mirror of
https://git.ffmpeg.org/ffmpeg.git
synced 2024-12-29 10:52:20 +00:00
153382e1b6
Add missing multiple inclusion guards; clean up #endif comments; add missing library prefixes; keep guard names consistent.
120 lines
3.5 KiB
C
120 lines
3.5 KiB
C
/*
|
|
* Header file for hardcoded PCM tables
|
|
*
|
|
* Copyright (c) 2010 Reimar Döffinger <Reimar.Doeffinger@gmx.de>
|
|
*
|
|
* This file is part of Libav.
|
|
*
|
|
* Libav 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.
|
|
*
|
|
* Libav 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 Libav; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
|
|
#ifndef AVCODEC_PCM_TABLEGEN_H
|
|
#define AVCODEC_PCM_TABLEGEN_H
|
|
|
|
#include <stdint.h>
|
|
#include "libavutil/attributes.h"
|
|
|
|
/* from g711.c by SUN microsystems (unrestricted use) */
|
|
|
|
#define SIGN_BIT (0x80) /* Sign bit for a A-law byte. */
|
|
#define QUANT_MASK (0xf) /* Quantization field mask. */
|
|
#define NSEGS (8) /* Number of A-law segments. */
|
|
#define SEG_SHIFT (4) /* Left shift for segment number. */
|
|
#define SEG_MASK (0x70) /* Segment field mask. */
|
|
|
|
#define BIAS (0x84) /* Bias for linear code. */
|
|
|
|
/*
|
|
* alaw2linear() - Convert an A-law value to 16-bit linear PCM
|
|
*
|
|
*/
|
|
static av_cold int alaw2linear(unsigned char a_val)
|
|
{
|
|
int t;
|
|
int seg;
|
|
|
|
a_val ^= 0x55;
|
|
|
|
t = a_val & QUANT_MASK;
|
|
seg = ((unsigned)a_val & SEG_MASK) >> SEG_SHIFT;
|
|
if(seg) t= (t + t + 1 + 32) << (seg + 2);
|
|
else t= (t + t + 1 ) << 3;
|
|
|
|
return (a_val & SIGN_BIT) ? t : -t;
|
|
}
|
|
|
|
static av_cold int ulaw2linear(unsigned char u_val)
|
|
{
|
|
int t;
|
|
|
|
/* Complement to obtain normal u-law value. */
|
|
u_val = ~u_val;
|
|
|
|
/*
|
|
* Extract and bias the quantization bits. Then
|
|
* shift up by the segment number and subtract out the bias.
|
|
*/
|
|
t = ((u_val & QUANT_MASK) << 3) + BIAS;
|
|
t <<= ((unsigned)u_val & SEG_MASK) >> SEG_SHIFT;
|
|
|
|
return (u_val & SIGN_BIT) ? (BIAS - t) : (t - BIAS);
|
|
}
|
|
|
|
#if CONFIG_HARDCODED_TABLES
|
|
#define pcm_alaw_tableinit()
|
|
#define pcm_ulaw_tableinit()
|
|
#include "libavcodec/pcm_tables.h"
|
|
#else
|
|
/* 16384 entries per table */
|
|
static uint8_t linear_to_alaw[16384];
|
|
static uint8_t linear_to_ulaw[16384];
|
|
|
|
static av_cold void build_xlaw_table(uint8_t *linear_to_xlaw,
|
|
int (*xlaw2linear)(unsigned char),
|
|
int mask)
|
|
{
|
|
int i, j, v, v1, v2;
|
|
|
|
j = 0;
|
|
for(i=0;i<128;i++) {
|
|
if (i != 127) {
|
|
v1 = xlaw2linear(i ^ mask);
|
|
v2 = xlaw2linear((i + 1) ^ mask);
|
|
v = (v1 + v2 + 4) >> 3;
|
|
} else {
|
|
v = 8192;
|
|
}
|
|
for(;j<v;j++) {
|
|
linear_to_xlaw[8192 + j] = (i ^ mask);
|
|
if (j > 0)
|
|
linear_to_xlaw[8192 - j] = (i ^ (mask ^ 0x80));
|
|
}
|
|
}
|
|
linear_to_xlaw[0] = linear_to_xlaw[1];
|
|
}
|
|
|
|
static void pcm_alaw_tableinit(void)
|
|
{
|
|
build_xlaw_table(linear_to_alaw, alaw2linear, 0xd5);
|
|
}
|
|
|
|
static void pcm_ulaw_tableinit(void)
|
|
{
|
|
build_xlaw_table(linear_to_ulaw, ulaw2linear, 0xff);
|
|
}
|
|
#endif /* CONFIG_HARDCODED_TABLES */
|
|
|
|
#endif /* AVCODEC_PCM_TABLEGEN_H */
|