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FFmpeg/libavformat/rtpproto.c

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/*
* 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 rtpproto.c
* RTP protocol
*/
#include "libavutil/avstring.h"
#include "avformat.h"
#include <unistd.h>
#include <stdarg.h>
#include "network.h"
#include "os_support.h"
#include <fcntl.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 s1 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];
url_split(NULL, 0, NULL, 0, hostname, sizeof(hostname), &port,
path, sizeof(path), uri);
snprintf(buf, sizeof(buf), "udp://%s:%d%s", hostname, port, path);
udp_set_remote_url(s->rtp_hd, buf);
snprintf(buf, sizeof(buf), "udp://%s:%d%s", hostname, port + 1, 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)
{
snprintf(buf, buf_size, "udp://%s:%d", hostname, port);
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);
}
/**
* url syntax: rtp://host:port[?option=val...]
* option: 'ttl=n' : set the ttl value (for multicast only)
* 'localport=n' : set the local port to n
* 'pkt_size=n' : set max packet size
*
*/
static int rtp_open(URLContext *h, const char *uri, int flags)
{
RTPContext *s;
int port, is_output, ttl, local_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;
url_split(NULL, 0, NULL, 0, hostname, sizeof(hostname), &port,
path, sizeof(path), uri);
/* extract parameters */
ttl = -1;
local_port = -1;
max_packet_size = -1;
p = strchr(uri, '?');
if (p) {
if (find_info_tag(buf, sizeof(buf), "ttl", p)) {
ttl = strtol(buf, NULL, 10);
}
if (find_info_tag(buf, sizeof(buf), "localport", p)) {
local_port = strtol(buf, NULL, 10);
}
if (find_info_tag(buf, sizeof(buf), "pkt_size", p)) {
max_packet_size = strtol(buf, NULL, 10);
}
}
build_udp_url(buf, sizeof(buf),
hostname, port, local_port, ttl, max_packet_size);
if (url_open(&s->rtp_hd, buf, flags) < 0)
goto fail;
local_port = udp_get_local_port(s->rtp_hd);
/* XXX: need to open another connection if the port is not even */
/* well, should suppress localport in path */
build_udp_url(buf, sizeof(buf),
hostname, port + 1, local_port + 1, ttl, max_packet_size);
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 = udp_get_file_handle(s->rtp_hd);
s->rtcp_fd = udp_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_in from;
socklen_t from_len;
int len, fd_max, n;
fd_set rfds;
#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() == FF_NETERROR(EAGAIN) ||
ff_neterrno() == FF_NETERROR(EINTR))
continue;
return AVERROR(EIO);
}
break;
}
#else
for(;;) {
/* build fdset to listen to RTP and RTCP packets */
FD_ZERO(&rfds);
fd_max = s->rtp_fd;
FD_SET(s->rtp_fd, &rfds);
if (s->rtcp_fd > fd_max)
fd_max = s->rtcp_fd;
FD_SET(s->rtcp_fd, &rfds);
n = select(fd_max + 1, &rfds, NULL, NULL, NULL);
if (n > 0) {
/* first try RTCP */
if (FD_ISSET(s->rtcp_fd, &rfds)) {
from_len = sizeof(from);
len = recvfrom (s->rtcp_fd, buf, size, 0,
(struct sockaddr *)&from, &from_len);
if (len < 0) {
if (ff_neterrno() == FF_NETERROR(EAGAIN) ||
ff_neterrno() == FF_NETERROR(EINTR))
continue;
return AVERROR(EIO);
}
break;
}
/* then RTP */
if (FD_ISSET(s->rtp_fd, &rfds)) {
from_len = sizeof(from);
len = recvfrom (s->rtp_fd, buf, size, 0,
(struct sockaddr *)&from, &from_len);
if (len < 0) {
if (ff_neterrno() == FF_NETERROR(EAGAIN) ||
ff_neterrno() == FF_NETERROR(EINTR))
continue;
return AVERROR(EIO);
}
break;
}
}
}
#endif
return len;
}
static int rtp_write(URLContext *h, uint8_t *buf, int size)
{
RTPContext *s = h->priv_data;
int ret;
URLContext *hd;
if (buf[1] >= 200 && buf[1] <= 204) {
/* 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 port used by the RTP connection
* @param s1 media file context
* @return the local port number
*/
int rtp_get_local_port(URLContext *h)
{
RTPContext *s = h->priv_data;
return udp_get_local_port(s->rtp_hd);
}
/**
* Return the rtp and rtcp file handles for select() usage to wait for
* several RTP streams at the same time.
* @param h media file context
*/
void rtp_get_file_handles(URLContext *h, int *prtp_fd, int *prtcp_fd)
{
RTPContext *s = h->priv_data;
*prtp_fd = s->rtp_fd;
*prtcp_fd = s->rtcp_fd;
}
URLProtocol rtp_protocol = {
"rtp",
rtp_open,
rtp_read,
rtp_write,
NULL, /* seek */
rtp_close,
};