1 files changed, 177 insertions, 0 deletions
diff --git a/gr-audio/lib/oss/audio_oss_source.cc b/gr-audio/lib/oss/audio_oss_source.cc
new file mode 100644
index 000000000..b7d53931d
--- /dev/null
+++ b/gr-audio/lib/oss/audio_oss_source.cc
@@ -0,0 +1,177 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2004-2011 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_audio_registry.h"
+#include <audio_oss_source.h>
+#include <gr_io_signature.h>
+#include <gr_prefs.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>
+
+AUDIO_REGISTER_SOURCE(REG_PRIO_LOW, oss)(
+    int sampling_rate, const std::string &device_name, bool ok_to_block
+){
+    return audio_source::sptr(new audio_oss_source(sampling_rate, device_name, ok_to_block));
+}
+
+static std::string
+default_device_name ()
+{
+  return gr_prefs::singleton()->get_string("audio_oss", "default_input_device", "/dev/dsp");
+}
+
+audio_oss_source::audio_oss_source (int sampling_rate,
+				    const std::string device_name,
+				    bool ok_to_block)
+  : audio_source ("audio_oss_source",
+		   gr_make_io_signature (0, 0, 0),
+		   gr_make_io_signature (1, 2, sizeof (float))),
+    d_sampling_rate (sampling_rate),
+    d_device_name (device_name.empty() ? default_device_name() : device_name),
+    d_fd (-1), d_buffer (0), d_chunk_size (0)
+{
+  if ((d_fd = open (d_device_name.c_str (), O_RDONLY)) < 0){
+    fprintf (stderr, "audio_oss_source: ");
+    perror (d_device_name.c_str ());
+    throw std::runtime_error ("audio_oss_source");
+  }
+
+  double CHUNK_TIME =
+    std::max(0.001, gr_prefs::singleton()->get_double("audio_oss", "latency", 0.005));
+
+  d_chunk_size = (int) (d_sampling_rate * 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_oss_source: " << d_device_name << " ioctl failed\n";
+    perror (d_device_name.c_str ());
+    throw std::runtime_error ("audio_oss_source");
+  }
+
+  if (format != orig_format){
+    fprintf (stderr, "audio_oss_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_oss_source: could not set STEREO mode");
+    throw std::runtime_error ("audio_oss_source");
+  }
+
+  // set sampling freq
+  int sf = sampling_rate;
+  if (ioctl (d_fd, SNDCTL_DSP_SPEED, &sf) < 0){
+    std::cerr << "audio_oss_source: "
+	      << d_device_name << ": invalid sampling_rate "
+	      << sampling_rate << "\n";
+    sampling_rate = 8000;
+    if (ioctl (d_fd, SNDCTL_DSP_SPEED, &sf) < 0){
+      std::cerr << "audio_oss_source: failed to set sampling_rate to 8000\n";
+      throw std::runtime_error ("audio_oss_source");
+    }
+  }
+}
+
+audio_oss_source::~audio_oss_source ()
+{
+  close (d_fd);
+  delete [] d_buffer;
+}
+
+int
+audio_oss_source::work (int noutput_items,
+			gr_vector_const_void_star &input_items,
+			gr_vector_void_star &output_items)
+{
+  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.  
+
+  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_oss_source");
+      return -1;		// say we're done
+    }
+
+    if ((result_nbytes & (bytes_per_item - 1)) != 0){
+      fprintf (stderr, "audio_oss_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;
+}