived_tbl *dctbl, c_derived_tbl *actbl) {
 	register int temp, temp2;
@@ -205,3 +247,25 @@ int encode_one_block(working_state *state, JCOEFPTR block, int last_dc_val, c_de
 	}
 	return TRUE;
 }
+
+/*
+ * Module initialization routine for Huffman entropy encoding.
+ */
+
+void jinit_huff_encoder(j_compress_ptr cinfo) {
+  huff_entropy_ptr entropy;
+  int i;
+
+  entropy = (huff_entropy_ptr) malloc((size_t) sizeof(huff_entropy_encoder));
+
+  cinfo->entropy = (struct jpeg_entropy_encoder *) entropy;
+  entropy->pub.start_pass = start_pass_huff;
+
+  /* Mark tables unallocated */
+  for (i = 0; i < NUM_HUFF_TBLS; i++) {
+    entropy->dc_derived_tbls[i] = entropy->ac_derived_tbls[i] = NULL;
+#ifdef ENTROPY_OPT_SUPPORTED
+    entropy->dc_count_ptrs[i] = entropy->ac_count_ptrs[i] = NULL;
+#endif
+  }
+}
-- 
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