git.sesse.net Git - ffmpeg/blob - libswresample/swresample.c

   1 /*
   2  * Copyright (C) 2011 Michael Niedermayer (michaelni@gmx.at)
   3  *
   4  * This file is part of libswresample
   5  *
   6  * libswresample is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * libswresample is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with libswresample; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #include "libavutil/opt.h"
  22 #include "swresample_internal.h"
  23 #include "audioconvert.h"
  24 #include "libavutil/avassert.h"
  25 #include "libavutil/audioconvert.h"
  26
  27 #define  C30DB  M_SQRT2
  28 #define  C15DB  1.189207115
  29 #define C__0DB  1.0
  30 #define C_15DB  0.840896415
  31 #define C_30DB  M_SQRT1_2
  32 #define C_45DB  0.594603558
  33 #define C_60DB  0.5
  34
  35
  36 //TODO split options array out?
  37 #define OFFSET(x) offsetof(SwrContext,x)
  38 static const AVOption options[]={
  39 {"ich",  "input channel count", OFFSET( in.ch_count   ), AV_OPT_TYPE_INT, {.dbl=2}, 0, SWR_CH_MAX, 0},
  40 {"och", "output channel count", OFFSET(out.ch_count   ), AV_OPT_TYPE_INT, {.dbl=2}, 0, SWR_CH_MAX, 0},
  41 {"uch",   "used channel count", OFFSET(used_ch_count  ), AV_OPT_TYPE_INT, {.dbl=0}, 0, SWR_CH_MAX, 0},
  42 {"isr",  "input sample rate"  , OFFSET( in_sample_rate), AV_OPT_TYPE_INT, {.dbl=48000}, 1, INT_MAX, 0},
  43 {"osr", "output sample rate"  , OFFSET(out_sample_rate), AV_OPT_TYPE_INT, {.dbl=48000}, 1, INT_MAX, 0},
  44 //{"ip" ,  "input planar"       , OFFSET( in.planar     ), AV_OPT_TYPE_INT, {.dbl=0},    0,       1, 0},
  45 //{"op" , "output planar"       , OFFSET(out.planar     ), AV_OPT_TYPE_INT, {.dbl=0},    0,       1, 0},
  46 {"isf",  "input sample format", OFFSET( in_sample_fmt ), AV_OPT_TYPE_INT, {.dbl=AV_SAMPLE_FMT_S16}, 0, AV_SAMPLE_FMT_NB-1+256, 0},
  47 {"osf", "output sample format", OFFSET(out_sample_fmt ), AV_OPT_TYPE_INT, {.dbl=AV_SAMPLE_FMT_S16}, 0, AV_SAMPLE_FMT_NB-1+256, 0},
  48 {"tsf", "internal sample format", OFFSET(int_sample_fmt ), AV_OPT_TYPE_INT, {.dbl=AV_SAMPLE_FMT_NONE}, -1, AV_SAMPLE_FMT_FLT, 0},
  49 {"icl",  "input channel layout" , OFFSET( in_ch_layout), AV_OPT_TYPE_INT64, {.dbl=0}, 0, INT64_MAX, 0, "channel_layout"},
  50 {"ocl",  "output channel layout", OFFSET(out_ch_layout), AV_OPT_TYPE_INT64, {.dbl=0}, 0, INT64_MAX, 0, "channel_layout"},
  51 {"clev", "center mix level"     , OFFSET(clev)         , AV_OPT_TYPE_FLOAT, {.dbl=C_30DB}, 0, 4, 0},
  52 {"slev", "sourround mix level"  , OFFSET(slev)         , AV_OPT_TYPE_FLOAT, {.dbl=C_30DB}, 0, 4, 0},
  53 {"rmvol", "rematrix volume"     , OFFSET(rematrix_volume), AV_OPT_TYPE_FLOAT, {.dbl=1.0}, -1000, 1000, 0},
  54 {"flags", NULL                  , OFFSET(flags)        , AV_OPT_TYPE_FLAGS, {.dbl=0}, 0,  UINT_MAX, 0, "flags"},
  55 {"res", "force resampling", 0, AV_OPT_TYPE_CONST, {.dbl=SWR_FLAG_RESAMPLE}, INT_MIN, INT_MAX, 0, "flags"},
  56 {"dither", "dither method"      , OFFSET(dither_method), AV_OPT_TYPE_INT, {.dbl=0}, 0, SWR_DITHER_NB-1, 0, "dither_method"},
  57 {"rectangular", "rectangular dither", 0, AV_OPT_TYPE_CONST, {.dbl=SWR_DITHER_RECTANGULAR}, INT_MIN, INT_MAX, 0, "dither_method"},
  58 {"triangular" , "triangular dither" , 0, AV_OPT_TYPE_CONST, {.dbl=SWR_DITHER_TRIANGULAR }, INT_MIN, INT_MAX, 0, "dither_method"},
  59
  60 {0}
  61 };
  62
  63 static const char* context_to_name(void* ptr) {
  64     return "SWR";
  65 }
  66
  67 static const AVClass av_class = {
  68     .class_name                = "SwrContext",
  69     .item_name                 = context_to_name,
  70     .option                    = options,
  71     .version                   = LIBAVUTIL_VERSION_INT,
  72     .log_level_offset_offset   = OFFSET(log_level_offset),
  73     .parent_log_context_offset = OFFSET(log_ctx),
  74 };
  75
  76 unsigned swresample_version(void)
  77 {
  78     av_assert0(LIBSWRESAMPLE_VERSION_MICRO >= 100);
  79     return LIBSWRESAMPLE_VERSION_INT;
  80 }
  81
  82 const char *swresample_configuration(void)
  83 {
  84     return FFMPEG_CONFIGURATION;
  85 }
  86
  87 const char *swresample_license(void)
  88 {
  89 #define LICENSE_PREFIX "libswresample license: "
  90     return LICENSE_PREFIX FFMPEG_LICENSE + sizeof(LICENSE_PREFIX) - 1;
  91 }
  92
  93 int swr_set_channel_mapping(struct SwrContext *s, const int *channel_map){
  94     if(!s || s->in_convert) // s needs to be allocated but not initialized
  95         return AVERROR(EINVAL);
  96     s->channel_map = channel_map;
  97     return 0;
  98 }
  99
 100 const AVClass *swr_get_class(void)
 101 {
 102     return &av_class;
 103 }
 104
 105 struct SwrContext *swr_alloc(void){
 106     SwrContext *s= av_mallocz(sizeof(SwrContext));
 107     if(s){
 108         s->av_class= &av_class;
 109         av_opt_set_defaults(s);
 110     }
 111     return s;
 112 }
 113
 114 struct SwrContext *swr_alloc_set_opts(struct SwrContext *s,
 115                                       int64_t out_ch_layout, enum AVSampleFormat out_sample_fmt, int out_sample_rate,
 116                                       int64_t  in_ch_layout, enum AVSampleFormat  in_sample_fmt, int  in_sample_rate,
 117                                       int log_offset, void *log_ctx){
 118     if(!s) s= swr_alloc();
 119     if(!s) return NULL;
 120
 121     s->log_level_offset= log_offset;
 122     s->log_ctx= log_ctx;
 123
 124     av_opt_set_int(s, "ocl", out_ch_layout,   0);
 125     av_opt_set_int(s, "osf", out_sample_fmt,  0);
 126     av_opt_set_int(s, "osr", out_sample_rate, 0);
 127     av_opt_set_int(s, "icl", in_ch_layout,    0);
 128     av_opt_set_int(s, "isf", in_sample_fmt,   0);
 129     av_opt_set_int(s, "isr", in_sample_rate,  0);
 130     av_opt_set_int(s, "tsf", AV_SAMPLE_FMT_NONE,   0);
 131     av_opt_set_int(s, "ich", av_get_channel_layout_nb_channels(s-> in_ch_layout), 0);
 132     av_opt_set_int(s, "och", av_get_channel_layout_nb_channels(s->out_ch_layout), 0);
 133     av_opt_set_int(s, "uch", 0, 0);
 134     return s;
 135 }
 136
 137
 138 static void free_temp(AudioData *a){
 139     av_free(a->data);
 140     memset(a, 0, sizeof(*a));
 141 }
 142
 143 void swr_free(SwrContext **ss){
 144     SwrContext *s= *ss;
 145     if(s){
 146         free_temp(&s->postin);
 147         free_temp(&s->midbuf);
 148         free_temp(&s->preout);
 149         free_temp(&s->in_buffer);
 150         free_temp(&s->dither);
 151         swri_audio_convert_free(&s-> in_convert);
 152         swri_audio_convert_free(&s->out_convert);
 153         swri_audio_convert_free(&s->full_convert);
 154         swri_resample_free(&s->resample);
 155     }
 156
 157     av_freep(ss);
 158 }
 159
 160 int swr_init(struct SwrContext *s){
 161     s->in_buffer_index= 0;
 162     s->in_buffer_count= 0;
 163     s->resample_in_constraint= 0;
 164     free_temp(&s->postin);
 165     free_temp(&s->midbuf);
 166     free_temp(&s->preout);
 167     free_temp(&s->in_buffer);
 168     free_temp(&s->dither);
 169     swri_audio_convert_free(&s-> in_convert);
 170     swri_audio_convert_free(&s->out_convert);
 171     swri_audio_convert_free(&s->full_convert);
 172
 173     s->flushed = 0;
 174
 175     s-> in.planar= av_sample_fmt_is_planar(s-> in_sample_fmt);
 176     s->out.planar= av_sample_fmt_is_planar(s->out_sample_fmt);
 177     s-> in_sample_fmt= av_get_alt_sample_fmt(s-> in_sample_fmt, 0);
 178     s->out_sample_fmt= av_get_alt_sample_fmt(s->out_sample_fmt, 0);
 179
 180     if(s-> in_sample_fmt >= AV_SAMPLE_FMT_NB){
 181         av_log(s, AV_LOG_ERROR, "Requested input sample format %d is invalid\n", s->in_sample_fmt);
 182         return AVERROR(EINVAL);
 183     }
 184     if(s->out_sample_fmt >= AV_SAMPLE_FMT_NB){
 185         av_log(s, AV_LOG_ERROR, "Requested output sample format %d is invalid\n", s->out_sample_fmt);
 186         return AVERROR(EINVAL);
 187     }
 188
 189     //FIXME should we allow/support using FLT on material that doesnt need it ?
 190     if(s->in_sample_fmt <= AV_SAMPLE_FMT_S16 || s->int_sample_fmt==AV_SAMPLE_FMT_S16){
 191         s->int_sample_fmt= AV_SAMPLE_FMT_S16;
 192     }else
 193         s->int_sample_fmt= AV_SAMPLE_FMT_FLT;
 194
 195     if(   s->int_sample_fmt != AV_SAMPLE_FMT_S16
 196         &&s->int_sample_fmt != AV_SAMPLE_FMT_S32
 197         &&s->int_sample_fmt != AV_SAMPLE_FMT_FLT){
 198         av_log(s, AV_LOG_ERROR, "Requested sample format %s is not supported internally, S16/S32/FLT is supported\n", av_get_sample_fmt_name(s->int_sample_fmt));
 199         return AVERROR(EINVAL);
 200     }
 201
 202     if (s->out_sample_rate!=s->in_sample_rate || (s->flags & SWR_FLAG_RESAMPLE)){
 203         s->resample = swri_resample_init(s->resample, s->out_sample_rate, s->in_sample_rate, 16, 10, 0, 0.8, s->int_sample_fmt);
 204     }else
 205         swri_resample_free(&s->resample);
 206     if(    s->int_sample_fmt != AV_SAMPLE_FMT_S16
 207         && s->int_sample_fmt != AV_SAMPLE_FMT_S32
 208         && s->int_sample_fmt != AV_SAMPLE_FMT_FLT
 209         && s->resample){
 210         av_log(s, AV_LOG_ERROR, "Resampling only supported with internal s16/s32/flt\n");
 211         return -1;
 212     }
 213
 214     if(!s->used_ch_count)
 215         s->used_ch_count= s->in.ch_count;
 216
 217     if(s->used_ch_count && s-> in_ch_layout && s->used_ch_count != av_get_channel_layout_nb_channels(s-> in_ch_layout)){
 218         av_log(s, AV_LOG_WARNING, "Input channel layout has a different number of channels than the number of used channels, ignoring layout\n");
 219         s-> in_ch_layout= 0;
 220     }
 221
 222     if(!s-> in_ch_layout)
 223         s-> in_ch_layout= av_get_default_channel_layout(s->used_ch_count);
 224     if(!s->out_ch_layout)
 225         s->out_ch_layout= av_get_default_channel_layout(s->out.ch_count);
 226
 227     s->rematrix= s->out_ch_layout  !=s->in_ch_layout || s->rematrix_volume!=1.0 ||
 228                  s->rematrix_custom;
 229
 230 #define RSC 1 //FIXME finetune
 231     if(!s-> in.ch_count)
 232         s-> in.ch_count= av_get_channel_layout_nb_channels(s-> in_ch_layout);
 233     if(!s->used_ch_count)
 234         s->used_ch_count= s->in.ch_count;
 235     if(!s->out.ch_count)
 236         s->out.ch_count= av_get_channel_layout_nb_channels(s->out_ch_layout);
 237
 238     if(!s-> in.ch_count){
 239         av_assert0(!s->in_ch_layout);
 240         av_log(s, AV_LOG_ERROR, "Input channel count and layout are unset\n");
 241         return -1;
 242     }
 243
 244     if ((!s->out_ch_layout || !s->in_ch_layout) && s->used_ch_count != s->out.ch_count && !s->rematrix_custom) {
 245         av_log(s, AV_LOG_ERROR, "Rematrix is needed but there is not enough information to do it\n");
 246         return -1;
 247     }
 248
 249 av_assert0(s->used_ch_count);
 250 av_assert0(s->out.ch_count);
 251     s->resample_first= RSC*s->out.ch_count/s->in.ch_count - RSC < s->out_sample_rate/(float)s-> in_sample_rate - 1.0;
 252
 253     s-> in.bps= av_get_bytes_per_sample(s-> in_sample_fmt);
 254     s->int_bps= av_get_bytes_per_sample(s->int_sample_fmt);
 255     s->out.bps= av_get_bytes_per_sample(s->out_sample_fmt);
 256     s->in_buffer= s->in;
 257
 258     if(!s->resample && !s->rematrix && !s->channel_map){
 259         s->full_convert = swri_audio_convert_alloc(s->out_sample_fmt,
 260                                                    s-> in_sample_fmt, s-> in.ch_count, NULL, 0);
 261         return 0;
 262     }
 263
 264     s->in_convert = swri_audio_convert_alloc(s->int_sample_fmt,
 265                                              s-> in_sample_fmt, s->used_ch_count, s->channel_map, 0);
 266     s->out_convert= swri_audio_convert_alloc(s->out_sample_fmt,
 267                                              s->int_sample_fmt, s->out.ch_count, NULL, 0);
 268
 269
 270     s->postin= s->in;
 271     s->preout= s->out;
 272     s->midbuf= s->in;
 273
 274     if(s->channel_map){
 275         s->postin.ch_count=
 276         s->midbuf.ch_count= s->used_ch_count;
 277         if(s->resample)
 278             s->in_buffer.ch_count= s->used_ch_count;
 279     }
 280     if(!s->resample_first){
 281         s->midbuf.ch_count= s->out.ch_count;
 282         if(s->resample)
 283             s->in_buffer.ch_count = s->out.ch_count;
 284     }
 285
 286     s->postin.bps    = s->midbuf.bps    = s->preout.bps    =  s->int_bps;
 287     s->postin.planar = s->midbuf.planar = s->preout.planar =  1;
 288
 289     if(s->resample){
 290         s->in_buffer.bps    = s->int_bps;
 291         s->in_buffer.planar = 1;
 292     }
 293
 294     s->dither = s->preout;
 295
 296     if(s->rematrix)
 297         return swri_rematrix_init(s);
 298
 299     return 0;
 300 }
 301
 302 static int realloc_audio(AudioData *a, int count){
 303     int i, countb;
 304     AudioData old;
 305
 306     if(a->count >= count)
 307         return 0;
 308
 309     count*=2;
 310
 311     countb= FFALIGN(count*a->bps, 32);
 312     old= *a;
 313
 314     av_assert0(a->bps);
 315     av_assert0(a->ch_count);
 316
 317     a->data= av_malloc(countb*a->ch_count);
 318     if(!a->data)
 319         return AVERROR(ENOMEM);
 320     for(i=0; i<a->ch_count; i++){
 321         a->ch[i]= a->data + i*(a->planar ? countb : a->bps);
 322         if(a->planar) memcpy(a->ch[i], old.ch[i], a->count*a->bps);
 323     }
 324     if(!a->planar) memcpy(a->ch[0], old.ch[0], a->count*a->ch_count*a->bps);
 325     av_free(old.data);
 326     a->count= count;
 327
 328     return 1;
 329 }
 330
 331 static void copy(AudioData *out, AudioData *in,
 332                  int count){
 333     av_assert0(out->planar == in->planar);
 334     av_assert0(out->bps == in->bps);
 335     av_assert0(out->ch_count == in->ch_count);
 336     if(out->planar){
 337         int ch;
 338         for(ch=0; ch<out->ch_count; ch++)
 339             memcpy(out->ch[ch], in->ch[ch], count*out->bps);
 340     }else
 341         memcpy(out->ch[0], in->ch[0], count*out->ch_count*out->bps);
 342 }
 343
 344 static void fill_audiodata(AudioData *out, uint8_t *in_arg [SWR_CH_MAX]){
 345     int i;
 346     if(out->planar){
 347         for(i=0; i<out->ch_count; i++)
 348             out->ch[i]= in_arg[i];
 349     }else{
 350         for(i=0; i<out->ch_count; i++)
 351             out->ch[i]= in_arg[0] + i*out->bps;
 352     }
 353 }
 354
 355 /**
 356  *
 357  * out may be equal in.
 358  */
 359 static void buf_set(AudioData *out, AudioData *in, int count){
 360     if(in->planar){
 361         int ch;
 362         for(ch=0; ch<out->ch_count; ch++)
 363             out->ch[ch]= in->ch[ch] + count*out->bps;
 364     }else
 365         out->ch[0]= in->ch[0] + count*out->ch_count*out->bps;
 366 }
 367
 368 /**
 369  *
 370  * @return number of samples output per channel
 371  */
 372 static int resample(SwrContext *s, AudioData *out_param, int out_count,
 373                              const AudioData * in_param, int in_count){
 374     AudioData in, out, tmp;
 375     int ret_sum=0;
 376     int border=0;
 377
 378     tmp=out=*out_param;
 379     in =  *in_param;
 380
 381     do{
 382         int ret, size, consumed;
 383         if(!s->resample_in_constraint && s->in_buffer_count){
 384             buf_set(&tmp, &s->in_buffer, s->in_buffer_index);
 385             ret= swri_multiple_resample(s->resample, &out, out_count, &tmp, s->in_buffer_count, &consumed);
 386             out_count -= ret;
 387             ret_sum += ret;
 388             buf_set(&out, &out, ret);
 389             s->in_buffer_count -= consumed;
 390             s->in_buffer_index += consumed;
 391
 392             if(!in_count)
 393                 break;
 394             if(s->in_buffer_count <= border){
 395                 buf_set(&in, &in, -s->in_buffer_count);
 396                 in_count += s->in_buffer_count;
 397                 s->in_buffer_count=0;
 398                 s->in_buffer_index=0;
 399                 border = 0;
 400             }
 401         }
 402
 403         if(in_count && !s->in_buffer_count){
 404             s->in_buffer_index=0;
 405             ret= swri_multiple_resample(s->resample, &out, out_count, &in, in_count, &consumed);
 406             out_count -= ret;
 407             ret_sum += ret;
 408             buf_set(&out, &out, ret);
 409             in_count -= consumed;
 410             buf_set(&in, &in, consumed);
 411         }
 412
 413         //TODO is this check sane considering the advanced copy avoidance below
 414         size= s->in_buffer_index + s->in_buffer_count + in_count;
 415         if(   size > s->in_buffer.count
 416            && s->in_buffer_count + in_count <= s->in_buffer_index){
 417             buf_set(&tmp, &s->in_buffer, s->in_buffer_index);
 418             copy(&s->in_buffer, &tmp, s->in_buffer_count);
 419             s->in_buffer_index=0;
 420         }else
 421             if((ret=realloc_audio(&s->in_buffer, size)) < 0)
 422                 return ret;
 423
 424         if(in_count){
 425             int count= in_count;
 426             if(s->in_buffer_count && s->in_buffer_count+2 < count && out_count) count= s->in_buffer_count+2;
 427
 428             buf_set(&tmp, &s->in_buffer, s->in_buffer_index + s->in_buffer_count);
 429             copy(&tmp, &in, /*in_*/count);
 430             s->in_buffer_count += count;
 431             in_count -= count;
 432             border += count;
 433             buf_set(&in, &in, count);
 434             s->resample_in_constraint= 0;
 435             if(s->in_buffer_count != count || in_count)
 436                 continue;
 437         }
 438         break;
 439     }while(1);
 440
 441     s->resample_in_constraint= !!out_count;
 442
 443     return ret_sum;
 444 }
 445
 446 static int swr_convert_internal(struct SwrContext *s, AudioData *out, int out_count,
 447                                                       AudioData *in , int  in_count){
 448     AudioData *postin, *midbuf, *preout;
 449     int ret/*, in_max*/;
 450     AudioData preout_tmp, midbuf_tmp;
 451
 452     if(s->full_convert){
 453         av_assert0(!s->resample);
 454         swri_audio_convert(s->full_convert, out, in, in_count);
 455         return out_count;
 456     }
 457
 458 //     in_max= out_count*(int64_t)s->in_sample_rate / s->out_sample_rate + resample_filter_taps;
 459 //     in_count= FFMIN(in_count, in_in + 2 - s->hist_buffer_count);
 460
 461     if((ret=realloc_audio(&s->postin, in_count))<0)
 462         return ret;
 463     if(s->resample_first){
 464         av_assert0(s->midbuf.ch_count == s->used_ch_count);
 465         if((ret=realloc_audio(&s->midbuf, out_count))<0)
 466             return ret;
 467     }else{
 468         av_assert0(s->midbuf.ch_count ==  s->out.ch_count);
 469         if((ret=realloc_audio(&s->midbuf,  in_count))<0)
 470             return ret;
 471     }
 472     if((ret=realloc_audio(&s->preout, out_count))<0)
 473         return ret;
 474
 475     postin= &s->postin;
 476
 477     midbuf_tmp= s->midbuf;
 478     midbuf= &midbuf_tmp;
 479     preout_tmp= s->preout;
 480     preout= &preout_tmp;
 481
 482     if(s->int_sample_fmt == s-> in_sample_fmt && s->in.planar)
 483         postin= in;
 484
 485     if(s->resample_first ? !s->resample : !s->rematrix)
 486         midbuf= postin;
 487
 488     if(s->resample_first ? !s->rematrix : !s->resample)
 489         preout= midbuf;
 490
 491     if(s->int_sample_fmt == s->out_sample_fmt && s->out.planar){
 492         if(preout==in){
 493             out_count= FFMIN(out_count, in_count); //TODO check at the end if this is needed or redundant
 494             av_assert0(s->in.planar); //we only support planar internally so it has to be, we support copying non planar though
 495             copy(out, in, out_count);
 496             return out_count;
 497         }
 498         else if(preout==postin) preout= midbuf= postin= out;
 499         else if(preout==midbuf) preout= midbuf= out;
 500         else                    preout= out;
 501     }
 502
 503     if(in != postin){
 504         swri_audio_convert(s->in_convert, postin, in, in_count);
 505     }
 506
 507     if(s->resample_first){
 508         if(postin != midbuf)
 509             out_count= resample(s, midbuf, out_count, postin, in_count);
 510         if(midbuf != preout)
 511             swri_rematrix(s, preout, midbuf, out_count, preout==out);
 512     }else{
 513         if(postin != midbuf)
 514             swri_rematrix(s, midbuf, postin, in_count, midbuf==out);
 515         if(midbuf != preout)
 516             out_count= resample(s, preout, out_count, midbuf, in_count);
 517     }
 518
 519     if(preout != out && out_count){
 520         if(s->dither_method){
 521             int ch;
 522             int dither_count= FFMAX(out_count, 1<<16);
 523             av_assert0(preout != in);
 524
 525             if((ret=realloc_audio(&s->dither, dither_count))<0)
 526                 return ret;
 527             if(ret)
 528                 for(ch=0; ch<s->dither.ch_count; ch++)
 529                     swri_get_dither(s->dither.ch[ch], s->dither.count, 12345678913579<<ch, s->out_sample_fmt, s->int_sample_fmt, s->dither_method);
 530             av_assert0(s->dither.ch_count == preout->ch_count);
 531
 532             if(s->dither_pos + out_count > s->dither.count)
 533                 s->dither_pos = 0;
 534             for(ch=0; ch<preout->ch_count; ch++)
 535                 swri_sum2(s->int_sample_fmt, preout->ch[ch], preout->ch[ch], s->dither.ch[ch] + s->dither.bps * s->dither_pos, 1, 1, out_count);
 536
 537             s->dither_pos += out_count;
 538         }
 539 //FIXME packed doesnt need more than 1 chan here!
 540         swri_audio_convert(s->out_convert, out, preout, out_count);
 541     }
 542     return out_count;
 543 }
 544
 545 int swr_convert(struct SwrContext *s, uint8_t *out_arg[SWR_CH_MAX], int out_count,
 546                                 const uint8_t *in_arg [SWR_CH_MAX], int  in_count){
 547     AudioData * in= &s->in;
 548     AudioData *out= &s->out;
 549
 550     if(!in_arg){
 551         if(s->in_buffer_count){
 552             if (s->resample && !s->flushed) {
 553                 AudioData *a= &s->in_buffer;
 554                 int i, j, ret;
 555                 if((ret=realloc_audio(a, s->in_buffer_index + 2*s->in_buffer_count)) < 0)
 556                     return ret;
 557                 av_assert0(a->planar);
 558                 for(i=0; i<a->ch_count; i++){
 559                     for(j=0; j<s->in_buffer_count; j++){
 560                         memcpy(a->ch[i] + (s->in_buffer_index+s->in_buffer_count+j  )*a->bps,
 561                             a->ch[i] + (s->in_buffer_index+s->in_buffer_count-j-1)*a->bps, a->bps);
 562                     }
 563                 }
 564                 s->in_buffer_count += (s->in_buffer_count+1)/2;
 565                 s->resample_in_constraint = 0;
 566                 s->flushed = 1;
 567             }
 568         }else{
 569             return 0;
 570         }
 571     }else
 572         fill_audiodata(in ,  (void*)in_arg);
 573
 574     fill_audiodata(out, out_arg);
 575
 576     if(s->resample){
 577         return swr_convert_internal(s, out, out_count, in, in_count);
 578     }else{
 579         AudioData tmp= *in;
 580         int ret2=0;
 581         int ret, size;
 582         size = FFMIN(out_count, s->in_buffer_count);
 583         if(size){
 584             buf_set(&tmp, &s->in_buffer, s->in_buffer_index);
 585             ret= swr_convert_internal(s, out, size, &tmp, size);
 586             if(ret<0)
 587                 return ret;
 588             ret2= ret;
 589             s->in_buffer_count -= ret;
 590             s->in_buffer_index += ret;
 591             buf_set(out, out, ret);
 592             out_count -= ret;
 593             if(!s->in_buffer_count)
 594                 s->in_buffer_index = 0;
 595         }
 596
 597         if(in_count){
 598             size= s->in_buffer_index + s->in_buffer_count + in_count - out_count;
 599
 600             if(in_count > out_count) { //FIXME move after swr_convert_internal
 601                 if(   size > s->in_buffer.count
 602                 && s->in_buffer_count + in_count - out_count <= s->in_buffer_index){
 603                     buf_set(&tmp, &s->in_buffer, s->in_buffer_index);
 604                     copy(&s->in_buffer, &tmp, s->in_buffer_count);
 605                     s->in_buffer_index=0;
 606                 }else
 607                     if((ret=realloc_audio(&s->in_buffer, size)) < 0)
 608                         return ret;
 609             }
 610
 611             if(out_count){
 612                 size = FFMIN(in_count, out_count);
 613                 ret= swr_convert_internal(s, out, size, in, size);
 614                 if(ret<0)
 615                     return ret;
 616                 buf_set(in, in, ret);
 617                 in_count -= ret;
 618                 ret2 += ret;
 619             }
 620             if(in_count){
 621                 buf_set(&tmp, &s->in_buffer, s->in_buffer_index);
 622                 copy(&tmp, in, in_count);
 623                 s->in_buffer_count += in_count;
 624             }
 625         }
 626         return ret2;
 627     }
 628 }
 629