libsamplerate/examples/varispeed-play.c

   1 /*
   2 ** Copyright (c) 2002-2016, Erik de Castro Lopo <erikd@mega-nerd.com>
   3 ** All rights reserved.
   4 **
   5 ** This code is released under 2-clause BSD license. Please see the
   6 ** file at : https://github.com/erikd/libsamplerate/blob/master/COPYING
   7 */
   8
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <unistd.h>
  12 #include <string.h>
  13
  14 #include "config.h"
  15
  16 #include <float_cast.h>
  17
  18 #if (HAVE_SNDFILE)
  19
  20 #include <samplerate.h>
  21 #include <sndfile.h>
  22
  23 #include "audio_out.h"
  24
  25 #define ARRAY_LEN(x)    ((int) (sizeof (x) / sizeof ((x) [0])))
  26
  27 #define BUFFER_LEN                      4096
  28 #define VARISPEED_BLOCK_LEN     64
  29
  30 #define MIN(a,b)                ((a) < (b) ? (a) : (b))
  31
  32 #define SRC_MAGIC               ((int) ('S' << 16) + ('R' << 8) + ('C'))
  33 #define SNDFILE_MAGIC   ((int) ('s' << 24) + ('n' << 20) + ('d' << 16) + ('f' << 12) + ('i' << 8) + ('l' << 4) + 'e')
  34
  35 #ifndef M_PI
  36 #define M_PI                    3.14159265358979323846264338
  37 #endif
  38
  39
  40 typedef struct
  41 {       int                     magic ;
  42         SNDFILE         *sndfile ;
  43         SF_INFO         sfinfo ;
  44
  45         float           buffer  [BUFFER_LEN] ;
  46 } SNDFILE_CB_DATA ;
  47
  48 typedef struct
  49 {       int                     magic ;
  50
  51         SNDFILE_CB_DATA sf ;
  52
  53         int                     freq_point ;
  54
  55         SRC_STATE       *src_state ;
  56
  57 } SRC_CB_DATA ;
  58
  59 static int varispeed_get_data (SRC_CB_DATA *data, float *samples, int frames) ;
  60 static void varispeed_play (const char *filename, int converter) ;
  61
  62 static long src_input_callback (void *cb_data, float **data) ;
  63
  64 int
  65 main (int argc, char *argv [])
  66 {       const char      *cptr, *progname, *filename ;
  67         int                     k, converter ;
  68
  69         converter = SRC_SINC_FASTEST ;
  70
  71         progname = argv [0] ;
  72
  73         if ((cptr = strrchr (progname, '/')) != NULL)
  74                 progname = cptr + 1 ;
  75
  76         if ((cptr = strrchr (progname, '\\')) != NULL)
  77                 progname = cptr + 1 ;
  78
  79         printf ("\n"
  80                 "  %s\n"
  81                 "\n"
  82                 "  This is a demo program which plays the given file at a slowly \n"
  83                 "  varying speed. Lots of fun with drum loops and full mixes.\n"
  84                 "\n"
  85                 "  It uses Secret Rabbit Code (aka libsamplerate) to perform the \n"
  86                 "  vari-speeding and libsndfile for file I/O.\n"
  87                 "\n", progname) ;
  88
  89         if (argc == 2)
  90                 filename = argv [1] ;
  91         else if (argc == 4 && strcmp (argv [1], "-c") == 0)
  92         {       filename = argv [3] ;
  93                 converter = atoi (argv [2]) ;
  94                 }
  95         else
  96         {       printf ("  Usage :\n\n       %s [-c <number>] <input file>\n\n", progname) ;
  97                 puts (
  98                         "  The optional -c argument allows the converter type to be chosen from\n"
  99                         "  the following list :"
 100                         "\n"
 101                         ) ;
 102
 103                 for (k = 0 ; (cptr = src_get_name (k)) != NULL ; k++)
 104                         printf ("       %d : %s\n", k, cptr) ;
 105
 106                 puts ("") ;
 107                 exit (1) ;
 108                 } ;
 109
 110         varispeed_play (filename, converter) ;
 111
 112         return 0 ;
 113 } /* main */
 114
 115 /*==============================================================================
 116 */
 117
 118 static void
 119 varispeed_play (const char *filename, int converter)
 120 {       SRC_CB_DATA             data ;
 121         AUDIO_OUT               *audio_out ;
 122         int                             error ;
 123
 124         memset (&data, 0, sizeof (data)) ;
 125
 126         data.magic = SRC_MAGIC ;
 127         data.sf.magic = SNDFILE_MAGIC ;
 128
 129         if ((data.sf.sndfile = sf_open (filename, SFM_READ, &data.sf.sfinfo)) == NULL)
 130         {       puts (sf_strerror (NULL)) ;
 131                 exit (1) ;
 132                 } ;
 133
 134         /* Initialize the sample rate converter. */
 135         if ((data.src_state = src_callback_new (src_input_callback, converter, data.sf.sfinfo.channels, &error, &data.sf)) == NULL)
 136         {       printf ("\n\nError : src_new() failed : %s.\n\n", src_strerror (error)) ;
 137                 exit (1) ;
 138                 } ;
 139
 140         printf (
 141
 142                 "  Playing   : %s\n"
 143                 "  Converter : %s\n"
 144                 "\n"
 145                 "  Press <control-c> to exit.\n"
 146                 "\n",
 147                 filename, src_get_name (converter)) ;
 148
 149         if ((audio_out = audio_open (data.sf.sfinfo.channels, data.sf.sfinfo.samplerate)) == NULL)
 150         {       printf ("\n\nError : audio_open () failed.\n") ;
 151                 exit (1) ;
 152                 } ;
 153
 154         /* Pass the data and the callbacl function to audio_play */
 155         audio_play ((get_audio_callback_t) varispeed_get_data, audio_out, &data) ;
 156
 157         /* Cleanup */
 158         audio_close (audio_out) ;
 159         sf_close (data.sf.sndfile) ;
 160         src_delete (data.src_state) ;
 161
 162 } /* varispeed_play */
 163
 164 static long
 165 src_input_callback (void *cb_data, float **audio)
 166 {       SNDFILE_CB_DATA * data = (SNDFILE_CB_DATA *) cb_data ;
 167         const int input_frames = ARRAY_LEN (data->buffer) / data->sfinfo.channels ;
 168         int             read_frames ;
 169
 170         if (data->magic != SNDFILE_MAGIC)
 171         {       printf ("\n\n%s:%d Eeeek, something really bad happened!\n", __FILE__, __LINE__) ;
 172                 exit (1) ;
 173                 } ;
 174
 175         for (read_frames = 0 ; read_frames < input_frames ; )
 176         {       sf_count_t position ;
 177
 178                 read_frames += sf_readf_float (data->sndfile, data->buffer + read_frames * data->sfinfo.channels, input_frames - read_frames) ;
 179
 180                 position = sf_seek (data->sndfile, 0, SEEK_CUR) ;
 181
 182                 if (position < 0 || position == data->sfinfo.frames)
 183                         sf_seek (data->sndfile, 0, SEEK_SET) ;
 184                 } ;
 185
 186         *audio = & (data->buffer [0]) ;
 187
 188         return input_frames ;
 189 } /* src_input_callback */
 190
 191
 192 /*==============================================================================
 193 */
 194
 195 static int
 196 varispeed_get_data (SRC_CB_DATA *data, float *samples, int out_frames)
 197 {       float   *output ;
 198         int             rc, out_frame_count ;
 199
 200         if (data->magic != SRC_MAGIC)
 201         {       printf ("\n\n%s:%d Eeeek, something really bad happened!\n", __FILE__, __LINE__) ;
 202                 exit (1) ;
 203                 } ;
 204
 205         for (out_frame_count = 0 ; out_frame_count < out_frames ; out_frame_count += VARISPEED_BLOCK_LEN)
 206         {       double  src_ratio = 1.0 - 0.5 * sin (data->freq_point * 2 * M_PI / 20000) ;
 207
 208                 data->freq_point ++ ;
 209
 210                 output = samples + out_frame_count * data->sf.sfinfo.channels ;
 211
 212                 if ((rc = src_callback_read (data->src_state, src_ratio, VARISPEED_BLOCK_LEN, output)) < VARISPEED_BLOCK_LEN)
 213                 {       printf ("\nError : src_callback_read short output (%d instead of %d)\n\n", rc, VARISPEED_BLOCK_LEN) ;
 214                         exit (1) ;
 215                         } ;
 216                 } ;
 217
 218         return out_frames ;
 219 } /* varispeed_get_data */
 220
 221 /*==============================================================================
 222 */
 223
 224 #else /* (HAVE_SNFILE == 0) */
 225
 226 /* Alternative main function when libsndfile is not available. */
 227
 228 int
 229 main (void)
 230 {       puts (
 231                 "\n"
 232                 "****************************************************************\n"
 233                 " This example program was compiled without libsndfile \n"
 234                 " (http://www.zip.com.au/~erikd/libsndfile/).\n"
 235                 " It is therefore completely broken and non-functional.\n"
 236                 "****************************************************************\n"
 237                 "\n"
 238                 ) ;
 239
 240         return 0 ;
 241 } /* main */
 242
 243 #endif
 244