src/sound_mxf_writer.cc

   1 /*
   2     Copyright (C) 2012-2014 Carl Hetherington <cth@carlh.net>
   3
   4     This program is free software; you can redistribute it and/or modify
   5     it under the terms of the GNU General Public License as published by
   6     the Free Software Foundation; either version 2 of the License, or
   7     (at your option) any later version.
   8
   9     This program is distributed in the hope that it will be useful,
  10     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12     GNU General Public License for more details.
  13
  14     You should have received a copy of the GNU General Public License
  15     along with this program; if not, write to the Free Software
  16     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17
  18 */
  19
  20 #include "sound_mxf_writer.h"
  21 #include "sound_mxf.h"
  22 #include "exceptions.h"
  23 #include "compose.hpp"
  24 #include "AS_DCP.h"
  25
  26 using namespace dcp;
  27
  28 struct SoundMXFWriter::ASDCPState
  29 {
  30         ASDCP::PCM::MXFWriter mxf_writer;
  31         ASDCP::PCM::FrameBuffer frame_buffer;
  32         ASDCP::WriterInfo writer_info;
  33         ASDCP::PCM::AudioDescriptor audio_desc;
  34         ASDCP::AESEncContext* encryption_context;
  35 };
  36
  37 SoundMXFWriter::SoundMXFWriter (SoundMXF* m, boost::filesystem::path file, Standard standard)
  38         : MXFWriter (m, file)
  39         , _state (new SoundMXFWriter::ASDCPState)
  40         , _sound_mxf (m)
  41         , _frame_buffer_offset (0)
  42 {
  43         _state->encryption_context = m->encryption_context ();
  44
  45         /* Derived from ASDCP::Wav::SimpleWaveHeader::FillADesc */
  46         _state->audio_desc.EditRate = ASDCP::Rational (_sound_mxf->edit_rate().numerator, _sound_mxf->edit_rate().denominator);
  47         _state->audio_desc.AudioSamplingRate = ASDCP::Rational (_sound_mxf->sampling_rate(), 1);
  48         _state->audio_desc.Locked = 0;
  49         _state->audio_desc.ChannelCount = _sound_mxf->channels ();
  50         _state->audio_desc.QuantizationBits = 24;
  51         _state->audio_desc.BlockAlign = 3 * _sound_mxf->channels();
  52         _state->audio_desc.AvgBps = _sound_mxf->sampling_rate() * _state->audio_desc.BlockAlign;
  53         _state->audio_desc.LinkedTrackID = 0;
  54         _state->audio_desc.ChannelFormat = ASDCP::PCM::CF_NONE;
  55
  56         _state->frame_buffer.Capacity (ASDCP::PCM::CalcFrameBufferSize (_state->audio_desc));
  57         _state->frame_buffer.Size (ASDCP::PCM::CalcFrameBufferSize (_state->audio_desc));
  58         memset (_state->frame_buffer.Data(), 0, _state->frame_buffer.Capacity());
  59
  60         _sound_mxf->fill_writer_info (&_state->writer_info, standard);
  61
  62         Kumu::Result_t r = _state->mxf_writer.OpenWrite (file.string().c_str(), _state->writer_info, _state->audio_desc);
  63         if (ASDCP_FAILURE (r)) {
  64                 boost::throw_exception (FileError ("could not open audio MXF for writing", file.string(), r));
  65         }
  66 }
  67
  68 void
  69 SoundMXFWriter::write (float const * const * data, int frames)
  70 {
  71         assert (!_finalized);
  72
  73         for (int i = 0; i < frames; ++i) {
  74
  75                 byte_t* out = _state->frame_buffer.Data() + _frame_buffer_offset;
  76
  77                 /* Write one sample per channel */
  78                 for (int j = 0; j < _sound_mxf->channels(); ++j) {
  79                         int32_t const s = data[j][i] * (1 << 23);
  80                         *out++ = (s & 0xff);
  81                         *out++ = (s & 0xff00) >> 8;
  82                         *out++ = (s & 0xff0000) >> 16;
  83                 }
  84                 _frame_buffer_offset += 3 * _sound_mxf->channels();
  85
  86                 assert (_frame_buffer_offset <= int (_state->frame_buffer.Capacity()));
  87
  88                 /* Finish the MXF frame if required */
  89                 if (_frame_buffer_offset == int (_state->frame_buffer.Capacity())) {
  90                         write_current_frame ();
  91                         _frame_buffer_offset = 0;
  92                         memset (_state->frame_buffer.Data(), 0, _state->frame_buffer.Capacity());
  93                 }
  94         }
  95 }
  96
  97 void
  98 SoundMXFWriter::write_current_frame ()
  99 {
 100         ASDCP::Result_t const r = _state->mxf_writer.WriteFrame (_state->frame_buffer, _state->encryption_context, 0);
 101         if (ASDCP_FAILURE (r)) {
 102                 boost::throw_exception (MiscError (String::compose ("could not write audio MXF frame (%1)", int (r))));
 103         }
 104
 105         ++_frames_written;
 106 }
 107
 108 void
 109 SoundMXFWriter::finalize ()
 110 {
 111         if (_frame_buffer_offset > 0) {
 112                 write_current_frame ();
 113         }
 114
 115         if (ASDCP_FAILURE (_state->mxf_writer.Finalize())) {
 116                 boost::throw_exception (MiscError ("could not finalise audio MXF"));
 117         }
 118
 119         MXFWriter::finalize ();
 120 }