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
22 #include "rtpenc.h"
23
24 /* Based on a draft spec for VP8 RTP.
25 * ( http://tools.ietf.org/html/draft-ietf-payload-vp8-05 ) */
ff_rtp_send_vp8(AVFormatContext * s1,const uint8_t * buf,int size)26 void ff_rtp_send_vp8(AVFormatContext *s1, const uint8_t *buf, int size)
27 {
28 RTPMuxContext *s = s1->priv_data;
29 int len, max_packet_size, header_size;
30
31 s->buf_ptr = s->buf;
32 s->timestamp = s->cur_timestamp;
33
34 // extended control bit set, reference frame, start of partition,
35 // partition id 0
36 *s->buf_ptr++ = 0x90;
37 *s->buf_ptr++ = 0x80; // Picture id present
38 *s->buf_ptr++ = s->frame_count++ & 0x7f;
39 // Calculate the number of remaining bytes
40 header_size = s->buf_ptr - s->buf;
41 max_packet_size = s->max_payload_size - header_size;
42
43 while (size > 0) {
44 len = FFMIN(size, max_packet_size);
45
46 memcpy(s->buf_ptr, buf, len);
47 // marker bit is last packet in frame
48 ff_rtp_send_data(s1, s->buf, len + header_size, size == len);
49
50 size -= len;
51 buf += len;
52 // Clear the partition start bit, keep the rest of the header untouched
53 s->buf[0] &= ~0x10;
54 }
55 }
56