+
+bool
+Config::have_write_permission () const
+{
+ auto f = fopen_boost (config_file(), "r+");
+ if (!f) {
+ return false;
+ }
+
+ fclose (f);
+ return true;
+}
+
+/** @param output_channels Number of output channels in use.
+ * @return Audio mapping for this output channel count (may be a default).
+ */
+AudioMapping
+Config::audio_mapping (int output_channels)
+{
+ if (!_audio_mapping || _audio_mapping->output_channels() != output_channels) {
+ /* Set up a default */
+ _audio_mapping = AudioMapping (MAX_DCP_AUDIO_CHANNELS, output_channels);
+ if (output_channels == 2) {
+ /* Special case for stereo output.
+ Map so that Lt = L(-3dB) + Ls(-3dB) + C(-6dB) + Lfe(-10dB)
+ Rt = R(-3dB) + Rs(-3dB) + C(-6dB) + Lfe(-10dB)
+ */
+ _audio_mapping->set (dcp::Channel::LEFT, 0, 1 / sqrt(2)); // L -> Lt
+ _audio_mapping->set (dcp::Channel::RIGHT, 1, 1 / sqrt(2)); // R -> Rt
+ _audio_mapping->set (dcp::Channel::CENTRE, 0, 1 / 2.0); // C -> Lt
+ _audio_mapping->set (dcp::Channel::CENTRE, 1, 1 / 2.0); // C -> Rt
+ _audio_mapping->set (dcp::Channel::LFE, 0, 1 / sqrt(10)); // Lfe -> Lt
+ _audio_mapping->set (dcp::Channel::LFE, 1, 1 / sqrt(10)); // Lfe -> Rt
+ _audio_mapping->set (dcp::Channel::LS, 0, 1 / sqrt(2)); // Ls -> Lt
+ _audio_mapping->set (dcp::Channel::RS, 1, 1 / sqrt(2)); // Rs -> Rt
+ } else {
+ /* 1:1 mapping */
+ for (int i = 0; i < min (MAX_DCP_AUDIO_CHANNELS, output_channels); ++i) {
+ _audio_mapping->set (i, i, 1);
+ }
+ }
+ }
+
+ return *_audio_mapping;
+}
+
+void
+Config::set_audio_mapping (AudioMapping m)
+{
+ _audio_mapping = m;
+ changed (AUDIO_MAPPING);
+}
+
+void
+Config::set_audio_mapping_to_default ()
+{
+ DCPOMATIC_ASSERT (_audio_mapping);
+ auto const ch = _audio_mapping->output_channels ();
+ _audio_mapping = boost::none;
+ _audio_mapping = audio_mapping (ch);
+ changed (AUDIO_MAPPING);
+}
+
+
+void
+Config::add_custom_language (dcp::LanguageTag tag)
+{
+ if (find(_custom_languages.begin(), _custom_languages.end(), tag) == _custom_languages.end()) {
+ _custom_languages.push_back (tag);
+ changed ();
+ }
+}
+