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audioconvert.c
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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 */