libavcodec/audioconvert.c

   1 /*
   2  * audio conversion
   3  * Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
   4  *
   5  * This file is part of Libav.
   6  *
   7  * Libav 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  * Libav 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 Libav; 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
  24  * audio conversion
  25  * @author Michael Niedermayer <michaelni@gmx.at>
  26  */
  27
  28 #include "libavutil/avstring.h"
  29 #include "libavutil/libm.h"
  30 #include "libavutil/samplefmt.h"
  31 #include "avcodec.h"
  32 #include "audioconvert.h"
  33
  34 struct AVAudioConvert {
  35     int in_channels, out_channels;
  36     int fmt_pair;
  37 };
  38
  39 AVAudioConvert *av_audio_convert_alloc(enum AVSampleFormat out_fmt, int out_channels,
  40                                        enum AVSampleFormat in_fmt, int in_channels,
  41                                        const float *matrix, int flags)
  42 {
  43     AVAudioConvert *ctx;
  44     if (in_channels!=out_channels)
  45         return NULL;  /* FIXME: not supported */
  46     ctx = av_malloc(sizeof(AVAudioConvert));
  47     if (!ctx)
  48         return NULL;
  49     ctx->in_channels = in_channels;
  50     ctx->out_channels = out_channels;
  51     ctx->fmt_pair = out_fmt + AV_SAMPLE_FMT_NB*in_fmt;
  52     return ctx;
  53 }
  54
  55 void av_audio_convert_free(AVAudioConvert *ctx)
  56 {
  57     av_free(ctx);
  58 }
  59
  60 int av_audio_convert(AVAudioConvert *ctx,
  61                            void * const out[6], const int out_stride[6],
  62                      const void * const  in[6], const int  in_stride[6], int len)
  63 {
  64     int ch;
  65
  66     //FIXME optimize common cases
  67
  68     for(ch=0; ch<ctx->out_channels; ch++){
  69         const int is=  in_stride[ch];
  70         const int os= out_stride[ch];
  71         const uint8_t *pi=  in[ch];
  72         uint8_t *po= out[ch];
  73         uint8_t *end= po + os*len;
  74         if(!out[ch])
  75             continue;
  76
  77 #define CONV(ofmt, otype, ifmt, expr)\
  78 if(ctx->fmt_pair == ofmt + AV_SAMPLE_FMT_NB*ifmt){\
  79     do{\
  80         *(otype*)po = expr; pi += is; po += os;\
  81     }while(po < end);\
  82 }
  83
  84 //FIXME put things below under ifdefs so we do not waste space for cases no codec will need
  85 //FIXME rounding ?
  86
  87              CONV(AV_SAMPLE_FMT_U8 , uint8_t, AV_SAMPLE_FMT_U8 ,  *(const uint8_t*)pi)
  88         else CONV(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_U8 , (*(const uint8_t*)pi - 0x80)<<8)
  89         else CONV(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_U8 , (*(const uint8_t*)pi - 0x80)<<24)
  90         else CONV(AV_SAMPLE_FMT_FLT, float  , AV_SAMPLE_FMT_U8 , (*(const uint8_t*)pi - 0x80)*(1.0 / (1<<7)))
  91         else CONV(AV_SAMPLE_FMT_DBL, double , AV_SAMPLE_FMT_U8 , (*(const uint8_t*)pi - 0x80)*(1.0 / (1<<7)))
  92         else CONV(AV_SAMPLE_FMT_U8 , uint8_t, AV_SAMPLE_FMT_S16, (*(const int16_t*)pi>>8) + 0x80)
  93         else CONV(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_S16,  *(const int16_t*)pi)
  94         else CONV(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_S16,  *(const int16_t*)pi<<16)
  95         else CONV(AV_SAMPLE_FMT_FLT, float  , AV_SAMPLE_FMT_S16,  *(const int16_t*)pi*(1.0 / (1<<15)))
  96         else CONV(AV_SAMPLE_FMT_DBL, double , AV_SAMPLE_FMT_S16,  *(const int16_t*)pi*(1.0 / (1<<15)))
  97         else CONV(AV_SAMPLE_FMT_U8 , uint8_t, AV_SAMPLE_FMT_S32, (*(const int32_t*)pi>>24) + 0x80)
  98         else CONV(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_S32,  *(const int32_t*)pi>>16)
  99         else CONV(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_S32,  *(const int32_t*)pi)
 100         else CONV(AV_SAMPLE_FMT_FLT, float  , AV_SAMPLE_FMT_S32,  *(const int32_t*)pi*(1.0 / (1U<<31)))
 101         else CONV(AV_SAMPLE_FMT_DBL, double , AV_SAMPLE_FMT_S32,  *(const int32_t*)pi*(1.0 / (1U<<31)))
 102         else CONV(AV_SAMPLE_FMT_U8 , uint8_t, AV_SAMPLE_FMT_FLT, av_clip_uint8(  lrintf(*(const float*)pi * (1<<7)) + 0x80))
 103         else CONV(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_FLT, av_clip_int16(  lrintf(*(const float*)pi * (1<<15))))
 104         else CONV(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_FLT, av_clipl_int32(llrintf(*(const float*)pi * (1U<<31))))
 105         else CONV(AV_SAMPLE_FMT_FLT, float  , AV_SAMPLE_FMT_FLT, *(const float*)pi)
 106         else CONV(AV_SAMPLE_FMT_DBL, double , AV_SAMPLE_FMT_FLT, *(const float*)pi)
 107         else CONV(AV_SAMPLE_FMT_U8 , uint8_t, AV_SAMPLE_FMT_DBL, av_clip_uint8(  lrint(*(const double*)pi * (1<<7)) + 0x80))
 108         else CONV(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_DBL, av_clip_int16(  lrint(*(const double*)pi * (1<<15))))
 109         else CONV(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_DBL, av_clipl_int32(llrint(*(const double*)pi * (1U<<31))))
 110         else CONV(AV_SAMPLE_FMT_FLT, float  , AV_SAMPLE_FMT_DBL, *(const double*)pi)
 111         else CONV(AV_SAMPLE_FMT_DBL, double , AV_SAMPLE_FMT_DBL, *(const double*)pi)
 112         else return -1;
 113     }
 114     return 0;
 115 }