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 #include <common/utility/algorithm.h>\r
  25 \r
  26 #if defined(_MSC_VER)\r
  27 #pragma warning (push)\r
  28 #pragma warning (disable : 4244)\r
  29 #endif\r
  30 extern "C" \r
  31 {\r
  32         #define __STDC_CONSTANT_MACROS\r
  33         #define __STDC_LIMIT_MACROS\r
  34         #include <libavformat/avformat.h>\r
  35         #include <libavcodec/avcodec.h>\r
  36 }\r
  37 #if defined(_MSC_VER)\r
  38 #pragma warning (pop)\r
  39 #endif\r
  40 \r
  41 namespace caspar {\r
  42 \r
  43 struct audio_decoder::implementation : boost::noncopyable\r
  44 {       \r
  45         AVCodecContext* codec_context_;\r
  46                 \r
  47         const core::video_format_desc format_desc_;\r
  48 \r
  49         std::vector<short> 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)\r
  57                 {       \r
  58                         BOOST_THROW_EXCEPTION(\r
  59                                 null_argument() << \r
  60                                 arg_name_info("codec_context"));        \r
  61                 }\r
  62 \r
  63                 if(codec_context_->sample_rate != static_cast<int>(format_desc_.audio_sample_rate) || \r
  64                    codec_context_->channels != static_cast<int>(format_desc_.audio_channels))\r
  65                 {       \r
  66                         BOOST_THROW_EXCEPTION(\r
  67                                 file_read_error()  <<\r
  68                                 msg_info("Invalid sample-rate or number of channels.") <<\r
  69                                 arg_value_info(boost::lexical_cast<std::string>(codec_context_->sample_rate)) << \r
  70                                 arg_name_info("codec_context"));\r
  71                 }\r
  72         }\r
  73                 \r
  74         std::vector<std::vector<short>> execute(const std::shared_ptr<aligned_buffer>& audio_packet)\r
  75         {                               \r
  76                 if(!audio_packet)\r
  77                         return std::vector<std::vector<short>>();\r
  78 \r
  79                 if(audio_packet->empty()) // Need to flush\r
  80                 {\r
  81                         avcodec_flush_buffers(codec_context_);\r
  82                         return std::vector<std::vector<short>>();\r
  83                 }\r
  84 \r
  85                 auto s = current_chunk_.size();\r
  86                 current_chunk_.resize(s + 4*format_desc_.audio_sample_rate*2+FF_INPUT_BUFFER_PADDING_SIZE/2);\r
  87                 \r
  88                 int written_bytes = (current_chunk_.size() - s)*2 - FF_INPUT_BUFFER_PADDING_SIZE;\r
  89                 const int errn = avcodec_decode_audio2(codec_context_, &current_chunk_[s], &written_bytes, audio_packet->data(), audio_packet->size());\r
  90                 if(errn < 0)\r
  91                 {       \r
  92                         BOOST_THROW_EXCEPTION(\r
  93                                 invalid_operation() <<\r
  94                                 boost::errinfo_api_function("avcodec_decode_audio2") <<\r
  95                                 boost::errinfo_errno(AVUNERROR(errn)));\r
  96                 }\r
  97 \r
  98                 current_chunk_.resize(s + written_bytes/2);\r
  99 \r
 100                 auto chunks = split(current_chunk_, format_desc_.audio_samples_per_frame);\r
 101 \r
 102                 current_chunk_ = chunks.back();\r
 103                 chunks.pop_back();\r
 104                 \r
 105                 return chunks;\r
 106         }\r
 107 };\r
 108 \r
 109 audio_decoder::audio_decoder(AVCodecContext* codec_context, const core::video_format_desc& format_desc) : impl_(new implementation(codec_context, format_desc)){}\r
 110 std::vector<std::vector<short>> audio_decoder::execute(const std::shared_ptr<aligned_buffer>& audio_packet){return impl_->execute(audio_packet);}\r
 111 }