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         typedef std::vector<short, tbb::cache_aligned_allocator<short>> aligned_buffer;\r
  44         \r
  45         AVCodecContext& codec_context_;\r
  46                 \r
  47         const core::video_format_desc format_desc_;\r
  48 \r
  49         aligned_buffer current_chunk_;\r
  50 \r
  51 public:\r
  52         explicit implementation(AVCodecContext& codec_context, const core::video_format_desc& format_desc) \r
  53                 : codec_context_(codec_context)\r
  54                 , format_desc_(format_desc)             \r
  55         {\r
  56                 if(codec_context_.sample_rate != static_cast<int>(format_desc_.audio_sample_rate) || \r
  57                    codec_context_.channels != static_cast<int>(format_desc_.audio_channels))\r
  58                 {       \r
  59                         BOOST_THROW_EXCEPTION(\r
  60                                 file_read_error()  <<\r
  61                                 msg_info("Invalid sample-rate or number of channels.") <<\r
  62                                 arg_value_info(boost::lexical_cast<std::string>(codec_context_.sample_rate)) << \r
  63                                 arg_name_info("codec_context"));\r
  64                 }\r
  65         }\r
  66                 \r
  67         std::vector<std::vector<short>> execute(packet&& audio_packet)\r
  68         {       \r
  69                 std::vector<std::vector<short>> result;\r
  70 \r
  71                 switch(audio_packet.type)\r
  72                 {\r
  73                 case flush_packet:\r
  74                         avcodec_flush_buffers(&codec_context_);\r
  75                         break;\r
  76                 case data_packet:\r
  77                         auto s = current_chunk_.size();\r
  78                         current_chunk_.resize(s + 4*format_desc_.audio_sample_rate*2+FF_INPUT_BUFFER_PADDING_SIZE/2);\r
  79                 \r
  80                         int written_bytes = (current_chunk_.size() - s)*2 - FF_INPUT_BUFFER_PADDING_SIZE;\r
  81                         const int errn = avcodec_decode_audio3(&codec_context_, &current_chunk_[s], &written_bytes, audio_packet.av_packet.get());\r
  82                         if(errn < 0)\r
  83                         {       \r
  84                                 BOOST_THROW_EXCEPTION(\r
  85                                         invalid_operation() <<\r
  86                                         boost::errinfo_api_function("avcodec_decode_audio2") <<\r
  87                                         boost::errinfo_errno(AVUNERROR(errn)));\r
  88                         }\r
  89 \r
  90                         current_chunk_.resize(s + written_bytes/2);\r
  91 \r
  92                         const auto last = current_chunk_.end() - current_chunk_.size() % format_desc_.audio_samples_per_frame;\r
  93                 \r
  94                         for(auto it = current_chunk_.begin(); it != last; it += format_desc_.audio_samples_per_frame)           \r
  95                                 result.push_back(std::vector<short>(it, it + format_desc_.audio_samples_per_frame));            \r
  96 \r
  97                         current_chunk_.erase(current_chunk_.begin(), last);\r
  98                 }\r
  99                                 \r
 100                 return result;\r
 101         }\r
 102 };\r
 103 \r
 104 audio_decoder::audio_decoder(AVCodecContext& codec_context, const core::video_format_desc& format_desc) : impl_(new implementation(codec_context, format_desc)){}\r
 105 std::vector<std::vector<short>> audio_decoder::execute(packet&& audio_packet){return impl_->execute(std::move(audio_packet));}\r
 106 }