ffserver.c

ffmpeg的完整源代码和作者自己写的文档。不但有在Linux的工程哦

            }
            if (!feed->pid) {
                /* In child */
                char pathname[1024];
                char *slash;
                int i;

                for (i = 3; i < 256; i++)
                    close(i);

                if (!ffserver_debug) {
                    i = open("/dev/null", O_RDWR);
                    if (i)
                        dup2(i, 0);
                    dup2(i, 1);
                    dup2(i, 2);
                    if (i)
                        close(i);
                }

                av_strlcpy(pathname, my_program_name, sizeof(pathname));

                slash = strrchr(pathname, '/');
                if (!slash)
                    slash = pathname;
                else
                    slash++;
                strcpy(slash, "ffmpeg");

                /* This is needed to make relative pathnames work */
                chdir(my_program_dir);

                signal(SIGPIPE, SIG_DFL);

                execvp(pathname, feed->child_argv);

                _exit(1);
            }
        }
    }
}

/* open a listening socket */
static int socket_open_listen(struct sockaddr_in *my_addr)
{
    int server_fd, tmp;

    server_fd = socket(AF_INET,SOCK_STREAM,0);
    if (server_fd < 0) {
        perror ("socket");
        return -1;
    }

    tmp = 1;
    setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR, &tmp, sizeof(tmp));

    if (bind (server_fd, (struct sockaddr *) my_addr, sizeof (*my_addr)) < 0) {
        char bindmsg[32];
        snprintf(bindmsg, sizeof(bindmsg), "bind(port %d)", ntohs(my_addr->sin_port));
        perror (bindmsg);
        closesocket(server_fd);
        return -1;
    }

    if (listen (server_fd, 5) < 0) {
        perror ("listen");
        closesocket(server_fd);
        return -1;
    }
    ff_socket_nonblock(server_fd, 1);

    return server_fd;
}

/* start all multicast streams */
static void start_multicast(void)
{
    FFStream *stream;
    char session_id[32];
    HTTPContext *rtp_c;
    struct sockaddr_in dest_addr;
    int default_port, stream_index;

    default_port = 6000;
    for(stream = first_stream; stream != NULL; stream = stream->next) {
        if (stream->is_multicast) {
            /* open the RTP connection */
            snprintf(session_id, sizeof(session_id), "%08x%08x",
                     av_random(&random_state), av_random(&random_state));

            /* choose a port if none given */
            if (stream->multicast_port == 0) {
                stream->multicast_port = default_port;
                default_port += 100;
            }

            dest_addr.sin_family = AF_INET;
            dest_addr.sin_addr = stream->multicast_ip;
            dest_addr.sin_port = htons(stream->multicast_port);

            rtp_c = rtp_new_connection(&dest_addr, stream, session_id,
                                       RTSP_PROTOCOL_RTP_UDP_MULTICAST);
            if (!rtp_c)
                continue;

            if (open_input_stream(rtp_c, "") < 0) {
                fprintf(stderr, "Could not open input stream for stream '%s'\n",
                        stream->filename);
                continue;
            }

            /* open each RTP stream */
            for(stream_index = 0; stream_index < stream->nb_streams;
                stream_index++) {
                dest_addr.sin_port = htons(stream->multicast_port +
                                           2 * stream_index);
                if (rtp_new_av_stream(rtp_c, stream_index, &dest_addr, NULL) < 0) {
                    fprintf(stderr, "Could not open output stream '%s/streamid=%d'\n",
                            stream->filename, stream_index);
                    exit(1);
                }
            }

            /* change state to send data */
            rtp_c->state = HTTPSTATE_SEND_DATA;
        }
    }
}

/* main loop of the http server */
static int http_server(void)
{
    int server_fd, ret, rtsp_server_fd, delay, delay1;
    struct pollfd poll_table[HTTP_MAX_CONNECTIONS + 2], *poll_entry;
    HTTPContext *c, *c_next;

    server_fd = socket_open_listen(&my_http_addr);
    if (server_fd < 0)
        return -1;

    rtsp_server_fd = socket_open_listen(&my_rtsp_addr);
    if (rtsp_server_fd < 0)
        return -1;

    http_log("ffserver started.\n");

    start_children(first_feed);

    first_http_ctx = NULL;
    nb_connections = 0;

    start_multicast();

    for(;;) {
        poll_entry = poll_table;
        poll_entry->fd = server_fd;
        poll_entry->events = POLLIN;
        poll_entry++;

        poll_entry->fd = rtsp_server_fd;
        poll_entry->events = POLLIN;
        poll_entry++;

        /* wait for events on each HTTP handle */
        c = first_http_ctx;
        delay = 1000;
        while (c != NULL) {
            int fd;
            fd = c->fd;
            switch(c->state) {
            case HTTPSTATE_SEND_HEADER:
            case RTSPSTATE_SEND_REPLY:
            case RTSPSTATE_SEND_PACKET:
                c->poll_entry = poll_entry;
                poll_entry->fd = fd;
                poll_entry->events = POLLOUT;
                poll_entry++;
                break;
            case HTTPSTATE_SEND_DATA_HEADER:
            case HTTPSTATE_SEND_DATA:
            case HTTPSTATE_SEND_DATA_TRAILER:
                if (!c->is_packetized) {
                    /* for TCP, we output as much as we can (may need to put a limit) */
                    c->poll_entry = poll_entry;
                    poll_entry->fd = fd;
                    poll_entry->events = POLLOUT;
                    poll_entry++;
                } else {
                    /* when ffserver is doing the timing, we work by
                       looking at which packet need to be sent every
                       10 ms */
                    delay1 = 10; /* one tick wait XXX: 10 ms assumed */
                    if (delay1 < delay)
                        delay = delay1;
                }
                break;
            case HTTPSTATE_WAIT_REQUEST:
            case HTTPSTATE_RECEIVE_DATA:
            case HTTPSTATE_WAIT_FEED:
            case RTSPSTATE_WAIT_REQUEST:
                /* need to catch errors */
                c->poll_entry = poll_entry;
                poll_entry->fd = fd;
                poll_entry->events = POLLIN;/* Maybe this will work */
                poll_entry++;
                break;
            default:
                c->poll_entry = NULL;
                break;
            }
            c = c->next;
        }

        /* wait for an event on one connection. We poll at least every
           second to handle timeouts */
        do {
            ret = poll(poll_table, poll_entry - poll_table, delay);
            if (ret < 0 && ff_neterrno() != FF_NETERROR(EAGAIN) &&
                ff_neterrno() != FF_NETERROR(EINTR))
                return -1;
        } while (ret < 0);

        cur_time = av_gettime() / 1000;

        if (need_to_start_children) {
            need_to_start_children = 0;
            start_children(first_feed);
        }

        /* now handle the events */
        for(c = first_http_ctx; c != NULL; c = c_next) {
            c_next = c->next;
            if (handle_connection(c) < 0) {
                /* close and free the connection */
                log_connection(c);
                close_connection(c);
            }
        }

        poll_entry = poll_table;
        /* new HTTP connection request ? */
        if (poll_entry->revents & POLLIN)
            new_connection(server_fd, 0);
        poll_entry++;
        /* new RTSP connection request ? */
        if (poll_entry->revents & POLLIN)
            new_connection(rtsp_server_fd, 1);
    }
}

/* start waiting for a new HTTP/RTSP request */
static void start_wait_request(HTTPContext *c, int is_rtsp)
{
    c->buffer_ptr = c->buffer;
    c->buffer_end = c->buffer + c->buffer_size - 1; /* leave room for '\0' */

    if (is_rtsp) {
        c->timeout = cur_time + RTSP_REQUEST_TIMEOUT;
        c->state = RTSPSTATE_WAIT_REQUEST;
    } else {
        c->timeout = cur_time + HTTP_REQUEST_TIMEOUT;
        c->state = HTTPSTATE_WAIT_REQUEST;
    }
}

static void new_connection(int server_fd, int is_rtsp)
{
    struct sockaddr_in from_addr;
    int fd, len;
    HTTPContext *c = NULL;

    len = sizeof(from_addr);
    fd = accept(server_fd, (struct sockaddr *)&from_addr,
                &len);
    if (fd < 0)
        return;
    ff_socket_nonblock(fd, 1);

    /* XXX: should output a warning page when coming
       close to the connection limit */
    if (nb_connections >= nb_max_connections)
        goto fail;

    /* add a new connection */
    c = av_mallocz(sizeof(HTTPContext));
    if (!c)
        goto fail;

    c->fd = fd;
    c->poll_entry = NULL;
    c->from_addr = from_addr;
    c->buffer_size = IOBUFFER_INIT_SIZE;
    c->buffer = av_malloc(c->buffer_size);
    if (!c->buffer)
        goto fail;

    c->next = first_http_ctx;
    first_http_ctx = c;
    nb_connections++;

    start_wait_request(c, is_rtsp);

    return;

 fail:
    if (c) {
        av_free(c->buffer);
        av_free(c);
    }
    closesocket(fd);
}

static void close_connection(HTTPContext *c)
{
    HTTPContext **cp, *c1;
    int i, nb_streams;
    AVFormatContext *ctx;
    URLContext *h;
    AVStream *st;

    /* remove connection from list */
    cp = &first_http_ctx;
    while ((*cp) != NULL) {
        c1 = *cp;
        if (c1 == c)
            *cp = c->next;
        else
            cp = &c1->next;
    }

    /* remove references, if any (XXX: do it faster) */
    for(c1 = first_http_ctx; c1 != NULL; c1 = c1->next) {
        if (c1->rtsp_c == c)
            c1->rtsp_c = NULL;
    }

    /* remove connection associated resources */
    if (c->fd >= 0)
        closesocket(c->fd);
    if (c->fmt_in) {
        /* close each frame parser */
        for(i=0;i<c->fmt_in->nb_streams;i++) {
            st = c->fmt_in->streams[i];
            if (st->codec->codec)
                avcodec_close(st->codec);
        }
        av_close_input_file(c->fmt_in);
    }

    /* free RTP output streams if any */
    nb_streams = 0;
    if (c->stream)
        nb_streams = c->stream->nb_streams;

    for(i=0;i<nb_streams;i++) {
        ctx = c->rtp_ctx[i];
        if (ctx) {
            av_write_trailer(ctx);
            av_free(ctx);
        }
        h = c->rtp_handles[i];
        if (h)
            url_close(h);
    }

    ctx = &c->fmt_ctx;

    if (!c->last_packet_sent) {
        if (ctx->oformat) {
            /* prepare header */
            if (url_open_dyn_buf(&ctx->pb) >= 0) {
                av_write_trailer(ctx);
                url_close_dyn_buf(&ctx->pb, &c->pb_buffer);
            }
        }
    }

    for(i=0; i<ctx->nb_streams; i++)
        av_free(ctx->streams[i]);