2 ** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding
3 ** Copyright (C) 2003-2005 M. Bakker, Nero AG, http://www.nero.com
5 ** This program is free software; you can redistribute it and/or modify
6 ** it under the terms of the GNU General Public License as published by
7 ** the Free Software Foundation; either version 2 of the License, or
8 ** (at your option) any later version.
10 ** This program is distributed in the hope that it will be useful,
11 ** but WITHOUT ANY WARRANTY; without even the implied warranty of
12 ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 ** GNU General Public License for more details.
15 ** You should have received a copy of the GNU General Public License
16 ** along with this program; if not, write to the Free Software
17 ** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19 ** Any non-GPL usage of this software or parts of this software is strictly
22 ** The "appropriate copyright message" mentioned in section 2c of the GPLv2
23 ** must read: "Code from FAAD2 is copyright (c) Nero AG, www.nero.com"
25 ** Commercial non-GPL licensing of this software is possible.
26 ** For more info contact Nero AG through Mpeg4AAClicense@nero.com.
28 ** $Id: bits.c,v 1.44 2007/11/01 12:33:29 menno Exp $
37 /* initialize buffer, call once before first getbits or showbits */
38 void faad_initbits(bitfile *ld, const void *_buffer, const uint32_t buffer_size)
46 //memset(ld, 0, sizeof(bitfile));
48 if (buffer_size == 0 || _buffer == NULL)
56 ld->buffer_size = buffer_size;
57 ld->bytes_left = buffer_size;
59 if (ld->bytes_left >= 4)
61 tmp = getdword((uint32_t*)ld->buffer);
64 tmp = getdword_n((uint32_t*)ld->buffer, ld->bytes_left);
69 if (ld->bytes_left >= 4)
71 tmp = getdword((uint32_t*)ld->buffer + 1);
74 tmp = getdword_n((uint32_t*)ld->buffer + 1, ld->bytes_left);
79 ld->start = (uint32_t*)ld->buffer;
80 ld->tail = ((uint32_t*)ld->buffer + 2);
87 void faad_endbits(bitfile *ld)
92 uint32_t faad_get_processed_bits(bitfile *ld)
94 return (uint32_t)(8 * (4*(ld->tail - ld->start) - 4) - (ld->bits_left));
97 uint8_t faad_byte_align(bitfile *ld)
99 int remainder = (32 - ld->bits_left) & 0x7;
103 faad_flushbits(ld, 8 - remainder);
104 return (uint8_t)(8 - remainder);
109 void faad_flushbits_ex(bitfile *ld, uint32_t bits)
114 if (ld->bytes_left >= 4)
116 tmp = getdword(ld->tail);
119 tmp = getdword_n(ld->tail, ld->bytes_left);
124 ld->bits_left += (32 - bits);
125 //ld->bytes_left -= 4;
126 // if (ld->bytes_left == 0)
127 // ld->no_more_reading = 1;
128 // if (ld->bytes_left < 0)
132 /* rewind to beginning */
133 void faad_rewindbits(bitfile *ld)
137 ld->bytes_left = ld->buffer_size;
139 if (ld->bytes_left >= 4)
141 tmp = getdword((uint32_t*)&ld->start[0]);
144 tmp = getdword_n((uint32_t*)&ld->start[0], ld->bytes_left);
149 if (ld->bytes_left >= 4)
151 tmp = getdword((uint32_t*)&ld->start[1]);
154 tmp = getdword_n((uint32_t*)&ld->start[1], ld->bytes_left);
160 ld->tail = &ld->start[2];
163 /* reset to a certain point */
164 void faad_resetbits(bitfile *ld, int bits)
167 int words = bits >> 5;
168 int remainder = bits & 0x1F;
170 ld->bytes_left = ld->buffer_size - words*4;
172 if (ld->bytes_left >= 4)
174 tmp = getdword(&ld->start[words]);
177 tmp = getdword_n(&ld->start[words], ld->bytes_left);
182 if (ld->bytes_left >= 4)
184 tmp = getdword(&ld->start[words+1]);
187 tmp = getdword_n(&ld->start[words+1], ld->bytes_left);
192 ld->bits_left = 32 - remainder;
193 ld->tail = &ld->start[words+2];
195 /* recheck for reading too many bytes */
197 // if (ld->bytes_left == 0)
198 // ld->no_more_reading = 1;
199 // if (ld->bytes_left < 0)
203 uint8_t *faad_getbitbuffer(bitfile *ld, uint32_t bits
208 int bytes = bits >> 3;
209 int remainder = bits & 0x7;
211 uint8_t *buffer = (uint8_t*)faad_malloc((bytes+1)*sizeof(uint8_t));
213 for (i = 0; i < bytes; i++)
215 buffer[i] = (uint8_t)faad_getbits(ld, 8 DEBUGVAR(print,var,dbg));
220 temp = faad_getbits(ld, remainder DEBUGVAR(print,var,dbg)) << (8-remainder);
222 buffer[bytes] = (uint8_t)temp;
229 /* return the original data buffer */
230 void *faad_origbitbuffer(bitfile *ld)
232 return (void*)ld->start;
235 /* return the original data buffer size */
236 uint32_t faad_origbitbuffer_size(bitfile *ld)
238 return ld->buffer_size;
242 /* reversed bit reading routines, used for RVLC and HCR */
243 void faad_initbits_rev(bitfile *ld, void *buffer,
244 uint32_t bits_in_buffer)
249 ld->buffer_size = bit2byte(bits_in_buffer);
251 index = (bits_in_buffer+31)/32 - 1;
253 ld->start = (uint32_t*)buffer + index - 2;
255 tmp = getdword((uint32_t*)buffer + index);
258 tmp = getdword((uint32_t*)buffer + index - 1);
261 ld->tail = (uint32_t*)buffer + index;
263 ld->bits_left = bits_in_buffer % 32;
264 if (ld->bits_left == 0)
267 ld->bytes_left = ld->buffer_size;