/*
  * RTP packetization for MPEG video

  * Copyright (c) 2002 Fabrice Bellard
  * Copyright (c) 2007 Luca Abeni

  *
  * This file is part of FFmpeg.
  *
  * FFmpeg 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.
  *
  * FFmpeg 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 FFmpeg; 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 = avpriv_mpv_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;

     }
 }