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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 FFmpeg.
00006  *
00007  * FFmpeg 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  * FFmpeg 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 FFmpeg; 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 "avcodec.h"
00031 #include "audioconvert.h"
00032 
00033 typedef struct SampleFmtInfo {
00034     const char *name;
00035     int bits;
00036 } SampleFmtInfo;
00037 
00039 static const SampleFmtInfo sample_fmt_info[SAMPLE_FMT_NB] = {
00040     [SAMPLE_FMT_U8]  = { .name = "u8",  .bits = 8 },
00041     [SAMPLE_FMT_S16] = { .name = "s16", .bits = 16 },
00042     [SAMPLE_FMT_S32] = { .name = "s32", .bits = 32 },
00043     [SAMPLE_FMT_FLT] = { .name = "flt", .bits = 32 },
00044     [SAMPLE_FMT_DBL] = { .name = "dbl", .bits = 64 },
00045 };
00046 
00047 const char *avcodec_get_sample_fmt_name(int sample_fmt)
00048 {
00049     if (sample_fmt < 0 || sample_fmt >= SAMPLE_FMT_NB)
00050         return NULL;
00051     return sample_fmt_info[sample_fmt].name;
00052 }
00053 
00054 enum SampleFormat avcodec_get_sample_fmt(const char* name)
00055 {
00056     int i;
00057 
00058     for (i=0; i < SAMPLE_FMT_NB; i++)
00059         if (!strcmp(sample_fmt_info[i].name, name))
00060             return i;
00061     return SAMPLE_FMT_NONE;
00062 }
00063 
00064 void avcodec_sample_fmt_string (char *buf, int buf_size, int sample_fmt)
00065 {
00066     /* print header */
00067     if (sample_fmt < 0)
00068         snprintf (buf, buf_size, "name  " " depth");
00069     else if (sample_fmt < SAMPLE_FMT_NB) {
00070         SampleFmtInfo info= sample_fmt_info[sample_fmt];
00071         snprintf (buf, buf_size, "%-6s" "   %2d ", info.name, info.bits);
00072     }
00073 }
00074 
00075 static const char* const channel_names[]={
00076     "FL", "FR", "FC", "LFE", "BL",  "BR",  "FLC", "FRC",
00077     "BC", "SL", "SR", "TC",  "TFL", "TFC", "TFR", "TBL",
00078     "TBC", "TBR",
00079     [29] = "DL",
00080     [30] = "DR",
00081 };
00082 
00083 static const char *get_channel_name(int channel_id)
00084 {
00085     if (channel_id<0 || channel_id>=FF_ARRAY_ELEMS(channel_names))
00086         return NULL;
00087     return channel_names[channel_id];
00088 }
00089 
00090 int64_t avcodec_guess_channel_layout(int nb_channels, enum CodecID codec_id, const char *fmt_name)
00091 {
00092     switch(nb_channels) {
00093     case 1: return CH_LAYOUT_MONO;
00094     case 2: return CH_LAYOUT_STEREO;
00095     case 3: return CH_LAYOUT_SURROUND;
00096     case 4: return CH_LAYOUT_QUAD;
00097     case 5: return CH_LAYOUT_5POINT0;
00098     case 6: return CH_LAYOUT_5POINT1;
00099     case 8: return CH_LAYOUT_7POINT1;
00100     default: return 0;
00101     }
00102 }
00103 
00104 static const struct {
00105     const char *name;
00106     int         nb_channels;
00107     int64_t     layout;
00108 } channel_layout_map[] = {
00109     { "mono",        1,  CH_LAYOUT_MONO },
00110     { "stereo",      2,  CH_LAYOUT_STEREO },
00111     { "4.0",         4,  CH_LAYOUT_4POINT0 },
00112     { "quad",        4,  CH_LAYOUT_QUAD },
00113     { "5.0",         5,  CH_LAYOUT_5POINT0 },
00114     { "5.0",         5,  CH_LAYOUT_5POINT0_BACK },
00115     { "5.1",         6,  CH_LAYOUT_5POINT1 },
00116     { "5.1",         6,  CH_LAYOUT_5POINT1_BACK },
00117     { "5.1+downmix", 8,  CH_LAYOUT_5POINT1|CH_LAYOUT_STEREO_DOWNMIX, },
00118     { "7.1",         8,  CH_LAYOUT_7POINT1 },
00119     { "7.1(wide)",   8,  CH_LAYOUT_7POINT1_WIDE },
00120     { "7.1+downmix", 10, CH_LAYOUT_7POINT1|CH_LAYOUT_STEREO_DOWNMIX, },
00121     { 0 }
00122 };
00123 
00124 void avcodec_get_channel_layout_string(char *buf, int buf_size, int nb_channels, int64_t channel_layout)
00125 {
00126     int i;
00127 
00128     for (i=0; channel_layout_map[i].name; i++)
00129         if (nb_channels    == channel_layout_map[i].nb_channels &&
00130             channel_layout == channel_layout_map[i].layout) {
00131             av_strlcpy(buf, channel_layout_map[i].name, buf_size);
00132             return;
00133         }
00134 
00135     snprintf(buf, buf_size, "%d channels", nb_channels);
00136     if (channel_layout) {
00137         int i,ch;
00138         av_strlcat(buf, " (", buf_size);
00139         for(i=0,ch=0; i<64; i++) {
00140             if ((channel_layout & (1L<<i))) {
00141                 const char *name = get_channel_name(i);
00142                 if (name) {
00143                     if (ch>0) av_strlcat(buf, "|", buf_size);
00144                     av_strlcat(buf, name, buf_size);
00145                 }
00146                 ch++;
00147             }
00148         }
00149         av_strlcat(buf, ")", buf_size);
00150     }
00151 }
00152 
00153 int avcodec_channel_layout_num_channels(int64_t channel_layout)
00154 {
00155     int count;
00156     uint64_t x = channel_layout;
00157     for (count = 0; x; count++)
00158         x &= x-1; // unset lowest set bit
00159     return count;
00160 }
00161 
00162 struct AVAudioConvert {
00163     int in_channels, out_channels;
00164     int fmt_pair;
00165 };
00166 
00167 AVAudioConvert *av_audio_convert_alloc(enum SampleFormat out_fmt, int out_channels,
00168                                        enum SampleFormat in_fmt, int in_channels,
00169                                        const float *matrix, int flags)
00170 {
00171     AVAudioConvert *ctx;
00172     if (in_channels!=out_channels)
00173         return NULL;  /* FIXME: not supported */
00174     ctx = av_malloc(sizeof(AVAudioConvert));
00175     if (!ctx)
00176         return NULL;
00177     ctx->in_channels = in_channels;
00178     ctx->out_channels = out_channels;
00179     ctx->fmt_pair = out_fmt + SAMPLE_FMT_NB*in_fmt;
00180     return ctx;
00181 }
00182 
00183 void av_audio_convert_free(AVAudioConvert *ctx)
00184 {
00185     av_free(ctx);
00186 }
00187 
00188 int av_audio_convert(AVAudioConvert *ctx,
00189                            void * const out[6], const int out_stride[6],
00190                      const void * const  in[6], const int  in_stride[6], int len)
00191 {
00192     int ch;
00193 
00194     //FIXME optimize common cases
00195 
00196     for(ch=0; ch<ctx->out_channels; ch++){
00197         const int is=  in_stride[ch];
00198         const int os= out_stride[ch];
00199         const uint8_t *pi=  in[ch];
00200         uint8_t *po= out[ch];
00201         uint8_t *end= po + os*len;
00202         if(!out[ch])
00203             continue;
00204 
00205 #define CONV(ofmt, otype, ifmt, expr)\
00206 if(ctx->fmt_pair == ofmt + SAMPLE_FMT_NB*ifmt){\
00207     do{\
00208         *(otype*)po = expr; pi += is; po += os;\
00209     }while(po < end);\
00210 }
00211 
00212 //FIXME put things below under ifdefs so we do not waste space for cases no codec will need
00213 //FIXME rounding ?
00214 
00215              CONV(SAMPLE_FMT_U8 , uint8_t, SAMPLE_FMT_U8 ,  *(const uint8_t*)pi)
00216         else CONV(SAMPLE_FMT_S16, int16_t, SAMPLE_FMT_U8 , (*(const uint8_t*)pi - 0x80)<<8)
00217         else CONV(SAMPLE_FMT_S32, int32_t, SAMPLE_FMT_U8 , (*(const uint8_t*)pi - 0x80)<<24)
00218         else CONV(SAMPLE_FMT_FLT, float  , SAMPLE_FMT_U8 , (*(const uint8_t*)pi - 0x80)*(1.0 / (1<<7)))
00219         else CONV(SAMPLE_FMT_DBL, double , SAMPLE_FMT_U8 , (*(const uint8_t*)pi - 0x80)*(1.0 / (1<<7)))
00220         else CONV(SAMPLE_FMT_U8 , uint8_t, SAMPLE_FMT_S16, (*(const int16_t*)pi>>8) + 0x80)
00221         else CONV(SAMPLE_FMT_S16, int16_t, SAMPLE_FMT_S16,  *(const int16_t*)pi)
00222         else CONV(SAMPLE_FMT_S32, int32_t, SAMPLE_FMT_S16,  *(const int16_t*)pi<<16)
00223         else CONV(SAMPLE_FMT_FLT, float  , SAMPLE_FMT_S16,  *(const int16_t*)pi*(1.0 / (1<<15)))
00224         else CONV(SAMPLE_FMT_DBL, double , SAMPLE_FMT_S16,  *(const int16_t*)pi*(1.0 / (1<<15)))
00225         else CONV(SAMPLE_FMT_U8 , uint8_t, SAMPLE_FMT_S32, (*(const int32_t*)pi>>24) + 0x80)
00226         else CONV(SAMPLE_FMT_S16, int16_t, SAMPLE_FMT_S32,  *(const int32_t*)pi>>16)
00227         else CONV(SAMPLE_FMT_S32, int32_t, SAMPLE_FMT_S32,  *(const int32_t*)pi)
00228         else CONV(SAMPLE_FMT_FLT, float  , SAMPLE_FMT_S32,  *(const int32_t*)pi*(1.0 / (1<<31)))
00229         else CONV(SAMPLE_FMT_DBL, double , SAMPLE_FMT_S32,  *(const int32_t*)pi*(1.0 / (1<<31)))
00230         else CONV(SAMPLE_FMT_U8 , uint8_t, SAMPLE_FMT_FLT, av_clip_uint8(  lrintf(*(const float*)pi * (1<<7)) + 0x80))
00231         else CONV(SAMPLE_FMT_S16, int16_t, SAMPLE_FMT_FLT, av_clip_int16(  lrintf(*(const float*)pi * (1<<15))))
00232         else CONV(SAMPLE_FMT_S32, int32_t, SAMPLE_FMT_FLT, av_clipl_int32(llrintf(*(const float*)pi * (1U<<31))))
00233         else CONV(SAMPLE_FMT_FLT, float  , SAMPLE_FMT_FLT, *(const float*)pi)
00234         else CONV(SAMPLE_FMT_DBL, double , SAMPLE_FMT_FLT, *(const float*)pi)
00235         else CONV(SAMPLE_FMT_U8 , uint8_t, SAMPLE_FMT_DBL, av_clip_uint8(  lrint(*(const double*)pi * (1<<7)) + 0x80))
00236         else CONV(SAMPLE_FMT_S16, int16_t, SAMPLE_FMT_DBL, av_clip_int16(  lrint(*(const double*)pi * (1<<15))))
00237         else CONV(SAMPLE_FMT_S32, int32_t, SAMPLE_FMT_DBL, av_clipl_int32(llrint(*(const double*)pi * (1U<<31))))
00238         else CONV(SAMPLE_FMT_FLT, float  , SAMPLE_FMT_DBL, *(const double*)pi)
00239         else CONV(SAMPLE_FMT_DBL, double , SAMPLE_FMT_DBL, *(const double*)pi)
00240         else return -1;
00241     }
00242     return 0;
00243 }

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