added rtp protocol

Originally committed as revision 720 to svn://svn.ffmpeg.org/ffmpeg/trunk

libav/rtpproto.c

+/*
+ * RTP network protocol
+ * Copyright (c) 2002 Fabrice Bellard.
+ *
+ * This library 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 of the License, or (at your option) any later version.
+ *
+ * This library 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 this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+#include "avformat.h"
+
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <netdb.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.
+ *
+ * url syntax: rtp://host:port[?option=val...]
+ * option: 'multicast=1' : enable multicast 
+ *         'ttl=n'       : set the ttl value (for multicast only)
+ *
+ * @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, 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;
+}
+
+
+static int rtp_open(URLContext *h, const char *uri, int flags)
+{
+    RTPContext *s;
+    int port, is_output, local_port;
+    char hostname[256];
+    char buf[1024];
+    char path[1024];
+    URLContext *tmp_hd;
+    
+    is_output = (flags & URL_WRONLY);
+
+    s = av_mallocz(sizeof(RTPContext));
+    if (!s)
+        return -ENOMEM;
+    h->priv_data = s;
+    
+    url_split(NULL, 0, hostname, sizeof(hostname), &port, 
+              path, sizeof(path), uri);
+
+    snprintf(buf, sizeof(buf), "udp://%s:%d%s", 
+             hostname, port, path);
+    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 connexion if the port is not even */
+
+    /* well, should suppress localport in path */
+    
+    snprintf(buf, sizeof(buf), "udp://%s:%d%s%clocalport=%d",
+             hostname, port + 1, path, 
+             strchr(path, '?') != NULL ? '&' : '?',
+             local_port + 1);
+    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 -EIO;
+}
+
+static int rtp_read(URLContext *h, UINT8 *buf, int size)
+{
+    RTPContext *s = h->priv_data;
+    struct sockaddr_in from;
+    int from_len, 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 (errno == EAGAIN || errno == EINTR)
+                continue;
+            return -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 (errno == EAGAIN || errno == EINTR)
+                        continue;
+                    return -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 (errno == EAGAIN || errno == EINTR)
+                        continue;
+                    return -EIO;
+                }
+                break;
+            }
+        }
+    }
+#endif
+    return len;
+}
+
+static int rtp_write(URLContext *h, UINT8 *buf, int size)
+{
+    RTPContext *s = h->priv_data;
+    int ret, fd;
+    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 connexion
+ * @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,
+};