ffmpeg/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
  24  * audio conversion
  25  * @author Michael Niedermayer <michaelni@gmx.at>
  26  */
  27
  28 #include "libavutil/avstring.h"
  29 #include "libavutil/common.h"
  30 #include "libavutil/libm.h"
  31 #include "libavutil/samplefmt.h"
  32 #include "avcodec.h"
  33 #include "audioconvert.h"
  34
  35 #if FF_API_AUDIO_CONVERT
  36
  37 struct AVAudioConvert {
  38     int in_channels, out_channels;
  39     int fmt_pair;
  40 };
  41
  42 AVAudioConvert *av_audio_convert_alloc(enum AVSampleFormat out_fmt, int out_channels,
  43                                        enum AVSampleFormat in_fmt, int in_channels,
  44                                        const float *matrix, int flags)
  45 {
  46     AVAudioConvert *ctx;
  47     if (in_channels!=out_channels)
  48         return NULL;  /* FIXME: not supported */
  49     ctx = av_malloc(sizeof(AVAudioConvert));
  50     if (!ctx)
  51         return NULL;
  52     ctx->in_channels = in_channels;
  53     ctx->out_channels = out_channels;
  54     ctx->fmt_pair = out_fmt + AV_SAMPLE_FMT_NB*in_fmt;
  55     return ctx;
  56 }
  57
  58 void av_audio_convert_free(AVAudioConvert *ctx)
  59 {
  60     av_free(ctx);
  61 }
  62
  63 int av_audio_convert(AVAudioConvert *ctx,
  64                            void * const out[6], const int out_stride[6],
  65                      const void * const  in[6], const int  in_stride[6], int len)
  66 {
  67     int ch;
  68
  69     //FIXME optimize common cases
  70
  71     for(ch=0; ch<ctx->out_channels; ch++){
  72         const int is=  in_stride[ch];
  73         const int os= out_stride[ch];
  74         const uint8_t *pi=  in[ch];
  75         uint8_t *po= out[ch];
  76         uint8_t *end= po + os*len;
  77         if(!out[ch])
  78             continue;
  79
  80 #define CONV(ofmt, otype, ifmt, expr)\
  81 if(ctx->fmt_pair == ofmt + AV_SAMPLE_FMT_NB*ifmt){\
  82     do{\
  83         *(otype*)po = expr; pi += is; po += os;\
  84     }while(po < end);\
  85 }
  86
  87 //FIXME put things below under ifdefs so we do not waste space for cases no codec will need
  88 //FIXME rounding ?
  89
  90              CONV(AV_SAMPLE_FMT_U8 , uint8_t, AV_SAMPLE_FMT_U8 ,  *(const uint8_t*)pi)
  91         else CONV(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_U8 , (*(const uint8_t*)pi - 0x80)<<8)
  92         else CONV(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_U8 , (*(const uint8_t*)pi - 0x80)<<24)
  93         else CONV(AV_SAMPLE_FMT_FLT, float  , AV_SAMPLE_FMT_U8 , (*(const uint8_t*)pi - 0x80)*(1.0 / (1<<7)))
  94         else CONV(AV_SAMPLE_FMT_DBL, double , AV_SAMPLE_FMT_U8 , (*(const uint8_t*)pi - 0x80)*(1.0 / (1<<7)))
  95         else CONV(AV_SAMPLE_FMT_U8 , uint8_t, AV_SAMPLE_FMT_S16, (*(const int16_t*)pi>>8) + 0x80)
  96         else CONV(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_S16,  *(const int16_t*)pi)
  97         else CONV(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_S16,  *(const int16_t*)pi<<16)
  98         else CONV(AV_SAMPLE_FMT_FLT, float  , AV_SAMPLE_FMT_S16,  *(const int16_t*)pi*(1.0 / (1<<15)))
  99         else CONV(AV_SAMPLE_FMT_DBL, double , AV_SAMPLE_FMT_S16,  *(const int16_t*)pi*(1.0 / (1<<15)))
 100         else CONV(AV_SAMPLE_FMT_U8 , uint8_t, AV_SAMPLE_FMT_S32, (*(const int32_t*)pi>>24) + 0x80)
 101         else CONV(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_S32,  *(const int32_t*)pi>>16)
 102         else CONV(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_S32,  *(const int32_t*)pi)
 103         else CONV(AV_SAMPLE_FMT_FLT, float  , AV_SAMPLE_FMT_S32,  *(const int32_t*)pi*(1.0 / (1U<<31)))
 104         else CONV(AV_SAMPLE_FMT_DBL, double , AV_SAMPLE_FMT_S32,  *(const int32_t*)pi*(1.0 / (1U<<31)))
 105         else CONV(AV_SAMPLE_FMT_U8 , uint8_t, AV_SAMPLE_FMT_FLT, av_clip_uint8(  lrintf(*(const float*)pi * (1<<7)) + 0x80))
 106         else CONV(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_FLT, av_clip_int16(  lrintf(*(const float*)pi * (1<<15))))
 107         else CONV(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_FLT, av_clipl_int32(llrintf(*(const float*)pi * (1U<<31))))
 108         else CONV(AV_SAMPLE_FMT_FLT, float  , AV_SAMPLE_FMT_FLT, *(const float*)pi)
 109         else CONV(AV_SAMPLE_FMT_DBL, double , AV_SAMPLE_FMT_FLT, *(const float*)pi)
 110         else CONV(AV_SAMPLE_FMT_U8 , uint8_t, AV_SAMPLE_FMT_DBL, av_clip_uint8(  lrint(*(const double*)pi * (1<<7)) + 0x80))
 111         else CONV(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_DBL, av_clip_int16(  lrint(*(const double*)pi * (1<<15))))
 112         else CONV(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_DBL, av_clipl_int32(llrint(*(const double*)pi * (1U<<31))))
 113         else CONV(AV_SAMPLE_FMT_FLT, float  , AV_SAMPLE_FMT_DBL, *(const double*)pi)
 114         else CONV(AV_SAMPLE_FMT_DBL, double , AV_SAMPLE_FMT_DBL, *(const double*)pi)
 115         else return -1;
 116     }
 117     return 0;
 118 }
 119
 120 #endif /* FF_API_AUDIO_CONVERT */