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         input&                                                  input_;\r
  44         AVCodecContext&                                 codec_context_;         \r
  45         const core::video_format_desc   format_desc_;\r
  46         std::vector<short>                              current_chunk_;\r
  47         std::vector<std::vector<short>> chunks_;                \r
  48         size_t                                                  frame_number_;\r
  49         bool                                                    restarting_;\r
  50 public:\r
  51         explicit implementation(input& input, const core::video_format_desc& format_desc) \r
  52                 : input_(input)\r
  53                 , codec_context_(*input_.get_audio_codec_context())\r
  54                 , format_desc_(format_desc)     \r
  55                 , frame_number_(0)\r
  56                 , restarting_(false)\r
  57         {\r
  58                 if(codec_context_.sample_rate != static_cast<int>(format_desc_.audio_sample_rate) || \r
  59                    codec_context_.channels != static_cast<int>(format_desc_.audio_channels))\r
  60                 {       \r
  61                         BOOST_THROW_EXCEPTION(\r
  62                                 file_read_error()  <<\r
  63                                 msg_info("Invalid sample-rate or number of channels.") <<\r
  64                                 arg_value_info(boost::lexical_cast<std::string>(codec_context_.sample_rate)) << \r
  65                                 arg_name_info("codec_context"));\r
  66                 }\r
  67         }\r
  68                 \r
  69         std::deque<std::pair<int, std::vector<short>>> receive()\r
  70         {\r
  71                 std::deque<std::pair<int, std::vector<short>>> result;\r
  72                 \r
  73                 std::shared_ptr<AVPacket> pkt;\r
  74                 for(int n = 0; n < 32 && result.empty() && input_.try_pop_audio_packet(pkt); ++n)       \r
  75                         result = decode(pkt);\r
  76 \r
  77                 return result;\r
  78         }\r
  79 \r
  80         std::deque<std::pair<int, std::vector<short>>> decode(const std::shared_ptr<AVPacket>& audio_packet)\r
  81         {                       \r
  82                 std::deque<std::pair<int, std::vector<short>>> result;\r
  83 \r
  84                 if(!audio_packet)\r
  85                 {       \r
  86                         avcodec_flush_buffers(&codec_context_);\r
  87                         current_chunk_.clear();\r
  88                         frame_number_ = 0;\r
  89                         restarting_ = false;\r
  90                         return result;\r
  91                 }\r
  92 \r
  93                 if(restarting_)\r
  94                         return result;\r
  95                                 \r
  96                 auto s = current_chunk_.size();\r
  97                 current_chunk_.resize(s + 4*format_desc_.audio_sample_rate*2+FF_INPUT_BUFFER_PADDING_SIZE/2, 0);\r
  98                 \r
  99                 int written_bytes = (current_chunk_.size() - s)*2 - FF_INPUT_BUFFER_PADDING_SIZE;\r
 100                 const int errn = avcodec_decode_audio3(&codec_context_, &current_chunk_[s], &written_bytes, audio_packet.get());\r
 101                 if(errn < 0)\r
 102                 {       \r
 103                         BOOST_THROW_EXCEPTION(\r
 104                                 invalid_operation() <<\r
 105                                 boost::errinfo_api_function("avcodec_decode_audio2") <<\r
 106                                 boost::errinfo_errno(AVUNERROR(errn)));\r
 107                 }\r
 108 \r
 109                 current_chunk_.resize(s + written_bytes/2);\r
 110 \r
 111                 const auto last = current_chunk_.end() - current_chunk_.size() % format_desc_.audio_samples_per_frame;\r
 112                 \r
 113                 for(auto it = current_chunk_.begin(); it != last; it += format_desc_.audio_samples_per_frame)           \r
 114                         result.push_back(std::make_pair(frame_number_++, std::vector<short>(it, it + format_desc_.audio_samples_per_frame)));           \r
 115 \r
 116                 current_chunk_.erase(current_chunk_.begin(), last);\r
 117 \r
 118                 return result;\r
 119         }\r
 120 \r
 121         void restart()\r
 122         {\r
 123                 restarting_ = true;\r
 124         }\r
 125 };\r
 126 \r
 127 audio_decoder::audio_decoder(input& input, const core::video_format_desc& format_desc) : impl_(new implementation(input, format_desc)){}\r
 128 std::deque<std::pair<int, std::vector<short>>> audio_decoder::receive(){return impl_->receive();}\r
 129 void audio_decoder::restart(){impl_->restart();}\r
 130 }