FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
rtpenc_amr.c
Go to the documentation of this file.
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 &&
42  len + size - 1 > s->max_payload_size ||
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 }
const char * s
Definition: avisynth_c.h:631
int max_payload_size
Definition: rtpenc.h:38
Format I/O context.
Definition: avformat.h:1319
uint8_t
int max_frames_per_packet
Definition: rtpenc.h:52
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1387
uint8_t * buf
Definition: rtpenc.h:49
ptrdiff_t size
Definition: opengl_enc.c:101
int av_compare_ts(int64_t ts_a, AVRational tb_a, int64_t ts_b, AVRational tb_b)
Compare 2 timestamps each in its own timebases.
Definition: mathematics.c:147
void ff_rtp_send_amr(AVFormatContext *s1, const uint8_t *buff, int size)
Packetize AMR frames into RTP packets according to RFC 3267, in octet-aligned mode.
Definition: rtpenc_amr.c:30
void ff_rtp_send_data(AVFormatContext *s1, const uint8_t *buf1, int len, int m)
Definition: rtpenc.c:319
Stream structure.
Definition: avformat.h:876
uint32_t cur_timestamp
Definition: rtpenc.h:37
AVStream * st
Definition: rtpenc.h:30
#define AV_TIME_BASE_Q
Internal time base represented as fractional value.
Definition: avutil.h:252
#define s1
Definition: regdef.h:38
int num_frames
Definition: rtpenc.h:39
uint8_t * buf_ptr
Definition: rtpenc.h:50
Main libavformat public API header.
uint32_t timestamp
Definition: rtpenc.h:35
int len
void * priv_data
Format private data.
Definition: avformat.h:1347
AVRational time_base
This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented...
Definition: avformat.h:913