/*
  * Header file for hardcoded PCM tables
  *
  * Copyright (c) 2010 Reimar Döffinger <Reimar.Doeffinger@gmx.de>
  *
  * 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
  */
 

 #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 */