git.sesse.net Git - casparcg/blob - modules/ffmpeg/producer/audio/audio_decoder.cpp

   1 /*
   2 * Copyright (c) 2011 Sveriges Television AB <info@casparcg.com>
   3 *
   4 * This file is part of CasparCG (www.casparcg.com).
   5 *
   6 * CasparCG is free software: you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License as published by
   8 * the Free Software Foundation, either version 3 of the License, or
   9 * (at your option) any later version.
  10 *
  11 * CasparCG is distributed in the hope that it will be useful,
  12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 * GNU General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with CasparCG. If not, see <http://www.gnu.org/licenses/>.
  18 *
  19 * Author: Robert Nagy, ronag89@gmail.com
  20 */
  21
  22 #include "../../stdafx.h"
  23
  24 #include "audio_decoder.h"
  25
  26 #include "../util/util.h"
  27 #include "../input/input.h"
  28 #include "../../ffmpeg_error.h"
  29
  30 #include <core/video_format.h>
  31
  32 #include <common/log.h>
  33
  34 #include <tbb/cache_aligned_allocator.h>
  35
  36 #include <queue>
  37
  38 #if defined(_MSC_VER)
  39 #pragma warning (push)
  40 #pragma warning (disable : 4244)
  41 #endif
  42 extern "C"
  43 {
  44         #include <libavformat/avformat.h>
  45         #include <libavcodec/avcodec.h>
  46         #include <libswresample/swresample.h>
  47 }
  48 #if defined(_MSC_VER)
  49 #pragma warning (pop)
  50 #endif
  51
  52 namespace caspar { namespace ffmpeg {
  53
  54 uint64_t get_channel_layout(AVCodecContext* dec)
  55 {
  56         auto layout = (dec->channel_layout && dec->channels == av_get_channel_layout_nb_channels(dec->channel_layout)) ? dec->channel_layout : av_get_default_channel_layout(dec->channels);
  57         return layout;
  58 }
  59
  60 struct audio_decoder::impl : boost::noncopyable
  61 {
  62         monitor::basic_subject                                                                          event_subject_;
  63         input*                                                                                                          input_;
  64         int                                                                                                                     index_;
  65         const spl::shared_ptr<AVCodecContext>                                           codec_context_;
  66         const core::video_format_desc                                                           format_desc_;
  67
  68         std::shared_ptr<SwrContext>                                                                     swr_;
  69
  70         std::vector<uint8_t, tbb::cache_aligned_allocator<int8_t>>      buffer_;
  71
  72         std::shared_ptr<AVPacket>                                                                       current_packet_;
  73
  74 public:
  75         explicit impl(input& in, const core::video_format_desc& format_desc)
  76                 : input_(&in)
  77                 , format_desc_(format_desc)
  78                 , codec_context_(open_codec(input_->context(), AVMEDIA_TYPE_AUDIO, index_))
  79                 , swr_(swr_alloc_set_opts(nullptr,
  80                                                                                 av_get_default_channel_layout(format_desc_.audio_channels), AV_SAMPLE_FMT_S32, format_desc_.audio_sample_rate,
  81                                                                                 get_channel_layout(codec_context_.get()), codec_context_->sample_fmt, codec_context_->sample_rate,
  82                                                                                 0, nullptr), [](SwrContext* p){swr_free(&p);})
  83                 , buffer_(AVCODEC_MAX_AUDIO_FRAME_SIZE*4)
  84         {
  85                 if(!swr_)
  86                         CASPAR_THROW_EXCEPTION(bad_alloc());
  87
  88                 THROW_ON_ERROR2(swr_init(swr_.get()), "[audio_decoder]");
  89         }
  90
  91         std::shared_ptr<AVFrame> poll()
  92         {
  93                 if(!current_packet_ && !input_->try_pop_audio(current_packet_))
  94                         return nullptr;
  95
  96                 std::shared_ptr<AVFrame> audio;
  97
  98                 if(!current_packet_)
  99                 {
 100                         avcodec_flush_buffers(codec_context_.get());
 101                 }
 102                 else if(!current_packet_->data)
 103                 {
 104                         if(codec_context_->codec->capabilities & CODEC_CAP_DELAY)
 105                                 audio = decode(*current_packet_);
 106
 107                         if(!audio)
 108                                 current_packet_.reset();
 109                 }
 110                 else
 111                 {
 112                         audio = decode(*current_packet_);
 113
 114                         if(current_packet_->size == 0)
 115                                 current_packet_.reset();
 116                 }
 117
 118                 return audio ? audio : poll();
 119         }
 120
 121         std::shared_ptr<AVFrame> decode(AVPacket& pkt)
 122         {
 123                 auto frame = create_frame();
 124
 125                 int got_frame = 0;
 126                 auto len = THROW_ON_ERROR2(avcodec_decode_audio4(codec_context_.get(), frame.get(), &got_frame, &pkt), "[audio_decoder]");
 127
 128                 if(len == 0)
 129                 {
 130                         pkt.size = 0;
 131                         return nullptr;
 132                 }
 133
 134         pkt.data += len;
 135         pkt.size -= len;
 136
 137                 if(!got_frame)
 138                         return nullptr;
 139
 140                 const uint8_t *in[] = {frame->data[0]};
 141                 uint8_t* out[]          = {buffer_.data()};
 142
 143                 auto channel_samples = swr_convert(swr_.get(),
 144                                                                                         out, static_cast<int>(buffer_.size()) / format_desc_.audio_channels / av_get_bytes_per_sample(AV_SAMPLE_FMT_S32),
 145                                                                                         in, frame->nb_samples);
 146
 147                 frame->data[0]          = buffer_.data();
 148                 frame->linesize[0]      = channel_samples * format_desc_.audio_channels * av_get_bytes_per_sample(AV_SAMPLE_FMT_S32);
 149                 frame->nb_samples       = channel_samples;
 150                 frame->format           = AV_SAMPLE_FMT_S32;
 151
 152                 event_subject_  << monitor::event("file/audio/sample-rate")     % codec_context_->sample_rate
 153                                                 << monitor::event("file/audio/channels")        % codec_context_->channels
 154                                                 << monitor::event("file/audio/format")          % u8(av_get_sample_fmt_name(codec_context_->sample_fmt))
 155                                                 << monitor::event("file/audio/codec")           % u8(codec_context_->codec->long_name);
 156
 157                 return frame;
 158         }
 159
 160         uint32_t nb_frames() const
 161         {
 162                 return 0;
 163         }
 164
 165         std::wstring print() const
 166         {
 167                 return L"[audio-decoder] " + u16(codec_context_->codec->long_name);
 168         }
 169 };
 170
 171 audio_decoder::audio_decoder(input& input, const core::video_format_desc& format_desc) : impl_(new impl(input, format_desc)){}
 172 audio_decoder::audio_decoder(audio_decoder&& other) : impl_(std::move(other.impl_)){}
 173 audio_decoder& audio_decoder::operator=(audio_decoder&& other){impl_ = std::move(other.impl_); return *this;}
 174 std::shared_ptr<AVFrame> audio_decoder::operator()(){return impl_->poll();}
 175 uint32_t audio_decoder::nb_frames() const{return impl_->nb_frames();}
 176 std::wstring audio_decoder::print() const{return impl_->print();}
 177 void audio_decoder::subscribe(const monitor::observable::observer_ptr& o){impl_->event_subject_.subscribe(o);}
 178 void audio_decoder::unsubscribe(const monitor::observable::observer_ptr& o){impl_->event_subject_.unsubscribe(o);}
 179
 180 }}