X-Git-Url: http://git.ieval.ro/?a=blobdiff_plain;f=libsamplerate%2Fexamples%2Fvarispeed-play.c;fp=libsamplerate%2Fexamples%2Fvarispeed-play.c;h=0d0b597326333387604b8221cd8cf5a5b7931619;hb=8529da432e52c7903e8ef3488e60725a099e6e63;hp=0000000000000000000000000000000000000000;hpb=27013d8f68878b8ed2d3f747e26f562d08d7d678;p=audio-libsamplerate.git diff --git a/libsamplerate/examples/varispeed-play.c b/libsamplerate/examples/varispeed-play.c new file mode 100644 index 0000000..0d0b597 --- /dev/null +++ b/libsamplerate/examples/varispeed-play.c @@ -0,0 +1,244 @@ +/* +** Copyright (c) 2002-2016, Erik de Castro Lopo +** All rights reserved. +** +** This code is released under 2-clause BSD license. Please see the +** file at : https://github.com/erikd/libsamplerate/blob/master/COPYING +*/ + +#include +#include +#include +#include + +#include "config.h" + +#include + +#if (HAVE_SNDFILE) + +#include +#include + +#include "audio_out.h" + +#define ARRAY_LEN(x) ((int) (sizeof (x) / sizeof ((x) [0]))) + +#define BUFFER_LEN 4096 +#define VARISPEED_BLOCK_LEN 64 + +#define MIN(a,b) ((a) < (b) ? (a) : (b)) + +#define SRC_MAGIC ((int) ('S' << 16) + ('R' << 8) + ('C')) +#define SNDFILE_MAGIC ((int) ('s' << 24) + ('n' << 20) + ('d' << 16) + ('f' << 12) + ('i' << 8) + ('l' << 4) + 'e') + +#ifndef M_PI +#define M_PI 3.14159265358979323846264338 +#endif + + +typedef struct +{ int magic ; + SNDFILE *sndfile ; + SF_INFO sfinfo ; + + float buffer [BUFFER_LEN] ; +} SNDFILE_CB_DATA ; + +typedef struct +{ int magic ; + + SNDFILE_CB_DATA sf ; + + int freq_point ; + + SRC_STATE *src_state ; + +} SRC_CB_DATA ; + +static int varispeed_get_data (SRC_CB_DATA *data, float *samples, int frames) ; +static void varispeed_play (const char *filename, int converter) ; + +static long src_input_callback (void *cb_data, float **data) ; + +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 ] \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) +{ SRC_CB_DATA data ; + AUDIO_OUT *audio_out ; + int error ; + + memset (&data, 0, sizeof (data)) ; + + data.magic = SRC_MAGIC ; + data.sf.magic = SNDFILE_MAGIC ; + + if ((data.sf.sndfile = sf_open (filename, SFM_READ, &data.sf.sfinfo)) == NULL) + { puts (sf_strerror (NULL)) ; + exit (1) ; + } ; + + /* Initialize the sample rate converter. */ + if ((data.src_state = src_callback_new (src_input_callback, converter, data.sf.sfinfo.channels, &error, &data.sf)) == NULL) + { printf ("\n\nError : src_new() failed : %s.\n\n", src_strerror (error)) ; + exit (1) ; + } ; + + printf ( + + " Playing : %s\n" + " Converter : %s\n" + "\n" + " Press to exit.\n" + "\n", + filename, src_get_name (converter)) ; + + if ((audio_out = audio_open (data.sf.sfinfo.channels, data.sf.sfinfo.samplerate)) == NULL) + { printf ("\n\nError : audio_open () failed.\n") ; + exit (1) ; + } ; + + /* 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.sf.sndfile) ; + src_delete (data.src_state) ; + +} /* varispeed_play */ + +static long +src_input_callback (void *cb_data, float **audio) +{ SNDFILE_CB_DATA * data = (SNDFILE_CB_DATA *) cb_data ; + const int input_frames = ARRAY_LEN (data->buffer) / data->sfinfo.channels ; + int read_frames ; + + if (data->magic != SNDFILE_MAGIC) + { printf ("\n\n%s:%d Eeeek, something really bad happened!\n", __FILE__, __LINE__) ; + exit (1) ; + } ; + + for (read_frames = 0 ; read_frames < input_frames ; ) + { sf_count_t position ; + + read_frames += sf_readf_float (data->sndfile, data->buffer + read_frames * data->sfinfo.channels, input_frames - read_frames) ; + + position = sf_seek (data->sndfile, 0, SEEK_CUR) ; + + if (position < 0 || position == data->sfinfo.frames) + sf_seek (data->sndfile, 0, SEEK_SET) ; + } ; + + *audio = & (data->buffer [0]) ; + + return input_frames ; +} /* src_input_callback */ + + +/*============================================================================== +*/ + +static int +varispeed_get_data (SRC_CB_DATA *data, float *samples, int out_frames) +{ float *output ; + int rc, out_frame_count ; + + if (data->magic != SRC_MAGIC) + { printf ("\n\n%s:%d Eeeek, something really bad happened!\n", __FILE__, __LINE__) ; + exit (1) ; + } ; + + for (out_frame_count = 0 ; out_frame_count < out_frames ; out_frame_count += VARISPEED_BLOCK_LEN) + { double src_ratio = 1.0 - 0.5 * sin (data->freq_point * 2 * M_PI / 20000) ; + + data->freq_point ++ ; + + output = samples + out_frame_count * data->sf.sfinfo.channels ; + + if ((rc = src_callback_read (data->src_state, src_ratio, VARISPEED_BLOCK_LEN, output)) < VARISPEED_BLOCK_LEN) + { printf ("\nError : src_callback_read short output (%d instead of %d)\n\n", rc, VARISPEED_BLOCK_LEN) ; + exit (1) ; + } ; + } ; + + return out_frames ; +} /* 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 +