Line data    Source code

       1             : /*
       2             :  * RTP packetization for MPEG video
       3             :  * Copyright (c) 2002 Fabrice Bellard
       4             :  * Copyright (c) 2007 Luca Abeni
       5             :  *
       6             :  * This file is part of FFmpeg.
       7             :  *
       8             :  * FFmpeg is free software; you can redistribute it and/or
       9             :  * modify it under the terms of the GNU Lesser General Public
      10             :  * License as published by the Free Software Foundation; either
      11             :  * version 2.1 of the License, or (at your option) any later version.
      12             :  *
      13             :  * FFmpeg is distributed in the hope that it will be useful,
      14             :  * but WITHOUT ANY WARRANTY; without even the implied warranty of
      15             :  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      16             :  * Lesser General Public License for more details.
      17             :  *
      18             :  * You should have received a copy of the GNU Lesser General Public
      19             :  * License along with FFmpeg; if not, write to the Free Software
      20             :  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
      21             :  */
      22             : 
      23             : #include "libavcodec/internal.h"
      24             : #include "avformat.h"
      25             : #include "rtpenc.h"
      26             : 
      27             : /* NOTE: a single frame must be passed with sequence header if
      28             :    needed. XXX: use slices. */
      29           0 : void ff_rtp_send_mpegvideo(AVFormatContext *s1, const uint8_t *buf1, int size)
      30             : {
      31           0 :     RTPMuxContext *s = s1->priv_data;
      32             :     int len, h, max_packet_size;
      33             :     uint8_t *q;
      34           0 :     const uint8_t *end = buf1 + size;
      35             :     int begin_of_slice, end_of_slice, frame_type, temporal_reference;
      36             : 
      37           0 :     max_packet_size = s->max_payload_size;
      38           0 :     begin_of_slice = 1;
      39           0 :     end_of_slice = 0;
      40           0 :     frame_type = 0;
      41           0 :     temporal_reference = 0;
      42             : 
      43           0 :     while (size > 0) {
      44             :         int begin_of_sequence;
      45             : 
      46           0 :         begin_of_sequence = 0;
      47           0 :         len = max_packet_size - 4;
      48             : 
      49           0 :         if (len >= size) {
      50           0 :             len = size;
      51           0 :             end_of_slice = 1;
      52             :         } else {
      53             :             const uint8_t *r, *r1;
      54             :             int start_code;
      55             : 
      56           0 :             r1 = buf1;
      57             :             while (1) {
      58           0 :                 start_code = -1;
      59           0 :                 r = avpriv_find_start_code(r1, end, &start_code);
      60           0 :                 if((start_code & 0xFFFFFF00) == 0x100) {
      61             :                     /* New start code found */
      62           0 :                     if (start_code == 0x100) {
      63           0 :                         frame_type = (r[1] & 0x38) >> 3;
      64           0 :                         temporal_reference = (int)r[0] << 2 | r[1] >> 6;
      65             :                     }
      66           0 :                     if (start_code == 0x1B8) {
      67           0 :                         begin_of_sequence = 1;
      68             :                     }
      69             : 
      70           0 :                     if (r - buf1 - 4 <= len) {
      71             :                         /* The current slice fits in the packet */
      72           0 :                         if (begin_of_slice == 0) {
      73             :                             /* no slice at the beginning of the packet... */
      74           0 :                             end_of_slice = 1;
      75           0 :                             len = r - buf1 - 4;
      76           0 :                             break;
      77             :                         }
      78           0 :                         r1 = r;
      79             :                     } else {
      80           0 :                         if ((r1 - buf1 > 4) && (r - r1 < max_packet_size)) {
      81           0 :                             len = r1 - buf1 - 4;
      82           0 :                             end_of_slice = 1;
      83             :                         }
      84           0 :                         break;
      85             :                     }
      86             :                 } else {
      87           0 :                     break;
      88             :                 }
      89             :             }
      90             :         }
      91             : 
      92           0 :         h = 0;
      93           0 :         h |= temporal_reference << 16;
      94           0 :         h |= begin_of_sequence << 13;
      95           0 :         h |= begin_of_slice << 12;
      96           0 :         h |= end_of_slice << 11;
      97           0 :         h |= frame_type << 8;
      98             : 
      99           0 :         q = s->buf;
     100           0 :         *q++ = h >> 24;
     101           0 :         *q++ = h >> 16;
     102           0 :         *q++ = h >> 8;
     103           0 :         *q++ = h;
     104             : 
     105           0 :         memcpy(q, buf1, len);
     106           0 :         q += len;
     107             : 
     108             :         /* 90kHz time stamp */
     109           0 :         s->timestamp = s->cur_timestamp;
     110           0 :         ff_rtp_send_data(s1, s->buf, q - s->buf, (len == size));
     111             : 
     112           0 :         buf1 += len;
     113           0 :         size -= len;
     114           0 :         begin_of_slice = end_of_slice;
     115           0 :         end_of_slice = 0;
     116             :     }
     117           0 : }