libsound/WAVWriter.cpp

   1 // WAVWriter.cpp: .wav audio writer
   2 //
   3 //   Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010 Free Software
   4 //   Foundation, Inc
   5 //
   6 // This program is free software; you can redistribute it and/or modify
   7 // it under the terms of the GNU General Public License as published by
   8 // the Free Software Foundation; either version 3 of the License, or
   9 // (at your option) any later version.
  10 //
  11 // This program is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15 //
  16 // You should have received a copy of the GNU General Public License
  17 // along with this program; if not, write to the Free Software
  18 // Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19
  20 #include "WAVWriter.h"
  21
  22 #include <cstring> // for strncpy
  23 #include <boost/cstdint.hpp>
  24 #include <fstream> // for composition (file_stream)
  25 #include <iostream>
  26
  27 #include "GnashException.h" // for SoundException
  28 #include "log.h" // will import boost::format too
  29
  30 namespace gnash {
  31 namespace sound {
  32
  33 namespace { // anonymous
  34
  35 // Header of a wave file
  36 // http://ftp.iptel.org/pub/sems/doc/full/current/wav__hdr_8c-source.html
  37 typedef struct{
  38      char rID[4];            // 'RIFF'
  39      boost::uint32_t rLen;
  40      char wID[4];            // 'WAVE'
  41      char fId[4];            // 'fmt '
  42      boost::uint32_t pcm_header_len;   // varies...
  43      boost::int16_t wFormatTag;
  44      boost::int16_t nChannels;      // 1,2 for stereo data is (l,r) pairs
  45      boost::uint32_t nSamplesPerSec;
  46      boost::uint32_t nAvgBytesPerSec;
  47      boost::int16_t nBlockAlign;
  48      boost::int16_t nBitsPerSample;
  49 } WAV_HDR;
  50
  51 // Chunk of wave file
  52 // http://ftp.iptel.org/pub/sems/doc/full/current/wav__hdr_8c-source.html
  53 typedef struct{
  54     char dId[4];            // 'data' or 'fact'
  55     boost::uint32_t dLen;
  56 } CHUNK_HDR;
  57
  58 } // end of anonymous namespace
  59
  60 /* public */
  61 WAVWriter::WAVWriter(const std::string& wavefile)
  62 {
  63         file_stream.open(wavefile.c_str());
  64         if (file_stream.fail()) {
  65             boost::format fmt = boost::format(_("Unable to write file %1%"))
  66                 % wavefile;
  67             throw SoundException(fmt.str());
  68         }
  69         else {
  70             write_wave_header(file_stream);
  71             std::cout << "# Created 44100 16Mhz stereo wave file:\n" <<
  72                     "AUDIOFILE=" << wavefile << std::endl;
  73         }
  74 }
  75
  76 /* public */
  77 WAVWriter::~WAVWriter()
  78 {
  79     if (file_stream) file_stream.close();
  80 }
  81
  82 /* public */
  83 void
  84 WAVWriter::pushSamples(boost::int16_t* from, unsigned int nSamples)
  85 {
  86     // NOTE: if muted, the samples will be silent already
  87         boost::uint8_t* stream = reinterpret_cast<boost::uint8_t*>(from);
  88         unsigned int len = nSamples*2;
  89         file_stream.write((char*) stream, len);
  90
  91 }
  92
  93 /* private */
  94 void
  95 WAVWriter::write_wave_header(std::ofstream& outfile)
  96 {
  97
  98   // allocate wav header
  99   WAV_HDR wav;
 100   CHUNK_HDR chk;
 101
 102   // setup wav header
 103   std::strncpy(wav.rID, "RIFF", 4);
 104   std::strncpy(wav.wID, "WAVE", 4);
 105   std::strncpy(wav.fId, "fmt ", 4);
 106
 107   wav.nBitsPerSample = 16;
 108   wav.nSamplesPerSec = 44100;
 109   wav.nAvgBytesPerSec = 44100;
 110   wav.nAvgBytesPerSec *= wav.nBitsPerSample / 8;
 111   wav.nAvgBytesPerSec *= 2;
 112   wav.nChannels = 2;
 113
 114   wav.pcm_header_len = 16;
 115   wav.wFormatTag = 1;
 116   wav.rLen = sizeof(WAV_HDR) + sizeof(CHUNK_HDR);
 117   wav.nBlockAlign = 2 * wav.nBitsPerSample / 8;
 118
 119   // setup chunk header
 120   std::strncpy(chk.dId, "data", 4);
 121   chk.dLen = 0;
 122
 123   /* write riff/wav header */
 124   outfile.write((char *)&wav, sizeof(WAV_HDR));
 125
 126   /* write chunk header */
 127   outfile.write((char *)&chk, sizeof(CHUNK_HDR));
 128
 129 }
 130
 131
 132 } // gnash.sound namespace
 133 } // namespace gnash