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diff --git a/gr-audio/lib/alsa/audio_alsa_sink.h b/gr-audio/lib/alsa/audio_alsa_sink.h
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+/* -*- 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 */