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/frame_transform.h>\r
  26 \r
  27 #include <tbb/parallel_for.h>\r
  28 \r
  29 #include <stack>\r
  30 #include <deque>\r
  31 \r
  32 namespace caspar { namespace core {\r
  33 \r
  34 struct audio_item\r
  35 {\r
  36         const void*                             tag;\r
  37         frame_transform                 transform;\r
  38         std::vector<int16_t>    audio_data;\r
  39 };\r
  40         \r
  41 struct audio_mixer::implementation\r
  42 {\r
  43         std::stack<core::frame_transform>                               transform_stack_;\r
  44         std::map<const void*, core::frame_transform>    prev_frame_transforms_;\r
  45         const core::video_format_desc                                   format_desc_;\r
  46         std::vector<audio_item>                                                 items;\r
  47 \r
  48 public:\r
  49         implementation(const core::video_format_desc& format_desc)\r
  50                 : format_desc_(format_desc)\r
  51         {\r
  52                 transform_stack_.push(core::frame_transform());\r
  53         }\r
  54         \r
  55         void begin(core::basic_frame& frame)\r
  56         {\r
  57                 transform_stack_.push(transform_stack_.top()*frame.get_frame_transform());\r
  58         }\r
  59 \r
  60         void visit(const core::write_frame& frame)\r
  61         {\r
  62                 // We only care about the last field.\r
  63                 if(format_desc_.field_mode == field_mode::upper && transform_stack_.top().field_mode == field_mode::upper)\r
  64                         return;\r
  65 \r
  66                 if(format_desc_.field_mode == field_mode::lower && transform_stack_.top().field_mode == field_mode::lower)\r
  67                         return;\r
  68 \r
  69                 // Skip empty audio.\r
  70                 if(transform_stack_.top().volume < 0.002 || frame.audio_data().empty())\r
  71                         return;\r
  72 \r
  73                 audio_item item;\r
  74                 item.tag                = frame.tag();\r
  75                 item.transform  = transform_stack_.top();\r
  76                 item.audio_data = std::vector<int16_t>(frame.audio_data().begin(), frame.audio_data().end());\r
  77 \r
  78                 items.push_back(item);          \r
  79         }\r
  80 \r
  81         void begin(const core::frame_transform& transform)\r
  82         {\r
  83                 transform_stack_.push(transform_stack_.top()*transform);\r
  84         }\r
  85                 \r
  86         void end()\r
  87         {\r
  88                 transform_stack_.pop();\r
  89         }\r
  90         \r
  91         std::vector<int16_t> mix()\r
  92         {\r
  93                 auto result = std::vector<int16_t>(format_desc_.audio_samples_per_frame);\r
  94 \r
  95                 std::map<const void*, core::frame_transform> next_frame_transforms;\r
  96 \r
  97                 BOOST_FOREACH(auto& item, items)\r
  98                 {                               \r
  99                         const auto next = item.transform;\r
 100                         auto prev = next;\r
 101 \r
 102                         const auto it = prev_frame_transforms_.find(item.tag);\r
 103                         if(it != prev_frame_transforms_.end())\r
 104                                 prev = it->second;\r
 105                                 \r
 106                         next_frame_transforms[item.tag] = next; // Store all active tags, inactive tags will be removed at the end.\r
 107                                 \r
 108                         if(next.volume < 0.001 && prev.volume < 0.001)\r
 109                                 continue;\r
 110                 \r
 111                         static const int BASE = 1<<15;\r
 112 \r
 113                         const auto next_volume = static_cast<int>(next.volume*BASE);\r
 114                         const auto prev_volume = static_cast<int>(prev.volume*BASE);\r
 115                 \r
 116                         const int n_samples = result.size();\r
 117                 \r
 118                         const auto in_size = static_cast<size_t>(item.audio_data.size());\r
 119                         CASPAR_VERIFY(in_size == 0 || in_size == result.size());\r
 120 \r
 121                         if(in_size > result.size())\r
 122                                 continue;\r
 123 \r
 124                         tbb::parallel_for\r
 125                         (\r
 126                                 tbb::blocked_range<size_t>(0, item.audio_data.size()),\r
 127                                 [&](const tbb::blocked_range<size_t>& r)\r
 128                                 {\r
 129                                         for(size_t n = r.begin(); n < r.end(); ++n)\r
 130                                         {\r
 131                                                 const int sample_volume = (prev_volume - (prev_volume * n)/n_samples) + (next_volume * n)/n_samples;\r
 132                                                 const int sample = (static_cast<int>(item.audio_data[n])*sample_volume)/BASE;\r
 133                                                 result[n] = static_cast<int16_t>((static_cast<int>(result[n]) + sample) & 0xFFFF);\r
 134                                         }\r
 135                                 }\r
 136                         );\r
 137                 }\r
 138 \r
 139                 items.clear();\r
 140                 prev_frame_transforms_ = std::move(next_frame_transforms);      \r
 141 \r
 142                 return std::move(result);\r
 143         }\r
 144 };\r
 145 \r
 146 audio_mixer::audio_mixer(const core::video_format_desc& format_desc) : impl_(new implementation(format_desc)){}\r
 147 void audio_mixer::begin(core::basic_frame& frame){impl_->begin(frame);}\r
 148 void audio_mixer::visit(core::write_frame& frame){impl_->visit(frame);}\r
 149 void audio_mixer::end(){impl_->end();}\r
 150 std::vector<int16_t> audio_mixer::mix(){return impl_->mix();}\r
 151 audio_mixer& audio_mixer::operator=(audio_mixer&& other)\r
 152 {\r
 153         impl_ = std::move(other.impl_);\r
 154         return *this;\r
 155 }\r
 156 \r
 157 }}