/*

  * This file is part of FFmpeg.

  *

  * FFmpeg is free software; you can redistribute it and/or

  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *

  * FFmpeg is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public

  * License along with FFmpeg; if not, write to the Free Software

  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 /**
  * @file
  * Haivision Open SRT (Secure Reliable Transport) protocol
  */
 
 #include <srt/srt.h>
 
 #include "libavutil/avassert.h"
 #include "libavutil/opt.h"
 #include "libavutil/parseutils.h"
 #include "libavutil/time.h"
 
 #include "avformat.h"
 #include "internal.h"
 #include "network.h"
 #include "os_support.h"
 #include "url.h"
 

 /* This is for MPEG-TS and it's a default SRTO_PAYLOADSIZE for SRTT_LIVE (8 TS packets) */
 #ifndef SRT_LIVE_DEFAULT_PAYLOAD_SIZE
 #define SRT_LIVE_DEFAULT_PAYLOAD_SIZE 1316
 #endif
 
 /* This is the maximum payload size for Live mode, should you have a different payload type than MPEG-TS */
 #ifndef SRT_LIVE_MAX_PAYLOAD_SIZE
 #define SRT_LIVE_MAX_PAYLOAD_SIZE 1456
 #endif
 

 enum SRTMode {
     SRT_MODE_CALLER = 0,
     SRT_MODE_LISTENER = 1,
     SRT_MODE_RENDEZVOUS = 2
 };
 
 typedef struct SRTContext {
     const AVClass *class;
     int fd;
     int eid;
     int64_t rw_timeout;
     int64_t listen_timeout;
     int recv_buffer_size;
     int send_buffer_size;
 
     int64_t maxbw;
     int pbkeylen;
     char *passphrase;

 #if SRT_VERSION_VALUE >= 0x010302

     int enforced_encryption;
     int kmrefreshrate;
     int kmpreannounce;

 #endif

     int mss;
     int ffs;
     int ipttl;
     int iptos;
     int64_t inputbw;
     int oheadbw;

     int64_t latency;

     int tlpktdrop;
     int nakreport;
     int64_t connect_timeout;

     int payload_size;

     int64_t rcvlatency;
     int64_t peerlatency;

     enum SRTMode mode;

     int sndbuf;
     int rcvbuf;
     int lossmaxttl;
     int minversion;
     char *streamid;
     char *smoother;
     int messageapi;
     SRT_TRANSTYPE transtype;

     int linger;

 } SRTContext;
 
 #define D AV_OPT_FLAG_DECODING_PARAM
 #define E AV_OPT_FLAG_ENCODING_PARAM
 #define OFFSET(x) offsetof(SRTContext, x)
 static const AVOption libsrt_options[] = {

     { "timeout",        "Timeout of socket I/O operations (in microseconds)",                   OFFSET(rw_timeout),       AV_OPT_TYPE_INT64, { .i64 = -1 }, -1, INT64_MAX, .flags = D|E },
     { "listen_timeout", "Connection awaiting timeout (in microseconds)" ,                       OFFSET(listen_timeout),   AV_OPT_TYPE_INT64, { .i64 = -1 }, -1, INT64_MAX, .flags = D|E },

     { "send_buffer_size", "Socket send buffer size (in bytes)",                                 OFFSET(send_buffer_size), AV_OPT_TYPE_INT,      { .i64 = -1 }, -1, INT_MAX,   .flags = D|E },
     { "recv_buffer_size", "Socket receive buffer size (in bytes)",                              OFFSET(recv_buffer_size), AV_OPT_TYPE_INT,      { .i64 = -1 }, -1, INT_MAX,   .flags = D|E },

     { "pkt_size",       "Maximum SRT packet size",                                              OFFSET(payload_size),     AV_OPT_TYPE_INT,      { .i64 = -1 }, -1, SRT_LIVE_MAX_PAYLOAD_SIZE, .flags = D|E, "payload_size" },
     { "payload_size",   "Maximum SRT packet size",                                              OFFSET(payload_size),     AV_OPT_TYPE_INT,      { .i64 = -1 }, -1, SRT_LIVE_MAX_PAYLOAD_SIZE, .flags = D|E, "payload_size" },
     { "ts_size",        NULL, 0, AV_OPT_TYPE_CONST,  { .i64 = SRT_LIVE_DEFAULT_PAYLOAD_SIZE }, INT_MIN, INT_MAX, .flags = D|E, "payload_size" },
     { "max_size",       NULL, 0, AV_OPT_TYPE_CONST,  { .i64 = SRT_LIVE_MAX_PAYLOAD_SIZE },     INT_MIN, INT_MAX, .flags = D|E, "payload_size" },

     { "maxbw",          "Maximum bandwidth (bytes per second) that the connection can use",     OFFSET(maxbw),            AV_OPT_TYPE_INT64,    { .i64 = -1 }, -1, INT64_MAX, .flags = D|E },
     { "pbkeylen",       "Crypto key len in bytes {16,24,32} Default: 16 (128-bit)",             OFFSET(pbkeylen),         AV_OPT_TYPE_INT,      { .i64 = -1 }, -1, 32,        .flags = D|E },
     { "passphrase",     "Crypto PBKDF2 Passphrase size[0,10..64] 0:disable crypto",             OFFSET(passphrase),       AV_OPT_TYPE_STRING,   { .str = NULL },              .flags = D|E },

 #if SRT_VERSION_VALUE >= 0x010302
     { "enforced_encryption", "Enforces that both connection parties have the same passphrase set",                              OFFSET(enforced_encryption), AV_OPT_TYPE_BOOL,  { .i64 = -1 }, -1, 1,         .flags = D|E },

     { "kmrefreshrate",       "The number of packets to be transmitted after which the encryption key is switched to a new key", OFFSET(kmrefreshrate),       AV_OPT_TYPE_INT,   { .i64 = -1 }, -1, INT_MAX,   .flags = D|E },
     { "kmpreannounce",       "The interval between when a new encryption key is sent and when switchover occurs",               OFFSET(kmpreannounce),       AV_OPT_TYPE_INT,   { .i64 = -1 }, -1, INT_MAX,   .flags = D|E },

 #endif

     { "mss",            "The Maximum Segment Size",                                             OFFSET(mss),              AV_OPT_TYPE_INT,      { .i64 = -1 }, -1, 1500,      .flags = D|E },
     { "ffs",            "Flight flag size (window size) (in bytes)",                            OFFSET(ffs),              AV_OPT_TYPE_INT,      { .i64 = -1 }, -1, INT_MAX,   .flags = D|E },
     { "ipttl",          "IP Time To Live",                                                      OFFSET(ipttl),            AV_OPT_TYPE_INT,      { .i64 = -1 }, -1, 255,       .flags = D|E },
     { "iptos",          "IP Type of Service",                                                   OFFSET(iptos),            AV_OPT_TYPE_INT,      { .i64 = -1 }, -1, 255,       .flags = D|E },
     { "inputbw",        "Estimated input stream rate",                                          OFFSET(inputbw),          AV_OPT_TYPE_INT64,    { .i64 = -1 }, -1, INT64_MAX, .flags = D|E },
     { "oheadbw",        "MaxBW ceiling based on % over input stream rate",                      OFFSET(oheadbw),          AV_OPT_TYPE_INT,      { .i64 = -1 }, -1, 100,       .flags = D|E },

     { "latency",        "receiver delay (in microseconds) to absorb bursts of missed packet retransmissions",                     OFFSET(latency),          AV_OPT_TYPE_INT64, { .i64 = -1 }, -1, INT64_MAX, .flags = D|E },

     { "tsbpddelay",     "deprecated, same effect as latency option",                            OFFSET(latency),          AV_OPT_TYPE_INT64, { .i64 = -1 }, -1, INT64_MAX, .flags = D|E },

     { "rcvlatency",     "receive latency (in microseconds)",                                    OFFSET(rcvlatency),       AV_OPT_TYPE_INT64, { .i64 = -1 }, -1, INT64_MAX, .flags = D|E },
     { "peerlatency",    "peer latency (in microseconds)",                                       OFFSET(peerlatency),      AV_OPT_TYPE_INT64, { .i64 = -1 }, -1, INT64_MAX, .flags = D|E },

     { "tlpktdrop",      "Enable receiver pkt drop",                                             OFFSET(tlpktdrop),        AV_OPT_TYPE_BOOL,     { .i64 = -1 }, -1, 1,         .flags = D|E },
     { "nakreport",      "Enable receiver to send periodic NAK reports",                         OFFSET(nakreport),        AV_OPT_TYPE_BOOL,     { .i64 = -1 }, -1, 1,         .flags = D|E },

     { "connect_timeout", "Connect timeout(in milliseconds). Caller default: 3000, rendezvous (x 10)",                            OFFSET(connect_timeout),  AV_OPT_TYPE_INT64, { .i64 = -1 }, -1, INT64_MAX, .flags = D|E },

     { "mode",           "Connection mode (caller, listener, rendezvous)",                       OFFSET(mode),             AV_OPT_TYPE_INT,      { .i64 = SRT_MODE_CALLER }, SRT_MODE_CALLER, SRT_MODE_RENDEZVOUS, .flags = D|E, "mode" },
     { "caller",         NULL, 0, AV_OPT_TYPE_CONST,  { .i64 = SRT_MODE_CALLER },     INT_MIN, INT_MAX, .flags = D|E, "mode" },
     { "listener",       NULL, 0, AV_OPT_TYPE_CONST,  { .i64 = SRT_MODE_LISTENER },   INT_MIN, INT_MAX, .flags = D|E, "mode" },
     { "rendezvous",     NULL, 0, AV_OPT_TYPE_CONST,  { .i64 = SRT_MODE_RENDEZVOUS }, INT_MIN, INT_MAX, .flags = D|E, "mode" },

     { "sndbuf",         "Send buffer size (in bytes)",                                          OFFSET(sndbuf),           AV_OPT_TYPE_INT,      { .i64 = -1 }, -1, INT_MAX,   .flags = D|E },
     { "rcvbuf",         "Receive buffer size (in bytes)",                                       OFFSET(rcvbuf),           AV_OPT_TYPE_INT,      { .i64 = -1 }, -1, INT_MAX,   .flags = D|E },
     { "lossmaxttl",     "Maximum possible packet reorder tolerance",                            OFFSET(lossmaxttl),       AV_OPT_TYPE_INT,      { .i64 = -1 }, -1, INT_MAX,   .flags = D|E },
     { "minversion",     "The minimum SRT version that is required from the peer",               OFFSET(minversion),       AV_OPT_TYPE_INT,      { .i64 = -1 }, -1, INT_MAX,   .flags = D|E },
     { "streamid",       "A string of up to 512 characters that an Initiator can pass to a Responder",  OFFSET(streamid),  AV_OPT_TYPE_STRING,   { .str = NULL },              .flags = D|E },
     { "smoother",       "The type of Smoother used for the transmission for that socket",       OFFSET(smoother),         AV_OPT_TYPE_STRING,   { .str = NULL },              .flags = D|E },

     { "messageapi",     "Enable message API",                                                   OFFSET(messageapi),       AV_OPT_TYPE_BOOL,     { .i64 = -1 }, -1, 1,         .flags = D|E },

     { "transtype",      "The transmission type for the socket",                                 OFFSET(transtype),        AV_OPT_TYPE_INT,      { .i64 = SRTT_INVALID }, SRTT_LIVE, SRTT_INVALID, .flags = D|E, "transtype" },
     { "live",           NULL, 0, AV_OPT_TYPE_CONST,  { .i64 = SRTT_LIVE }, INT_MIN, INT_MAX, .flags = D|E, "transtype" },
     { "file",           NULL, 0, AV_OPT_TYPE_CONST,  { .i64 = SRTT_FILE }, INT_MIN, INT_MAX, .flags = D|E, "transtype" },

     { "linger",         "Number of seconds that the socket waits for unsent data when closing", OFFSET(linger),           AV_OPT_TYPE_INT,      { .i64 = -1 }, -1, INT_MAX,   .flags = D|E },

     { NULL }
 };
 
 static int libsrt_neterrno(URLContext *h)
 {

     int os_errno;
     int err = srt_getlasterror(&os_errno);
     if (err == SRT_EASYNCRCV || err == SRT_EASYNCSND)

         return AVERROR(EAGAIN);

     av_log(h, AV_LOG_ERROR, "%s\n", srt_getlasterror_str());
     return os_errno ? AVERROR(os_errno) : AVERROR_UNKNOWN;

 }
 
 static int libsrt_socket_nonblock(int socket, int enable)
 {

     int ret, blocking = enable ? 0 : 1;
     /* Setting SRTO_{SND,RCV}SYN options to 1 enable blocking mode, setting them to 0 enable non-blocking mode. */
     ret = srt_setsockopt(socket, 0, SRTO_SNDSYN, &blocking, sizeof(blocking));

     if (ret < 0)
         return ret;

     return srt_setsockopt(socket, 0, SRTO_RCVSYN, &blocking, sizeof(blocking));

 }
 
 static int libsrt_network_wait_fd(URLContext *h, int eid, int fd, int write)
 {

     int ret, len = 1, errlen = 1;
     int modes = SRT_EPOLL_ERR | (write ? SRT_EPOLL_OUT : SRT_EPOLL_IN);

     SRTSOCKET ready[1];

     SRTSOCKET error[1];

 
     if (srt_epoll_add_usock(eid, fd, &modes) < 0)
         return libsrt_neterrno(h);
     if (write) {

         ret = srt_epoll_wait(eid, error, &errlen, ready, &len, POLLING_TIME, 0, 0, 0, 0);

     } else {

         ret = srt_epoll_wait(eid, ready, &len, error, &errlen, POLLING_TIME, 0, 0, 0, 0);

     }
     if (ret < 0) {
         if (srt_getlasterror(NULL) == SRT_ETIMEOUT)
             ret = AVERROR(EAGAIN);
         else
             ret = libsrt_neterrno(h);
     } else {

         ret = errlen ? AVERROR(EIO) : 0;

     }
     if (srt_epoll_remove_usock(eid, fd) < 0)
         return libsrt_neterrno(h);
     return ret;
 }
 
 /* TODO de-duplicate code from ff_network_wait_fd_timeout() */
 
 static int libsrt_network_wait_fd_timeout(URLContext *h, int eid, int fd, int write, int64_t timeout, AVIOInterruptCB *int_cb)
 {
     int ret;
     int64_t wait_start = 0;
 
     while (1) {
         if (ff_check_interrupt(int_cb))
             return AVERROR_EXIT;
         ret = libsrt_network_wait_fd(h, eid, fd, write);
         if (ret != AVERROR(EAGAIN))
             return ret;
         if (timeout > 0) {
             if (!wait_start)
                 wait_start = av_gettime_relative();
             else if (av_gettime_relative() - wait_start > timeout)
                 return AVERROR(ETIMEDOUT);
         }
     }
 }
 

 static int libsrt_listen(int eid, int fd, const struct sockaddr *addr, socklen_t addrlen, URLContext *h, int64_t timeout)

 {
     int ret;
     int reuse = 1;
     if (srt_setsockopt(fd, SOL_SOCKET, SRTO_REUSEADDR, &reuse, sizeof(reuse))) {
         av_log(h, AV_LOG_WARNING, "setsockopt(SRTO_REUSEADDR) failed\n");
     }
     ret = srt_bind(fd, addr, addrlen);
     if (ret)
         return libsrt_neterrno(h);
 
     ret = srt_listen(fd, 1);
     if (ret)
         return libsrt_neterrno(h);
 

     ret = libsrt_network_wait_fd_timeout(h, eid, fd, 1, timeout, &h->interrupt_callback);
     if (ret < 0)
         return ret;

 
     ret = srt_accept(fd, NULL, NULL);
     if (ret < 0)
         return libsrt_neterrno(h);
     if (libsrt_socket_nonblock(ret, 1) < 0)
         av_log(h, AV_LOG_DEBUG, "libsrt_socket_nonblock failed\n");
 
     return ret;
 }
 

 static int libsrt_listen_connect(int eid, int fd, const struct sockaddr *addr, socklen_t addrlen, int64_t timeout, URLContext *h, int will_try_next)

 {
     int ret;
 

     ret = srt_connect(fd, addr, addrlen);
     if (ret < 0)
         return libsrt_neterrno(h);
 
     ret = libsrt_network_wait_fd_timeout(h, eid, fd, 1, timeout, &h->interrupt_callback);
     if (ret < 0) {
         if (will_try_next) {
             av_log(h, AV_LOG_WARNING,
                    "Connection to %s failed (%s), trying next address\n",
                    h->filename, av_err2str(ret));
         } else {
             av_log(h, AV_LOG_ERROR, "Connection to %s failed: %s\n",
                    h->filename, av_err2str(ret));

         }
     }
     return ret;
 }
 
 static int libsrt_setsockopt(URLContext *h, int fd, SRT_SOCKOPT optname, const char * optnamestr, const void * optval, int optlen)
 {
     if (srt_setsockopt(fd, 0, optname, optval, optlen) < 0) {
         av_log(h, AV_LOG_ERROR, "failed to set option %s on socket: %s\n", optnamestr, srt_getlasterror_str());
         return AVERROR(EIO);
     }
     return 0;
 }
 

 static int libsrt_getsockopt(URLContext *h, int fd, SRT_SOCKOPT optname, const char * optnamestr, void * optval, int * optlen)
 {
     if (srt_getsockopt(fd, 0, optname, optval, optlen) < 0) {
         av_log(h, AV_LOG_ERROR, "failed to get option %s on socket: %s\n", optnamestr, srt_getlasterror_str());
         return AVERROR(EIO);
     }
     return 0;
 }
 

 /* - The "POST" options can be altered any time on a connected socket.
      They MAY have also some meaning when set prior to connecting; such
      option is SRTO_RCVSYN, which makes connect/accept call asynchronous.
      Because of that this option is treated special way in this app. */
 static int libsrt_set_options_post(URLContext *h, int fd)
 {
     SRTContext *s = h->priv_data;
 
     if ((s->inputbw >= 0 && libsrt_setsockopt(h, fd, SRTO_INPUTBW, "SRTO_INPUTBW", &s->inputbw, sizeof(s->inputbw)) < 0) ||
         (s->oheadbw >= 0 && libsrt_setsockopt(h, fd, SRTO_OHEADBW, "SRTO_OHEADBW", &s->oheadbw, sizeof(s->oheadbw)) < 0)) {
         return AVERROR(EIO);
     }
     return 0;
 }
 
 /* - The "PRE" options must be set prior to connecting and can't be altered
      on a connected socket, however if set on a listening socket, they are
      derived by accept-ed socket. */
 static int libsrt_set_options_pre(URLContext *h, int fd)
 {
     SRTContext *s = h->priv_data;
     int yes = 1;

     int latency = s->latency / 1000;
     int rcvlatency = s->rcvlatency / 1000;
     int peerlatency = s->peerlatency / 1000;

     int connect_timeout = s->connect_timeout;
 
     if ((s->mode == SRT_MODE_RENDEZVOUS && libsrt_setsockopt(h, fd, SRTO_RENDEZVOUS, "SRTO_RENDEZVOUS", &yes, sizeof(yes)) < 0) ||

         (s->transtype != SRTT_INVALID && libsrt_setsockopt(h, fd, SRTO_TRANSTYPE, "SRTO_TRANSTYPE", &s->transtype, sizeof(s->transtype)) < 0) ||

         (s->maxbw >= 0 && libsrt_setsockopt(h, fd, SRTO_MAXBW, "SRTO_MAXBW", &s->maxbw, sizeof(s->maxbw)) < 0) ||
         (s->pbkeylen >= 0 && libsrt_setsockopt(h, fd, SRTO_PBKEYLEN, "SRTO_PBKEYLEN", &s->pbkeylen, sizeof(s->pbkeylen)) < 0) ||

         (s->passphrase && libsrt_setsockopt(h, fd, SRTO_PASSPHRASE, "SRTO_PASSPHRASE", s->passphrase, strlen(s->passphrase)) < 0) ||

 #if SRT_VERSION_VALUE >= 0x010302
         /* SRTO_STRICTENC == SRTO_ENFORCEDENCRYPTION (53), but for compatibility, we used SRTO_STRICTENC */
         (s->enforced_encryption >= 0 && libsrt_setsockopt(h, fd, SRTO_STRICTENC, "SRTO_STRICTENC", &s->enforced_encryption, sizeof(s->enforced_encryption)) < 0) ||

         (s->kmrefreshrate >= 0 && libsrt_setsockopt(h, fd, SRTO_KMREFRESHRATE, "SRTO_KMREFRESHRATE", &s->kmrefreshrate, sizeof(s->kmrefreshrate)) < 0) ||
         (s->kmpreannounce >= 0 && libsrt_setsockopt(h, fd, SRTO_KMPREANNOUNCE, "SRTO_KMPREANNOUNCE", &s->kmpreannounce, sizeof(s->kmpreannounce)) < 0) ||

 #endif

         (s->mss >= 0 && libsrt_setsockopt(h, fd, SRTO_MSS, "SRTO_MSS", &s->mss, sizeof(s->mss)) < 0) ||

         (s->ffs >= 0 && libsrt_setsockopt(h, fd, SRTO_FC, "SRTO_FC", &s->ffs, sizeof(s->ffs)) < 0) ||

         (s->ipttl >= 0 && libsrt_setsockopt(h, fd, SRTO_IPTTL, "SRTO_IPTTL", &s->ipttl, sizeof(s->ipttl)) < 0) ||

         (s->iptos >= 0 && libsrt_setsockopt(h, fd, SRTO_IPTOS, "SRTO_IPTOS", &s->iptos, sizeof(s->iptos)) < 0) ||

         (s->latency >= 0 && libsrt_setsockopt(h, fd, SRTO_LATENCY, "SRTO_LATENCY", &latency, sizeof(latency)) < 0) ||
         (s->rcvlatency >= 0 && libsrt_setsockopt(h, fd, SRTO_RCVLATENCY, "SRTO_RCVLATENCY", &rcvlatency, sizeof(rcvlatency)) < 0) ||
         (s->peerlatency >= 0 && libsrt_setsockopt(h, fd, SRTO_PEERLATENCY, "SRTO_PEERLATENCY", &peerlatency, sizeof(peerlatency)) < 0) ||

         (s->tlpktdrop >= 0 && libsrt_setsockopt(h, fd, SRTO_TLPKTDROP, "SRTO_TLPKDROP", &s->tlpktdrop, sizeof(s->tlpktdrop)) < 0) ||
         (s->nakreport >= 0 && libsrt_setsockopt(h, fd, SRTO_NAKREPORT, "SRTO_NAKREPORT", &s->nakreport, sizeof(s->nakreport)) < 0) ||

         (connect_timeout >= 0 && libsrt_setsockopt(h, fd, SRTO_CONNTIMEO, "SRTO_CONNTIMEO", &connect_timeout, sizeof(connect_timeout)) <0 ) ||

         (s->sndbuf >= 0 && libsrt_setsockopt(h, fd, SRTO_SNDBUF, "SRTO_SNDBUF", &s->sndbuf, sizeof(s->sndbuf)) < 0) ||
         (s->rcvbuf >= 0 && libsrt_setsockopt(h, fd, SRTO_RCVBUF, "SRTO_RCVBUF", &s->rcvbuf, sizeof(s->rcvbuf)) < 0) ||
         (s->lossmaxttl >= 0 && libsrt_setsockopt(h, fd, SRTO_LOSSMAXTTL, "SRTO_LOSSMAXTTL", &s->lossmaxttl, sizeof(s->lossmaxttl)) < 0) ||
         (s->minversion >= 0 && libsrt_setsockopt(h, fd, SRTO_MINVERSION, "SRTO_MINVERSION", &s->minversion, sizeof(s->minversion)) < 0) ||
         (s->streamid && libsrt_setsockopt(h, fd, SRTO_STREAMID, "SRTO_STREAMID", s->streamid, strlen(s->streamid)) < 0) ||
         (s->smoother && libsrt_setsockopt(h, fd, SRTO_SMOOTHER, "SRTO_SMOOTHER", s->smoother, strlen(s->smoother)) < 0) ||
         (s->messageapi >= 0 && libsrt_setsockopt(h, fd, SRTO_MESSAGEAPI, "SRTO_MESSAGEAPI", &s->messageapi, sizeof(s->messageapi)) < 0) ||

         (s->payload_size >= 0 && libsrt_setsockopt(h, fd, SRTO_PAYLOADSIZE, "SRTO_PAYLOADSIZE", &s->payload_size, sizeof(s->payload_size)) < 0) ||
         ((h->flags & AVIO_FLAG_WRITE) && libsrt_setsockopt(h, fd, SRTO_SENDER, "SRTO_SENDER", &yes, sizeof(yes)) < 0)) {

         return AVERROR(EIO);
     }

 
     if (s->linger >= 0) {
         struct linger lin;
         lin.l_linger = s->linger;
         lin.l_onoff  = lin.l_linger > 0 ? 1 : 0;
         if (libsrt_setsockopt(h, fd, SRTO_LINGER, "SRTO_LINGER", &lin, sizeof(lin)) < 0)
             return AVERROR(EIO);
     }

     return 0;
 }
 
 
 static int libsrt_setup(URLContext *h, const char *uri, int flags)
 {
     struct addrinfo hints = { 0 }, *ai, *cur_ai;
     int port, fd = -1;
     SRTContext *s = h->priv_data;
     const char *p;
     char buf[256];
     int ret;
     char hostname[1024],proto[1024],path[1024];
     char portstr[10];

     int64_t open_timeout = 0;

     int eid;
 
     eid = srt_epoll_create();
     if (eid < 0)
         return libsrt_neterrno(h);
     s->eid = eid;
 
     av_url_split(proto, sizeof(proto), NULL, 0, hostname, sizeof(hostname),
         &port, path, sizeof(path), uri);
     if (strcmp(proto, "srt"))
         return AVERROR(EINVAL);
     if (port <= 0 || port >= 65536) {
         av_log(h, AV_LOG_ERROR, "Port missing in uri\n");
         return AVERROR(EINVAL);
     }
     p = strchr(uri, '?');
     if (p) {
         if (av_find_info_tag(buf, sizeof(buf), "timeout", p)) {
             s->rw_timeout = strtol(buf, NULL, 10);
         }
         if (av_find_info_tag(buf, sizeof(buf), "listen_timeout", p)) {
             s->listen_timeout = strtol(buf, NULL, 10);
         }
     }
     if (s->rw_timeout >= 0) {
         open_timeout = h->rw_timeout = s->rw_timeout;
     }
     hints.ai_family = AF_UNSPEC;
     hints.ai_socktype = SOCK_DGRAM;
     snprintf(portstr, sizeof(portstr), "%d", port);
     if (s->mode == SRT_MODE_LISTENER)
         hints.ai_flags |= AI_PASSIVE;
     ret = getaddrinfo(hostname[0] ? hostname : NULL, portstr, &hints, &ai);
     if (ret) {
         av_log(h, AV_LOG_ERROR,
                "Failed to resolve hostname %s: %s\n",
                hostname, gai_strerror(ret));
         return AVERROR(EIO);
     }
 
     cur_ai = ai;
 
  restart:
 
     fd = srt_socket(cur_ai->ai_family, cur_ai->ai_socktype, 0);
     if (fd < 0) {
         ret = libsrt_neterrno(h);
         goto fail;
     }
 
     if ((ret = libsrt_set_options_pre(h, fd)) < 0) {
         goto fail;
     }
 
     /* Set the socket's send or receive buffer sizes, if specified.
        If unspecified or setting fails, system default is used. */
     if (s->recv_buffer_size > 0) {
         srt_setsockopt(fd, SOL_SOCKET, SRTO_UDP_RCVBUF, &s->recv_buffer_size, sizeof (s->recv_buffer_size));
     }
     if (s->send_buffer_size > 0) {
         srt_setsockopt(fd, SOL_SOCKET, SRTO_UDP_SNDBUF, &s->send_buffer_size, sizeof (s->send_buffer_size));
     }

     if (libsrt_socket_nonblock(fd, 1) < 0)
         av_log(h, AV_LOG_DEBUG, "libsrt_socket_nonblock failed\n");
 

     if (s->mode == SRT_MODE_LISTENER) {
         // multi-client

         if ((ret = libsrt_listen(s->eid, fd, cur_ai->ai_addr, cur_ai->ai_addrlen, h, s->listen_timeout)) < 0)

             goto fail1;
         fd = ret;
     } else {
         if (s->mode == SRT_MODE_RENDEZVOUS) {
             ret = srt_bind(fd, cur_ai->ai_addr, cur_ai->ai_addrlen);
             if (ret)
                 goto fail1;
         }
 
         if ((ret = libsrt_listen_connect(s->eid, fd, cur_ai->ai_addr, cur_ai->ai_addrlen,

                                           open_timeout, h, !!cur_ai->ai_next)) < 0) {

             if (ret == AVERROR_EXIT)
                 goto fail1;
             else
                 goto fail;
         }
     }
     if ((ret = libsrt_set_options_post(h, fd)) < 0) {
         goto fail;
     }
 

     if (flags & AVIO_FLAG_WRITE) {
         int packet_size = 0;
         int optlen = sizeof(packet_size);
         ret = libsrt_getsockopt(h, fd, SRTO_PAYLOADSIZE, "SRTO_PAYLOADSIZE", &packet_size, &optlen);
         if (ret < 0)
             goto fail1;
         if (packet_size > 0)
             h->max_packet_size = packet_size;
     }
 

     h->is_streamed = 1;
     s->fd = fd;
 
     freeaddrinfo(ai);
     return 0;
 
  fail:
     if (cur_ai->ai_next) {
         /* Retry with the next sockaddr */
         cur_ai = cur_ai->ai_next;
         if (fd >= 0)
             srt_close(fd);
         ret = 0;
         goto restart;
     }
  fail1:
     if (fd >= 0)
         srt_close(fd);
     freeaddrinfo(ai);
     return ret;
 }
 
 static int libsrt_open(URLContext *h, const char *uri, int flags)
 {
     SRTContext *s = h->priv_data;
     const char * p;
     char buf[256];

     int ret = 0;

 
     if (srt_startup() < 0) {
         return AVERROR_UNKNOWN;
     }
 
     /* SRT options (srt/srt.h) */
     p = strchr(uri, '?');
     if (p) {
         if (av_find_info_tag(buf, sizeof(buf), "maxbw", p)) {
             s->maxbw = strtoll(buf, NULL, 0);
         }
         if (av_find_info_tag(buf, sizeof(buf), "pbkeylen", p)) {
             s->pbkeylen = strtol(buf, NULL, 10);
         }
         if (av_find_info_tag(buf, sizeof(buf), "passphrase", p)) {

             av_freep(&s->passphrase);

             s->passphrase = av_strndup(buf, strlen(buf));
         }

 #if SRT_VERSION_VALUE >= 0x010302

         if (av_find_info_tag(buf, sizeof(buf), "enforced_encryption", p)) {
             s->enforced_encryption = strtol(buf, NULL, 10);
         }
         if (av_find_info_tag(buf, sizeof(buf), "kmrefreshrate", p)) {
             s->kmrefreshrate = strtol(buf, NULL, 10);
         }
         if (av_find_info_tag(buf, sizeof(buf), "kmpreannounce", p)) {
             s->kmpreannounce = strtol(buf, NULL, 10);
         }

 #endif

         if (av_find_info_tag(buf, sizeof(buf), "mss", p)) {
             s->mss = strtol(buf, NULL, 10);
         }
         if (av_find_info_tag(buf, sizeof(buf), "ffs", p)) {
             s->ffs = strtol(buf, NULL, 10);
         }
         if (av_find_info_tag(buf, sizeof(buf), "ipttl", p)) {
             s->ipttl = strtol(buf, NULL, 10);
         }
         if (av_find_info_tag(buf, sizeof(buf), "iptos", p)) {
             s->iptos = strtol(buf, NULL, 10);
         }
         if (av_find_info_tag(buf, sizeof(buf), "inputbw", p)) {
             s->inputbw = strtoll(buf, NULL, 10);
         }
         if (av_find_info_tag(buf, sizeof(buf), "oheadbw", p)) {
             s->oheadbw = strtoll(buf, NULL, 10);
         }

         if (av_find_info_tag(buf, sizeof(buf), "latency", p)) {
             s->latency = strtol(buf, NULL, 10);
         }

         if (av_find_info_tag(buf, sizeof(buf), "tsbpddelay", p)) {

             s->latency = strtol(buf, NULL, 10);
         }
         if (av_find_info_tag(buf, sizeof(buf), "rcvlatency", p)) {
             s->rcvlatency = strtol(buf, NULL, 10);
         }
         if (av_find_info_tag(buf, sizeof(buf), "peerlatency", p)) {
             s->peerlatency = strtol(buf, NULL, 10);

         }
         if (av_find_info_tag(buf, sizeof(buf), "tlpktdrop", p)) {
             s->tlpktdrop = strtol(buf, NULL, 10);
         }
         if (av_find_info_tag(buf, sizeof(buf), "nakreport", p)) {
             s->nakreport = strtol(buf, NULL, 10);
         }
         if (av_find_info_tag(buf, sizeof(buf), "connect_timeout", p)) {
             s->connect_timeout = strtol(buf, NULL, 10);
         }

         if (av_find_info_tag(buf, sizeof(buf), "payload_size", p) ||
             av_find_info_tag(buf, sizeof(buf), "pkt_size", p)) {

             s->payload_size = strtol(buf, NULL, 10);
         }

         if (av_find_info_tag(buf, sizeof(buf), "mode", p)) {
             if (!strcmp(buf, "caller")) {
                 s->mode = SRT_MODE_CALLER;
             } else if (!strcmp(buf, "listener")) {
                 s->mode = SRT_MODE_LISTENER;
             } else if (!strcmp(buf, "rendezvous")) {
                 s->mode = SRT_MODE_RENDEZVOUS;
             } else {
                 return AVERROR(EIO);
             }
         }

         if (av_find_info_tag(buf, sizeof(buf), "sndbuf", p)) {
             s->sndbuf = strtol(buf, NULL, 10);
         }
         if (av_find_info_tag(buf, sizeof(buf), "rcvbuf", p)) {
             s->rcvbuf = strtol(buf, NULL, 10);
         }
         if (av_find_info_tag(buf, sizeof(buf), "lossmaxttl", p)) {
             s->lossmaxttl = strtol(buf, NULL, 10);
         }
         if (av_find_info_tag(buf, sizeof(buf), "minversion", p)) {
             s->minversion = strtol(buf, NULL, 0);
         }
         if (av_find_info_tag(buf, sizeof(buf), "streamid", p)) {
             av_freep(&s->streamid);
             s->streamid = av_strdup(buf);

             if (!s->streamid) {
                 ret = AVERROR(ENOMEM);
                 goto err;
             }

         }
         if (av_find_info_tag(buf, sizeof(buf), "smoother", p)) {
             av_freep(&s->smoother);
             s->smoother = av_strdup(buf);

             if(!s->smoother) {
                 ret = AVERROR(ENOMEM);
                 goto err;
             }

         }
         if (av_find_info_tag(buf, sizeof(buf), "messageapi", p)) {
             s->messageapi = strtol(buf, NULL, 10);
         }
         if (av_find_info_tag(buf, sizeof(buf), "transtype", p)) {
             if (!strcmp(buf, "live")) {
                 s->transtype = SRTT_LIVE;
             } else if (!strcmp(buf, "file")) {
                 s->transtype = SRTT_FILE;
             } else {

                 ret = AVERROR(EINVAL);
                 goto err;

             }
         }

         if (av_find_info_tag(buf, sizeof(buf), "linger", p)) {
             s->linger = strtol(buf, NULL, 10);
         }

     }
     return libsrt_setup(h, uri, flags);

 err:
     av_freep(&s->smoother);
     av_freep(&s->streamid);
     return ret;

 }
 
 static int libsrt_read(URLContext *h, uint8_t *buf, int size)
 {
     SRTContext *s = h->priv_data;
     int ret;
 
     if (!(h->flags & AVIO_FLAG_NONBLOCK)) {
         ret = libsrt_network_wait_fd_timeout(h, s->eid, s->fd, 0, h->rw_timeout, &h->interrupt_callback);
         if (ret)
             return ret;
     }
 
     ret = srt_recvmsg(s->fd, buf, size);
     if (ret < 0) {
         ret = libsrt_neterrno(h);
     }
 
     return ret;
 }
 
 static int libsrt_write(URLContext *h, const uint8_t *buf, int size)
 {
     SRTContext *s = h->priv_data;
     int ret;
 
     if (!(h->flags & AVIO_FLAG_NONBLOCK)) {
         ret = libsrt_network_wait_fd_timeout(h, s->eid, s->fd, 1, h->rw_timeout, &h->interrupt_callback);
         if (ret)
             return ret;
     }
 
     ret = srt_sendmsg(s->fd, buf, size, -1, 0);
     if (ret < 0) {
         ret = libsrt_neterrno(h);
     }
 
     return ret;
 }
 
 static int libsrt_close(URLContext *h)
 {
     SRTContext *s = h->priv_data;
 
     srt_close(s->fd);
 
     srt_epoll_release(s->eid);
 
     srt_cleanup();
 
     return 0;
 }
 
 static int libsrt_get_file_handle(URLContext *h)
 {
     SRTContext *s = h->priv_data;
     return s->fd;
 }
 
 static const AVClass libsrt_class = {
     .class_name = "libsrt",
     .item_name  = av_default_item_name,
     .option     = libsrt_options,
     .version    = LIBAVUTIL_VERSION_INT,
 };
 
 const URLProtocol ff_libsrt_protocol = {
     .name                = "srt",
     .url_open            = libsrt_open,
     .url_read            = libsrt_read,
     .url_write           = libsrt_write,
     .url_close           = libsrt_close,
     .url_get_file_handle = libsrt_get_file_handle,
     .priv_data_size      = sizeof(SRTContext),
     .flags               = URL_PROTOCOL_FLAG_NETWORK,
     .priv_data_class     = &libsrt_class,
 };