doc/doxygen-3.3.0/gr__wavfile__source_8h_source.html

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