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libavcodec/audioconvert.c

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00001 /*
00002  * audio conversion
00003  * Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
00004  *
00005  * This file is part of Libav.
00006  *
00007  * Libav is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * Libav is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with Libav; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00028 #include "libavutil/avstring.h"
00029 #include "libavutil/libm.h"
00030 #include "libavutil/samplefmt.h"
00031 #include "avcodec.h"
00032 #include "audioconvert.h"
00033 
00034 #if FF_API_OLD_SAMPLE_FMT
00035 const char *avcodec_get_sample_fmt_name(int sample_fmt)
00036 {
00037     return av_get_sample_fmt_name(sample_fmt);
00038 }
00039 
00040 enum AVSampleFormat avcodec_get_sample_fmt(const char* name)
00041 {
00042     return av_get_sample_fmt(name);
00043 }
00044 
00045 void avcodec_sample_fmt_string (char *buf, int buf_size, int sample_fmt)
00046 {
00047     av_get_sample_fmt_string(buf, buf_size, sample_fmt);
00048 }
00049 #endif
00050 
00051 uint64_t avcodec_guess_channel_layout(int nb_channels, enum CodecID codec_id, const char *fmt_name)
00052 {
00053     switch(nb_channels) {
00054     case 1: return AV_CH_LAYOUT_MONO;
00055     case 2: return AV_CH_LAYOUT_STEREO;
00056     case 3: return AV_CH_LAYOUT_SURROUND;
00057     case 4: return AV_CH_LAYOUT_QUAD;
00058     case 5: return AV_CH_LAYOUT_5POINT0;
00059     case 6: return AV_CH_LAYOUT_5POINT1;
00060     case 8: return AV_CH_LAYOUT_7POINT1;
00061     default: return 0;
00062     }
00063 }
00064 
00065 #if FF_API_OLD_AUDIOCONVERT
00066 int64_t avcodec_get_channel_layout(const char *name)
00067 {
00068     return av_get_channel_layout(name);
00069 }
00070 
00071 void avcodec_get_channel_layout_string(char *buf, int buf_size, int nb_channels, int64_t channel_layout)
00072 {
00073     av_get_channel_layout_string(buf, buf_size, nb_channels, channel_layout);
00074 }
00075 
00076 int avcodec_channel_layout_num_channels(int64_t channel_layout)
00077 {
00078     return av_get_channel_layout_nb_channels(channel_layout);
00079 }
00080 #endif
00081 
00082 struct AVAudioConvert {
00083     int in_channels, out_channels;
00084     int fmt_pair;
00085 };
00086 
00087 AVAudioConvert *av_audio_convert_alloc(enum AVSampleFormat out_fmt, int out_channels,
00088                                        enum AVSampleFormat in_fmt, int in_channels,
00089                                        const float *matrix, int flags)
00090 {
00091     AVAudioConvert *ctx;
00092     if (in_channels!=out_channels)
00093         return NULL;  /* FIXME: not supported */
00094     ctx = av_malloc(sizeof(AVAudioConvert));
00095     if (!ctx)
00096         return NULL;
00097     ctx->in_channels = in_channels;
00098     ctx->out_channels = out_channels;
00099     ctx->fmt_pair = out_fmt + AV_SAMPLE_FMT_NB*in_fmt;
00100     return ctx;
00101 }
00102 
00103 void av_audio_convert_free(AVAudioConvert *ctx)
00104 {
00105     av_free(ctx);
00106 }
00107 
00108 int av_audio_convert(AVAudioConvert *ctx,
00109                            void * const out[6], const int out_stride[6],
00110                      const void * const  in[6], const int  in_stride[6], int len)
00111 {
00112     int ch;
00113 
00114     //FIXME optimize common cases
00115 
00116     for(ch=0; ch<ctx->out_channels; ch++){
00117         const int is=  in_stride[ch];
00118         const int os= out_stride[ch];
00119         const uint8_t *pi=  in[ch];
00120         uint8_t *po= out[ch];
00121         uint8_t *end= po + os*len;
00122         if(!out[ch])
00123             continue;
00124 
00125 #define CONV(ofmt, otype, ifmt, expr)\
00126 if(ctx->fmt_pair == ofmt + AV_SAMPLE_FMT_NB*ifmt){\
00127     do{\
00128         *(otype*)po = expr; pi += is; po += os;\
00129     }while(po < end);\
00130 }
00131 
00132 //FIXME put things below under ifdefs so we do not waste space for cases no codec will need
00133 //FIXME rounding ?
00134 
00135              CONV(AV_SAMPLE_FMT_U8 , uint8_t, AV_SAMPLE_FMT_U8 ,  *(const uint8_t*)pi)
00136         else CONV(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_U8 , (*(const uint8_t*)pi - 0x80)<<8)
00137         else CONV(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_U8 , (*(const uint8_t*)pi - 0x80)<<24)
00138         else CONV(AV_SAMPLE_FMT_FLT, float  , AV_SAMPLE_FMT_U8 , (*(const uint8_t*)pi - 0x80)*(1.0 / (1<<7)))
00139         else CONV(AV_SAMPLE_FMT_DBL, double , AV_SAMPLE_FMT_U8 , (*(const uint8_t*)pi - 0x80)*(1.0 / (1<<7)))
00140         else CONV(AV_SAMPLE_FMT_U8 , uint8_t, AV_SAMPLE_FMT_S16, (*(const int16_t*)pi>>8) + 0x80)
00141         else CONV(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_S16,  *(const int16_t*)pi)
00142         else CONV(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_S16,  *(const int16_t*)pi<<16)
00143         else CONV(AV_SAMPLE_FMT_FLT, float  , AV_SAMPLE_FMT_S16,  *(const int16_t*)pi*(1.0 / (1<<15)))
00144         else CONV(AV_SAMPLE_FMT_DBL, double , AV_SAMPLE_FMT_S16,  *(const int16_t*)pi*(1.0 / (1<<15)))
00145         else CONV(AV_SAMPLE_FMT_U8 , uint8_t, AV_SAMPLE_FMT_S32, (*(const int32_t*)pi>>24) + 0x80)
00146         else CONV(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_S32,  *(const int32_t*)pi>>16)
00147         else CONV(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_S32,  *(const int32_t*)pi)
00148         else CONV(AV_SAMPLE_FMT_FLT, float  , AV_SAMPLE_FMT_S32,  *(const int32_t*)pi*(1.0 / (1U<<31)))
00149         else CONV(AV_SAMPLE_FMT_DBL, double , AV_SAMPLE_FMT_S32,  *(const int32_t*)pi*(1.0 / (1U<<31)))
00150         else CONV(AV_SAMPLE_FMT_U8 , uint8_t, AV_SAMPLE_FMT_FLT, av_clip_uint8(  lrintf(*(const float*)pi * (1<<7)) + 0x80))
00151         else CONV(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_FLT, av_clip_int16(  lrintf(*(const float*)pi * (1<<15))))
00152         else CONV(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_FLT, av_clipl_int32(llrintf(*(const float*)pi * (1U<<31))))
00153         else CONV(AV_SAMPLE_FMT_FLT, float  , AV_SAMPLE_FMT_FLT, *(const float*)pi)
00154         else CONV(AV_SAMPLE_FMT_DBL, double , AV_SAMPLE_FMT_FLT, *(const float*)pi)
00155         else CONV(AV_SAMPLE_FMT_U8 , uint8_t, AV_SAMPLE_FMT_DBL, av_clip_uint8(  lrint(*(const double*)pi * (1<<7)) + 0x80))
00156         else CONV(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_DBL, av_clip_int16(  lrint(*(const double*)pi * (1<<15))))
00157         else CONV(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_DBL, av_clipl_int32(llrint(*(const double*)pi * (1U<<31))))
00158         else CONV(AV_SAMPLE_FMT_FLT, float  , AV_SAMPLE_FMT_DBL, *(const double*)pi)
00159         else CONV(AV_SAMPLE_FMT_DBL, double , AV_SAMPLE_FMT_DBL, *(const double*)pi)
00160         else return -1;
00161     }
00162     return 0;
00163 }
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