Merge branch 'master' of gnuradio.org:gnuradio

1 files changed, 104 insertions, 0 deletions

diff --git a/gr-audio/lib/alsa/audio_alsa_sink.h b/gr-audio/lib/alsa/audio_alsa_sink.h
new file mode 100644
index 000000000..23e406d6b
--- /dev/null
+++ b/gr-audio/lib/alsa/audio_alsa_sink.h
@@ -0,0 +1,104 @@
+/* -*- 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.
+ */
+
+#ifndef INCLUDED_AUDIO_ALSA_SINK_H
+#define INCLUDED_AUDIO_ALSA_SINK_H
+
+// use new ALSA API
+#define ALSA_PCM_NEW_HW_PARAMS_API
+#define ALSA_PCM_NEW_SW_PARAMS_API
+
+#include <gr_audio_sink.h>
+#include <string>
+#include <alsa/asoundlib.h>
+#include <stdexcept>
+
+/*!
+ * \brief audio sink using ALSA
+ *
+ * The sink has N input streams of floats, where N depends
+ * on the hardware characteristics of the selected device.
+ *
+ * Input samples must be in the range [-1,1].
+ */
+class audio_alsa_sink : public audio_sink {
+  // typedef for pointer to class work method
+  typedef int (audio_alsa_sink::*work_t)(int noutput_items,
+					 gr_vector_const_void_star &input_items,
+					 gr_vector_void_star &output_items);
+
+  unsigned int		d_sampling_rate;
+  std::string		d_device_name;
+  snd_pcm_t            *d_pcm_handle;
+  snd_pcm_hw_params_t  *d_hw_params;
+  snd_pcm_sw_params_t  *d_sw_params;
+  snd_pcm_format_t	d_format;
+  unsigned int		d_nperiods;
+  unsigned int		d_period_time_us;	// microseconds
+  snd_pcm_uframes_t	d_period_size;		// in frames
+  unsigned int		d_buffer_size_bytes;	// sizeof of d_buffer
+  char		       *d_buffer;
+  work_t	        d_worker;		// the work method to use
+  bool			d_special_case_mono_to_stereo;
+
+  // random stats
+  int			d_nunderuns;		// count of underruns
+  int			d_nsuspends;		// count of suspends
+  bool			d_ok_to_block;      // defaults to "true", controls blocking/non-block I/O
+
+  void output_error_msg (const char *msg, int err);
+  void bail (const char *msg, int err) throw (std::runtime_error);
+
+public:
+  audio_alsa_sink (int sampling_rate, const std::string device_name,
+		   bool ok_to_block);
+
+  ~audio_alsa_sink ();
+  
+  bool check_topology (int ninputs, int noutputs);
+
+  int work (int noutput_items,
+	    gr_vector_const_void_star &input_items,
+	    gr_vector_void_star &output_items);
+
+
+protected:
+  bool write_buffer (const void *buffer, unsigned nframes, unsigned sizeof_frame);
+
+  int work_s16 (int noutput_items,
+		gr_vector_const_void_star &input_items,
+		gr_vector_void_star &output_items);
+
+  int work_s16_1x2 (int noutput_items,
+		    gr_vector_const_void_star &input_items,
+		    gr_vector_void_star &output_items);
+
+  int work_s32 (int noutput_items,
+		gr_vector_const_void_star &input_items,
+		gr_vector_void_star &output_items);
+
+  int work_s32_1x2 (int noutput_items,
+		    gr_vector_const_void_star &input_items,
+		    gr_vector_void_star &output_items);
+};
+
+#endif /* INCLUDED_AUDIO_ALSA_SINK_H */