sl@0: /*
sl@0: * Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).
sl@0: * All rights reserved.
sl@0: * This component and the accompanying materials are made available
sl@0: * under the terms of "Eclipse Public License v1.0"
sl@0: * which accompanies this distribution, and is available
sl@0: * at the URL "http://www.eclipse.org/legal/epl-v10.html".
sl@0: *
sl@0: * Initial Contributors:
sl@0: * Nokia Corporation - initial contribution.
sl@0: *
sl@0: * Contributors:
sl@0: *
sl@0: * Description: 
sl@0: *
sl@0: */
sl@0: 
sl@0: #include <sys/stat.h>
sl@0: #include <fcntl.h>
sl@0: #include <unistd.h>
sl@0: #include <stdlib.h>
sl@0: #include <stdio.h>
sl@0: #include <string.h>
sl@0: 
sl@0: #include <liboil/liboil.h>
sl@0: #include <liboil/liboildebug.h>
sl@0: 
sl@0: #include "jpeg_huffman.h"
sl@0: #include "jpeg_debug.h"
sl@0: 
sl@0: /* misc helper function definitions */
sl@0: 
sl@0: static char *sprintbits (char *str, unsigned int bits, int n);
sl@0: 
sl@0: 
sl@0: #define TRUE 1
sl@0: #define FALSE 0
sl@0: 
sl@0: void
sl@0: huffman_table_dump (HuffmanTable * table)
sl@0: {
sl@0:   unsigned int n_bits;
sl@0:   unsigned int code;
sl@0:   char str[33];
sl@0:   int i;
sl@0:   HuffmanEntry *entry;
sl@0: 
sl@0:   OIL_DEBUG ("dumping huffman table %p", table);
sl@0:   for (i = 0; i < table->len; i++) {
sl@0:     entry = table->entries + i;
sl@0:     n_bits = entry->n_bits;
sl@0:     code = entry->symbol >> (16 - n_bits);
sl@0:     sprintbits (str, code, n_bits);
sl@0:     OIL_DEBUG ("%s --> %d", str, entry->value);
sl@0:   }
sl@0: }
sl@0: 
sl@0: 
sl@0: 
sl@0: void
sl@0: huffman_table_init (HuffmanTable *table)
sl@0: {
sl@0:   memset (table, 0, sizeof(HuffmanTable));
sl@0: }
sl@0: 
sl@0: void
sl@0: huffman_table_add (HuffmanTable * table, uint32_t code, int n_bits, int value)
sl@0: {
sl@0:   HuffmanEntry *entry = table->entries + table->len;
sl@0: 
sl@0:   entry->value = value;
sl@0:   entry->symbol = code << (16 - n_bits);
sl@0:   entry->mask = 0xffff ^ (0xffff >> n_bits);
sl@0:   entry->n_bits = n_bits;
sl@0: 
sl@0:   table->len++;
sl@0: }
sl@0: 
sl@0: unsigned int
sl@0: huffman_table_decode_jpeg (HuffmanTable * tab, JpegBits * bits)
sl@0: {
sl@0:   unsigned int code;
sl@0:   int i;
sl@0:   char str[33];
sl@0:   HuffmanEntry *entry;
sl@0: 
sl@0:   code = peekbits (bits, 16);
sl@0:   for (i = 0; i < tab->len; i++) {
sl@0:     entry = tab->entries + i;
sl@0:     if ((code & entry->mask) == entry->symbol) {
sl@0:       code = getbits (bits, entry->n_bits);
sl@0:       sprintbits (str, code, entry->n_bits);
sl@0:       OIL_DEBUG ("%s --> %d", str, entry->value);
sl@0:       return entry->value;
sl@0:     }
sl@0:   }
sl@0:   printf ("huffman sync lost");
sl@0: 
sl@0:   return -1;
sl@0: }
sl@0: 
sl@0: int
sl@0: huffman_table_decode_macroblock (short *block, HuffmanTable * dc_tab,
sl@0:     HuffmanTable * ac_tab, JpegBits * bits)
sl@0: {
sl@0:   int r, s, x, rs;
sl@0:   int k;
sl@0:   char str[33];
sl@0: 
sl@0:   memset (block, 0, sizeof (short) * 64);
sl@0: 
sl@0:   s = huffman_table_decode_jpeg (dc_tab, bits);
sl@0:   if (s < 0)
sl@0:     return -1;
sl@0:   x = getbits (bits, s);
sl@0:   if ((x >> (s - 1)) == 0) {
sl@0:     x -= (1 << s) - 1;
sl@0:   }
sl@0:   OIL_DEBUG ("s=%d (block[0]=%d)", s, x);
sl@0:   block[0] = x;
sl@0: 
sl@0:   for (k = 1; k < 64; k++) {
sl@0:     rs = huffman_table_decode_jpeg (ac_tab, bits);
sl@0:     if (rs < 0) {
sl@0:       OIL_DEBUG ("huffman error");
sl@0:       return -1;
sl@0:     }
sl@0:     if (bits->ptr > bits->end) {
sl@0:       OIL_DEBUG ("overrun");
sl@0:       return -1;
sl@0:     }
sl@0:     s = rs & 0xf;
sl@0:     r = rs >> 4;
sl@0:     if (s == 0) {
sl@0:       if (r == 15) {
sl@0:         OIL_DEBUG ("r=%d s=%d (skip 16)", r, s);
sl@0:         k += 15;
sl@0:       } else {
sl@0:         OIL_DEBUG ("r=%d s=%d (eob)", r, s);
sl@0:         break;
sl@0:       }
sl@0:     } else {
sl@0:       k += r;
sl@0:       if (k >= 64) {
sl@0:         printf ("macroblock overrun");
sl@0:         return -1;
sl@0:       }
sl@0:       x = getbits (bits, s);
sl@0:       sprintbits (str, x, s);
sl@0:       if ((x >> (s - 1)) == 0) {
sl@0:         x -= (1 << s) - 1;
sl@0:       }
sl@0:       block[k] = x;
sl@0:       OIL_DEBUG ("r=%d s=%d (%s -> block[%d]=%d)", r, s, str, k, x);
sl@0:     }
sl@0:   }
sl@0:   return 0;
sl@0: }
sl@0: 
sl@0: int
sl@0: huffman_table_decode (HuffmanTable * dc_tab, HuffmanTable * ac_tab,
sl@0:     JpegBits * bits)
sl@0: {
sl@0:   int16_t zz[64];
sl@0:   int ret;
sl@0: 
sl@0:   while (bits->ptr < bits->end) {
sl@0:     ret = huffman_table_decode_macroblock (zz, dc_tab, ac_tab, bits);
sl@0:     if (ret < 0)
sl@0:       return -1;
sl@0:   }
sl@0: 
sl@0:   return 0;
sl@0: }
sl@0: 
sl@0: /* misc helper functins */
sl@0: 
sl@0: static char *
sl@0: sprintbits (char *str, unsigned int bits, int n)
sl@0: {
sl@0:   int i;
sl@0:   int bit = 1 << (n - 1);
sl@0: 
sl@0:   for (i = 0; i < n; i++) {
sl@0:     str[i] = (bits & bit) ? '1' : '0';
sl@0:     bit >>= 1;
sl@0:   }
sl@0:   str[i] = 0;
sl@0: 
sl@0:   return str;
sl@0: }