PeerStreamer

/*

 * RTP packetization for MPEG video

 * Copyright (c) 2002 Fabrice Bellard

 * Copyright (c) 2007 Luca Abeni

 *

 * This file is part of Libav.

 *

 * Libav 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.

 *

 * Libav 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 Libav; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

#include "libavcodec/mpegvideo.h"

#include "avformat.h"

#include "rtpenc.h"

/* NOTE: a single frame must be passed with sequence header if

   needed. XXX: use slices. */

void ff_rtp_send_mpegvideo(AVFormatContext *s1, const uint8_t *buf1, int size)

{

    RTPMuxContext *s = s1->priv_data;

    int len, h, max_packet_size;

    uint8_t *q;

    const uint8_t *end = buf1 + size;

    int begin_of_slice, end_of_slice, frame_type, temporal_reference;

    max_packet_size = s->max_payload_size;

    begin_of_slice = 1;

    end_of_slice = 0;

    frame_type = 0;

    temporal_reference = 0;

    while (size > 0) {

        int begin_of_sequence;

        begin_of_sequence = 0;

        len = max_packet_size - 4;

        if (len >= size) {

            len = size;

            end_of_slice = 1;

        } else {

            const uint8_t *r, *r1;

            int start_code;

            r1 = buf1;

            while (1) {

                start_code = -1;

                r = ff_find_start_code(r1, end, &start_code);

                if((start_code & 0xFFFFFF00) == 0x100) {

                    /* New start code found */

                    if (start_code == 0x100) {

                        frame_type = (r[1] & 0x38) >> 3;

                        temporal_reference = (int)r[0] << 2 | r[1] >> 6;

                    }

                    if (start_code == 0x1B8) {

                        begin_of_sequence = 1;

                    }

                    if (r - buf1 - 4 <= len) {

                        /* The current slice fits in the packet */

                        if (begin_of_slice == 0) {

                            /* no slice at the beginning of the packet... */

                            end_of_slice = 1;

                            len = r - buf1 - 4;

                            break;

                        }

                        r1 = r;

                    } else {

                        if ((r1 - buf1 > 4) && (r - r1 < max_packet_size)) {

                            len = r1 - buf1 - 4;

                            end_of_slice = 1;

                        }

                        break;

                    }

                } else {

                    break;

                }

            }

        }

        h = 0;

        h |= temporal_reference << 16;

        h |= begin_of_sequence << 13;

        h |= begin_of_slice << 12;

        h |= end_of_slice << 11;

        h |= frame_type << 8;

        q = s->buf;

        *q++ = h >> 24;

        *q++ = h >> 16;

        *q++ = h >> 8;

        *q++ = h;

        memcpy(q, buf1, len);

        q += len;

        /* 90kHz time stamp */

        s->timestamp = s->cur_timestamp;

        ff_rtp_send_data(s1, s->buf, q - s->buf, (len == size));

        buf1 += len;

        size -= len;

        begin_of_slice = end_of_slice;

        end_of_slice = 0;

    }

}