diff options
Diffstat (limited to 'faad2/src/libfaad/bits.c')
| -rw-r--r-- | faad2/src/libfaad/bits.c | 271 |
1 files changed, 271 insertions, 0 deletions
diff --git a/faad2/src/libfaad/bits.c b/faad2/src/libfaad/bits.c new file mode 100644 index 0000000..66c6a13 --- /dev/null +++ b/faad2/src/libfaad/bits.c @@ -0,0 +1,271 @@ +/*
+** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding
+** Copyright (C) 2003-2005 M. Bakker, Nero AG, http://www.nero.com
+**
+** This program is free software; you can redistribute it and/or modify
+** it under the terms of the GNU General Public License as published by
+** the Free Software Foundation; either version 2 of the License, or
+** (at your option) any later version.
+**
+** This program is distributed in the hope that it will be useful,
+** but WITHOUT ANY WARRANTY; without even the implied warranty of
+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+** GNU General Public License for more details.
+**
+** You should have received a copy of the GNU General Public License
+** along with this program; if not, write to the Free Software
+** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+**
+** Any non-GPL usage of this software or parts of this software is strictly
+** forbidden.
+**
+** The "appropriate copyright message" mentioned in section 2c of the GPLv2
+** must read: "Code from FAAD2 is copyright (c) Nero AG, www.nero.com"
+**
+** Commercial non-GPL licensing of this software is possible.
+** For more info contact Nero AG through Mpeg4AAClicense@nero.com.
+**
+** $Id: bits.c,v 1.44 2007/11/01 12:33:29 menno Exp $
+**/
+
+#include "common.h"
+#include "structs.h"
+
+#include <stdlib.h>
+#include "bits.h"
+
+/* initialize buffer, call once before first getbits or showbits */
+void faad_initbits(bitfile *ld, const void *_buffer, const uint32_t buffer_size)
+{
+ uint32_t tmp;
+
+ if (ld == NULL)
+ return;
+
+ // useless
+ //memset(ld, 0, sizeof(bitfile));
+
+ if (buffer_size == 0 || _buffer == NULL)
+ {
+ ld->error = 1;
+ return;
+ }
+
+ ld->buffer = _buffer;
+
+ ld->buffer_size = buffer_size;
+ ld->bytes_left = buffer_size;
+
+ if (ld->bytes_left >= 4)
+ {
+ tmp = getdword((uint32_t*)ld->buffer);
+ ld->bytes_left -= 4;
+ } else {
+ tmp = getdword_n((uint32_t*)ld->buffer, ld->bytes_left);
+ ld->bytes_left = 0;
+ }
+ ld->bufa = tmp;
+
+ if (ld->bytes_left >= 4)
+ {
+ tmp = getdword((uint32_t*)ld->buffer + 1);
+ ld->bytes_left -= 4;
+ } else {
+ tmp = getdword_n((uint32_t*)ld->buffer + 1, ld->bytes_left);
+ ld->bytes_left = 0;
+ }
+ ld->bufb = tmp;
+
+ ld->start = (uint32_t*)ld->buffer;
+ ld->tail = ((uint32_t*)ld->buffer + 2);
+
+ ld->bits_left = 32;
+
+ ld->error = 0;
+}
+
+void faad_endbits(bitfile *ld)
+{
+ // void
+}
+
+uint32_t faad_get_processed_bits(bitfile *ld)
+{
+ return (uint32_t)(8 * (4*(ld->tail - ld->start) - 4) - (ld->bits_left));
+}
+
+uint8_t faad_byte_align(bitfile *ld)
+{
+ int remainder = (32 - ld->bits_left) & 0x7;
+
+ if (remainder)
+ {
+ faad_flushbits(ld, 8 - remainder);
+ return (uint8_t)(8 - remainder);
+ }
+ return 0;
+}
+
+void faad_flushbits_ex(bitfile *ld, uint32_t bits)
+{
+ uint32_t tmp;
+
+ ld->bufa = ld->bufb;
+ if (ld->bytes_left >= 4)
+ {
+ tmp = getdword(ld->tail);
+ ld->bytes_left -= 4;
+ } else {
+ tmp = getdword_n(ld->tail, ld->bytes_left);
+ ld->bytes_left = 0;
+ }
+ ld->bufb = tmp;
+ ld->tail++;
+ ld->bits_left += (32 - bits);
+ //ld->bytes_left -= 4;
+// if (ld->bytes_left == 0)
+// ld->no_more_reading = 1;
+// if (ld->bytes_left < 0)
+// ld->error = 1;
+}
+
+/* rewind to beginning */
+void faad_rewindbits(bitfile *ld)
+{
+ uint32_t tmp;
+
+ ld->bytes_left = ld->buffer_size;
+
+ if (ld->bytes_left >= 4)
+ {
+ tmp = getdword((uint32_t*)&ld->start[0]);
+ ld->bytes_left -= 4;
+ } else {
+ tmp = getdword_n((uint32_t*)&ld->start[0], ld->bytes_left);
+ ld->bytes_left = 0;
+ }
+ ld->bufa = tmp;
+
+ if (ld->bytes_left >= 4)
+ {
+ tmp = getdword((uint32_t*)&ld->start[1]);
+ ld->bytes_left -= 4;
+ } else {
+ tmp = getdword_n((uint32_t*)&ld->start[1], ld->bytes_left);
+ ld->bytes_left = 0;
+ }
+ ld->bufb = tmp;
+
+ ld->bits_left = 32;
+ ld->tail = &ld->start[2];
+}
+
+/* reset to a certain point */
+void faad_resetbits(bitfile *ld, int bits)
+{
+ uint32_t tmp;
+ int words = bits >> 5;
+ int remainder = bits & 0x1F;
+
+ ld->bytes_left = ld->buffer_size - words*4;
+
+ if (ld->bytes_left >= 4)
+ {
+ tmp = getdword(&ld->start[words]);
+ ld->bytes_left -= 4;
+ } else {
+ tmp = getdword_n(&ld->start[words], ld->bytes_left);
+ ld->bytes_left = 0;
+ }
+ ld->bufa = tmp;
+
+ if (ld->bytes_left >= 4)
+ {
+ tmp = getdword(&ld->start[words+1]);
+ ld->bytes_left -= 4;
+ } else {
+ tmp = getdword_n(&ld->start[words+1], ld->bytes_left);
+ ld->bytes_left = 0;
+ }
+ ld->bufb = tmp;
+
+ ld->bits_left = 32 - remainder;
+ ld->tail = &ld->start[words+2];
+
+ /* recheck for reading too many bytes */
+ ld->error = 0;
+// if (ld->bytes_left == 0)
+// ld->no_more_reading = 1;
+// if (ld->bytes_left < 0)
+// ld->error = 1;
+}
+
+uint8_t *faad_getbitbuffer(bitfile *ld, uint32_t bits
+ DEBUGDEC)
+{
+ int i;
+ unsigned int temp;
+ int bytes = bits >> 3;
+ int remainder = bits & 0x7;
+
+ uint8_t *buffer = (uint8_t*)faad_malloc((bytes+1)*sizeof(uint8_t));
+
+ for (i = 0; i < bytes; i++)
+ {
+ buffer[i] = (uint8_t)faad_getbits(ld, 8 DEBUGVAR(print,var,dbg));
+ }
+
+ if (remainder)
+ {
+ temp = faad_getbits(ld, remainder DEBUGVAR(print,var,dbg)) << (8-remainder);
+
+ buffer[bytes] = (uint8_t)temp;
+ }
+
+ return buffer;
+}
+
+#ifdef DRM
+/* return the original data buffer */
+void *faad_origbitbuffer(bitfile *ld)
+{
+ return (void*)ld->start;
+}
+
+/* return the original data buffer size */
+uint32_t faad_origbitbuffer_size(bitfile *ld)
+{
+ return ld->buffer_size;
+}
+#endif
+
+/* reversed bit reading routines, used for RVLC and HCR */
+void faad_initbits_rev(bitfile *ld, void *buffer,
+ uint32_t bits_in_buffer)
+{
+ uint32_t tmp;
+ int32_t index;
+
+ ld->buffer_size = bit2byte(bits_in_buffer);
+
+ index = (bits_in_buffer+31)/32 - 1;
+
+ ld->start = (uint32_t*)buffer + index - 2;
+
+ tmp = getdword((uint32_t*)buffer + index);
+ ld->bufa = tmp;
+
+ tmp = getdword((uint32_t*)buffer + index - 1);
+ ld->bufb = tmp;
+
+ ld->tail = (uint32_t*)buffer + index;
+
+ ld->bits_left = bits_in_buffer % 32;
+ if (ld->bits_left == 0)
+ ld->bits_left = 32;
+
+ ld->bytes_left = ld->buffer_size;
+ ld->error = 0;
+}
+
+/* EOF */
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