Merge pull request #25 from obs-ai/roy.add_external_whisper_model_file

Add the option to select an external Whisper.cpp model file

src/transcription-filter.cpp

@@ -216,6 +216,24 @@ void set_text_callback(struct transcription_filter_data *gf, const std::string &
 	}
 };
 
+void shutdown_whisper_thread(struct transcription_filter_data *gf)
+{
+	if (gf->whisper_context != nullptr) {
+		// acquire the mutex before freeing the context
+		if (!gf->whisper_ctx_mutex || !gf->wshiper_thread_cv) {
+			obs_log(LOG_ERROR, "whisper_ctx_mutex is null");
+			return;
+		}
+		std::lock_guard<std::mutex> lock(*gf->whisper_ctx_mutex);
+		whisper_free(gf->whisper_context);
+		gf->whisper_context = nullptr;
+		gf->wshiper_thread_cv->notify_all();
+	}
+	if (gf->whisper_thread.joinable()) {
+		gf->whisper_thread.join();
+	}
+}
+
 void transcription_filter_update(void *data, obs_data_t *s)
 {
 	struct transcription_filter_data *gf =
@@ -296,22 +314,13 @@ void transcription_filter_update(void *data, obs_data_t *s)
 	if (new_model_path != gf->whisper_model_path) {
 		// model path changed, reload the model
 		obs_log(LOG_INFO, "model path changed, reloading model");
-		if (gf->whisper_context != nullptr) {
+		shutdown_whisper_thread(gf);
-			// acquire the mutex before freeing the context
+
-			if (!gf->whisper_ctx_mutex || !gf->wshiper_thread_cv) {
-				obs_log(LOG_ERROR, "whisper_ctx_mutex is null");
-				return;
-			}
-			std::lock_guard<std::mutex> lock(*gf->whisper_ctx_mutex);
-			whisper_free(gf->whisper_context);
-			gf->whisper_context = nullptr;
-			gf->wshiper_thread_cv->notify_all();
-		}
-		if (gf->whisper_thread.joinable()) {
-			gf->whisper_thread.join();
-		}
 		gf->whisper_model_path = new_model_path;
 
+		// check if the new model is external file
+		if (new_model_path.find("!!!external!!!") == std::string::npos) {
+			// new model is not external file
 			// check if the model exists, if not, download it
 			std::string model_file_found = find_model_file(gf->whisper_model_path);
 			if (model_file_found == "") {
@@ -320,9 +329,12 @@ void transcription_filter_update(void *data, obs_data_t *s)
 					gf->whisper_model_path,
 					[gf](int download_status, const std::string &path) {
 						if (download_status == 0) {
-						obs_log(LOG_INFO, "Model download complete");
+							obs_log(LOG_INFO,
-						gf->whisper_context = init_whisper_context(path);
+								"Model download complete");
-						std::thread new_whisper_thread(whisper_loop, gf);
+							gf->whisper_context =
+								init_whisper_context(path);
+							std::thread new_whisper_thread(whisper_loop,
+										       gf);
 							gf->whisper_thread.swap(new_whisper_thread);
 						} else {
 							obs_log(LOG_ERROR, "Model download failed");
@@ -334,6 +346,14 @@ void transcription_filter_update(void *data, obs_data_t *s)
 				std::thread new_whisper_thread(whisper_loop, gf);
 				gf->whisper_thread.swap(new_whisper_thread);
 			}
+		} else {
+			// new model is local file, get file location from file property
+			std::string external_model_file_path =
+				obs_data_get_string(s, "whisper_model_path_external");
+			gf->whisper_context = init_whisper_context(external_model_file_path);
+			std::thread new_whisper_thread(whisper_loop, gf);
+			gf->whisper_thread.swap(new_whisper_thread);
+		}
 	}
 
 	if (!gf->whisper_ctx_mutex) {
@@ -495,6 +515,9 @@ void transcription_filter_defaults(obs_data_t *s)
 
 obs_properties_t *transcription_filter_properties(void *data)
 {
+	struct transcription_filter_data *gf =
+		static_cast<struct transcription_filter_data *>(data);
+
 	obs_properties_t *ppts = obs_properties_create();
 
 	obs_properties_add_bool(ppts, "vad_enabled", "VAD Enabled");
@@ -564,6 +587,51 @@ obs_properties_t *transcription_filter_properties(void *data)
 	obs_property_list_add_string(whisper_models_list, "Small (Eng) 466Mb",
 				     "models/ggml-small.en.bin");
 	obs_property_list_add_string(whisper_models_list, "Small 466Mb", "models/ggml-small.bin");
+	obs_property_list_add_string(whisper_models_list, "Load external model file",
+				     "!!!external!!!");
+
+	// Add a file selection input to select an external model file
+	obs_property_t *whisper_model_path_external =
+		obs_properties_add_path(ppts, "whisper_model_path_external", "External model file",
+					OBS_PATH_FILE, "Model (*.bin)", NULL);
+	// Hide the external model file selection input
+	obs_property_set_visible(obs_properties_get(ppts, "whisper_model_path_external"), false);
+
+	obs_property_set_modified_callback2(
+		whisper_model_path_external,
+		[](void *data_, obs_properties_t *props, obs_property_t *property,
+		   obs_data_t *settings) {
+			UNUSED_PARAMETER(property);
+			UNUSED_PARAMETER(props);
+			struct transcription_filter_data *gf_ =
+				static_cast<struct transcription_filter_data *>(data_);
+			shutdown_whisper_thread(gf_);
+			std::string external_model_file_path =
+				obs_data_get_string(settings, "whisper_model_path_external");
+			gf_->whisper_context = init_whisper_context(external_model_file_path);
+			std::thread new_whisper_thread(whisper_loop, gf_);
+			gf_->whisper_thread.swap(new_whisper_thread);
+			return true;
+		},
+		gf);
+
+	// Add a callback to the model list to handle the external model file selection
+	obs_property_set_modified_callback(whisper_models_list, [](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, "whisper_model_path");
+		if (strcmp(new_model_path, "!!!external!!!") == 0) {
+			obs_property_set_visible(
+				obs_properties_get(props, "whisper_model_path_external"), true);
+		} else {
+			obs_property_set_visible(
+				obs_properties_get(props, "whisper_model_path_external"), false);
+		}
+		return true;
+	});
 
 	obs_properties_t *whisper_params_group = obs_properties_create();
 	obs_properties_add_group(ppts, "whisper_params_group", "Whisper Parameters",