Blame view

ffmpeg-4.2.2/libavformat/rtpenc_amr.c 2.29 KB
aac5773f   hucm   功能基本完成,接口待打磨
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
  /*
   * RTP packetization for AMR audio
   * Copyright (c) 2007 Luca Abeni
   * Copyright (c) 2009 Martin Storsjo
   *
   * This file is part of FFmpeg.
   *
   * FFmpeg is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * FFmpeg is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with FFmpeg; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
   */
  
  #include "avformat.h"
  #include "rtpenc.h"
  
  /**
   * Packetize AMR frames into RTP packets according to RFC 3267,
   * in octet-aligned mode.
   */
  void ff_rtp_send_amr(AVFormatContext *s1, const uint8_t *buff, int size)
  {
      RTPMuxContext *s          = s1->priv_data;
      AVStream *st              = s1->streams[0];
      int max_header_toc_size   = 1 + s->max_frames_per_packet;
      uint8_t *p;
      int len;
  
      /* Test if the packet must be sent. */
      len = s->buf_ptr - s->buf;
      if (s->num_frames &&
          (s->num_frames == s->max_frames_per_packet ||
           len + size - 1 > s->max_payload_size ||
           av_compare_ts(s->cur_timestamp - s->timestamp, st->time_base,
                         s1->max_delay, AV_TIME_BASE_Q) >= 0)) {
          int header_size = s->num_frames + 1;
          p = s->buf + max_header_toc_size - header_size;
          if (p != s->buf)
              memmove(p, s->buf, header_size);
  
          ff_rtp_send_data(s1, p, s->buf_ptr - p, 1);
  
          s->num_frames = 0;
      }
  
      if (!s->num_frames) {
          s->buf[0]    = 0xf0;
          s->buf_ptr   = s->buf + max_header_toc_size;
          s->timestamp = s->cur_timestamp;
      } else {
          /* Mark the previous TOC entry as having more entries following. */
          s->buf[1 + s->num_frames - 1] |= 0x80;
      }
  
      /* Copy the frame type and quality bits. */
      s->buf[1 + s->num_frames++] = buff[0] & 0x7C;
      buff++;
      size--;
      memcpy(s->buf_ptr, buff, size);
      s->buf_ptr += size;
  }