libsound/StreamingSound.cpp

   1 // StreamingSound.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 "StreamingSound.h"
  22
  23 #include <cmath>
  24
  25 #include "AudioDecoder.h"
  26 #include "log.h"
  27 #include "SoundUtils.h"
  28
  29 namespace gnash {
  30 namespace sound {
  31
  32 namespace {
  33
  34 int
  35 getInPoint(StreamingSoundData& data, size_t block)
  36 {
  37     if (block >= data.blockCount()) return 0;
  38     const int latency = data.soundinfo.getDelaySeek();
  39
  40     // For the first block just return the latency.
  41     if (block == 0) return latency;
  42
  43     // For subsequent blocks add latency to seekSamples. This is documented
  44     // but not verified.
  45     return swfToOutSamples(data.soundinfo,
  46             latency + data.getSeekSamples(block));
  47 }
  48
  49 }
  50
  51 StreamingSound::StreamingSound(StreamingSoundData& sd,
  52             media::MediaHandler& mh, sound_handler::StreamBlockId block)
  53         :
  54         LiveSound(mh, sd.soundinfo, getInPoint(sd, block)),
  55         _currentBlock(block),
  56         _positionInBlock(0),
  57         _soundDef(sd)
  58 {
  59 }
  60
  61 bool
  62 StreamingSound::moreData()
  63 {
  64     if (decodingCompleted()) return false;
  65
  66     decodeNextBlock();
  67     return true;
  68 }
  69
  70 void
  71 StreamingSound::decodeNextBlock()
  72 {
  73     assert(!decodingCompleted());
  74
  75     // Get the current block of sound data.
  76     const SimpleBuffer& block = _soundDef.getBlock(_currentBlock);
  77
  78     // If we didn't decode all of a block, do so now. Not sure if this
  79     // can happen.
  80     const std::uint32_t inputSize = block.size() - _positionInBlock;
  81
  82     std::uint32_t consumed = 0;
  83
  84     // Empty blocks serve to synchronize, so don't decode but carry on.
  85     if (inputSize) {
  86         std::uint32_t decodedDataSize = 0;
  87         const std::uint8_t* input = block.data() + _positionInBlock;
  88         std::uint8_t* decodedData = decoder().decode(input, inputSize,
  89                 decodedDataSize, consumed);
  90
  91         assert(!(decodedDataSize % 2));
  92
  93         std::int16_t* samples =
  94             reinterpret_cast<std::int16_t*>(decodedData);
  95         unsigned int nSamples = decodedDataSize / 2;
  96
  97         if (_soundDef.volume != 100) {
  98             adjustVolume(samples, samples + nSamples, _soundDef.volume/100.0);
  99         }
 100
 101         // decodedData ownership transferred here
 102         appendDecodedData(decodedData, decodedDataSize);
 103     }
 104
 105     // Check if the entire block was consumed.
 106     if (consumed == block.size()) {
 107         // Go to next block
 108         ++_currentBlock;
 109         _positionInBlock = 0;
 110     }
 111     else _positionInBlock += consumed;
 112
 113 }
 114
 115 bool
 116 StreamingSound::eof() const
 117 {
 118     // it isn't threaded, but just in case, we call decodingCompleted first
 119     return (decodingCompleted() && !decodedSamplesAhead());
 120 }
 121
 122 StreamingSound::~StreamingSound()
 123 {
 124     _soundDef.eraseActiveSound(this);
 125 }
 126
 127 } // gnash.sound namespace
 128 } // namespace gnash
 129