2 Copyright (C) 2012-2014 Carl Hetherington <cth@carlh.net>
4 This file is part of libdcp.
6 libdcp 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 2 of the License, or
9 (at your option) any later version.
11 libdcp 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.
16 You should have received a copy of the GNU General Public License
17 along with libdcp. If not, see <http://www.gnu.org/licenses/>.
19 In addition, as a special exception, the copyright holders give
20 permission to link the code of portions of this program with the
21 OpenSSL library under certain conditions as described in each
22 individual source file, and distribute linked combinations
25 You must obey the GNU General Public License in all respects
26 for all of the code used other than OpenSSL. If you modify
27 file(s) with this exception, you may extend this exception to your
28 version of the file(s), but you are not obligated to do so. If you
29 do not wish to do so, delete this exception statement from your
30 version. If you delete this exception statement from all source
31 files in the program, then also delete it here.
34 #include "sound_asset_writer.h"
35 #include "sound_asset.h"
36 #include "exceptions.h"
37 #include "dcp_assert.h"
38 #include "compose.hpp"
39 #include "crypto_context.h"
40 #include <asdcp/AS_DCP.h>
48 struct SoundAssetWriter::ASDCPState
50 ASDCP::PCM::MXFWriter mxf_writer;
51 ASDCP::PCM::FrameBuffer frame_buffer;
52 ASDCP::WriterInfo writer_info;
53 ASDCP::PCM::AudioDescriptor desc;
56 SoundAssetWriter::SoundAssetWriter (SoundAsset* asset, boost::filesystem::path file)
57 : AssetWriter (asset, file)
58 , _state (new SoundAssetWriter::ASDCPState)
60 , _frame_buffer_offset (0)
62 /* Derived from ASDCP::Wav::SimpleWaveHeader::FillADesc */
63 _state->desc.EditRate = ASDCP::Rational (_asset->edit_rate().numerator, _asset->edit_rate().denominator);
64 _state->desc.AudioSamplingRate = ASDCP::Rational (_asset->sampling_rate(), 1);
65 _state->desc.Locked = 0;
66 _state->desc.ChannelCount = _asset->channels ();
67 _state->desc.QuantizationBits = 24;
68 _state->desc.BlockAlign = 3 * _asset->channels();
69 _state->desc.AvgBps = _asset->sampling_rate() * _state->desc.BlockAlign;
70 _state->desc.LinkedTrackID = 0;
71 if (asset->standard() == INTEROP) {
72 _state->desc.ChannelFormat = ASDCP::PCM::CF_NONE;
74 /* Just use WTF ("wild track format") for SMPTE for now; searches suggest that this
75 uses the same assignment as Interop.
77 _state->desc.ChannelFormat = ASDCP::PCM::CF_CFG_4;
80 /* I'm fairly sure this is not necessary, as ContainerDuration is written
81 in ASDCP's WriteMXFFooter, but it stops a valgrind warning.
83 _state->desc.ContainerDuration = 0;
85 _state->frame_buffer.Capacity (ASDCP::PCM::CalcFrameBufferSize (_state->desc));
86 _state->frame_buffer.Size (ASDCP::PCM::CalcFrameBufferSize (_state->desc));
87 memset (_state->frame_buffer.Data(), 0, _state->frame_buffer.Capacity());
89 _asset->fill_writer_info (&_state->writer_info, _asset->id());
93 SoundAssetWriter::write (float const * const * data, int frames)
95 DCP_ASSERT (!_finalized);
96 DCP_ASSERT (frames > 0);
98 static float const clip = 1.0f - (1.0f / pow (2, 23));
101 Kumu::Result_t r = _state->mxf_writer.OpenWrite (_file.string().c_str(), _state->writer_info, _state->desc);
102 if (ASDCP_FAILURE (r)) {
103 boost::throw_exception (FileError ("could not open audio MXF for writing", _file.string(), r));
106 _asset->set_file (_file);
110 int const ch = _asset->channels ();
112 for (int i = 0; i < frames; ++i) {
114 byte_t* out = _state->frame_buffer.Data() + _frame_buffer_offset;
116 /* Write one sample per channel */
117 for (int j = 0; j < ch; ++j) {
118 /* Convert sample to 24-bit int, clipping if necessary. */
119 float x = data[j][i];
122 } else if (x < -clip) {
125 int32_t const s = x * (1 << 23);
127 *out++ = (s & 0xff00) >> 8;
128 *out++ = (s & 0xff0000) >> 16;
130 _frame_buffer_offset += 3 * ch;
132 DCP_ASSERT (_frame_buffer_offset <= int (_state->frame_buffer.Capacity()));
134 /* Finish the MXF frame if required */
135 if (_frame_buffer_offset == int (_state->frame_buffer.Capacity())) {
136 write_current_frame ();
137 _frame_buffer_offset = 0;
138 memset (_state->frame_buffer.Data(), 0, _state->frame_buffer.Capacity());
144 SoundAssetWriter::write_current_frame ()
146 ASDCP::Result_t const r = _state->mxf_writer.WriteFrame (_state->frame_buffer, _crypto_context->context(), _crypto_context->hmac());
147 if (ASDCP_FAILURE (r)) {
148 boost::throw_exception (MiscError (String::compose ("could not write audio MXF frame (%1)", int (r))));
155 SoundAssetWriter::finalize ()
157 if (_frame_buffer_offset > 0) {
158 write_current_frame ();
162 ASDCP::Result_t const r = _state->mxf_writer.Finalize();
163 if (ASDCP_FAILURE(r)) {
164 boost::throw_exception (MiscError (String::compose ("could not finalise audio MXF (%1)", int(r))));
168 _asset->_intrinsic_duration = _frames_written;
169 return AssetWriter::finalize ();