refactor: Add external model option to translation settings

data/locale/en-US.ini

@@ -58,3 +58,5 @@ buffered_output="Buffered output (Experimental)"
 translate_model="Translation Model"
 Whisper-Based-Translation="Whisper-Based Translation"
 sentence_psum_accept_thresh="Sentence prob. threshold"
+external_model_folder="External model folder"
+load_external_model="Load external model"

src/transcription-filter-data.h

@@ -105,6 +105,7 @@ struct transcription_filter_data {
 	// translation context
 	struct translation_context translation_ctx;
 	std::string translation_model_index;
+	std::string translation_model_path_external;
 
 	TokenBufferThread captions_monitor;
 

src/transcription-filter.cpp

@@ -328,6 +328,8 @@ void transcription_filter_update(void *data, obs_data_t *s)
 	gf->translation_output = obs_data_get_string(s, "translate_output");
 	gf->suppress_sentences = obs_data_get_string(s, "suppress_sentences");
 	gf->translation_model_index = obs_data_get_string(s, "translate_model");
+	gf->translation_model_path_external =
+		obs_data_get_string(s, "translation_model_path_external");
 
 	if (new_translate != gf->translate) {
 		if (new_translate) {
@@ -800,6 +802,29 @@ obs_properties_t *transcription_filter_properties(void *data)
 						     model_info.first.c_str());
 		}
 	}
+	// add external model option
+	obs_property_list_add_string(prop_translate_model, MT_("load_external_model"),
+				     "!!!external!!!");
+	// add callback to handle the external model file selection
+	obs_property_t *translation_model_path_external = obs_properties_add_path(
+		translation_group, "translation_model_path_external", MT_("external_model_folder"),
+		OBS_PATH_DIRECTORY, "CT2 Model folder", NULL);
+	// Hide the external model file selection input
+	obs_property_set_visible(obs_properties_get(ppts, "translation_model_path_external"),
+				 false);
+	// Add a callback to the model list to handle the external model file selection
+	obs_property_set_modified_callback(prop_translate_model, [](obs_properties_t *props,
+								    obs_property_t *property,
+								    obs_data_t *settings) {
+		UNUSED_PARAMETER(property);
+		// If the selected model is the external model, show the external model file selection
+		// input
+		const char *new_model_path = obs_data_get_string(settings, "translate_model");
+		const bool is_external = (strcmp(new_model_path, "!!!external!!!") == 0);
+		obs_property_set_visible(
+			obs_properties_get(props, "translation_model_path_external"), is_external);
+		return true;
+	});
 	// add target language selection
 	obs_property_t *prop_tgt = obs_properties_add_list(
 		translation_group, "translate_target_language", MT_("target_language"),
@@ -840,6 +865,11 @@ obs_properties_t *transcription_filter_properties(void *data)
 			obs_property_set_visible(obs_properties_get(props, prop),
 						 translate_enabled);
 		}
+		const bool is_external = (strcmp(obs_data_get_string(settings, "translate_model"),
+						 "!!!external!!!") == 0);
+		obs_property_set_visible(obs_properties_get(props,
+							    "translation_model_path_external"),
+					 is_external && translate_enabled);
 		return true;
 	});
 
@@ -855,7 +885,7 @@ obs_properties_t *transcription_filter_properties(void *data)
 		     {"whisper_params_group", "log_words", "caption_to_stream", "buffer_size_msec",
 		      "overlap_size_msec", "step_by_step_processing", "min_sub_duration",
 		      "process_while_muted", "buffered_output", "vad_enabled", "log_level",
-		      "suppress_sentences"}) {
+		      "suppress_sentences", "sentence_psum_accept_thresh"}) {
 			obs_property_set_visible(obs_properties_get(props, prop_name.c_str()),
 						 show_hide);
 		}

src/translation/translation-utils.cpp

@@ -11,6 +11,18 @@ void start_translation(struct transcription_filter_data *gf)
 {
 	obs_log(LOG_INFO, "Starting translation...");
 
+	if (gf->translation_model_index == "!!!external!!!") {
+		obs_log(LOG_INFO, "External model selected.");
+		if (gf->translation_model_path_external.empty()) {
+			obs_log(LOG_ERROR, "External model path is empty.");
+			gf->translate = false;
+			return;
+		}
+		std::string model_file_found = gf->translation_model_path_external;
+		build_and_enable_translation(gf, model_file_found);
+		return;
+	}
+
 	const ModelInfo &translation_model_info = models_info[gf->translation_model_index];
 	std::string model_file_found = find_model_folder(translation_model_info);
 	if (model_file_found == "") {

src/translation/translation.cpp

@@ -30,7 +30,7 @@ int build_translation_context(struct translation_context &translation_ctx)
 	obs_log(LOG_INFO, "Building translation context from '%s'...", local_model_path.c_str());
 	// find the SPM file in the model folder
 	std::string local_spm_path = find_file_in_folder_by_regex_expression(
-		local_model_path, "(sentencepiece|spm).*?\\.model");
+		local_model_path, "(sentencepiece|spm|spiece).*?\\.model");
 
 	try {
 		obs_log(LOG_INFO, "Loading SPM from %s", local_spm_path.c_str());