libaf/af_delay.c

   1 /*
   2  * This audio filter delays the output signal for the different
   3  * channels and can be used for simple position panning.
   4  * An extension for this filter would be a reverb.
   5  *
   6  * This file is part of MPlayer.
   7  *
   8  * MPlayer is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * MPlayer is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License along
  19  * with MPlayer; if not, write to the Free Software Foundation, Inc.,
  20  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  21  */
  22
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <inttypes.h>
  27
  28 #include "af.h"
  29
  30 #define L 65536
  31
  32 #define UPDATEQI(qi) qi=(qi+1)&(L-1)
  33
  34 // Data for specific instances of this filter
  35 typedef struct af_delay_s
  36 {
  37   void* q[AF_NCH];      // Circular queues used for delaying audio signal
  38   int   wi[AF_NCH];     // Write index
  39   int   ri;             // Read index
  40   float d[AF_NCH];      // Delay [ms]
  41 }af_delay_t;
  42
  43 // Initialization and runtime control
  44 static int control(struct af_instance_s* af, int cmd, void* arg)
  45 {
  46   af_delay_t* s = af->setup;
  47   switch(cmd){
  48   case AF_CONTROL_REINIT:{
  49     int i;
  50
  51     // Free prevous delay queues
  52     for(i=0;i<af->data->nch;i++){
  53       if(s->q[i])
  54         free(s->q[i]);
  55     }
  56
  57     af->data->rate   = ((af_data_t*)arg)->rate;
  58     af->data->nch    = ((af_data_t*)arg)->nch;
  59     af->data->format = ((af_data_t*)arg)->format;
  60     af->data->bps    = ((af_data_t*)arg)->bps;
  61
  62     // Allocate new delay queues
  63     for(i=0;i<af->data->nch;i++){
  64       s->q[i] = calloc(L,af->data->bps);
  65       if(NULL == s->q[i])
  66         mp_msg(MSGT_AFILTER, MSGL_FATAL, "[delay] Out of memory\n");
  67     }
  68
  69     return control(af,AF_CONTROL_DELAY_LEN | AF_CONTROL_SET,s->d);
  70   }
  71   case AF_CONTROL_COMMAND_LINE:{
  72     int n = 1;
  73     int i = 0;
  74     char* cl = arg;
  75     while(n && i < AF_NCH ){
  76       sscanf(cl,"%f:%n",&s->d[i],&n);
  77       if(n==0 || cl[n-1] == '\0')
  78         break;
  79       cl=&cl[n];
  80       i++;
  81     }
  82     return AF_OK;
  83   }
  84   case AF_CONTROL_DELAY_LEN | AF_CONTROL_SET:{
  85     int i;
  86     if(AF_OK != af_from_ms(AF_NCH, arg, s->wi, af->data->rate, 0.0, 1000.0))
  87       return AF_ERROR;
  88     s->ri = 0;
  89     for(i=0;i<AF_NCH;i++){
  90       mp_msg(MSGT_AFILTER, MSGL_DBG2, "[delay] Channel %i delayed by %0.3fms\n",
  91              i,clamp(s->d[i],0.0,1000.0));
  92       mp_msg(MSGT_AFILTER, MSGL_DBG3, "[delay] Channel %i delayed by %i samples\n",
  93              i,s->wi[i]);
  94     }
  95     return AF_OK;
  96   }
  97   case AF_CONTROL_DELAY_LEN | AF_CONTROL_GET:{
  98     int i;
  99     for(i=0;i<AF_NCH;i++){
 100       if(s->ri > s->wi[i])
 101         s->wi[i] = L - (s->ri - s->wi[i]);
 102       else
 103         s->wi[i] = s->wi[i] - s->ri;
 104     }
 105     return af_to_ms(AF_NCH, s->wi, arg, af->data->rate);
 106   }
 107   }
 108   return AF_UNKNOWN;
 109 }
 110
 111 // Deallocate memory
 112 static void uninit(struct af_instance_s* af)
 113 {
 114   int i;
 115   if(af->data)
 116     free(af->data);
 117   for(i=0;i<AF_NCH;i++)
 118     if(((af_delay_t*)(af->setup))->q[i])
 119       free(((af_delay_t*)(af->setup))->q[i]);
 120   if(af->setup)
 121     free(af->setup);
 122 }
 123
 124 // Filter data through filter
 125 static af_data_t* play(struct af_instance_s* af, af_data_t* data)
 126 {
 127   af_data_t*    c   = data;      // Current working data
 128   af_delay_t*   s   = af->setup; // Setup for this instance
 129   int           nch = c->nch;    // Number of channels
 130   int           len = c->len/c->bps; // Number of sample in data chunk
 131   int           ri  = 0;
 132   int           ch,i;
 133   for(ch=0;ch<nch;ch++){
 134     switch(c->bps){
 135     case 1:{
 136       int8_t* a = c->audio;
 137       int8_t* q = s->q[ch];
 138       int wi = s->wi[ch];
 139       ri = s->ri;
 140       for(i=ch;i<len;i+=nch){
 141         q[wi] = a[i];
 142         a[i]  = q[ri];
 143         UPDATEQI(wi);
 144         UPDATEQI(ri);
 145       }
 146       s->wi[ch] = wi;
 147       break;
 148     }
 149     case 2:{
 150       int16_t* a = c->audio;
 151       int16_t* q = s->q[ch];
 152       int wi = s->wi[ch];
 153       ri = s->ri;
 154       for(i=ch;i<len;i+=nch){
 155         q[wi] = a[i];
 156         a[i]  = q[ri];
 157         UPDATEQI(wi);
 158         UPDATEQI(ri);
 159       }
 160       s->wi[ch] = wi;
 161       break;
 162     }
 163     case 4:{
 164       int32_t* a = c->audio;
 165       int32_t* q = s->q[ch];
 166       int wi = s->wi[ch];
 167       ri = s->ri;
 168       for(i=ch;i<len;i+=nch){
 169         q[wi] = a[i];
 170         a[i]  = q[ri];
 171         UPDATEQI(wi);
 172         UPDATEQI(ri);
 173       }
 174       s->wi[ch] = wi;
 175       break;
 176     }
 177     }
 178   }
 179   s->ri = ri;
 180   return c;
 181 }
 182
 183 // Allocate memory and set function pointers
 184 static int af_open(af_instance_t* af){
 185   af->control=control;
 186   af->uninit=uninit;
 187   af->play=play;
 188   af->mul=1;
 189   af->data=calloc(1,sizeof(af_data_t));
 190   af->setup=calloc(1,sizeof(af_delay_t));
 191   if(af->data == NULL || af->setup == NULL)
 192     return AF_ERROR;
 193   return AF_OK;
 194 }
 195
 196 // Description of this filter
 197 af_info_t af_info_delay = {
 198     "Delay audio filter",
 199     "delay",
 200     "Anders",
 201     "",
 202     AF_FLAGS_REENTRANT,
 203     af_open
 204 };
 205
 206