2 * Copyright (c) 2011 Sveriges Television AB <info@casparcg.com>
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4 * This file is part of CasparCG (www.casparcg.com).
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6 * CasparCG is free software: you can redistribute it and/or modify
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7 * it under the terms of the GNU General Public License as published by
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8 * the Free Software Foundation, either version 3 of the License, or
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9 * (at your option) any later version.
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11 * CasparCG is distributed in the hope that it will be useful,
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12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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14 * GNU General Public License for more details.
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16 * You should have received a copy of the GNU General Public License
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17 * along with CasparCG. If not, see <http://www.gnu.org/licenses/>.
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19 * Author: Robert Nagy, ronag89@gmail.com
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22 #include "../../stdafx.h"
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24 #include "audio_mixer.h"
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26 #include <core/mixer/write_frame.h>
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27 #include <core/producer/frame/frame_transform.h>
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29 #include <tbb/cache_aligned_allocator.h>
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31 #include <boost/range/adaptors.hpp>
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32 #include <boost/range/distance.hpp>
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38 namespace caspar { namespace core {
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43 frame_transform transform;
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44 audio_buffer audio_data;
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50 audio_item(audio_item&& other)
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51 : tag(std::move(other.tag))
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52 , transform(std::move(other.transform))
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53 , audio_data(std::move(other.audio_data))
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58 typedef std::vector<float, tbb::cache_aligned_allocator<float>> audio_buffer_ps;
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62 frame_transform prev_transform;
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63 audio_buffer_ps audio_data;
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66 struct audio_mixer::implementation
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68 std::stack<core::frame_transform> transform_stack_;
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69 std::map<const void*, audio_stream> audio_streams_;
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70 std::vector<audio_item> items_;
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71 std::vector<size_t> audio_cadence_;
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72 video_format_desc format_desc_;
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76 : format_desc_(video_format_desc::get(video_format::invalid))
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78 transform_stack_.push(core::frame_transform());
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81 void begin(core::basic_frame& frame)
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83 transform_stack_.push(transform_stack_.top()*frame.get_frame_transform());
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86 void visit(core::write_frame& frame)
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88 if(transform_stack_.top().volume < 0.002 || frame.audio_data().empty())
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92 item.tag = frame.tag();
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93 item.transform = transform_stack_.top();
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94 item.audio_data = std::move(frame.audio_data()); // Note: We don't need to care about upper/lower since audio_data is removed/moved from the last field.
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96 items_.push_back(std::move(item));
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99 void begin(const core::frame_transform& transform)
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101 transform_stack_.push(transform_stack_.top()*transform);
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106 transform_stack_.pop();
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109 audio_buffer mix(const video_format_desc& format_desc)
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111 if(format_desc_ != format_desc)
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113 audio_streams_.clear();
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114 audio_cadence_ = format_desc.audio_cadence;
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115 format_desc_ = format_desc;
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118 std::map<const void*, audio_stream> next_audio_streams;
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120 BOOST_FOREACH(auto& item, items_)
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122 audio_buffer_ps next_audio;
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124 auto next_transform = item.transform;
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125 auto prev_transform = next_transform;
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127 const auto it = audio_streams_.find(item.tag);
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128 if(it != audio_streams_.end())
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130 prev_transform = it->second.prev_transform;
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131 next_audio = std::move(it->second.audio_data);
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134 if(prev_transform.volume < 0.001 && next_transform.volume < 0.001)
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137 const float prev_volume = static_cast<float>(prev_transform.volume);
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138 const float next_volume = static_cast<float>(next_transform.volume);
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140 auto alpha = (next_volume-prev_volume)/static_cast<float>(item.audio_data.size()/format_desc.audio_channels);
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142 for(size_t n = 0; n < item.audio_data.size(); ++n)
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143 next_audio.push_back(item.audio_data[n] * (prev_volume + (n/format_desc_.audio_channels) * alpha));
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145 next_audio_streams[item.tag].prev_transform = std::move(next_transform); // Store all active tags, inactive tags will be removed at the end.
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146 next_audio_streams[item.tag].audio_data = std::move(next_audio);
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151 audio_streams_ = std::move(next_audio_streams);
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153 if(audio_streams_.empty())
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154 audio_streams_[nullptr].audio_data = audio_buffer_ps(audio_cadence_.front(), 0.0f);
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158 auto nb_invalid_streams = boost::count_if(audio_streams_ | boost::adaptors::map_values, [&](const audio_stream& x)
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160 return x.audio_data.size() < audio_cadence_.front();
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163 if(nb_invalid_streams > 0)
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164 CASPAR_LOG(trace) << "[audio_mixer] Incorrect frame audio cadence detected.";
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167 std::vector<float> result_ps(audio_cadence_.front(), 0.0f);
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168 BOOST_FOREACH(auto& stream, audio_streams_ | boost::adaptors::map_values)
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170 auto out = boost::range::transform(result_ps, stream.audio_data, std::begin(result_ps), std::plus<float>());
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171 stream.audio_data.erase(std::begin(stream.audio_data), std::begin(stream.audio_data) + std::distance(std::begin(result_ps), out));
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174 boost::range::rotate(audio_cadence_, std::begin(audio_cadence_)+1);
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176 audio_buffer result;
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177 result.reserve(result_ps.size());
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178 boost::range::transform(result_ps, std::back_inserter(result), [](float sample){return static_cast<int32_t>(sample);});
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183 audio_mixer::audio_mixer() : impl_(new implementation()){}
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184 void audio_mixer::begin(core::basic_frame& frame){impl_->begin(frame);}
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185 void audio_mixer::visit(core::write_frame& frame){impl_->visit(frame);}
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186 void audio_mixer::end(){impl_->end();}
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187 audio_buffer audio_mixer::operator()(const video_format_desc& format_desc){return impl_->mix(format_desc);}
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