libobs: Add optional reconnect callback to outputs

docs/sphinx/reference-outputs.rst

@@ -772,6 +772,28 @@ General Output Functions
 
    .. versionadded:: 31.0
 
+---------------------
+
+.. function:: void obs_output_set_reconnect_callback(obs_output_t *output, bool (*reconnect_cb)(void *data, obs_output_t *output, int code), void *param)
+
+   Sets a callback that can be used to decide whether or not to attempt reconnecting.
+   Can also be used to reconfigure the output within the callback before continuing the reconnection attempts,
+   e.g., to update the stream key after the previous one has expired.
+   
+   Passing in a `NULL` pointer removes the callback.
+
+   :param output:        The output to register the reconnect_cb() function against
+   :param reconnect_cb:  Function pointer to the callback function
+   :param param:         Data passed to the callback
+
+   reconnect_cb() arguments:
+   :param data:    Data passed to the callback
+   :param output:  The output associated with the invoked callback function
+   :param code:    Error code the output was stopped with
+   :return:        Whether or not to continue attempting to reconnect
+
+   .. versionadded:: 31.1
+
 Functions used by outputs
 -------------------------
 

libobs/obs-internal.h

@@ -78,6 +78,11 @@ struct packet_callback {
 	void *param;
 };
 
+struct reconnect_callback {
+	bool (*reconnect_cb)(void *data, obs_output_t *output, int code);
+	void *param;
+};
+
 /* ------------------------------------------------------------------------- */
 /* validity checks */
 
@@ -1150,6 +1155,8 @@ struct obs_output {
 	pthread_mutex_t pkt_callbacks_mutex;
 	DARRAY(struct packet_callback) pkt_callbacks;
 
+	struct reconnect_callback reconnect_callback;
+
 	bool valid;
 
 	uint64_t active_delay_ns;

libobs/obs-output.c

@@ -2874,10 +2874,21 @@ static void output_reconnect(struct obs_output *output)
 	}
 }
 
-static inline bool can_reconnect(const obs_output_t *output, int code)
+static inline bool check_reconnect_cb(obs_output_t *output, int code)
+{
+	if (!output->reconnect_callback.reconnect_cb)
+		return true;
+
+	return output->reconnect_callback.reconnect_cb(output->reconnect_callback.param, output, code);
+}
+
+static inline bool can_reconnect(obs_output_t *output, int code)
 {
 	bool reconnect_active = output->reconnect_retry_max != 0;
 
+	if (reconnect_active && !check_reconnect_cb(output, code))
+		return false;
+
 	return (reconnecting(output) && code != OBS_OUTPUT_SUCCESS) ||
 	       (reconnect_active && code == OBS_OUTPUT_DISCONNECTED);
 }
@@ -3190,3 +3201,15 @@ void obs_output_remove_packet_callback(obs_output_t *output,
 	da_erase_item(output->pkt_callbacks, &data);
 	pthread_mutex_unlock(&output->pkt_callbacks_mutex);
 }
+
+void obs_output_set_reconnect_callback(obs_output_t *output,
+				       bool (*reconnect_cb)(void *data, obs_output_t *output, int code), void *param)
+{
+	if (!reconnect_cb) {
+		output->reconnect_callback.reconnect_cb = NULL;
+		output->reconnect_callback.param = NULL;
+	} else {
+		output->reconnect_callback.reconnect_cb = reconnect_cb;
+		output->reconnect_callback.param = param;
+	}
+}

libobs/obs.h

@@ -2074,6 +2074,12 @@ EXPORT void obs_output_remove_packet_callback(obs_output_t *output,
 								struct encoder_packet_time *pkt_time, void *param),
 					      void *param);
 
+/* Sets a callback to be called when the output checks if it should attempt to reconnect.
+ * If the callback returns false, the output will not attempt to reconnect. */
+EXPORT void obs_output_set_reconnect_callback(obs_output_t *output,
+					      bool (*reconnect_cb)(void *data, obs_output_t *output, int code),
+					      void *param);
+
 /* ------------------------------------------------------------------------- */
 /* Functions used by outputs */