ref: e7049a7fde1f7646df3dcb5a24a877b54dad59b7
dir: /examples/sndfile-resample.c/
/*
** Copyright (C) 2002-2010 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 "config.h"
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <math.h>
#if (HAVE_SNDFILE)
#include <samplerate.h>
#include <sndfile.h>
#define DEFAULT_CONVERTER SRC_SINC_MEDIUM_QUALITY
#define BUFFER_LEN 4096 /*-(1<<16)-*/
static void usage_exit (const char *progname) ;
static sf_count_t sample_rate_convert (SNDFILE *infile, SNDFILE *outfile, int converter, double src_ratio, int channels, double * gain) ;
static double apply_gain (float * data, long frames, int channels, double max, double gain) ;
int
main (int argc, char *argv [])
{ SNDFILE *infile, *outfile = NULL ;
SF_INFO sfinfo ;
sf_count_t count ;
double src_ratio = -1.0, gain = 1.0 ;
int new_sample_rate = -1, k, converter, max_speed = SF_FALSE ;
if (argc == 2 && strcmp (argv [1], "--version") == 0)
{ char buffer [64], *cptr ;
if ((cptr = strrchr (argv [0], '/')) != NULL)
argv [0] = cptr + 1 ;
if ((cptr = strrchr (argv [0], '\\')) != NULL)
argv [0] = cptr + 1 ;
sf_command (NULL, SFC_GET_LIB_VERSION, buffer, sizeof (buffer)) ;
printf ("%s (%s,%s)\n", argv [0], src_get_version (), buffer) ;
exit (0) ;
} ;
if (argc != 5 && argc != 7 && argc != 8)
usage_exit (argv [0]) ;
/* Set default converter. */
converter = DEFAULT_CONVERTER ;
for (k = 1 ; k < argc - 2 ; k++)
{ if (strcmp (argv [k], "--max-speed") == 0)
max_speed = SF_TRUE ;
else if (strcmp (argv [k], "-to") == 0)
{ k ++ ;
new_sample_rate = atoi (argv [k]) ;
}
else if (strcmp (argv [k], "-by") == 0)
{ k ++ ;
src_ratio = atof (argv [k]) ;
}
else if (strcmp (argv [k], "-c") == 0)
{ k ++ ;
converter = atoi (argv [k]) ;
}
else
usage_exit (argv [0]) ;
} ;
if (new_sample_rate <= 0 && src_ratio <= 0.0)
usage_exit (argv [0]) ;
if (src_get_name (converter) == NULL)
{ printf ("Error : bad converter number.\n") ;
usage_exit (argv [0]) ;
} ;
if (strcmp (argv [argc - 2], argv [argc - 1]) == 0)
{ printf ("Error : input and output file names are the same.\n") ;
exit (1) ;
} ;
if ((infile = sf_open (argv [argc - 2], SFM_READ, &sfinfo)) == NULL)
{ printf ("Error : Not able to open input file '%s'\n", argv [argc - 2]) ;
exit (1) ;
} ;
printf ("Input File : %s\n", argv [argc - 2]) ;
printf ("Sample Rate : %d\n", sfinfo.samplerate) ;
printf ("Input Frames : %ld\n\n", (long) sfinfo.frames) ;
if (new_sample_rate > 0)
{ src_ratio = (1.0 * new_sample_rate) / sfinfo.samplerate ;
sfinfo.samplerate = new_sample_rate ;
}
else if (src_is_valid_ratio (src_ratio))
sfinfo.samplerate = (int) floor (sfinfo.samplerate * src_ratio) ;
else
{ printf ("Not able to determine new sample rate. Exiting.\n") ;
sf_close (infile) ;
exit (1) ;
} ;
if (fabs (src_ratio - 1.0) < 1e-20)
{ printf ("Target samplerate and input samplerate are the same. Exiting.\n") ;
sf_close (infile) ;
exit (0) ;
} ;
printf ("SRC Ratio : %f\n", src_ratio) ;
printf ("Converter : %s\n\n", src_get_name (converter)) ;
if (src_is_valid_ratio (src_ratio) == 0)
{ printf ("Error : Sample rate change out of valid range.\n") ;
sf_close (infile) ;
exit (1) ;
} ;
/* Delete the output file length to zero if already exists. */
remove (argv [argc - 1]) ;
printf ("Output file : %s\n", argv [argc - 1]) ;
printf ("Sample Rate : %d\n", sfinfo.samplerate) ;
do
{ sf_close (outfile) ;
if ((outfile = sf_open (argv [argc - 1], SFM_WRITE, &sfinfo)) == NULL)
{ printf ("Error : Not able to open output file '%s'\n", argv [argc - 1]) ;
sf_close (infile) ;
exit (1) ;
} ;
if (max_speed)
{ /* This is mainly for the comparison program tests/src-evaluate.c */
sf_command (outfile, SFC_SET_ADD_PEAK_CHUNK, NULL, SF_FALSE) ;
}
else
{ /* Update the file header after every write. */
sf_command (outfile, SFC_SET_UPDATE_HEADER_AUTO, NULL, SF_TRUE) ;
} ;
sf_command (outfile, SFC_SET_CLIPPING, NULL, SF_TRUE) ;
count = sample_rate_convert (infile, outfile, converter, src_ratio, sfinfo.channels, &gain) ;
}
while (count < 0) ;
printf ("Output Frames : %ld\n\n", (long) count) ;
sf_close (infile) ;
sf_close (outfile) ;
return 0 ;
} /* main */
/*==============================================================================
*/
static sf_count_t
sample_rate_convert (SNDFILE *infile, SNDFILE *outfile, int converter, double src_ratio, int channels, double * gain)
{ static float input [BUFFER_LEN] ;
static float output [BUFFER_LEN] ;
SRC_STATE *src_state ;
SRC_DATA src_data ;
int error ;
double max = 0.0 ;
sf_count_t output_count = 0 ;
sf_seek (infile, 0, SEEK_SET) ;
sf_seek (outfile, 0, SEEK_SET) ;
/* Initialize the sample rate converter. */
if ((src_state = src_new (converter, channels, &error)) == NULL)
{ printf ("\n\nError : src_new() failed : %s.\n\n", src_strerror (error)) ;
exit (1) ;
} ;
src_data.end_of_input = 0 ; /* Set this later. */
/* Start with zero to force load in while loop. */
src_data.input_frames = 0 ;
src_data.data_in = input ;
src_data.src_ratio = src_ratio ;
src_data.data_out = output ;
src_data.output_frames = BUFFER_LEN /channels ;
while (1)
{
/* If the input buffer is empty, refill it. */
if (src_data.input_frames == 0)
{ src_data.input_frames = sf_readf_float (infile, input, BUFFER_LEN / channels) ;
src_data.data_in = input ;
/* The last read will not be a full buffer, so snd_of_input. */
if (src_data.input_frames < BUFFER_LEN / channels)
src_data.end_of_input = SF_TRUE ;
} ;
if ((error = src_process (src_state, &src_data)))
{ printf ("\nError : %s\n", src_strerror (error)) ;
exit (1) ;
} ;
/* Terminate if done. */
if (src_data.end_of_input && src_data.output_frames_gen == 0)
break ;
max = apply_gain (src_data.data_out, src_data.output_frames_gen, channels, max, *gain) ;
/* Write output. */
sf_writef_float (outfile, output, src_data.output_frames_gen) ;
output_count += src_data.output_frames_gen ;
src_data.data_in += src_data.input_frames_used * channels ;
src_data.input_frames -= src_data.input_frames_used ;
} ;
src_state = src_delete (src_state) ;
if (max > 1.0)
{ *gain = 1.0 / max ;
printf ("\nOutput has clipped. Restarting conversion to prevent clipping.\n\n") ;
return -1 ;
} ;
return output_count ;
} /* sample_rate_convert */
static double
apply_gain (float * data, long frames, int channels, double max, double gain)
{
long k ;
for (k = 0 ; k < frames * channels ; k++)
{ data [k] *= gain ;
if (fabs (data [k]) > max)
max = fabs (data [k]) ;
} ;
return max ;
} /* apply_gain */
static void
usage_exit (const char *progname)
{ char lsf_ver [128] ;
const char *cptr ;
int k ;
if ((cptr = strrchr (progname, '/')) != NULL)
progname = cptr + 1 ;
if ((cptr = strrchr (progname, '\\')) != NULL)
progname = cptr + 1 ;
sf_command (NULL, SFC_GET_LIB_VERSION, lsf_ver, sizeof (lsf_ver)) ;
printf ("\n"
" A Sample Rate Converter using libsndfile for file I/O and Secret \n"
" Rabbit Code (aka libsamplerate) for performing the conversion.\n"
" It works on any file format supported by libsndfile with any \n"
" number of channels (limited only by host memory).\n"
"\n"
" %s\n"
" %s\n"
"\n"
" Usage : \n"
" %s -to <new sample rate> [-c <number>] <input file> <output file>\n"
" %s -by <amount> [-c <number>] <input file> <output file>\n"
"\n", src_get_version (), lsf_ver, progname, 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%s\n", k, cptr, k == DEFAULT_CONVERTER ? " (default)" : "") ;
puts ("") ;
exit (1) ;
} /* usage_exit */
/*==============================================================================
*/
#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.mega-nerd.com/libsndfile/).\n"
" It is therefore completely broken and non-functional.\n"
"****************************************************************\n"
"\n"
) ;
return 0 ;
} /* main */
#endif