audio_windows_source.cc

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/* -*- c++ -*- */
/*
 * Copyright 2004 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 <audio_windows_source.h>
#include <gr_io_signature.h>
//include <sys/soundcard.h>
//include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
#include <iostream>
#include <stdexcept>


static const double CHUNK_TIME = 0.005;	// 5 ms

// FIXME these should query some kind of user preference

static std::string
default_device_name ()
{
  return "/dev/dsp";
}

audio_windows_source::audio_windows_source (int sampling_freq, const std::string device_name)
  : gr_sync_block ("audio_windows_source",
		   gr_make_io_signature (0, 0, 0),
		   gr_make_io_signature (1, 2, sizeof (float))),
    d_sampling_freq (sampling_freq),
    d_device_name (device_name.empty ()? default_device_name () : device_name),
    d_fd (-1), d_buffer (0), d_chunk_size (0)
{
  //FIXME TODO implement me
#if 0
  if ((d_fd = open (d_device_name.c_str (), O_RDONLY)) < 0)
    {
      fprintf (stderr, "audio_windows_source: ");
      perror (d_device_name.c_str ());
      throw
      std::runtime_error ("audio_windows_source");
    }

  d_chunk_size = (int) (d_sampling_freq * CHUNK_TIME);
  set_output_multiple (d_chunk_size);

  d_buffer = new short[d_chunk_size * 2];

  int  format = AFMT_S16_NE;
  int  orig_format = format;
  if (ioctl (d_fd, SNDCTL_DSP_SETFMT, &format) < 0)
    {
      std::
	cerr << "audio_windows_source: " << d_device_name <<
	" ioctl failed\n";
      perror (d_device_name.c_str ());
      throw
      std::runtime_error ("audio_windows_source");
    }

  if (format != orig_format)
    {
      fprintf (stderr, "audio_windows_source: unable to support format %d\n",
	       orig_format);
      fprintf (stderr, "  card requested %d instead.\n", format);
    }

  // set to stereo no matter what.  Some hardware only does stereo
  int channels = 2;
  if (ioctl (d_fd, SNDCTL_DSP_CHANNELS, &channels) < 0 || channels != 2)
    {
      perror ("audio_windows_source: could not set STEREO mode");
      throw
      std::runtime_error ("audio_windows_source");
    }

  // set sampling freq
  int sf = sampling_freq;
  if (ioctl (d_fd, SNDCTL_DSP_SPEED, &sf) < 0)
    {
      std::cerr << "audio_windows_source: "
	<< d_device_name << ": invalid sampling_freq "
	<< sampling_freq << "\n";
      sampling_freq = 8000;
      if (ioctl (d_fd, SNDCTL_DSP_SPEED, &sf) < 0)
	{
	  std::
	    cerr <<
	    "audio_windows_source: failed to set sampling_freq to 8000\n";
	  throw
	  std::runtime_error ("audio_windows_source");
	}
    }
#endif
}

audio_windows_source::~audio_windows_source ()
{
  /*close (d_fd);
     delete [] d_buffer;
   */
}

audio_windows_source_sptr
audio_windows_make_source (int sampling_freq, const std::string dev)
{
  return audio_windows_source_sptr (new
				    audio_windows_source (sampling_freq,
							  dev));
}


int
audio_windows_source::work (int noutput_items,
			    gr_vector_const_void_star & input_items,
			    gr_vector_void_star & output_items)
{
  //FIXME TODO implement me
#if 0
  float *f0 = (float *) output_items[0];
  float *f1 = (float *) output_items[1];	// will be invalid if this is mono output

  const int shorts_per_item = 2;	// L + R
  const int bytes_per_item = shorts_per_item * sizeof (short);

  // To minimize latency, never return more than CHUNK_TIME
  // worth of samples per call to work.
  // FIXME, we need an API to set this value

  noutput_items = std::min (noutput_items, d_chunk_size);

  int base = 0;
  int ntogo = noutput_items;

  while (ntogo > 0)
    {
      int nbytes = std::min (ntogo, d_chunk_size) * bytes_per_item;
      int result_nbytes = read (d_fd, d_buffer, nbytes);

      if (result_nbytes < 0)
	{
	  perror ("audio_windows_source");
	  return -1;		// say we're done
	}

      if ((result_nbytes & (bytes_per_item - 1)) != 0)
	{
	  fprintf (stderr, "audio_windows_source: internal error.\n");
	  throw std::runtime_error ("internal error");
	}

      int result_nitems = result_nbytes / bytes_per_item;

      // now unpack samples into output streams

      switch (output_items.size ())
	{
	case 1:		// mono output
	  for (int i = 0; i < result_nitems; i++)
	    {
	      f0[base + i] = d_buffer[2 * i + 0] * (1.0 / 32767);
	    }
	  break;

	case 2:		// stereo output
	  for (int i = 0; i < result_nitems; i++)
	    {
	      f0[base + i] = d_buffer[2 * i + 0] * (1.0 / 32767);
	      f1[base + i] = d_buffer[2 * i + 1] * (1.0 / 32767);
	    }
	  break;

	default:
	  assert (0);
	}

      ntogo -= result_nitems;
      base += result_nitems;
    }

  return noutput_items - ntogo;
#endif
  return -1;			// EOF
}