mirror of https://github.com/FFmpeg/FFmpeg.git
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
77 lines
2.2 KiB
77 lines
2.2 KiB
/* |
|
* bitstream.h |
|
* Copyright (C) 2000-2003 Michel Lespinasse <walken@zoy.org> |
|
* Copyright (C) 1999-2000 Aaron Holtzman <aholtzma@ess.engr.uvic.ca> |
|
* |
|
* This file is part of a52dec, a free ATSC A-52 stream decoder. |
|
* See http://liba52.sourceforge.net/ for updates. |
|
* |
|
* a52dec 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. |
|
* |
|
* a52dec 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 |
|
*/ |
|
|
|
/* (stolen from the kernel) */ |
|
#ifdef WORDS_BIGENDIAN |
|
|
|
# define swab32(x) (x) |
|
|
|
#else |
|
|
|
# if 0 && defined (__i386__) |
|
|
|
# define swab32(x) __i386_swab32(x) |
|
static inline const uint32_t __i386_swab32(uint32_t x) |
|
{ |
|
__asm__("bswap %0" : "=r" (x) : "0" (x)); |
|
return x; |
|
} |
|
|
|
# else |
|
|
|
# define swab32(x)\ |
|
((((uint8_t*)&x)[0] << 24) | (((uint8_t*)&x)[1] << 16) | \ |
|
(((uint8_t*)&x)[2] << 8) | (((uint8_t*)&x)[3])) |
|
|
|
# endif |
|
#endif |
|
|
|
void a52_bitstream_set_ptr (a52_state_t * state, uint8_t * buf); |
|
uint32_t a52_bitstream_get_bh (a52_state_t * state, uint32_t num_bits); |
|
int32_t a52_bitstream_get_bh_2 (a52_state_t * state, uint32_t num_bits); |
|
|
|
static inline uint32_t bitstream_get (a52_state_t * state, uint32_t num_bits) |
|
{ |
|
uint32_t result; |
|
|
|
if (num_bits < state->bits_left) { |
|
result = (state->current_word << (32 - state->bits_left)) >> (32 - num_bits); |
|
state->bits_left -= num_bits; |
|
return result; |
|
} |
|
|
|
return a52_bitstream_get_bh (state, num_bits); |
|
} |
|
|
|
static inline int32_t bitstream_get_2 (a52_state_t * state, uint32_t num_bits) |
|
{ |
|
int32_t result; |
|
|
|
if (num_bits < state->bits_left) { |
|
result = (((int32_t)state->current_word) << (32 - state->bits_left)) >> (32 - num_bits); |
|
state->bits_left -= num_bits; |
|
return result; |
|
} |
|
|
|
return a52_bitstream_get_bh_2 (state, num_bits); |
|
}
|
|
|