libavcodec/audioconvert.c

   1 /*
   2  * audio conversion
   3  * Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 /**
  23  * @file audioconvert.c
  24  * audio conversion
  25  * @author Michael Niedermayer <michaelni@gmx.at>
  26  */
  27
  28 #include "avcodec.h"
  29
  30 int av_audio_convert(void *maybe_dspcontext_or_something_av_convert_specific,
  31                      void *out[6], int out_stride[6], enum SampleFormat out_fmt,
  32                      void * in[6], int  in_stride[6], enum SampleFormat  in_fmt, int len){
  33     int ch;
  34     const int isize= FFMIN( in_fmt+1, 4);
  35     const int osize= FFMIN(out_fmt+1, 4);
  36     const int fmt_pair= out_fmt + 5*in_fmt;
  37
  38     //FIXME optimize common cases
  39
  40     for(ch=0; ch<6; ch++){
  41         const int is=  in_stride[ch] * isize;
  42         const int os= out_stride[ch] * osize;
  43         uint8_t *pi=  in[ch];
  44         uint8_t *po= out[ch];
  45         uint8_t *end= po + os;
  46         if(!out[ch])
  47             continue;
  48
  49 #define CONV(ofmt, otype, ifmt, expr)\
  50 if(fmt_pair == ofmt + 5*ifmt){\
  51     do{\
  52         *(otype*)po = expr; pi += is; po += os;\
  53     }while(po < end);\
  54 }
  55
  56 //FIXME put things below under ifdefs so we do not waste space for cases no codec will need
  57 //FIXME rounding and clipping ?
  58
  59              CONV(SAMPLE_FMT_U8 , uint8_t, SAMPLE_FMT_U8 ,  *(uint8_t*)pi)
  60         else CONV(SAMPLE_FMT_S16, int16_t, SAMPLE_FMT_U8 , (*(uint8_t*)pi - 0x80)<<8)
  61         else CONV(SAMPLE_FMT_S32, int32_t, SAMPLE_FMT_U8 , (*(uint8_t*)pi - 0x80)<<24)
  62         else CONV(SAMPLE_FMT_FLT, float  , SAMPLE_FMT_U8 , (*(uint8_t*)pi - 0x80)*(1.0 / (1<<7)))
  63         else CONV(SAMPLE_FMT_U8 , uint8_t, SAMPLE_FMT_S16, (*(int16_t*)pi>>8) + 0x80)
  64         else CONV(SAMPLE_FMT_S16, int16_t, SAMPLE_FMT_S16,  *(int16_t*)pi)
  65         else CONV(SAMPLE_FMT_S32, int32_t, SAMPLE_FMT_S16,  *(int16_t*)pi<<16)
  66         else CONV(SAMPLE_FMT_FLT, float  , SAMPLE_FMT_S16,  *(int16_t*)pi*(1.0 / (1<<15)))
  67         else CONV(SAMPLE_FMT_U8 , uint8_t, SAMPLE_FMT_S32, (*(int32_t*)pi>>24) + 0x80)
  68         else CONV(SAMPLE_FMT_S16, int16_t, SAMPLE_FMT_S32,  *(int32_t*)pi>>16)
  69         else CONV(SAMPLE_FMT_S32, int32_t, SAMPLE_FMT_S32,  *(int32_t*)pi)
  70         else CONV(SAMPLE_FMT_FLT, float  , SAMPLE_FMT_S32,  *(int32_t*)pi*(1.0 / (1<<31)))
  71         else CONV(SAMPLE_FMT_U8 , uint8_t, SAMPLE_FMT_FLT, lrintf(*(float*)pi * (1<<7)) + 0x80)
  72         else CONV(SAMPLE_FMT_S16, int16_t, SAMPLE_FMT_FLT, lrintf(*(float*)pi * (1<<15)))
  73         else CONV(SAMPLE_FMT_S32, int32_t, SAMPLE_FMT_FLT, lrintf(*(float*)pi * (1<<31)))
  74         else CONV(SAMPLE_FMT_FLT, float  , SAMPLE_FMT_FLT, *(float*)pi)
  75         else return -1;
  76     }
  77     return 0;
  78 }