+ /* Special case: stereo output, at least 3 channel input.
+ Map so that Lt = L(-3dB) + Ls(-3dB) + C(-6dB) + Lfe(-10dB)
+ Rt = R(-3dB) + Rs(-3dB) + C(-6dB) + Lfe(-10dB)
+ */
+ if (_film->audio_channels() > 0) {
+ map.set (dcp::LEFT, 0, 1 / sqrt(2)); // L -> Lt
+ }
+ if (_film->audio_channels() > 1) {
+ map.set (dcp::RIGHT, 1, 1 / sqrt(2)); // R -> Rt
+ }
+ if (_film->audio_channels() > 2) {
+ map.set (dcp::CENTRE, 0, 1 / 2.0); // C -> Lt
+ map.set (dcp::CENTRE, 1, 1 / 2.0); // C -> Rt
+ }
+ if (_film->audio_channels() > 3) {
+ map.set (dcp::LFE, 0, 1 / sqrt(10)); // Lfe -> Lt
+ map.set (dcp::LFE, 1, 1 / sqrt(10)); // Lfe -> Rt
+ }
+ if (_film->audio_channels() > 4) {
+ map.set (dcp::LS, 0, 1 / sqrt(2)); // Ls -> Lt
+ }
+ if (_film->audio_channels() > 5) {
+ map.set (dcp::RS, 1, 1 / sqrt(2)); // Rs -> Rt
+ }