1 /*
2 * RTP VP8 Packetizer
3 * Copyright (c) 2010 Josh Allmann
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
23
24 /* Based on a draft spec for VP8 RTP.
25 * ( http://tools.ietf.org/html/draft-ietf-payload-vp8-05 ) */
27 {
29 int len, max_packet_size, header_size;
30
32 s->timestamp =
s->cur_timestamp;
33
34 // extended control bit set, reference frame, start of partition,
35 // partition id 0
37 *
s->buf_ptr++ = 0x80;
// Picture id present
38 *
s->buf_ptr++ = ((
s->frame_count & 0x7f00) >> 8) | 0x80;
39 *
s->buf_ptr++ =
s->frame_count++ & 0xff;
40 // Calculate the number of remaining bytes
41 header_size =
s->buf_ptr -
s->buf;
42 max_packet_size =
s->max_payload_size - header_size;
43
46
47 memcpy(
s->buf_ptr, buf,
len);
48 // marker bit is last packet in frame
50
53 // Clear the partition start bit, keep the rest of the header untouched
55 }
56 }