auto ms = make_shared<dcp::SoundAsset>(dcp::Fraction (24, 1), 48000, 1, dcp::LanguageTag("en-GB"), dcp::Standard::SMPTE);
ms->set_metadata (mxf_metadata);
ms->set_key (key);
auto ms = make_shared<dcp::SoundAsset>(dcp::Fraction (24, 1), 48000, 1, dcp::LanguageTag("en-GB"), dcp::Standard::SMPTE);
ms->set_metadata (mxf_metadata);
ms->set_key (key);