ref: 70079c2dcdc3c79f4f964daad4af6ee11a18c8b8
dir: /examples/varispeed-play.c/
/* ** Copyright (C) 2002,2003 Erik de Castro Lopo <erikd@mega-nerd.com> ** ** This program is free software; you can redistribute it and/or modify ** it under the terms of the GNU General Public License as published by ** the Free Software Foundation; either version 2 of the License, or ** (at your option) any later version. ** ** This program is distributed in the hope that it will be useful, ** but WITHOUT ANY WARRANTY; without even the implied warranty of ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ** GNU General Public License for more details. ** ** You should have received a copy of the GNU General Public License ** along with this program; if not, write to the Free Software ** Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA. */ #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <string.h> #include "config.h" #include <float_cast.h> #if (HAVE_SNDFILE) #include <samplerate.h> #include <sndfile.h> #include "audio_out.h" #define ARRAY_LEN(x) ((int) (sizeof (x) / sizeof ((x) [0]))) #define BUFFER_LEN 4096 #define INPUT_FRAMES 100 #define MIN(a,b) ((a) < (b) ? (a) : (b)) #define MAGIC_NUMBER ((int) ('S' << 16) + ('R' << 8) + ('C')) #ifndef M_PI #define M_PI 3.14159265358979323846264338 #endif typedef struct { int magic ; SNDFILE *sndfile ; SF_INFO sfinfo ; SRC_STATE *src_state ; SRC_DATA src_data ; int freq_point ; int buffer_out_start, buffer_out_end ; float buffer_in [BUFFER_LEN] ; float buffer_out [BUFFER_LEN] ; } CALLBACK_DATA ; static int varispeed_get_data (CALLBACK_DATA *data, float *samples, int frames) ; static void varispeed_play (const char *filename, int converter) ; int main (int argc, char *argv []) { const char *cptr, *progname, *filename ; int k, converter ; converter = SRC_SINC_FASTEST ; progname = argv [0] ; if ((cptr = strrchr (progname, '/')) != NULL) progname = cptr + 1 ; if ((cptr = strrchr (progname, '\\')) != NULL) progname = cptr + 1 ; printf ("\n" " %s\n" "\n" " This is a demo program which plays the given file at a slowly \n" " varying speed. Lots of fun with drum loops and full mixes.\n" "\n" " It uses Secret Rabbit Code (aka libsamplerate) to perform the \n" " vari-speeding and libsndfile for file I/O.\n" "\n", progname) ; if (argc == 2) filename = argv [1] ; else if (argc == 4 && strcmp (argv [1], "-c") == 0) { filename = argv [3] ; converter = atoi (argv [2]) ; } else { printf (" Usage :\n\n %s [-c <number>] <input file>\n\n", progname) ; puts ( " The optional -c argument allows the converter type to be chosen from\n" " the following list :" "\n" ) ; for (k = 0 ; (cptr = src_get_name (k)) != NULL ; k++) printf (" %d : %s\n", k, cptr) ; puts ("") ; exit (1) ; } ; varispeed_play (filename, converter) ; return 0 ; } /* main */ /*============================================================================== */ static void varispeed_play (const char *filename, int converter) { CALLBACK_DATA *data ; AUDIO_OUT *audio_out ; int error ; /* Allocate memory for the callback data. */ if ((data = calloc (1, sizeof (CALLBACK_DATA))) == NULL) { printf ("\n\n%s:%d Calloc failed!\n", __FILE__, __LINE__) ; exit (1) ; } ; data->magic = MAGIC_NUMBER ; if ((data->sndfile = sf_open (filename, SFM_READ, &data->sfinfo)) == NULL) { puts (sf_strerror (NULL)) ; exit (1) ; } ; /* Initialize the sample rate converter. */ if ((data->src_state = src_new (converter, data->sfinfo.channels, &error)) == NULL) { printf ("\n\nError : src_new() failed : %s.\n\n", src_strerror (error)) ; exit (1) ; } ; printf ( " Playing : %s\n" " Converter : %s\n" "\n" " Press <control-c> to exit.\n" "\n", filename, src_get_name (converter)) ; if ((audio_out = audio_open (data->sfinfo.channels, data->sfinfo.samplerate)) == NULL) { printf ("\n\nError : audio_open () failed.\n") ; exit (1) ; } ; /* Set up sample rate converter info. */ data->src_data.end_of_input = 0 ; /* Set this later. */ /* Start with zero to force load in while loop. */ data->src_data.input_frames = 0 ; data->src_data.data_in = data->buffer_in ; /* Start with output frames also zero. */ data->src_data.output_frames_gen = 0 ; data->buffer_out_start = data->buffer_out_end = 0 ; data->src_data.src_ratio = 1.0 ; /* Pass the data and the callbacl function to audio_play */ audio_play ((get_audio_callback_t) varispeed_get_data, audio_out, data) ; /* Cleanup */ audio_close (audio_out) ; sf_close (data->sndfile) ; src_delete (data->src_state) ; free (data) ; } /* varispeed_play */ /*============================================================================== */ static int varispeed_get_data (CALLBACK_DATA *data, float *samples, int frames) { int error, readframes, frame_count, direct_out ; if (data->magic != MAGIC_NUMBER) { printf ("\n\n%s:%d Eeeek, something really bad happened!\n", __FILE__, __LINE__) ; exit (1) ; } ; frame_count = 0 ; if (data->buffer_out_start < data->buffer_out_end) { frame_count = MIN (data->buffer_out_end - data->buffer_out_start, frames) ; memcpy (samples, data->buffer_out + data->sfinfo.channels * data->buffer_out_start, data->sfinfo.channels * frame_count * sizeof (float)) ; data->buffer_out_start += frame_count ; } ; data->buffer_out_start = data->buffer_out_end = 0 ; while (frame_count < frames) { /* Read INPUT_FRAMES frames worth looping at end of file. */ for (readframes = 0 ; readframes < INPUT_FRAMES ; ) { sf_count_t position ; readframes += sf_readf_float (data->sndfile, data->buffer_in + data->sfinfo.channels * readframes, INPUT_FRAMES - readframes) ; position = sf_seek (data->sndfile, 0, SEEK_CUR) ; if (position < 0 || position == data->sfinfo.frames) sf_seek (data->sndfile, 0, SEEK_SET) ; } ; data->src_data.input_frames = readframes ; data->src_data.src_ratio = 1.0 - 0.5 * sin (data->freq_point * 2 * M_PI / 20000) ; data->freq_point ++ ; direct_out = (data->src_data.src_ratio * readframes < frames - frame_count) ? 1 : 0 ; if (direct_out) { data->src_data.data_out = samples + frame_count * data->sfinfo.channels ; data->src_data.output_frames = frames - frame_count ; } else { data->src_data.data_out = data->buffer_out ; data->src_data.output_frames = BUFFER_LEN / data->sfinfo.channels ; } ; if ((error = src_process (data->src_state, &data->src_data))) { printf ("\nError : %s\n\n", src_strerror (error)) ; exit (1) ; } ; if (direct_out) { frame_count += data->src_data.output_frames_gen ; continue ; } ; memcpy (samples + frame_count * data->sfinfo.channels, data->buffer_out, (frames - frame_count) * data->sfinfo.channels * sizeof (float)) ; data->buffer_out_start = frames - frame_count ; data->buffer_out_end = data->src_data.output_frames_gen ; frame_count += frames - frame_count ; } ; return frame_count ; } /* varispeed_get_data */ /*============================================================================== */ #else /* (HAVE_SNFILE == 0) */ /* Alternative main function when libsndfile is not available. */ int main (void) { puts ( "\n" "****************************************************************\n" " This example program was compiled without libsndfile \n" " (http://www.zip.com.au/~erikd/libsndfile/).\n" " It is therefore completely broken and non-functional.\n" "****************************************************************\n" "\n" ) ; return 0 ; } /* main */ #endif /* ** Do not edit or modify anything in this comment block. ** The arch-tag line is a file identity tag for the GNU Arch ** revision control system. ** ** arch-tag: 598a9e5d-b4cd-4c16-9cce-1dc5808a804c */