libobs: Shut down encoder when not in use

This prevents encoders (hardware encoders in particular) from being
continually active when all outputs disconnect from an encoder.  This is
mostly just a temporary measure; the encoding interface may need a bit
of a redesign.  It will also definitely needs to be able to flush at
some point.  Currently when an output is stopped, the pending data is
discarded, which needs to be fixed.

libobs/obs-encoder.c

@@ -197,6 +197,7 @@ static void remove_connection(struct obs_encoder *encoder)
 		video_output_disconnect(encoder->media, receive_video,
 				encoder);
 
+	obs_encoder_shutdown(encoder);
 	encoder->active = false;
 }
 
@@ -368,9 +369,8 @@ bool obs_encoder_initialize(obs_encoder_t *encoder)
 
 	if (encoder->active)
 		return true;
-
 	if (encoder->context.data)
-		encoder->info.destroy(encoder->context.data);
+		return false;
 
 	if (encoder->info.create)
 		encoder->context.data = encoder->info.create(
@@ -387,6 +387,14 @@ bool obs_encoder_initialize(obs_encoder_t *encoder)
 	return true;
 }
 
+void obs_encoder_shutdown(obs_encoder_t *encoder)
+{
+	if (encoder->context.data) {
+		encoder->info.destroy(encoder->context.data);
+		encoder->context.data = NULL;
+	}
+}
+
 static inline size_t get_callback_idx(
 		const struct obs_encoder *encoder,
 		void (*new_packet)(void *param, struct encoder_packet *packet),

libobs/obs-internal.h

@@ -770,6 +770,7 @@ struct obs_encoder {
 extern struct obs_encoder_info *find_encoder(const char *id);
 
 extern bool obs_encoder_initialize(obs_encoder_t *encoder);
+extern void obs_encoder_shutdown(obs_encoder_t *encoder);
 
 extern void obs_encoder_start(obs_encoder_t *encoder,
 		void (*new_packet)(void *param, struct encoder_packet *packet),