GNU Radio 3.5.1 C++ API
gr_wavfile_source.h
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00001 /* -*- c++ -*- */
00002 /*
00003  * Copyright 2004,2008 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_GR_WAVFILE_SOURCE_H
00024 #define INCLUDED_GR_WAVFILE_SOURCE_H
00025 
00026 #include <gr_core_api.h>
00027 #include <gr_sync_block.h>
00028 #include <cstdio>  // for FILE
00029 
00030 class gr_wavfile_source;
00031 typedef boost::shared_ptr<gr_wavfile_source> gr_wavfile_source_sptr;
00032 
00033 GR_CORE_API gr_wavfile_source_sptr
00034 gr_make_wavfile_source (const char *filename, bool repeat = false);
00035 
00036 /*!
00037  * \brief Read stream from a Microsoft PCM (.wav) file, output floats
00038  *
00039  * Unless otherwise called, values are within [-1;1].
00040  * Check gr_make_wavfile_source() for extra info.
00041  *
00042  * \ingroup source_blk
00043  */
00044 
00045 class GR_CORE_API gr_wavfile_source : public gr_sync_block
00046 {
00047 private:
00048   friend GR_CORE_API gr_wavfile_source_sptr gr_make_wavfile_source (const char *filename,
00049                                                               bool repeat);
00050   gr_wavfile_source(const char *filename, bool repeat);
00051 
00052   FILE *d_fp;
00053   bool d_repeat;
00054   
00055   unsigned d_sample_rate;
00056   int d_nchans;
00057   int d_bytes_per_sample;
00058   int d_first_sample_pos;
00059   unsigned d_samples_per_chan;
00060   unsigned d_sample_idx;
00061   int d_normalize_shift;
00062   int d_normalize_fac;
00063   
00064   /*!
00065    * \brief Convert an integer sample value to a float value within [-1;1]
00066    */
00067   float convert_to_float(short int sample);
00068 
00069 public:
00070   ~gr_wavfile_source ();
00071   
00072   int work(int noutput_items,
00073            gr_vector_const_void_star &input_items,
00074            gr_vector_void_star &output_items);
00075 
00076   /*!
00077    * \brief Read the sample rate as specified in the wav file header
00078    */
00079   unsigned int sample_rate() const { return d_sample_rate; };
00080 
00081   /*!
00082    * \brief Return the number of bits per sample as specified in the wav
00083    * file header. Only 8 or 16 bit are supported here.
00084    */
00085   int bits_per_sample() const { return d_bytes_per_sample * 8; };
00086   
00087   /*!
00088    * \brief Return the number of channels in the wav file as specified in
00089    * the wav file header. This is also the max number of outputs you can
00090    * have.
00091    */
00092   int channels() const { return d_nchans; };
00093 };
00094 
00095 #endif /* INCLUDED_GR_WAVFILE_SOURCE_H */