blob: 8df5a3cf3e9990d346fa9def8aaa5297b9a0eb2a
1 | /* |
2 | * RTP packetization for AMR audio |
3 | * Copyright (c) 2007 Luca Abeni |
4 | * Copyright (c) 2009 Martin Storsjo |
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 "avformat.h" |
24 | #include "rtpenc.h" |
25 | |
26 | /** |
27 | * Packetize AMR frames into RTP packets according to RFC 3267, |
28 | * in octet-aligned mode. |
29 | */ |
30 | void ff_rtp_send_amr(AVFormatContext *s1, const uint8_t *buff, int size) |
31 | { |
32 | RTPMuxContext *s = s1->priv_data; |
33 | AVStream *st = s1->streams[0]; |
34 | int max_header_toc_size = 1 + s->max_frames_per_packet; |
35 | uint8_t *p; |
36 | int len; |
37 | |
38 | /* Test if the packet must be sent. */ |
39 | len = s->buf_ptr - s->buf; |
40 | if (s->num_frames && |
41 | (s->num_frames == s->max_frames_per_packet || |
42 | len + size - 1 > s->max_payload_size || |
43 | av_compare_ts(s->cur_timestamp - s->timestamp, st->time_base, |
44 | s1->max_delay, AV_TIME_BASE_Q) >= 0)) { |
45 | int header_size = s->num_frames + 1; |
46 | p = s->buf + max_header_toc_size - header_size; |
47 | if (p != s->buf) |
48 | memmove(p, s->buf, header_size); |
49 | |
50 | ff_rtp_send_data(s1, p, s->buf_ptr - p, 1); |
51 | |
52 | s->num_frames = 0; |
53 | } |
54 | |
55 | if (!s->num_frames) { |
56 | s->buf[0] = 0xf0; |
57 | s->buf_ptr = s->buf + max_header_toc_size; |
58 | s->timestamp = s->cur_timestamp; |
59 | } else { |
60 | /* Mark the previous TOC entry as having more entries following. */ |
61 | s->buf[1 + s->num_frames - 1] |= 0x80; |
62 | } |
63 | |
64 | /* Copy the frame type and quality bits. */ |
65 | s->buf[1 + s->num_frames++] = buff[0] & 0x7C; |
66 | buff++; |
67 | size--; |
68 | memcpy(s->buf_ptr, buff, size); |
69 | s->buf_ptr += size; |
70 | } |
71 |