/* SPDX-License-Identifier: GPL-2.0 */

/** \file vss.h The virtual streaming system API.
 *
 * The virtual streaming system (vss) is the sender-independent part of the
 * server which is responsible to communicate with the audio file selector
 * and the various senders. The functions declared here are implemented in
 * \ref vss.c.
 *
 * The init function \ref vss_init() is only called in server context to
 * register the vss task to the scheduler. Other functions, for example \ref
 * vss_playing() are only called in command handler context. The shutdown
 * function \ref vss_shutdown() is called in both contexts.
 *
 * The udp sender is based on a lossy protocol, so it uses forward error
 * correction (FEC) to deal with packet losses. The virtual streaming system
 * maintains the list of FEC clients and implements the functions declared
 * in this file to add or remove FEC clients from the list.
 */

void vss_init(int afs_socket, struct sched *s);
void vss_shutdown(void);
bool vss_playing(void);
bool vss_paused(void);
bool vss_stopped(void);
struct fec_client *vss_add_fec_client(struct sender_client *sc,
				      struct fec_client_parms *fcp);
void vss_del_fec_client(struct fec_client *fc);

/** Stop playing after current audio file. */
#define VSS_NOMORE 1
/** Skip remaining part of current audio file. */
#define VSS_NEXT 2
/** A reposition request was sent by a client. */
#define VSS_REPOS 4
/** Currently playing. */
#define VSS_PLAYING 8