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.
60 lines
1.7 KiB
60 lines
1.7 KiB
/* |
|
* AC-3 DSP utils |
|
* Copyright (c) 2011 Justin Ruggles |
|
* |
|
* This file is part of FFmpeg. |
|
* |
|
* FFmpeg is free software; you can redistribute it and/or |
|
* modify it under the terms of the GNU Lesser General Public |
|
* License as published by the Free Software Foundation; either |
|
* version 2.1 of the License, or (at your option) any later version. |
|
* |
|
* FFmpeg 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 |
|
* Lesser General Public License for more details. |
|
* |
|
* You should have received a copy of the GNU Lesser General Public |
|
* License along with FFmpeg; if not, write to the Free Software |
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
|
*/ |
|
|
|
#include "avcodec.h" |
|
#include "ac3dsp.h" |
|
|
|
static void ac3_exponent_min_c(uint8_t *exp, int num_reuse_blocks, int nb_coefs) |
|
{ |
|
int blk, i; |
|
|
|
if (!num_reuse_blocks) |
|
return; |
|
|
|
for (i = 0; i < nb_coefs; i++) { |
|
uint8_t min_exp = *exp; |
|
uint8_t *exp1 = exp + 256; |
|
for (blk = 0; blk < num_reuse_blocks; blk++) { |
|
uint8_t next_exp = *exp1; |
|
if (next_exp < min_exp) |
|
min_exp = next_exp; |
|
exp1 += 256; |
|
} |
|
*exp++ = min_exp; |
|
} |
|
} |
|
|
|
static int ac3_max_msb_abs_int16_c(const int16_t *src, int len) |
|
{ |
|
int i, v = 0; |
|
for (i = 0; i < len; i++) |
|
v |= abs(src[i]); |
|
return v; |
|
} |
|
|
|
av_cold void ff_ac3dsp_init(AC3DSPContext *c) |
|
{ |
|
c->ac3_exponent_min = ac3_exponent_min_c; |
|
c->ac3_max_msb_abs_int16 = ac3_max_msb_abs_int16_c; |
|
|
|
if (HAVE_MMX) |
|
ff_ac3dsp_init_x86(c); |
|
}
|
|
|