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

   1 /*\r
   2 * copyright (c) 2010 Sveriges Television AB <info@casparcg.com>\r
   3 *\r
   4 *  This file is part of CasparCG.\r
   5 *\r
   6 *    CasparCG is free software: you can redistribute it and/or modify\r
   7 *    it under the terms of the GNU General Public License as published by\r
   8 *    the Free Software Foundation, either version 3 of the License, or\r
   9 *    (at your option) any later version.\r
  10 *\r
  11 *    CasparCG is distributed in the hope that it will be useful,\r
  12 *    but WITHOUT ANY WARRANTY; without even the implied warranty of\r
  13 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the\r
  14 *    GNU General Public License for more details.\r
  15 \r
  16 *    You should have received a copy of the GNU General Public License\r
  17 *    along with CasparCG.  If not, see <http://www.gnu.org/licenses/>.\r
  18 *\r
  19 */\r
  20 #include "../../stdafx.h"\r
  21 \r
  22 #include "audio_mixer.h"\r
  23 \r
  24 #include <core/mixer/write_frame.h>\r
  25 #include <core/producer/frame/audio_transform.h>\r
  26 \r
  27 namespace caspar { namespace core {\r
  28         \r
  29 struct audio_mixer::implementation\r
  30 {\r
  31         std::deque<std::vector<int16_t>> audio_data_;\r
  32         std::stack<core::audio_transform> transform_stack_;\r
  33 \r
  34         std::map<int, core::audio_transform> prev_audio_transforms_;\r
  35         std::map<int, core::audio_transform> next_audio_transforms_;\r
  36 \r
  37         const core::video_format_desc format_desc_;\r
  38 \r
  39 public:\r
  40         implementation(const core::video_format_desc& format_desc)\r
  41                 : format_desc_(format_desc)\r
  42         {\r
  43                 transform_stack_.push(core::audio_transform());\r
  44                 audio_data_.push_back(std::vector<int16_t>()); // One frame delay\r
  45         }\r
  46         \r
  47         void begin(core::basic_frame& frame)\r
  48         {\r
  49                 transform_stack_.push(transform_stack_.top()*frame.get_audio_transform());\r
  50         }\r
  51 \r
  52         void visit(const core::write_frame& frame)\r
  53         {\r
  54                 if(!transform_stack_.top().get_has_audio() || frame.audio_data().empty())\r
  55                         return;\r
  56 \r
  57                 const auto& audio_data = frame.audio_data();\r
  58                 const auto tag = frame.tag(); // Get the identifier for the audio-stream.\r
  59                                 \r
  60                 const auto next = transform_stack_.top();\r
  61                 auto prev = next;\r
  62 \r
  63                 const auto it = prev_audio_transforms_.find(tag);\r
  64                 if(it != prev_audio_transforms_.end())\r
  65                         prev = it->second;\r
  66                                 \r
  67                 next_audio_transforms_[tag] = next; // Store all active tags, inactive tags will be removed in end_pass.\r
  68                                 \r
  69                 if(next.get_gain() < 0.001 && prev.get_gain() < 0.001)\r
  70                         return;\r
  71                 \r
  72                 static const int BASE = 1<<15;\r
  73 \r
  74                 const auto next_gain = static_cast<int>(next.get_gain()*BASE);\r
  75                 const auto prev_gain = static_cast<int>(prev.get_gain()*BASE);\r
  76                 \r
  77                 const int n_samples = audio_data_.back().size();\r
  78                 \r
  79                 const auto in_size = static_cast<size_t>(audio_data.size());\r
  80                 CASPAR_VERIFY(in_size == 0 || in_size == audio_data_.back().size());\r
  81 \r
  82                 if(in_size > audio_data_.back().size())\r
  83                         return;\r
  84 \r
  85                 tbb::parallel_for\r
  86                 (\r
  87                         tbb::blocked_range<size_t>(0, audio_data.size()),\r
  88                         [&](const tbb::blocked_range<size_t>& r)\r
  89                         {\r
  90                                 for(size_t n = r.begin(); n < r.end(); ++n)\r
  91                                 {\r
  92                                         const int sample_gain = (prev_gain - (prev_gain * n)/n_samples) + (next_gain * n)/n_samples;\r
  93                                         const int sample = (static_cast<int>(audio_data[n])*sample_gain)/BASE;\r
  94                                         audio_data_.back()[n] = static_cast<int16_t>((static_cast<int>(audio_data_.back()[n]) + sample) & 0xFFFF);\r
  95                                 }\r
  96                         }\r
  97                 );\r
  98         }\r
  99 \r
 100         void begin(const core::audio_transform& transform)\r
 101         {\r
 102                 transform_stack_.push(transform_stack_.top()*transform);\r
 103         }\r
 104                 \r
 105         void end()\r
 106         {\r
 107                 transform_stack_.pop();\r
 108         }\r
 109         \r
 110         std::vector<int16_t> mix()\r
 111         {\r
 112                 prev_audio_transforms_ = std::move(next_audio_transforms_);     \r
 113                 auto result = std::move(audio_data_.front());\r
 114                 audio_data_.pop_front();\r
 115                 audio_data_.push_back(std::vector<int16_t>(format_desc_.audio_samples_per_frame));\r
 116                 return std::move(result);\r
 117         }\r
 118 };\r
 119 \r
 120 audio_mixer::audio_mixer(const core::video_format_desc& format_desc) : impl_(new implementation(format_desc)){}\r
 121 void audio_mixer::begin(core::basic_frame& frame){impl_->begin(frame);}\r
 122 void audio_mixer::visit(core::write_frame& frame){impl_->visit(frame);}\r
 123 void audio_mixer::end(){impl_->end();}\r
 124 std::vector<int16_t> audio_mixer::mix(){return impl_->mix();}\r
 125 audio_mixer& audio_mixer::operator=(audio_mixer&& other)\r
 126 {\r
 127         impl_ = std::move(other.impl_);\r
 128         return *this;\r
 129 }\r
 130 \r
 131 }}