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 #include "audio_transform.h"\r
   5 \r
   6 namespace caspar { namespace core {\r
   7         \r
   8 struct audio_mixer::implementation\r
   9 {\r
  10         std::vector<short> audio_data_;\r
  11         std::stack<audio_transform> transform_stack_;\r
  12 \r
  13 public:\r
  14         implementation()\r
  15         {\r
  16                 transform_stack_.push(audio_transform());\r
  17         }\r
  18 \r
  19         void begin(const audio_transform& transform)\r
  20         {\r
  21                 transform_stack_.push(transform_stack_.top()*transform);\r
  22         }\r
  23 \r
  24         void process(const std::vector<short>& audio_data)\r
  25         {               \r
  26                 if(audio_data_.empty())\r
  27                         audio_data_.resize(audio_data.size(), 0);\r
  28 \r
  29                 double gain = transform_stack_.top().get_gain();\r
  30                 tbb::parallel_for\r
  31                 (\r
  32                         tbb::blocked_range<size_t>(0, audio_data.size()),\r
  33                         [&](const tbb::blocked_range<size_t>& r)\r
  34                         {\r
  35                                 for(size_t n = r.begin(); n < r.end(); ++n)\r
  36                                 {\r
  37                                         int sample = static_cast<int>(audio_data[n]);\r
  38                                         sample = (static_cast<int>(gain*8192.0)*sample)/8192;\r
  39                                         audio_data_[n] = static_cast<short>((static_cast<int>(audio_data_[n]) + sample) & 0xFFFF);\r
  40                                 }\r
  41                         }\r
  42                 );\r
  43         }\r
  44 \r
  45         void end()\r
  46         {\r
  47                 transform_stack_.pop();\r
  48         }\r
  49 \r
  50         std::vector<short> begin_pass()\r
  51         {\r
  52                 return std::move(audio_data_);\r
  53         }\r
  54 };\r
  55 \r
  56 audio_mixer::audio_mixer() : impl_(new implementation()){}\r
  57 void audio_mixer::begin(const audio_transform& transform){impl_->begin(transform);}\r
  58 void audio_mixer::process(const std::vector<short>& audio_data){impl_->process(audio_data);}\r
  59 void audio_mixer::end(){impl_->end();}\r
  60 std::vector<short> audio_mixer::begin_pass(){return impl_->begin_pass();}       \r
  61 void audio_mixer::end_pass(){}\r
  62 \r
  63 }}