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Diffstat (limited to 'gr-audio/lib/alsa/audio_alsa_sink.h')
-rw-r--r-- | gr-audio/lib/alsa/audio_alsa_sink.h | 104 |
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 */ |