rtsp.c

Trolltech公司发布的图形界面操作系统。可在qt-embedded-2.3.7平台上编译为嵌入式图形界面操作系统。

                if (av_open_input_file(&rtsp_st->ic, url, fmt, 0, NULL) < 0) {
                    err = AVERROR_INVALIDDATA;
                    goto fail;
                }
            }
            break;
        }
    }

    /* use callback if available to extend setup */
    if (ff_rtsp_callback) {
        if (ff_rtsp_callback(RTSP_ACTION_CLIENT_SETUP, rt->session_id, 
                             NULL, 0, rt->last_reply) < 0) {
            err = AVERROR_INVALIDDATA;
            goto fail;
        }
    }
                         
    /* start playing */
    snprintf(cmd, sizeof(cmd), 
             "PLAY %s RTSP/1.0\n",
             s->filename);
    rtsp_send_cmd(s, cmd, reply, NULL);
    if (reply->status_code != RTSP_STATUS_OK) {
        err = AVERROR_INVALIDDATA;
        goto fail;
    }

    /* open TCP with bufferized input */
    if (rt->protocol == RTSP_PROTOCOL_RTP_TCP) {
        if (url_fdopen(&rt->rtsp_gb, rt->rtsp_hd) < 0) {
            err = AVERROR_NOMEM;
            goto fail;
        }
    }

    return 0;
 fail:
    for(i=0;i<s->nb_streams;i++) {
        st = s->streams[i];
        rtsp_st = st->priv_data;
        if (rtsp_st) {
            if (rtsp_st->ic)
                av_close_input_file(rtsp_st->ic);
        }
        av_free(rtsp_st);
    }
    av_freep(&content);
    url_close(rt->rtsp_hd);
    return err;
}

static int tcp_read_packet(AVFormatContext *s,
                           AVPacket *pkt)
{
    RTSPState *rt = s->priv_data;
    ByteIOContext *rtsp_gb = &rt->rtsp_gb;
    int c, id, len, i, ret;
    AVStream *st;
    RTSPStream *rtsp_st;
    char buf[RTP_MAX_PACKET_LENGTH];

 redo:
    for(;;) {
        c = url_fgetc(rtsp_gb);
        if (c == URL_EOF)
            return AVERROR_IO;
        if (c == '$')
            break;
    }
    id = get_byte(rtsp_gb);
    len = get_be16(rtsp_gb);
    if (len > RTP_MAX_PACKET_LENGTH || len < 12)
        goto redo;
    /* get the data */
    get_buffer(rtsp_gb, buf, len);
    
    /* find the matching stream */
    for(i = 0; i < s->nb_streams; i++) {
        st = s->streams[i];
        rtsp_st = st->priv_data;
        if (i >= rtsp_st->interleaved_min && 
            i <= rtsp_st->interleaved_max) 
            goto found;
    }
    goto redo;
 found:
    ret = rtp_parse_packet(rtsp_st->ic, pkt, buf, len);
    if (ret < 0)
        goto redo;
    pkt->stream_index = i;
    return ret;
}

/* NOTE: output one packet at a time. May need to add a small fifo */
static int udp_read_packet(AVFormatContext *s,
                           AVPacket *pkt)
{
    AVFormatContext *ic;
    AVStream *st;
    RTSPStream *rtsp_st;
    fd_set rfds;
    int fd1, fd2, fd_max, n, i, ret;
    char buf[RTP_MAX_PACKET_LENGTH];
    struct timeval tv;

    for(;;) {
        if (rtsp_abort_req)
            return -EIO;
        FD_ZERO(&rfds);
        fd_max = -1;
        for(i = 0; i < s->nb_streams; i++) {
            st = s->streams[i];
            rtsp_st = st->priv_data;
            ic = rtsp_st->ic;
            /* currently, we cannot probe RTCP handle because of blocking restrictions */
            rtp_get_file_handles(url_fileno(&ic->pb), &fd1, &fd2);
            if (fd1 > fd_max)
                fd_max = fd1;
            FD_SET(fd1, &rfds);
        }
        /* XXX: also add proper API to abort */
        tv.tv_sec = 0;
        tv.tv_usec = 500000;
        n = select(fd_max + 1, &rfds, NULL, NULL, &tv);
        if (n > 0) {
            for(i = 0; i < s->nb_streams; i++) {
                st = s->streams[i];
                rtsp_st = st->priv_data;
                ic = rtsp_st->ic;
                rtp_get_file_handles(url_fileno(&ic->pb), &fd1, &fd2);
                if (FD_ISSET(fd1, &rfds)) {
                    ret = url_read(url_fileno(&ic->pb), buf, sizeof(buf));
                    if (ret >= 0 && 
                        rtp_parse_packet(ic, pkt, buf, ret) == 0) {
                        pkt->stream_index = i;
                        return ret;
                    }
                }
            }
        }
    }
}

static int rtsp_read_packet(AVFormatContext *s,
                            AVPacket *pkt)
{
    RTSPState *rt = s->priv_data;
    int ret;

    switch(rt->protocol) {
    default:
    case RTSP_PROTOCOL_RTP_TCP:
        ret = tcp_read_packet(s, pkt);
        break;
    case RTSP_PROTOCOL_RTP_UDP:
        ret = udp_read_packet(s, pkt);
        break;
    }
    return ret;
}

static int rtsp_read_close(AVFormatContext *s)
{
    RTSPState *rt = s->priv_data;
    AVStream *st;
    RTSPStream *rtsp_st;
    RTSPHeader reply1, *reply = &reply1;
    int i;
    char cmd[1024];

    /* NOTE: it is valid to flush the buffer here */
    if (rt->protocol == RTSP_PROTOCOL_RTP_TCP) {
        url_fclose(&rt->rtsp_gb);
    }

    snprintf(cmd, sizeof(cmd), 
             "TEARDOWN %s RTSP/1.0\n",
             s->filename);
    rtsp_send_cmd(s, cmd, reply, NULL);

    if (ff_rtsp_callback) {
        ff_rtsp_callback(RTSP_ACTION_CLIENT_TEARDOWN, rt->session_id, 
                         NULL, 0, NULL);
    }

    for(i=0;i<s->nb_streams;i++) {
        st = s->streams[i];
        rtsp_st = st->priv_data;
        if (rtsp_st) {
            if (rtsp_st->ic)
                av_close_input_file(rtsp_st->ic);
        }
        av_free(rtsp_st);
    }
    url_close(rt->rtsp_hd);
    return 0;
}

static AVInputFormat rtsp_demux = {
    "rtsp",
    "RTSP input format",
    sizeof(RTSPState),
    rtsp_probe,
    rtsp_read_header,
    rtsp_read_packet,
    rtsp_read_close,
    .flags = AVFMT_NOFILE,
};

static int sdp_probe(AVProbeData *p1)
{
    const char *p;

    /* we look for a line beginning "c=IN IP4" */
    p = p1->buf;
    while (*p != '\0') {
        if (strstart(p, "c=IN IP4", NULL))
            return AVPROBE_SCORE_MAX / 2;
        p = strchr(p, '\n');
        if (!p)
            break;
        p++;
        if (*p == '\r')
            p++;
    }
    return 0;
}

#define SDP_MAX_SIZE 8192

static int sdp_read_header(AVFormatContext *s,
                           AVFormatParameters *ap)
{
    AVStream *st;
    RTSPStream *rtsp_st;
    int size, i, err;
    char *content;
    char url[1024];

    /* read the whole sdp file */
    /* XXX: better loading */
    content = av_malloc(SDP_MAX_SIZE);
    size = get_buffer(&s->pb, content, SDP_MAX_SIZE - 1);
    if (size <= 0) {
        av_free(content);
        return AVERROR_INVALIDDATA;
    }
    content[size] ='\0';

    sdp_parse(s, content);
    av_free(content);

    /* open each RTP stream */
    for(i=0;i<s->nb_streams;i++) {
        st = s->streams[i];
        rtsp_st = st->priv_data;
        
        snprintf(url, sizeof(url), "rtp://%s:%d?multicast=1&ttl=%d", 
                 inet_ntoa(rtsp_st->sdp_ip), 
                 rtsp_st->sdp_port,
                 rtsp_st->sdp_ttl);
        if (av_open_input_file(&rtsp_st->ic, url, &rtp_demux, 0, NULL) < 0) {
            err = AVERROR_INVALIDDATA;
            goto fail;
        }
    }
    return 0;
 fail:
    for(i=0;i<s->nb_streams;i++) {
        st = s->streams[i];
        rtsp_st = st->priv_data;
        if (rtsp_st) {
            if (rtsp_st->ic)
                av_close_input_file(rtsp_st->ic);
        }
        av_free(rtsp_st);
    }
    return err;
}

static int sdp_read_packet(AVFormatContext *s,
                            AVPacket *pkt)
{
    return udp_read_packet(s, pkt);
}

static int sdp_read_close(AVFormatContext *s)
{
    AVStream *st;
    RTSPStream *rtsp_st;
    int i;

    for(i=0;i<s->nb_streams;i++) {
        st = s->streams[i];
        rtsp_st = st->priv_data;
        if (rtsp_st) {
            if (rtsp_st->ic)
                av_close_input_file(rtsp_st->ic);
        }
        av_free(rtsp_st);
    }
    return 0;
}


static AVInputFormat sdp_demux = {
    "sdp",
    "SDP",
    sizeof(RTSPState),
    sdp_probe,
    sdp_read_header,
    sdp_read_packet,
    sdp_read_close,
};


/* dummy redirector format (used directly in av_open_input_file now) */
static int redir_probe(AVProbeData *pd)
{
    const char *p;
    p = pd->buf;
    while (redir_isspace(*p))
        p++;
    if (strstart(p, "http://", NULL) ||
        strstart(p, "rtsp://", NULL))
        return AVPROBE_SCORE_MAX;
    return 0;
}

/* called from utils.c */
int redir_open(AVFormatContext **ic_ptr, ByteIOContext *f)
{
    char buf[4096], *q;
    int c;
    AVFormatContext *ic = NULL;

    /* parse each URL and try to open it */
    c = url_fgetc(f);
    while (c != URL_EOF) {
        /* skip spaces */
        for(;;) {
            if (!redir_isspace(c))
                break;
            c = url_fgetc(f);
        }
        if (c == URL_EOF)
            break;
        /* record url */
        q = buf;
        for(;;) {
            if (c == URL_EOF || redir_isspace(c))
                break;
            if ((q - buf) < sizeof(buf) - 1)
                *q++ = c;
            c = url_fgetc(f);
        }
        *q = '\0';
        //printf("URL='%s'\n", buf);
        /* try to open the media file */
        if (av_open_input_file(&ic, buf, NULL, 0, NULL) == 0)
            break;
    }
    *ic_ptr = ic;
    if (!ic)
        return AVERROR_IO;
    else
        return 0;
}

AVInputFormat redir_demux = {
    "redir",
    "Redirector format",
    0,
    redir_probe,
    NULL,
    NULL,
    NULL,
};

int rtsp_init(void)
{
    av_register_input_format(&rtsp_demux);
    av_register_input_format(&redir_demux);
    av_register_input_format(&sdp_demux);
    return 0;
}