git.sesse.net Git - casparcg/blob - core/mixer/audio/audio_mixer.cpp

   1 #include "../../stdafx.h"\r
   2 \r
   3 #include "audio_mixer.h"\r
   4 \r
   5 namespace caspar { namespace core {\r
   6         \r
   7 audio_transform::audio_transform()\r
   8         : gain_(1.0){}\r
   9 \r
  10 void audio_transform::set_gain(double value)\r
  11 {\r
  12         tbb::spin_mutex::scoped_lock lock(mutex_);\r
  13         gain_ = value;\r
  14 }\r
  15 \r
  16 double audio_transform::get_gain() const\r
  17 {\r
  18         tbb::spin_mutex::scoped_lock lock(mutex_);\r
  19         return gain_;\r
  20 }\r
  21 \r
  22 audio_transform& audio_transform::operator*=(const audio_transform &other) \r
  23 {\r
  24         tbb::spin_mutex::scoped_lock lock(mutex_);\r
  25         gain_ *= other.gain_;\r
  26         return *this;\r
  27 }\r
  28 \r
  29 const audio_transform audio_transform::operator*(const audio_transform &other) const \r
  30 {\r
  31         return audio_transform(*this) *= other;\r
  32 }\r
  33 \r
  34 struct audio_mixer::implementation\r
  35 {\r
  36         std::vector<short> audio_data_;\r
  37         std::stack<audio_transform> transform_stack_;\r
  38 \r
  39 public:\r
  40         implementation()\r
  41         {\r
  42                 transform_stack_.push(audio_transform());\r
  43         }\r
  44 \r
  45         void begin(const audio_transform& transform)\r
  46         {\r
  47                 transform_stack_.push(transform_stack_.top()*transform);\r
  48         }\r
  49 \r
  50         void process(const std::vector<short>& audio_data)\r
  51         {               \r
  52                 if(audio_data_.empty())\r
  53                         audio_data_.resize(audio_data.size(), 0);\r
  54 \r
  55                 double gain = transform_stack_.top().get_gain();\r
  56                 tbb::parallel_for\r
  57                 (\r
  58                         tbb::blocked_range<size_t>(0, audio_data.size()),\r
  59                         [&](const tbb::blocked_range<size_t>& r)\r
  60                         {\r
  61                                 for(size_t n = r.begin(); n < r.end(); ++n)\r
  62                                 {\r
  63                                         int sample = static_cast<int>(audio_data[n]);\r
  64                                         sample = (static_cast<int>(gain*8192.0)*sample)/8192;\r
  65                                         audio_data_[n] = static_cast<short>((static_cast<int>(audio_data_[n]) + sample) & 0xFFFF);\r
  66                                 }\r
  67                         }\r
  68                 );\r
  69         }\r
  70 \r
  71         void end()\r
  72         {\r
  73                 transform_stack_.pop();\r
  74         }\r
  75 \r
  76         std::vector<short> begin_pass()\r
  77         {\r
  78                 return std::move(audio_data_);\r
  79         }\r
  80 };\r
  81 \r
  82 audio_mixer::audio_mixer() : impl_(new implementation()){}\r
  83 void audio_mixer::begin(const audio_transform& transform){impl_->begin(transform);}\r
  84 void audio_mixer::process(const std::vector<short>& audio_data){impl_->process(audio_data);}\r
  85 void audio_mixer::end(){impl_->end();}\r
  86 std::vector<short> audio_mixer::begin_pass(){return impl_->begin_pass();}       \r
  87 void audio_mixer::end_pass(){}\r
  88 \r
  89 }}