libsound/LiveSound.cpp

   1 // LiveSound.cpp - instance of an embedded sound, for gnash
   2 //
   3 //   Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012
   4 //   Free Software 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
  21 #include "LiveSound.h"
  22
  23 #include <algorithm>
  24 #include <cassert>
  25
  26 #include "log.h"
  27 #include "SoundInfo.h"
  28 #include "MediaHandler.h"
  29
  30 namespace gnash {
  31 namespace sound {
  32
  33 LiveSound::LiveSound(media::MediaHandler& mh, const media::SoundInfo& info,
  34         size_t inPoint)
  35     :
  36     _inPoint(inPoint * 4),
  37     _playbackPosition(_inPoint),
  38     _samplesFetched(0)
  39 {
  40     createDecoder(mh, info);
  41 }
  42
  43 void
  44 LiveSound::createDecoder(media::MediaHandler& mh, const media::SoundInfo& si)
  45 {
  46
  47     media::AudioInfo info(si.getFormat(), si.getSampleRate(),
  48         si.is16bit() ? 2 : 1, si.isStereo(), 0, media::CODEC_TYPE_FLASH);
  49
  50     _decoder.reset(mh.createAudioDecoder(info).release());
  51 }
  52
  53 unsigned int
  54 LiveSound::fetchSamples(std::int16_t* to, unsigned int nSamples)
  55 {
  56     unsigned int fetchedSamples = 0;
  57
  58     while (nSamples) {
  59         unsigned int availableSamples = decodedSamplesAhead();
  60
  61         if (availableSamples) {
  62             const std::int16_t* data = getDecodedData(_playbackPosition);
  63
  64             if (availableSamples >= nSamples) {
  65                 std::copy(data, data + nSamples, to);
  66                 fetchedSamples += nSamples;
  67
  68                 // Update playback position (samples are 16bit)
  69                 _playbackPosition += nSamples * 2;
  70
  71                 break; // fetched all
  72             }
  73             else {
  74                 // not enough decoded samples available:
  75                 // copy what we have and go on
  76                 std::copy(data, data + availableSamples, to);
  77                 fetchedSamples += availableSamples;
  78
  79                 // Update playback position (samples are 16bit)
  80                 _playbackPosition += availableSamples * 2;
  81
  82                 to += availableSamples;
  83                 nSamples -= availableSamples;
  84                 assert(nSamples);
  85             }
  86         }
  87
  88         // Get more data if it's ready. This could involve looping.
  89         // Even if no data is available now, it can become available
  90         // later.
  91         if (!moreData()) break;
  92
  93         // We have looped.
  94         if (!_samplesFetched) continue;
  95     }
  96
  97     // update samples played
  98     _samplesFetched += fetchedSamples;
  99
 100     return fetchedSamples;
 101 }
 102
 103
 104 } // sound namespace
 105 } // namespace gnash
 106