GNU Radio 3.5.3.2 C++ API
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00001 /* -*- c++ -*- */ 00002 /* 00003 * Copyright 2004-2011 Free Software Foundation, Inc. 00004 * 00005 * This file is part of GNU Radio 00006 * 00007 * GNU Radio is free software; you can redistribute it and/or modify 00008 * it under the terms of the GNU General Public License as published by 00009 * the Free Software Foundation; either version 3, or (at your option) 00010 * any later version. 00011 * 00012 * GNU Radio is distributed in the hope that it will be useful, 00013 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00015 * GNU General Public License for more details. 00016 * 00017 * You should have received a copy of the GNU General Public License 00018 * along with GNU Radio; see the file COPYING. If not, write to 00019 * the Free Software Foundation, Inc., 51 Franklin Street, 00020 * Boston, MA 02110-1301, USA. 00021 */ 00022 00023 #ifndef INCLUDED_AUDIO_ALSA_SOURCE_H 00024 #define INCLUDED_AUDIO_ALSA_SOURCE_H 00025 00026 // use new ALSA API 00027 #define ALSA_PCM_NEW_HW_PARAMS_API 00028 #define ALSA_PCM_NEW_SW_PARAMS_API 00029 00030 #include <gr_audio_source.h> 00031 #include <string> 00032 #include <alsa/asoundlib.h> 00033 #include <stdexcept> 00034 00035 class audio_alsa_source; 00036 typedef boost::shared_ptr<audio_alsa_source> audio_alsa_source_sptr; 00037 00038 /*! 00039 * \brief audio source using ALSA 00040 * \ingroup audio_blk 00041 * 00042 * The source has between 1 and N input streams of floats, where N is 00043 * depends on the hardware characteristics of the selected device. 00044 * 00045 * Output samples will be in the range [-1,1]. 00046 */ 00047 class audio_alsa_source : public audio_source { 00048 // typedef for pointer to class work method 00049 typedef int (audio_alsa_source::*work_t)(int noutput_items, 00050 gr_vector_const_void_star &input_items, 00051 gr_vector_void_star &output_items); 00052 00053 unsigned int d_sampling_rate; 00054 std::string d_device_name; 00055 snd_pcm_t *d_pcm_handle; 00056 snd_pcm_hw_params_t *d_hw_params; 00057 snd_pcm_sw_params_t *d_sw_params; 00058 snd_pcm_format_t d_format; 00059 unsigned int d_nperiods; 00060 unsigned int d_period_time_us; // microseconds 00061 snd_pcm_uframes_t d_period_size; // in frames 00062 unsigned int d_buffer_size_bytes; // sizeof of d_buffer 00063 char *d_buffer; 00064 work_t d_worker; // the work method to use 00065 unsigned int d_hw_nchan; // # of configured h/w channels 00066 bool d_special_case_stereo_to_mono; 00067 00068 // random stats 00069 int d_noverruns; // count of overruns 00070 int d_nsuspends; // count of suspends 00071 00072 void output_error_msg (const char *msg, int err); 00073 void bail (const char *msg, int err) throw (std::runtime_error); 00074 00075 public: 00076 audio_alsa_source (int sampling_rate, const std::string device_name, 00077 bool ok_to_block); 00078 00079 ~audio_alsa_source (); 00080 00081 bool check_topology (int ninputs, int noutputs); 00082 00083 int work (int noutput_items, 00084 gr_vector_const_void_star &input_items, 00085 gr_vector_void_star &output_items); 00086 00087 protected: 00088 bool read_buffer (void *buffer, unsigned nframes, unsigned sizeof_frame); 00089 00090 int work_s16 (int noutput_items, 00091 gr_vector_const_void_star &input_items, 00092 gr_vector_void_star &output_items); 00093 00094 int work_s16_2x1 (int noutput_items, 00095 gr_vector_const_void_star &input_items, 00096 gr_vector_void_star &output_items); 00097 00098 int work_s32 (int noutput_items, 00099 gr_vector_const_void_star &input_items, 00100 gr_vector_void_star &output_items); 00101 00102 int work_s32_2x1 (int noutput_items, 00103 gr_vector_const_void_star &input_items, 00104 gr_vector_void_star &output_items); 00105 }; 00106 00107 #endif /* INCLUDED_AUDIO_ALSA_SOURCE_H */