gr_wavfile_source.cc

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/* -*- c++ -*- */
/*
 * Copyright 2004,2008 Free Software Foundation, Inc.
 *
 * This file is part of GNU Radio
 *
 * GNU Radio 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 3, or (at your option)
 * any later version.
 *
 * GNU Radio 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 GNU Radio; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street,
 * Boston, MA 02110-1301, USA.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <gr_wavfile_source.h>
#include <gr_io_signature.h>
#include <gri_wavfile.h>
#include <cstdio>
#include <sys/types.h>
#include <fcntl.h>
#include <stdexcept>

// win32 (mingw/msvc) specific
#ifdef HAVE_IO_H
#include <io.h>
#endif
#ifdef O_BINARY
#define	OUR_O_BINARY O_BINARY
#else
#define	OUR_O_BINARY 0
#endif
// should be handled via configure
#ifdef O_LARGEFILE
#define	OUR_O_LARGEFILE	O_LARGEFILE
#else
#define	OUR_O_LARGEFILE 0
#endif


gr_wavfile_source_sptr
gr_make_wavfile_source (const char *filename, bool repeat)
{
  return gr_wavfile_source_sptr (new gr_wavfile_source (filename, repeat));
}


gr_wavfile_source::gr_wavfile_source (const char *filename, bool repeat)
  : gr_sync_block ("wavfile_source",
		   gr_make_io_signature (0, 0, 0),
		   gr_make_io_signature (1, 2, sizeof(float))),
    d_fp(NULL), d_repeat(repeat),
    d_sample_rate(1), d_nchans(1), d_bytes_per_sample(2), d_first_sample_pos(0),
    d_samples_per_chan(0), d_sample_idx(0)
{
  // we use "open" to use to the O_LARGEFILE flag

  int fd;
  if ((fd = open (filename, O_RDONLY | OUR_O_LARGEFILE | OUR_O_BINARY)) < 0) {
    perror (filename);
    throw std::runtime_error ("can't open file");
  }

  if ((d_fp = fdopen (fd, "rb")) == NULL) {
    perror (filename);
    throw std::runtime_error ("can't open file");
  }

  // Scan headers, check file validity
  if (!gri_wavheader_parse(d_fp,
			   d_sample_rate,
			   d_nchans,
			   d_bytes_per_sample,
			   d_first_sample_pos,
			   d_samples_per_chan)) {
    throw std::runtime_error("is not a valid wav file");
  }
  
  if (d_samples_per_chan == 0) {
    throw std::runtime_error("WAV file does not contain any samples");
  }

  if (d_bytes_per_sample == 1) {
    d_normalize_fac   = 128;
    d_normalize_shift = 1;
  } else {
    d_normalize_fac   = 0x7FFF;
    d_normalize_shift = 0;
  }

  // Re-set the output signature
  set_output_signature(gr_make_io_signature(1, d_nchans, sizeof(float)));
}


gr_wavfile_source::~gr_wavfile_source ()
{
  fclose(d_fp);
}


int
gr_wavfile_source::work(int noutput_items,
			gr_vector_const_void_star &input_items,
			gr_vector_void_star &output_items)
{
  float **out = (float **) &output_items[0];
  int n_out_chans = output_items.size();

  int i;
  short sample;

  for (i = 0; i < noutput_items; i++) {
    if (d_sample_idx >= d_samples_per_chan) {
      if (!d_repeat) {
	// if nothing was read at all, say we're done.
	return i ? i : -1;
      }

      if (fseek (d_fp, d_first_sample_pos, SEEK_SET) == -1) {
	fprintf(stderr, "[%s] fseek failed\n", __FILE__);
	exit(-1);
      }

      d_sample_idx = 0;
    }
    
    for (int chan = 0; chan < d_nchans; chan++) {
      sample = gri_wav_read_sample(d_fp, d_bytes_per_sample);

      if (chan < n_out_chans) {
	out[chan][i] = convert_to_float(sample);
      }
    }

    d_sample_idx++;
    
    // OK, EOF is not necessarily an error. But we're not going to
    // deal with handling corrupt wav files, so if they give us any
    // trouble they won't be processed. Serves them bloody right.
    if (feof(d_fp) || ferror(d_fp)) {
      if (i == 0) {
	fprintf(stderr, "[%s] WAV file has corrupted header or i/o error\n", __FILE__);
	return -1;
      }
      return i;
    }
  }
  
  return noutput_items;
}


float
gr_wavfile_source::convert_to_float(short int sample)
{
  float sample_out = (float) sample;
  sample_out /= d_normalize_fac;
  sample_out -= d_normalize_shift;
  return sample_out;
}