/*
** 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) ;

int
main (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 void
src_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 void
src_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 void
simple_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 */

