diff src/libsamplerate-0.1.8/examples/varispeed-play.c @ 0:c7265573341e

Import initial set of sources

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/libsamplerate-0.1.8/examples/varispeed-play.c	Mon Mar 18 14:12:14 2013 +0000
@@ -0,0 +1,282 @@
+/*
+** Copyright (C) 2002-2011 Erik de Castro Lopo <[e-mail]>
+**
+** 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
+