git.sesse.net Git - casparcg/blob - modules/ffmpeg/producer/audio/audio_decoder.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_decoder.h"\r
  23 \r
  24 #if defined(_MSC_VER)\r
  25 #pragma warning (push)\r
  26 #pragma warning (disable : 4244)\r
  27 #endif\r
  28 extern "C" \r
  29 {\r
  30         #define __STDC_CONSTANT_MACROS\r
  31         #define __STDC_LIMIT_MACROS\r
  32         #include <libavformat/avformat.h>\r
  33         #include <libavcodec/avcodec.h>\r
  34 }\r
  35 #if defined(_MSC_VER)\r
  36 #pragma warning (pop)\r
  37 #endif\r
  38 \r
  39 namespace caspar {\r
  40 \r
  41 struct audio_decoder::implementation : boost::noncopyable\r
  42 {       \r
  43         AVCodecContext&                                 codec_context_;         \r
  44         const core::video_format_desc   format_desc_;\r
  45         std::vector<short>                              current_chunk_;\r
  46         std::vector<std::vector<short>> chunks_;                \r
  47         size_t                                                  frame_number_;\r
  48 public:\r
  49         explicit implementation(AVCodecContext& codec_context, const core::video_format_desc& format_desc) \r
  50                 : codec_context_(codec_context)\r
  51                 , format_desc_(format_desc)     \r
  52                 , frame_number_(0)\r
  53         {\r
  54                 if(codec_context_.sample_rate != static_cast<int>(format_desc_.audio_sample_rate) || \r
  55                    codec_context_.channels != static_cast<int>(format_desc_.audio_channels))\r
  56                 {       \r
  57                         BOOST_THROW_EXCEPTION(\r
  58                                 file_read_error()  <<\r
  59                                 msg_info("Invalid sample-rate or number of channels.") <<\r
  60                                 arg_value_info(boost::lexical_cast<std::string>(codec_context_.sample_rate)) << \r
  61                                 arg_name_info("codec_context"));\r
  62                 }\r
  63         }\r
  64                         \r
  65         void push(const std::shared_ptr<AVPacket>& audio_packet)\r
  66         {                       \r
  67                 if(!audio_packet)\r
  68                 {       \r
  69                         avcodec_flush_buffers(&codec_context_);\r
  70                         current_chunk_.clear();\r
  71                         frame_number_ = 0;\r
  72                         return;\r
  73                 }\r
  74                                 \r
  75                 auto s = current_chunk_.size();\r
  76                 current_chunk_.resize(s + 4*format_desc_.audio_sample_rate*2+FF_INPUT_BUFFER_PADDING_SIZE/2, 0);\r
  77                 \r
  78                 int written_bytes = (current_chunk_.size() - s)*2 - FF_INPUT_BUFFER_PADDING_SIZE;\r
  79                 const int errn = avcodec_decode_audio3(&codec_context_, &current_chunk_[s], &written_bytes, audio_packet.get());\r
  80                 if(errn < 0)\r
  81                 {       \r
  82                         BOOST_THROW_EXCEPTION(\r
  83                                 invalid_operation() <<\r
  84                                 boost::errinfo_api_function("avcodec_decode_audio2") <<\r
  85                                 boost::errinfo_errno(AVUNERROR(errn)));\r
  86                 }\r
  87 \r
  88                 current_chunk_.resize(s + written_bytes/2);\r
  89 \r
  90                 const auto last = current_chunk_.end() - current_chunk_.size() % format_desc_.audio_samples_per_frame;\r
  91                 \r
  92                 for(auto it = current_chunk_.begin(); it != last; it += format_desc_.audio_samples_per_frame)           \r
  93                         chunks_.push_back(std::vector<short>(it, it + format_desc_.audio_samples_per_frame));           \r
  94 \r
  95                 current_chunk_.erase(current_chunk_.begin(), last);\r
  96         }\r
  97 \r
  98         bool empty() const\r
  99         {\r
 100                 return chunks_.empty();\r
 101         }\r
 102 \r
 103         std::vector<short> front()\r
 104         {\r
 105                 return chunks_.front();\r
 106         }\r
 107 \r
 108         void pop()\r
 109         {\r
 110                 ++frame_number_;\r
 111                 chunks_.pop_back();\r
 112         }\r
 113 };\r
 114 \r
 115 audio_decoder::audio_decoder(AVCodecContext& codec_context, const core::video_format_desc& format_desc) : impl_(new implementation(codec_context, format_desc)){}\r
 116 void audio_decoder::push(const std::shared_ptr<AVPacket>& audio_packet){impl_->push(std::move(audio_packet));}\r
 117 bool audio_decoder::empty() const {return impl_->empty();}\r
 118 std::vector<short> audio_decoder::front() {return impl_->front();}\r
 119 void audio_decoder::pop(){impl_->pop();}\r
 120 size_t audio_decoder::frame_number() const{return impl_->frame_number_;}\r
 121 }