/*** Copyright (c) 2002-2016, Erik de Castro Lopo <erikd@mega-nerd.com>** All rights reserved.**** This code is released under 2-clause BSD license. Please see the** file at : https://github.com/libsndfile/libsamplerate/blob/master/COPYING*/ #include <stdio.h>#include <stdlib.h>#include <string.h>#include <math.h> #include <samplerate.h> #include "util.h" #define	BUFFER_LEN		2048 static void simple_test (int converter, double ratio) ;static void src_simple_produces_output (int converter, int channels, double src_ratio) ;static void src_simple_produces_output_test (int converter, double src_ratio) ; intmain (void){	static double src_ratios [] =	{	1.0001, 0.099, 0.1, 0.33333333, 0.789, 1.9, 3.1, 9.9, 256.0, 1.0 / 256.0	} ; 	int k ; 	puts ("") ; 	puts ("    Zero Order Hold interpolator :") ;	for (k = 0 ; k < ARRAY_LEN (src_ratios) ; k++)	{	simple_test (SRC_ZERO_ORDER_HOLD, src_ratios [k]) ;		src_simple_produces_output_test (SRC_ZERO_ORDER_HOLD, src_ratios [k]) ;		} 	puts ("    Linear interpolator :") ;	for (k = 0 ; k < ARRAY_LEN (src_ratios) ; k++)	{	simple_test (SRC_LINEAR, src_ratios [k]) ;		src_simple_produces_output_test (SRC_LINEAR, src_ratios [k]) ;		} 	puts ("    Sinc interpolator :") ;	for (k = 0 ; k < ARRAY_LEN (src_ratios) ; k++)	{	simple_test (SRC_SINC_FASTEST, src_ratios [k]) ;		src_simple_produces_output_test (SRC_SINC_FASTEST, src_ratios [k]) ;		} 	puts ("") ; 	return 0 ;} /* main */ static voidsrc_simple_produces_output_test (int converter, double src_ratio){	for (int channels = 1; channels <= 9; channels++)		src_simple_produces_output(converter, channels, src_ratio);} static voidsrc_simple_produces_output (int converter, int channels, double src_ratio){	// Choose a suitable number of frames.	// At least 256 so a conversion ratio of 1/256 can produce any output	const long NUM_FRAMES = 1000;	int error; 	printf ("\tproduces_output\t(SRC ratio = %6.4f, channels = %d) ... ", src_ratio, channels) ;	fflush (stdout) ; 	float *input = calloc (NUM_FRAMES * channels, sizeof (float));	float *output = calloc (NUM_FRAMES * channels, sizeof (float)); 	SRC_DATA src_data;	memset (&src_data, 0, sizeof (src_data)) ;	src_data.data_in = input;	src_data.data_out = output;	src_data.input_frames = NUM_FRAMES;	src_data.output_frames = NUM_FRAMES;	src_data.src_ratio = src_ratio; 	if ((error = src_simple (&src_data, converter, channels)))	{	printf ("\n\nLine %d : %s\n\n", __LINE__, src_strerror (error)) ;		exit (1) ;		} ;	if (src_data.input_frames_used == 0)	{	printf ("\n\nLine %d : No input frames used.\n\n", __LINE__) ;		exit (1) ;		} ;	if (src_data.output_frames_gen == 0)	{	printf ("\n\nLine %d : No output frames generated.\n\n", __LINE__) ;		exit (1) ;		} ;	free(input);	free(output);	puts ("ok") ;}  static voidsimple_test (int converter, double src_ratio){	static float input [BUFFER_LEN], output [BUFFER_LEN] ; 	SRC_DATA	src_data ; 	int input_len, output_len, error, terminate ; 	printf ("\tsimple_test\t(SRC ratio = %6.4f) ................. ", src_ratio) ;	fflush (stdout) ; 	/* Calculate maximun input and output lengths. */	if (src_ratio >= 1.0)	{	output_len = BUFFER_LEN ;		input_len = (int) floor (BUFFER_LEN / src_ratio) ;		}	else	{	input_len = BUFFER_LEN ;		output_len = (int) floor (BUFFER_LEN * src_ratio) ;		} ; 	/* Reduce input_len by 10 so output is longer than necessary. */	input_len -= 10 ; 	if (output_len > BUFFER_LEN)	{	printf ("\n\nLine %d : output_len > BUFFER_LEN\n\n", __LINE__) ;		exit (1) ;		} ; 	memset (&src_data, 0, sizeof (src_data)) ; 	src_data.data_in = input ;	src_data.input_frames = input_len ; 	src_data.src_ratio = src_ratio ; 	src_data.data_out = output ;	src_data.output_frames = BUFFER_LEN ; 	if ((error = src_simple (&src_data, converter, 1)))	{	printf ("\n\nLine %d : %s\n\n", __LINE__, src_strerror (error)) ;		exit (1) ;		} ; 	terminate = (int) ceil ((src_ratio >= 1.0) ? src_ratio : 1.0 / src_ratio) ; 	if (fabs (src_data.output_frames_gen - src_ratio * input_len) > 2 * terminate)	{	printf ("\n\nLine %d : bad output data length %ld should be %d.\n", __LINE__,					src_data.output_frames_gen, (int) floor (src_ratio * input_len)) ;		printf ("\tsrc_ratio  : %.4f\n", src_ratio) ;		printf ("\tinput_len  : %d\n\toutput_len : %d\n\n", input_len, output_len) ;		exit (1) ;		} ; 	puts ("ok") ; 	return ;} /* simple_test */