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<int16_t>                    current_chunk_; \r
  47         size_t                                                  frame_number_;\r
  48         bool                                                    restarting_;\r
  49 public:\r
  50         explicit implementation(input& input, const core::video_format_desc& format_desc) \r
  51                 : input_(input)\r
  52                 , codec_context_(*input_.get_audio_codec_context())\r
  53                 , format_desc_(format_desc)     \r
  54                 , frame_number_(0)\r
  55                 , restarting_(false)\r
  56         {\r
  57                 if(codec_context_.sample_rate != static_cast<int>(format_desc_.audio_sample_rate) || \r
  58                    codec_context_.channels != static_cast<int>(format_desc_.audio_channels))\r
  59                 {       \r
  60                         BOOST_THROW_EXCEPTION(\r
  61                                 file_read_error()  <<\r
  62                                 msg_info("Invalid sample-rate or number of channels.") <<\r
  63                                 arg_value_info(boost::lexical_cast<std::string>(codec_context_.sample_rate)) << \r
  64                                 arg_name_info("codec_context"));\r
  65                 }\r
  66         }\r
  67                 \r
  68         std::deque<std::pair<int, std::vector<short>>> receive()\r
  69         {\r
  70                 std::deque<std::pair<int, std::vector<short>>> result;\r
  71                 \r
  72                 std::shared_ptr<AVPacket> pkt;\r
  73                 for(int n = 0; n < 32 && result.empty() && input_.try_pop_audio_packet(pkt); ++n)       \r
  74                         result = decode(pkt);\r
  75 \r
  76                 return result;\r
  77         }\r
  78 \r
  79         std::deque<std::pair<int, std::vector<int16_t>>> decode(const std::shared_ptr<AVPacket>& audio_packet)\r
  80         {                       \r
  81                 std::deque<std::pair<int, std::vector<int16_t>>> result;\r
  82 \r
  83                 if(!audio_packet)\r
  84                 {       \r
  85                         avcodec_flush_buffers(&codec_context_);\r
  86                         current_chunk_.clear();\r
  87                         frame_number_ = 0;\r
  88                         restarting_ = false;\r
  89                         return result;\r
  90                 }\r
  91 \r
  92                 if(restarting_)\r
  93                         return result;\r
  94                                 \r
  95                 auto s = current_chunk_.size();\r
  96                 current_chunk_.resize(s + 4*format_desc_.audio_sample_rate*2+FF_INPUT_BUFFER_PADDING_SIZE/2, 0);\r
  97                 \r
  98                 int written_bytes = (current_chunk_.size() - s)*2 - FF_INPUT_BUFFER_PADDING_SIZE;\r
  99                 const int errn = avcodec_decode_audio3(&codec_context_, &current_chunk_[s], &written_bytes, audio_packet.get());\r
 100                 if(errn < 0)\r
 101                 {       \r
 102                         BOOST_THROW_EXCEPTION(\r
 103                                 invalid_operation() <<\r
 104                                 boost::errinfo_api_function("avcodec_decode_audio2") <<\r
 105                                 boost::errinfo_errno(AVUNERROR(errn)));\r
 106                 }\r
 107 \r
 108                 current_chunk_.resize(s + written_bytes/2);\r
 109 \r
 110                 const auto last = current_chunk_.end() - current_chunk_.size() % format_desc_.audio_samples_per_frame;\r
 111                 \r
 112                 for(auto it = current_chunk_.begin(); it != last; it += format_desc_.audio_samples_per_frame)           \r
 113                         result.push_back(std::make_pair(frame_number_++, std::vector<int16_t>(it, it + format_desc_.audio_samples_per_frame)));         \r
 114 \r
 115                 current_chunk_.erase(current_chunk_.begin(), last);\r
 116 \r
 117                 return result;\r
 118         }\r
 119 \r
 120         void restart()\r
 121         {\r
 122                 restarting_ = true;\r
 123         }\r
 124 };\r
 125 \r
 126 audio_decoder::audio_decoder(input& input, const core::video_format_desc& format_desc) : impl_(new implementation(input, format_desc)){}\r
 127 std::deque<std::pair<int, std::vector<int16_t>>> audio_decoder::receive(){return impl_->receive();}\r
 128 void audio_decoder::restart(){impl_->restart();}\r
 129 }