+
+shared_ptr<SoundAssetWriter>
+SoundAsset::start_write ()
+{
+ /* XXX: can't we use a shared_ptr here? */
+ return shared_ptr<SoundAssetWriter> (new SoundAssetWriter (this));
+}
+
+SoundAssetWriter::SoundAssetWriter (SoundAsset* a)
+ : _asset (a)
+ , _finalized (false)
+ , _frames_written (0)
+ , _frame_buffer_offset (0)
+{
+ /* Derived from ASDCP::Wav::SimpleWaveHeader::FillADesc */
+ _audio_desc.EditRate = ASDCP::Rational (_asset->frames_per_second(), 1);
+ _audio_desc.AudioSamplingRate = ASDCP::Rational (_asset->sampling_rate(), 0);
+ _audio_desc.Locked = 0;
+ _audio_desc.ChannelCount = _asset->channels ();
+ _audio_desc.QuantizationBits = 24;
+ _audio_desc.BlockAlign = 3 * _asset->channels();
+ _audio_desc.AvgBps = _asset->sampling_rate() * _audio_desc.BlockAlign;
+ _audio_desc.LinkedTrackID = 0;
+ _audio_desc.ChannelFormat = ASDCP::PCM::CF_NONE;
+
+ _frame_buffer.Capacity (ASDCP::PCM::CalcFrameBufferSize (_audio_desc));
+ _frame_buffer.Size (ASDCP::PCM::CalcFrameBufferSize (_audio_desc));
+ memset (_frame_buffer.Data(), 0, _frame_buffer.Capacity());
+
+ MXFAsset::fill_writer_info (&_writer_info, _asset->uuid ());
+
+ if (ASDCP_FAILURE (_mxf_writer.OpenWrite (_asset->path().c_str(), _writer_info, _audio_desc))) {
+ throw FileError ("could not open audio MXF for writing", _asset->path().string());
+ }
+}
+
+void
+SoundAssetWriter::write (float const * const * data, int frames)
+{
+ for (int i = 0; i < frames; ++i) {
+
+ byte_t* out = _frame_buffer.Data() + _frame_buffer_offset;
+
+ /* Write one sample per channel */
+ for (int j = 0; j < _asset->channels(); ++j) {
+ int32_t const s = data[j][i] * (1 << 23);
+ *out++ = (s & 0xff);
+ *out++ = (s & 0xff00) >> 8;
+ *out++ = (s & 0xff0000) >> 16;
+ }
+ _frame_buffer_offset += 3 * _asset->channels();
+
+ assert (_frame_buffer_offset <= int (_frame_buffer.Capacity()));
+
+ /* Finish the MXF frame if required */
+ if (_frame_buffer_offset == int (_frame_buffer.Capacity())) {
+ write_current_frame ();
+ _frame_buffer_offset = 0;
+ memset (_frame_buffer.Data(), 0, _frame_buffer.Capacity());
+ }
+ }
+}
+
+void
+SoundAssetWriter::write_current_frame ()
+{
+ if (ASDCP_FAILURE (_mxf_writer.WriteFrame (_frame_buffer, 0, 0))) {
+ throw MiscError ("could not write audio MXF frame");
+ }
+
+ ++_frames_written;
+}
+
+void
+SoundAssetWriter::finalize ()
+{
+ if (_frame_buffer_offset > 0) {
+ write_current_frame ();
+ }
+
+ if (ASDCP_FAILURE (_mxf_writer.Finalize())) {
+ throw MiscError ("could not finalise audio MXF");
+ }
+
+ _finalized = true;
+ _asset->set_intrinsic_duration (_frames_written);
+ _asset->set_duration (_frames_written);
+}
+
+SoundAssetWriter::~SoundAssetWriter ()
+{
+ assert (_finalized);
+}