1 files changed, 186 insertions, 0 deletions
diff --git a/gr-audio/lib/oss/oss_source.cc b/gr-audio/lib/oss/oss_source.cc
new file mode 100644
index 0000000000..6d6bafceb8
--- /dev/null
+++ b/gr-audio/lib/oss/oss_source.cc
@@ -0,0 +1,186 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2004-2011,2013 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_registry.h"
+#include <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>
+
+namespace gr {
+  namespace audio {
+
+    AUDIO_REGISTER_SOURCE(REG_PRIO_LOW, oss)(int sampling_rate,
+                                             const std::string &device_name,
+                                             bool ok_to_block)
+    {
+      return source::sptr
+        (new 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");
+    }
+
+    oss_source::oss_source(int sampling_rate,
+                           const std::string device_name,
+                           bool ok_to_block)
+      : gr_sync_block("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");
+        }
+      }
+    }
+
+    oss_source::~oss_source()
+    {
+      close(d_fd);
+      delete [] d_buffer;
+    }
+
+    int
+    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;
+    }
+
+  } /* namespace audio */
+} /* namespace gr */