libobs: Implement obs_service func to get max bitrates

(This commit also modifies rtmp-services)

Implements obs_service_get_max_bitrate, which allows retrieving the
maximum audio/video bitrates directly rather than being forced to use
the apply method. Makes it a bit easier to get the bitrate values.

libobs/obs-service.c

@@ -436,3 +436,19 @@ void obs_service_get_max_res_fps(const obs_service_t *service, int *cx, int *cy,
 		service->info.get_max_res_fps(service->context.data, cx, cy,
 					      fps);
 }
+
+void obs_service_get_max_bitrate(const obs_service_t *service,
+				 int *video_bitrate, int *audio_bitrate)
+{
+	if (video_bitrate)
+		*video_bitrate = 0;
+	if (audio_bitrate)
+		*audio_bitrate = 0;
+
+	if (!obs_service_valid(service, "obs_service_get_max_bitrate"))
+		return;
+
+	if (service->info.get_max_bitrate)
+		service->info.get_max_bitrate(service->context.data,
+					      video_bitrate, audio_bitrate);
+}

libobs/obs-service.h

@@ -75,6 +75,9 @@ struct obs_service_info {
 	const char *(*get_output_type)(void *data);
 
 	void (*get_max_res_fps)(void *data, int *cx, int *cy, int *fps);
+
+	void (*get_max_bitrate)(void *data, int *video_bitrate,
+				int *audio_bitrate);
 };
 
 EXPORT void obs_register_service_s(const struct obs_service_info *info,

libobs/obs.h

@@ -2234,6 +2234,9 @@ EXPORT const char *obs_service_get_id(const obs_service_t *service);
 EXPORT void obs_service_get_max_res_fps(const obs_service_t *service, int *cx,
 					int *cy, int *fps);
 
+EXPORT void obs_service_get_max_bitrate(const obs_service_t *service,
+					int *video_bitrate, int *audio_bitrate);
+
 /* NOTE: This function is temporary and should be removed/replaced at a later
  * date. */
 EXPORT const char *obs_service_get_output_type(const obs_service_t *service);

plugins/rtmp-services/rtmp-common.c

@@ -690,6 +690,42 @@ static void rtmp_common_get_max_res_fps(void *data, int *cx, int *cy, int *fps)
 		*fps = service->max_fps;
 }
 
+static void rtmp_common_get_max_bitrate(void *data, int *video_bitrate,
+					int *audio_bitrate)
+{
+	struct rtmp_common *service = data;
+	json_t *root = open_services_file();
+	json_t *item;
+
+	if (!root)
+		return;
+
+	json_t *json_service = find_service(root, service->service, NULL);
+	if (!json_service) {
+		goto fail;
+	}
+
+	json_t *recommended = json_object_get(json_service, "recommended");
+	if (!recommended) {
+		goto fail;
+	}
+
+	if (audio_bitrate) {
+		item = json_object_get(recommended, "max audio bitrate");
+		if (json_is_integer(item))
+			*audio_bitrate = (int)json_integer_value(item);
+	}
+
+	if (video_bitrate) {
+		item = json_object_get(recommended, "max video bitrate");
+		if (json_is_integer(item))
+			*video_bitrate = (int)json_integer_value(item);
+	}
+
+fail:
+	json_decref(root);
+}
+
 struct obs_service_info rtmp_common_service = {
 	.id = "rtmp_common",
 	.get_name = rtmp_common_getname,
@@ -702,4 +738,5 @@ struct obs_service_info rtmp_common_service = {
 	.apply_encoder_settings = rtmp_common_apply_settings,
 	.get_output_type = rtmp_common_get_output_type,
 	.get_max_res_fps = rtmp_common_get_max_res_fps,
+	.get_max_bitrate = rtmp_common_get_max_bitrate,
 };