ffserver.c

        goto sdp_done;

    for(i = 0; i < stream->nb_streams; i++) {
        avc->streams[i] = &avs[i];
        avc->streams[i]->codec = stream->streams[i]->codec;
    }
    *pbuffer = av_mallocz(2048);
    av_sdp_create(&avc, 1, *pbuffer, 2048);

 sdp_done:
    av_free(avc->streams);
    av_dict_free(&avc->metadata);
    av_free(avc);
    av_free(avs);

    return strlen(*pbuffer);
}

static void rtsp_cmd_options(HTTPContext *c, const char *url)
{
//    rtsp_reply_header(c, RTSP_STATUS_OK);
    avio_printf(c->pb, "RTSP/1.0 %d %s\r\n", RTSP_STATUS_OK, "OK");
    avio_printf(c->pb, "CSeq: %d\r\n", c->seq);
    avio_printf(c->pb, "Public: %s\r\n", "OPTIONS, DESCRIBE, SETUP, TEARDOWN, PLAY, PAUSE");
    avio_printf(c->pb, "\r\n");
}

static void rtsp_cmd_describe(HTTPContext *c, const char *url)
{
    FFStream *stream;
    char path1[1024];
    const char *path;
    uint8_t *content;
    int content_length;
    socklen_t len;
    struct sockaddr_in my_addr;

    /* find which URL is asked */
    av_url_split(NULL, 0, NULL, 0, NULL, 0, NULL, path1, sizeof(path1), url);
    path = path1;
    if (*path == '/')
        path++;

    for(stream = first_stream; stream != NULL; stream = stream->next) {
        if (!stream->is_feed &&
            stream->fmt && !strcmp(stream->fmt->name, "rtp") &&
            !strcmp(path, stream->filename)) {
            goto found;
        }
    }
    /* no stream found */
    rtsp_reply_error(c, RTSP_STATUS_SERVICE); /* XXX: right error ? */
    return;

 found:
    /* prepare the media description in SDP format */

    /* get the host IP */
    len = sizeof(my_addr);
    getsockname(c->fd, (struct sockaddr *)&my_addr, &len);
    content_length = prepare_sdp_description(stream, &content, my_addr.sin_addr);
    if (content_length < 0) {
        rtsp_reply_error(c, RTSP_STATUS_INTERNAL);
        return;
    }
    rtsp_reply_header(c, RTSP_STATUS_OK);
    avio_printf(c->pb, "Content-Base: %s/\r\n", url);
    avio_printf(c->pb, "Content-Type: application/sdp\r\n");
    avio_printf(c->pb, "Content-Length: %d\r\n", content_length);
    avio_printf(c->pb, "\r\n");
    avio_write(c->pb, content, content_length);
    av_free(content);
}

static HTTPContext *find_rtp_session(const char *session_id)
{
    HTTPContext *c;

    if (session_id[0] == '\0')
        return NULL;

    for(c = first_http_ctx; c != NULL; c = c->next) {
        if (!strcmp(c->session_id, session_id))
            return c;
    }
    return NULL;
}

static RTSPTransportField *find_transport(RTSPMessageHeader *h, enum RTSPLowerTransport lower_transport)
{
    RTSPTransportField *th;
    int i;

    for(i=0;i<h->nb_transports;i++) {
        th = &h->transports[i];
        if (th->lower_transport == lower_transport)
            return th;
    }
    return NULL;
}

static void rtsp_cmd_setup(HTTPContext *c, const char *url,
                           RTSPMessageHeader *h)
{
    FFStream *stream;
    int stream_index, rtp_port, rtcp_port;
    char buf[1024];
    char path1[1024];
    const char *path;
    HTTPContext *rtp_c;
    RTSPTransportField *th;
    struct sockaddr_in dest_addr;
    RTSPActionServerSetup setup;

    /* find which URL is asked */
    av_url_split(NULL, 0, NULL, 0, NULL, 0, NULL, path1, sizeof(path1), url);
    path = path1;
    if (*path == '/')
        path++;

    /* now check each stream */
    for(stream = first_stream; stream != NULL; stream = stream->next) {
        if (!stream->is_feed &&
            stream->fmt && !strcmp(stream->fmt->name, "rtp")) {
            /* accept aggregate filenames only if single stream */
            if (!strcmp(path, stream->filename)) {
                if (stream->nb_streams != 1) {
                    rtsp_reply_error(c, RTSP_STATUS_AGGREGATE);
                    return;
                }
                stream_index = 0;
                goto found;
            }

            for(stream_index = 0; stream_index < stream->nb_streams;
                stream_index++) {
                snprintf(buf, sizeof(buf), "%s/streamid=%d",
                         stream->filename, stream_index);
                if (!strcmp(path, buf))
                    goto found;
            }
        }
    }
    /* no stream found */
    rtsp_reply_error(c, RTSP_STATUS_SERVICE); /* XXX: right error ? */
    return;
 found:

    /* generate session id if needed */
    if (h->session_id[0] == '\0') {
        unsigned random0 = av_lfg_get(&random_state);
        unsigned random1 = av_lfg_get(&random_state);
        snprintf(h->session_id, sizeof(h->session_id), "%08x%08x",
                 random0, random1);
    }

    /* find RTP session, and create it if none found */
    rtp_c = find_rtp_session(h->session_id);
    if (!rtp_c) {
        /* always prefer UDP */
        th = find_transport(h, RTSP_LOWER_TRANSPORT_UDP);
        if (!th) {
            th = find_transport(h, RTSP_LOWER_TRANSPORT_TCP);
            if (!th) {
                rtsp_reply_error(c, RTSP_STATUS_TRANSPORT);
                return;
            }
        }

        rtp_c = rtp_new_connection(&c->from_addr, stream, h->session_id,
                                   th->lower_transport);
        if (!rtp_c) {
            rtsp_reply_error(c, RTSP_STATUS_BANDWIDTH);
            return;
        }

        /* open input stream */
        if (open_input_stream(rtp_c, "") < 0) {
            rtsp_reply_error(c, RTSP_STATUS_INTERNAL);
            return;
        }
    }

    /* test if stream is OK (test needed because several SETUP needs
       to be done for a given file) */
    if (rtp_c->stream != stream) {
        rtsp_reply_error(c, RTSP_STATUS_SERVICE);
        return;
    }

    /* test if stream is already set up */
    if (rtp_c->rtp_ctx[stream_index]) {
        rtsp_reply_error(c, RTSP_STATUS_STATE);
        return;
    }

    /* check transport */
    th = find_transport(h, rtp_c->rtp_protocol);
    if (!th || (th->lower_transport == RTSP_LOWER_TRANSPORT_UDP &&
                th->client_port_min <= 0)) {
        rtsp_reply_error(c, RTSP_STATUS_TRANSPORT);
        return;
    }

    /* setup default options */
    setup.transport_option[0] = '\0';
    dest_addr = rtp_c->from_addr;
    dest_addr.sin_port = htons(th->client_port_min);

    /* setup stream */
    if (rtp_new_av_stream(rtp_c, stream_index, &dest_addr, c) < 0) {
        rtsp_reply_error(c, RTSP_STATUS_TRANSPORT);
        return;
    }

    /* now everything is OK, so we can send the connection parameters */
    rtsp_reply_header(c, RTSP_STATUS_OK);
    /* session ID */
    avio_printf(c->pb, "Session: %s\r\n", rtp_c->session_id);

    switch(rtp_c->rtp_protocol) {
    case RTSP_LOWER_TRANSPORT_UDP:
        rtp_port = ff_rtp_get_local_rtp_port(rtp_c->rtp_handles[stream_index]);
        rtcp_port = ff_rtp_get_local_rtcp_port(rtp_c->rtp_handles[stream_index]);
        avio_printf(c->pb, "Transport: RTP/AVP/UDP;unicast;"
                    "client_port=%d-%d;server_port=%d-%d",
                    th->client_port_min, th->client_port_max,
                    rtp_port, rtcp_port);
        break;
    case RTSP_LOWER_TRANSPORT_TCP:
        avio_printf(c->pb, "Transport: RTP/AVP/TCP;interleaved=%d-%d",
                    stream_index * 2, stream_index * 2 + 1);
        break;
    default:
        break;
    }
    if (setup.transport_option[0] != '\0')
        avio_printf(c->pb, ";%s", setup.transport_option);
    avio_printf(c->pb, "\r\n");


    avio_printf(c->pb, "\r\n");
}


/* find an RTP connection by using the session ID. Check consistency
   with filename */
static HTTPContext *find_rtp_session_with_url(const char *url,
                                              const char *session_id)
{
    HTTPContext *rtp_c;
    char path1[1024];
    const char *path;
    char buf[1024];
    int s, len;

    rtp_c = find_rtp_session(session_id);
    if (!rtp_c)
        return NULL;

    /* find which URL is asked */
    av_url_split(NULL, 0, NULL, 0, NULL, 0, NULL, path1, sizeof(path1), url);
    path = path1;
    if (*path == '/')
        path++;
    if(!strcmp(path, rtp_c->stream->filename)) return rtp_c;
    for(s=0; s<rtp_c->stream->nb_streams; ++s) {
      snprintf(buf, sizeof(buf), "%s/streamid=%d",
        rtp_c->stream->filename, s);
      if(!strncmp(path, buf, sizeof(buf))) {
    // XXX: Should we reply with RTSP_STATUS_ONLY_AGGREGATE if nb_streams>1?
        return rtp_c;
      }
    }
    len = strlen(path);
    if (len > 0 && path[len - 1] == '/' &&
        !strncmp(path, rtp_c->stream->filename, len - 1))
        return rtp_c;
    return NULL;
}

static void rtsp_cmd_play(HTTPContext *c, const char *url, RTSPMessageHeader *h)
{
    HTTPContext *rtp_c;

    rtp_c = find_rtp_session_with_url(url, h->session_id);
    if (!rtp_c) {
        rtsp_reply_error(c, RTSP_STATUS_SESSION);
        return;
    }

    if (rtp_c->state != HTTPSTATE_SEND_DATA &&
        rtp_c->state != HTTPSTATE_WAIT_FEED &&
        rtp_c->state != HTTPSTATE_READY) {
        rtsp_reply_error(c, RTSP_STATUS_STATE);
        return;
    }

    rtp_c->state = HTTPSTATE_SEND_DATA;

    /* now everything is OK, so we can send the connection parameters */
    rtsp_reply_header(c, RTSP_STATUS_OK);
    /* session ID */
    avio_printf(c->pb, "Session: %s\r\n", rtp_c->session_id);
    avio_printf(c->pb, "\r\n");
}

static void rtsp_cmd_interrupt(HTTPContext *c, const char *url, RTSPMessageHeader *h, int pause_only)
{
    HTTPContext *rtp_c;

    rtp_c = find_rtp_session_with_url(url, h->session_id);
    if (!rtp_c) {
        rtsp_reply_error(c, RTSP_STATUS_SESSION);
        return;
    }

    if (pause_only) {
        if (rtp_c->state != HTTPSTATE_SEND_DATA &&
            rtp_c->state != HTTPSTATE_WAIT_FEED) {
            rtsp_reply_error(c, RTSP_STATUS_STATE);
            return;
        }
        rtp_c->state = HTTPSTATE_READY;
        rtp_c->first_pts = AV_NOPTS_VALUE;
    }

    /* now everything is OK, so we can send the connection parameters */
    rtsp_reply_header(c, RTSP_STATUS_OK);
    /* session ID */
    avio_printf(c->pb, "Session: %s\r\n", rtp_c->session_id);
    avio_printf(c->pb, "\r\n");

    if (!pause_only)
        close_connection(rtp_c);
}

/********************************************************************/
/* RTP handling */

static HTTPContext *rtp_new_connection(struct sockaddr_in *from_addr,
                                       FFStream *stream, const char *session_id,
                                       enum RTSPLowerTransport rtp_protocol)
{
    HTTPContext *c = NULL;
    const char *proto_str;

    /* 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 = -1;
    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;
    nb_connections++;
    c->stream = stream;
    av_strlcpy(c->session_id, session_id, sizeof(c->session_id));
    c->state = HTTPSTATE_READY;
    c->is_packetized = 1;
    c->rtp_protocol = rtp_protocol;

    /* protocol is shown in statistics */
    switch(c->rtp_protocol) {
    case RTSP_LOWER_TRANSPORT_UDP_MULTICAST:
        proto_str = "MCAST";
        break;
    case RTSP_LOWER_TRANSPORT_UDP:
        proto_str = "UDP";
        break;
    case RTSP_LOWER_TRANSPORT_TCP:
        proto_str = "TCP";
        break;
    default:
        proto_str = "???";
        break;
    }
    av_strlcpy(c->protocol, "RTP/", sizeof(c->protocol));
    av_strlcat(c->protocol, proto_str, sizeof(c->protocol));

    current_bandwidth += stream->bandwidth;

    c->next = first_http_ctx;
    first_http_ctx = c;
    return c;

 fail:
    if (c) {
        av_free(c->buffer);
        av_free(c);
    }
    return NULL;
}

/* add a new RTP stream in an RTP connection (used in RTSP SETUP
   command). If RTP/TCP protocol is used, TCP connection 'rtsp_c' is
   used. */
static int rtp_new_av_stream(HTTPContext *c,
                             int stream_index, struct sockaddr_in *dest_addr,
                             HTTPContext *rtsp_c)
{
    AVFormatContext *ctx;
    AVStream *st;
    char *ipaddr;
    URLContext *h = NULL;
    uint8_t *dummy_buf;
    int max_packet_size;

    /* now we can open the relevant output stream */
    ctx = avformat_alloc_context();
    if (!ctx)
        return -1;
    ctx->oformat = av_guess_format("rtp", NULL, NULL);

    st = av_mallocz(sizeof(AVStream));
    if (!st)
        goto fail;
    ctx->nb_streams = 1;
    ctx->streams = av_mallocz(sizeof(AVStream *) * ctx->nb_streams);
    if (!ctx->streams)
      goto fail;
    ctx->streams[0] = st;

    if (!c->stream->feed ||
        c->stream->feed == c->stream)
        memcpy(st, c->stream->streams[stream_index], sizeof(AVStream));
    else
        memcpy(st,
               c->stream->feed->streams[c->stream->feed_streams[stream_index]],
               sizeof(AVStream));
    st->priv_data = NULL;

    /* build destination RTP address */
    ipaddr = inet_ntoa(dest_addr->sin_addr);

    switch(c->rtp_protocol) {
    case RTSP_LOWER_TRANSPORT_UDP:
    case RTSP_LOWER_TRANSPORT_UDP_MULTICAST:
        /* RTP/UDP case */

        /* XXX: also pass as parameter to function ? */
        if (c->stream->is_multicast) {
            int ttl;
            ttl = c->stream->multicast_ttl;
            if (!ttl)
                ttl = 16;
            snprintf(ctx->filename, sizeof(ctx->filename),
                     "rtp://%s:%d?multicast=1&ttl=%d",
                     ipaddr, ntohs(dest_addr->sin_port), ttl);
        } else {
            snprintf(ctx->filename, sizeof(ctx->filename),
                     "rtp://%s:%d", ipaddr, ntohs(dest_addr->sin_port));
        }

        if (ffurl_open(&h, ctx->filename, AVIO_FLAG_WRITE, NULL, NULL) < 0)
            goto fail;
        c->rtp_handles[stream_index] = h;
        max_packet_size = h->max_packet_size;
        break;
    case RTSP_LOWER_TRANSPORT_TCP:
        /* RTP/TCP case */
        c->rtsp_c = rtsp_c;
        max_packet_size = RTSP_TCP_MAX_PACKET_SIZE;
        break;
    default:
        goto fail;
    }

    http_log("%s:%d - - \"PLAY %s/streamid=%d %s\"\n",
             ipaddr, ntohs(dest_addr->sin_port),
             c->stream->filename, stream_index, c->protocol);

    /* normally, no packets should be output here, but the packet size may
     * be checked */
    if (ffio_open_dyn_packet_buf(&ctx->pb, max_packet_size) < 0) {
        /* XXX: close stream */
        goto fail;
    }
    if (avformat_write_header(ctx, NULL) < 0) {
    fail:
        if (h)
            ffurl_close(h);
        av_free(st);
        av_free(ctx);
        return -1;
    }
    avio_close_dyn_buf(ctx->pb, &dummy_buf);
    av_free(dummy_buf);

    c->rtp_ctx[stream_index] = ctx;
    return 0;
}

/********************************************************************/
/* ffserver initialization */

static AVStream *add_av_stream1(FFStream *stream, AVCodecContext *codec, int copy)
{
    AVStream *fst;

    if(stream->nb_streams >= FF_ARRAY_ELEMS(stream->streams))
        return NULL;

    fst = av_mallocz(sizeof(AVStream));
    if (!fst)
        return NULL;
    if (copy) {
        fst->codec = avcodec_alloc_context3(NULL);
        memcpy(fst->codec, codec, sizeof(AVCodecContext));
        if (codec->extradata_size) {
            fst->codec->extradata = av_mallocz(codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
            memcpy(fst->codec->extradata, codec->extradata,
                codec->extradata_size);
        }
    } else {
        /* live streams must use the actual feed's codec since it may be
         * updated later to carry extradata needed by them.
         */
        fst->codec = codec;
    }
    fst->priv_data = av_mallocz(sizeof(FeedData));
    fst->index = stream->nb_streams;
    avpriv_set_pts_info(fst, 33, 1, 90000);
    fst->sample_aspect_ratio = codec->sample_aspect_ratio;
    stream->streams[stream->nb_streams++] = fst;
    return fst;
}

/* return the stream number in the feed */
static int add_av_stream(FFStream *feed, AVStream *st)
{
    AVStream *fst;
    AVCodecContext *av, *av1;
    int i;

    av = st->codec;
    for(i=0;i<feed->nb_streams;i++) {
        st = feed->streams[i];
        av1 = st->codec;
        if (av1->codec_id == av->codec_id &&
            av1->codec_type == av->codec_type &&
            av1->bit_rate == av->bit_rate) {

            switch(av->codec_type) {
            case AVMEDIA_TYPE_AUDIO:
                if (av1->channels == av->channels &&
                    av1->sample_rate == av->sample_rate)
                    return i;
                break;
            case AVMEDIA_TYPE_VIDEO:
                if (av1->width == av->width &&
                    av1->height == av->height &&
                    av1->time_base.den == av->time_base.den &&
                    av1->time_base.num == av->time_base.num &&
                    av1->gop_size == av->gop_size)
                    return i;
                break;
            default:
                abort();
            }
        }
    }

    fst = add_av_stream1(feed, av, 0);
    if (!fst)
        return -1;
    return feed->nb_streams - 1;
}

static void remove_stream(FFStream *stream)
{
    FFStream **ps;
    ps = &first_stream;
    while (*ps != NULL) {
        if (*ps == stream)
            *ps = (*ps)->next;
        else
            ps = &(*ps)->next;
    }
}

/* specific MPEG4 handling : we extract the raw parameters */
static void extract_mpeg4_header(AVFormatContext *infile)
{
    int mpeg4_count, i, size;
    AVPacket pkt;
    AVStream *st;
    const uint8_t *p;

    infile->flags |= AVFMT_FLAG_NOFILLIN | AVFMT_FLAG_NOPARSE;

    mpeg4_count = 0;
    for(i=0;i<infile->nb_streams;i++) {
        st = infile->streams[i];
        if (st->codec->codec_id == AV_CODEC_ID_MPEG4 &&
            st->codec->extradata_size == 0) {
            mpeg4_count++;
        }
    }
    if (!mpeg4_count)
        return;

    printf("MPEG4 without extra data: trying to find header in %s\n", infile->filename);
    while (mpeg4_count > 0) {
        if (av_read_frame(infile, &pkt) < 0)
            break;
        st = infile->streams[pkt.stream_index];
        if (st->codec->codec_id == AV_CODEC_ID_MPEG4 &&
            st->codec->extradata_size == 0) {
            av_freep(&st->codec->extradata);
            /* fill extradata with the header */
            /* XXX: we make hard suppositions here ! */
            p = pkt.data;
            while (p < pkt.data + pkt.size - 4) {
                /* stop when vop header is found */
                if (p[0] == 0x00 && p[1] == 0x00 &&
                    p[2] == 0x01 && p[3] == 0xb6) {
                    size = p - pkt.data;
                    //                    av_hex_dump_log(infile, AV_LOG_DEBUG, pkt.data, size);
                    st->codec->extradata = av_mallocz(size + FF_INPUT_BUFFER_PADDING_SIZE);
                    st->codec->extradata_size = size;
                    memcpy(st->codec->extradata, pkt.data, size);
                    break;
                }
                p++;
            }
            mpeg4_count--;
        }
        av_free_packet(&pkt);
    }
}

/* compute the needed AVStream for each file */
static void build_file_streams(void)
{
    FFStream *stream, *stream_next;
    int i, ret;

    /* gather all streams */
    for(stream = first_stream; stream != NULL; stream = stream_next) {
        AVFormatContext *infile = NULL;
        stream_next = stream->next;
        if (stream->stream_type == STREAM_TYPE_LIVE &&
            !stream->feed) {
            /* the stream comes from a file */
            /* try to open the file */
            /* open stream */
            if (stream->fmt && !strcmp(stream->fmt->name, "rtp")) {
                /* specific case : if transport stream output to RTP,
                   we use a raw transport stream reader */
                av_dict_set(&stream->in_opts, "mpeg2ts_compute_pcr", "1", 0);
            }

            if (!stream->feed_filename[0]) {
                http_log("Unspecified feed file for stream '%s'\n", stream->filename);
                goto fail;
            }

            http_log("Opening feed file '%s' for stream '%s'\n", stream->feed_filename, stream->filename);
            if ((ret = avformat_open_input(&infile, stream->feed_filename, stream->ifmt, &stream->in_opts)) < 0) {
                http_log("Could not open '%s': %s\n", stream->feed_filename, av_err2str(ret));
                /* remove stream (no need to spend more time on it) */
            fail:
                remove_stream(stream);
            } else {
                /* find all the AVStreams inside and reference them in
                   'stream' */
                if (avformat_find_stream_info(infile, NULL) < 0) {
                    http_log("Could not find codec parameters from '%s'\n",
                             stream->feed_filename);
                    avformat_close_input(&infile);
                    goto fail;
                }
                extract_mpeg4_header(infile);

                for(i=0;i<infile->nb_streams;i++)
                    add_av_stream1(stream, infile->streams[i]->codec, 1);

                avformat_close_input(&infile);
            }
        }
    }
}

/* compute the needed AVStream for each feed */
static void build_feed_streams(void)
{
    FFStream *stream, *feed;
    int i;

    /* gather all streams */
    for(stream = first_stream; stream != NULL; stream = stream->next) {
        feed = stream->feed;
        if (feed) {
            if (stream->is_feed) {
                for(i=0;i<stream->nb_streams;i++)
                    stream->feed_streams[i] = i;
            } else {
                /* we handle a stream coming from a feed */
                for(i=0;i<stream->nb_streams;i++)
                    stream->feed_streams[i] = add_av_stream(feed, stream->streams[i]);
            }
        }
    }

    /* create feed files if needed */
    for(feed = first_feed; feed != NULL; feed = feed->next_feed) {
        int fd;

        if (avio_check(feed->feed_filename, AVIO_FLAG_READ) > 0) {
            /* See if it matches */
            AVFormatContext *s = NULL;
            int matches = 0;

            if (avformat_open_input(&s, feed->feed_filename, NULL, NULL) >= 0) {
                /* set buffer size */
                ffio_set_buf_size(s->pb, FFM_PACKET_SIZE);
                /* Now see if it matches */
                if (s->nb_streams == feed->nb_streams) {
                    matches = 1;
                    for(i=0;i<s->nb_streams;i++) {
                        AVStream *sf, *ss;
                        sf = feed->streams[i];
                        ss = s->streams[i];

                        if (sf->index != ss->index ||
                            sf->id != ss->id) {
                            http_log("Index & Id do not match for stream %d (%s)\n",
                                   i, feed->feed_filename);
                            matches = 0;
                        } else {
                            AVCodecContext *ccf, *ccs;

                            ccf = sf->codec;
                            ccs = ss->codec;
#define CHECK_CODEC(x)  (ccf->x != ccs->x)

                            if (CHECK_CODEC(codec_id) || CHECK_CODEC(codec_type)) {
                                http_log("Codecs do not match for stream %d\n", i);
                                matches = 0;
                            } else if (CHECK_CODEC(bit_rate) || CHECK_CODEC(flags)) {
                                http_log("Codec bitrates do not match for stream %d\n", i);
                                matches = 0;
                            } else if (ccf->codec_type == AVMEDIA_TYPE_VIDEO) {
                                if (CHECK_CODEC(time_base.den) ||
                                    CHECK_CODEC(time_base.num) ||
                                    CHECK_CODEC(width) ||
                                    CHECK_CODEC(height)) {
                                    http_log("Codec width, height and framerate do not match for stream %d\n", i);
                                    matches = 0;
                                }
                            } else if (ccf->codec_type == AVMEDIA_TYPE_AUDIO) {
                                if (CHECK_CODEC(sample_rate) ||
                                    CHECK_CODEC(channels) ||
                                    CHECK_CODEC(frame_size)) {
                                    http_log("Codec sample_rate, channels, frame_size do not match for stream %d\n", i);
                                    matches = 0;
                                }
                            } else {
                                http_log("Unknown codec type\n");
                                matches = 0;
                            }
                        }
                        if (!matches)
                            break;
                    }
                } else
                    http_log("Deleting feed file '%s' as stream counts differ (%d != %d)\n",
                        feed->feed_filename, s->nb_streams, feed->nb_streams);

                avformat_close_input(&s);
            } else
                http_log("Deleting feed file '%s' as it appears to be corrupt\n",
                        feed->feed_filename);

            if (!matches) {
                if (feed->readonly) {
                    http_log("Unable to delete feed file '%s' as it is marked readonly\n",
                        feed->feed_filename);
                    exit(1);
                }
                unlink(feed->feed_filename);
            }
        }
        if (avio_check(feed->feed_filename, AVIO_FLAG_WRITE) <= 0) {
            AVFormatContext *s = avformat_alloc_context();

            if (feed->readonly) {
                http_log("Unable to create feed file '%s' as it is marked readonly\n",
                    feed->feed_filename);
                exit(1);
            }

            /* only write the header of the ffm file */
            if (avio_open(&s->pb, feed->feed_filename, AVIO_FLAG_WRITE) < 0) {
                http_log("Could not open output feed file '%s'\n",
                         feed->feed_filename);
                exit(1);
            }
            s->oformat = feed->fmt;
            s->nb_streams = feed->nb_streams;
            s->streams = feed->streams;
            if (avformat_write_header(s, NULL) < 0) {
                http_log("Container doesn't support the required parameters\n");
                exit(1);
            }
            /* XXX: need better API */
            av_freep(&s->priv_data);
            avio_close(s->pb);
            s->streams = NULL;
            s->nb_streams = 0;
            avformat_free_context(s);
        }
        /* get feed size and write index */
        fd = open(feed->feed_filename, O_RDONLY);
        if (fd < 0) {
            http_log("Could not open output feed file '%s'\n",
                    feed->feed_filename);
            exit(1);
        }

        feed->feed_write_index = FFMAX(ffm_read_write_index(fd), FFM_PACKET_SIZE);
        feed->feed_size = lseek(fd, 0, SEEK_END);
        /* ensure that we do not wrap before the end of file */
        if (feed->feed_max_size && feed->feed_max_size < feed->feed_size)
            feed->feed_max_size = feed->feed_size;

        close(fd);
    }
}

/* compute the bandwidth used by each stream */
static void compute_bandwidth(void)
{
    unsigned bandwidth;
    int i;
    FFStream *stream;

    for(stream = first_stream; stream != NULL; stream = stream->next) {
        bandwidth = 0;
        for(i=0;i<stream->nb_streams;i++) {
            AVStream *st = stream->streams[i];
            switch(st->codec->codec_type) {
            case AVMEDIA_TYPE_AUDIO:
            case AVMEDIA_TYPE_VIDEO:
                bandwidth += st->codec->bit_rate;
                break;
            default:
                break;
            }
        }
        stream->bandwidth = (bandwidth + 999) / 1000;
    }
}

/* add a codec and set the default parameters */
static void add_codec(FFStream *stream, AVCodecContext *av)
{
    AVStream *st;

    if(stream->nb_streams >= FF_ARRAY_ELEMS(stream->streams))
        return;

    /* compute default parameters */
    switch(av->codec_type) {
    case AVMEDIA_TYPE_AUDIO:
        if (av->bit_rate == 0)
            av->bit_rate = 64000;
        if (av->sample_rate == 0)
            av->sample_rate = 22050;
        if (av->channels == 0)
            av->channels = 1;
        break;
    case AVMEDIA_TYPE_VIDEO:
        if (av->bit_rate == 0)
            av->bit_rate = 64000;
        if (av->time_base.num == 0){
            av->time_base.den = 5;
            av->time_base.num = 1;
        }
        if (av->width == 0 || av->height == 0) {
            av->width = 160;
            av->height = 128;
        }
        /* Bitrate tolerance is less for streaming */
        if (av->bit_rate_tolerance == 0)
            av->bit_rate_tolerance = FFMAX(av->bit_rate / 4,
                      (int64_t)av->bit_rate*av->time_base.num/av->time_base.den);
        if (av->qmin == 0)
            av->qmin = 3;
        if (av->qmax == 0)
            av->qmax = 31;
        if (av->max_qdiff == 0)
            av->max_qdiff = 3;
        av->qcompress = 0.5;
        av->qblur = 0.5;

        if (!av->nsse_weight)
            av->nsse_weight = 8;

        av->frame_skip_cmp = FF_CMP_DCTMAX;
        if (!av->me_method)
            av->me_method = ME_EPZS;
        av->rc_buffer_aggressivity = 1.0;

        if (!av->rc_eq)
            av->rc_eq = av_strdup("tex^qComp");
        if (!av->i_quant_factor)
            av->i_quant_factor = -0.8;
        if (!av->b_quant_factor)
            av->b_quant_factor = 1.25;
        if (!av->b_quant_offset)
            av->b_quant_offset = 1.25;
        if (!av->rc_max_rate)
            av->rc_max_rate = av->bit_rate * 2;

        if (av->rc_max_rate && !av->rc_buffer_size) {
            av->rc_buffer_size = av->rc_max_rate;
        }


        break;
    default:
        abort();
    }

    st = av_mallocz(sizeof(AVStream));
    if (!st)
        return;
    st->codec = avcodec_alloc_context3(NULL);
    stream->streams[stream->nb_streams++] = st;
    memcpy(st->codec, av, sizeof(AVCodecContext));
}

static enum AVCodecID opt_codec(const char *name, enum AVMediaType type)
{
    AVCodec *codec = avcodec_find_encoder_by_name(name);

    if (!codec || codec->type != type)
        return AV_CODEC_ID_NONE;
    return codec->id;
}

static int ffserver_opt_default(const char *opt, const char *arg,
                       AVCodecContext *avctx, int type)
{
    int ret = 0;
    const AVOption *o = av_opt_find(avctx, opt, NULL, type, 0);
    if(o)
        ret = av_opt_set(avctx, opt, arg, 0);
    return ret;
}

static int ffserver_opt_preset(const char *arg,
                       AVCodecContext *avctx, int type,
                       enum AVCodecID *audio_id, enum AVCodecID *video_id)
{
    FILE *f=NULL;
    char filename[1000], tmp[1000], tmp2[1000], line[1000];
    int ret = 0;
    AVCodec *codec = avcodec_find_encoder(avctx->codec_id);

    if (!(f = get_preset_file(filename, sizeof(filename), arg, 0,
                              codec ? codec->name : NULL))) {
        fprintf(stderr, "File for preset '%s' not found\n", arg);
        return 1;
    }

    while(!feof(f)){
        int e= fscanf(f, "%999[^\n]\n", line) - 1;
        if(line[0] == '#' && !e)
            continue;
        e|= sscanf(line, "%999[^=]=%999[^\n]\n", tmp, tmp2) - 2;
        if(e){
            fprintf(stderr, "%s: Invalid syntax: '%s'\n", filename, line);
            ret = 1;
            break;
        }
        if(!strcmp(tmp, "acodec")){
            *audio_id = opt_codec(tmp2, AVMEDIA_TYPE_AUDIO);
        }else if(!strcmp(tmp, "vcodec")){
            *video_id = opt_codec(tmp2, AVMEDIA_TYPE_VIDEO);
        }else if(!strcmp(tmp, "scodec")){
            /* opt_subtitle_codec(tmp2); */
        }else if(ffserver_opt_default(tmp, tmp2, avctx, type) < 0){
            fprintf(stderr, "%s: Invalid option or argument: '%s', parsed as '%s' = '%s'\n", filename, line, tmp, tmp2);
            ret = 1;
            break;
        }
    }