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Diffstat (limited to 'gr-audio/lib/alsa/audio_alsa_source.h')
| -rw-r--r-- | gr-audio/lib/alsa/audio_alsa_source.h | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/gr-audio/lib/alsa/audio_alsa_source.h b/gr-audio/lib/alsa/audio_alsa_source.h new file mode 100644 index 000000000..e38af3872 --- /dev/null +++ b/gr-audio/lib/alsa/audio_alsa_source.h @@ -0,0 +1,106 @@ +/* -*- 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_SOURCE_H +#define INCLUDED_AUDIO_ALSA_SOURCE_H + +// use new ALSA API +#define ALSA_PCM_NEW_HW_PARAMS_API +#define ALSA_PCM_NEW_SW_PARAMS_API + +#include <gr_audio_source.h> +#include <string> +#include <alsa/asoundlib.h> +#include <stdexcept> + +class audio_alsa_source; +typedef boost::shared_ptr<audio_alsa_source> audio_alsa_source_sptr; + +/*! + * \brief audio source using ALSA + * + * The source has between 1 and N input streams of floats, where N is + * depends on the hardware characteristics of the selected device. + * + * Output samples will be in the range [-1,1]. + */ +class audio_alsa_source : public audio_source { + // typedef for pointer to class work method + typedef int (audio_alsa_source::*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 + unsigned int d_hw_nchan; // # of configured h/w channels + bool d_special_case_stereo_to_mono; + + // random stats + int d_noverruns; // count of overruns + int d_nsuspends; // count of suspends + + void output_error_msg (const char *msg, int err); + void bail (const char *msg, int err) throw (std::runtime_error); + +public: + audio_alsa_source (int sampling_rate, const std::string device_name, + bool ok_to_block); + + ~audio_alsa_source (); + + 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 read_buffer (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_2x1 (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_2x1 (int noutput_items, + gr_vector_const_void_star &input_items, + gr_vector_void_star &output_items); +}; + +#endif /* INCLUDED_AUDIO_ALSA_SOURCE_H */ |