PeerStreamer

/*

 * RTP network protocol

 * Copyright (c) 2002 Fabrice Bellard

 *

 * 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

 * RTP protocol

 */

#include "libavutil/parseutils.h"

#include "libavutil/avstring.h"

#include "avformat.h"

#include "rtpdec.h"

#include <unistd.h>

#include <stdarg.h>

#include "internal.h"

#include "network.h"

#include "os_support.h"

#include <fcntl.h>

#if HAVE_POLL_H

#include <sys/poll.h>

#endif

#include <sys/time.h>

#define RTP_TX_BUF_SIZE  (64 * 1024)

#define RTP_RX_BUF_SIZE  (128 * 1024)

typedef struct RTPContext {

    URLContext *rtp_hd, *rtcp_hd;

    int rtp_fd, rtcp_fd;

} RTPContext;

/**

 * If no filename is given to av_open_input_file because you want to

 * get the local port first, then you must call this function to set

 * the remote server address.

 *

 * @param h media file context

 * @param uri of the remote server

 * @return zero if no error.

 */

int rtp_set_remote_url(URLContext *h, const char *uri)

{

    RTPContext *s = h->priv_data;

    char hostname[256];

    int port;

    char buf[1024];

    char path[1024];

    av_url_split(NULL, 0, NULL, 0, hostname, sizeof(hostname), &port,

                 path, sizeof(path), uri);

    ff_url_join(buf, sizeof(buf), "udp", NULL, hostname, port, "%s", path);

    udp_set_remote_url(s->rtp_hd, buf);

    ff_url_join(buf, sizeof(buf), "udp", NULL, hostname, port + 1, "%s", path);

    udp_set_remote_url(s->rtcp_hd, buf);

    return 0;

}

/**

 * add option to url of the form:

 * "http://host:port/path?option1=val1&option2=val2...

 */

static void url_add_option(char *buf, int buf_size, const char *fmt, ...)

{

    char buf1[1024];

    va_list ap;

    va_start(ap, fmt);

    if (strchr(buf, '?'))

        av_strlcat(buf, "&", buf_size);

    else

        av_strlcat(buf, "?", buf_size);

    vsnprintf(buf1, sizeof(buf1), fmt, ap);

    av_strlcat(buf, buf1, buf_size);

    va_end(ap);

}

static void build_udp_url(char *buf, int buf_size,

                          const char *hostname, int port,

                          int local_port, int ttl,

                          int max_packet_size, int connect)

{

    ff_url_join(buf, buf_size, "udp", NULL, hostname, port, NULL);

    if (local_port >= 0)

        url_add_option(buf, buf_size, "localport=%d", local_port);

    if (ttl >= 0)

        url_add_option(buf, buf_size, "ttl=%d", ttl);

    if (max_packet_size >=0)

        url_add_option(buf, buf_size, "pkt_size=%d", max_packet_size);

    if (connect)

        url_add_option(buf, buf_size, "connect=1");

}

/**

 * url syntax: rtp://host:port[?option=val...]

 * option: 'ttl=n'            : set the ttl value (for multicast only)

 *         'rtcpport=n'       : set the remote rtcp port to n

 *         'localrtpport=n'   : set the local rtp port to n

 *         'localrtcpport=n'  : set the local rtcp port to n

 *         'pkt_size=n'       : set max packet size

 *         'connect=0/1'      : do a connect() on the UDP socket

 * deprecated option:

 *         'localport=n'      : set the local port to n

 *

 * if rtcpport isn't set the rtcp port will be the rtp port + 1

 * if local rtp port isn't set any available port will be used for the local

 * rtp and rtcp ports

 * if the local rtcp port is not set it will be the local rtp port + 1

 */

static int rtp_open(URLContext *h, const char *uri, int flags)

{

    RTPContext *s;

    int rtp_port, rtcp_port,

        is_output, ttl, connect,

        local_rtp_port, local_rtcp_port, max_packet_size;

    char hostname[256];

    char buf[1024];

    char path[1024];

    const char *p;

    is_output = (flags & URL_WRONLY);

    s = av_mallocz(sizeof(RTPContext));

    if (!s)

        return AVERROR(ENOMEM);

    h->priv_data = s;

    av_url_split(NULL, 0, NULL, 0, hostname, sizeof(hostname), &rtp_port,

                 path, sizeof(path), uri);

    /* extract parameters */

    ttl = -1;

    rtcp_port = rtp_port+1;

    local_rtp_port = -1;

    local_rtcp_port = -1;

    max_packet_size = -1;

    connect = 0;

    p = strchr(uri, '?');

    if (p) {

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

            ttl = strtol(buf, NULL, 10);

        }

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

            rtcp_port = strtol(buf, NULL, 10);

        }

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

            local_rtp_port = strtol(buf, NULL, 10);

        }

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

            local_rtp_port = strtol(buf, NULL, 10);

        }

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

            local_rtcp_port = strtol(buf, NULL, 10);

        }

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

            max_packet_size = strtol(buf, NULL, 10);

        }

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

            connect = strtol(buf, NULL, 10);

        }

    }

    build_udp_url(buf, sizeof(buf),

                  hostname, rtp_port, local_rtp_port, ttl, max_packet_size,

                  connect);

    if (url_open(&s->rtp_hd, buf, flags) < 0)

        goto fail;

    if (local_rtp_port>=0 && local_rtcp_port<0)

        local_rtcp_port = udp_get_local_port(s->rtp_hd) + 1;

    build_udp_url(buf, sizeof(buf),

                  hostname, rtcp_port, local_rtcp_port, ttl, max_packet_size,

                  connect);

    if (url_open(&s->rtcp_hd, buf, flags) < 0)

        goto fail;

    /* just to ease handle access. XXX: need to suppress direct handle

       access */

    s->rtp_fd = url_get_file_handle(s->rtp_hd);

    s->rtcp_fd = url_get_file_handle(s->rtcp_hd);

    h->max_packet_size = url_get_max_packet_size(s->rtp_hd);

    h->is_streamed = 1;

    return 0;

 fail:

    if (s->rtp_hd)

        url_close(s->rtp_hd);

    if (s->rtcp_hd)

        url_close(s->rtcp_hd);

    av_free(s);

    return AVERROR(EIO);

}

static int rtp_read(URLContext *h, uint8_t *buf, int size)

{

    RTPContext *s = h->priv_data;

    struct sockaddr_storage from;

    socklen_t from_len;

    int len, n;

    struct pollfd p[2] = {{s->rtp_fd, POLLIN, 0}, {s->rtcp_fd, POLLIN, 0}};

#if 0

    for(;;) {

        from_len = sizeof(from);

        len = recvfrom (s->rtp_fd, buf, size, 0,

                        (struct sockaddr *)&from, &from_len);

        if (len < 0) {

            if (ff_neterrno() == AVERROR(EAGAIN) ||

                ff_neterrno() == AVERROR(EINTR))

                continue;

            return AVERROR(EIO);

        }

        break;

    }

#else

    for(;;) {

        if (url_interrupt_cb())

            return AVERROR_EXIT;

        /* build fdset to listen to RTP and RTCP packets */

        n = poll(p, 2, 100);

        if (n > 0) {

            /* first try RTCP */

            if (p[1].revents & POLLIN) {

                from_len = sizeof(from);

                len = recvfrom (s->rtcp_fd, buf, size, 0,

                                (struct sockaddr *)&from, &from_len);

                if (len < 0) {

                    if (ff_neterrno() == AVERROR(EAGAIN) ||

                        ff_neterrno() == AVERROR(EINTR))

                        continue;

                    return AVERROR(EIO);

                }

                break;

            }

            /* then RTP */

            if (p[0].revents & POLLIN) {

                from_len = sizeof(from);

                len = recvfrom (s->rtp_fd, buf, size, 0,

                                (struct sockaddr *)&from, &from_len);

                if (len < 0) {

                    if (ff_neterrno() == AVERROR(EAGAIN) ||

                        ff_neterrno() == AVERROR(EINTR))

                        continue;

                    return AVERROR(EIO);

                }

                break;

            }

        } else if (n < 0) {

            if (ff_neterrno() == AVERROR(EINTR))

                continue;

            return AVERROR(EIO);

        }

    }

#endif

    return len;

}

static int rtp_write(URLContext *h, const uint8_t *buf, int size)

{

    RTPContext *s = h->priv_data;

    int ret;

    URLContext *hd;

    if (buf[1] >= RTCP_SR && buf[1] <= RTCP_APP) {

        /* RTCP payload type */

        hd = s->rtcp_hd;

    } else {

        /* RTP payload type */

        hd = s->rtp_hd;

    }

    ret = url_write(hd, buf, size);

#if 0

    {

        struct timespec ts;

        ts.tv_sec = 0;

        ts.tv_nsec = 10 * 1000000;

        nanosleep(&ts, NULL);

    }

#endif

    return ret;

}

static int rtp_close(URLContext *h)

{

    RTPContext *s = h->priv_data;

    url_close(s->rtp_hd);

    url_close(s->rtcp_hd);

    av_free(s);

    return 0;

}

/**

 * Return the local rtp port used by the RTP connection

 * @param h media file context

 * @return the local port number

 */

int rtp_get_local_rtp_port(URLContext *h)

{

    RTPContext *s = h->priv_data;

    return udp_get_local_port(s->rtp_hd);

}

/**

 * Return the local rtcp port used by the RTP connection

 * @param h media file context

 * @return the local port number

 */

int rtp_get_local_rtcp_port(URLContext *h)

{

    RTPContext *s = h->priv_data;

    return udp_get_local_port(s->rtcp_hd);

}

static int rtp_get_file_handle(URLContext *h)

{

    RTPContext *s = h->priv_data;

    return s->rtp_fd;

}

int rtp_get_rtcp_file_handle(URLContext *h) {

    RTPContext *s = h->priv_data;

    return s->rtcp_fd;

}

URLProtocol ff_rtp_protocol = {

    "rtp",

    rtp_open,

    rtp_read,

    rtp_write,

    NULL, /* seek */

    rtp_close,

    .url_get_file_handle = rtp_get_file_handle,

};