1 /*
2  * copyright (c) 2007 Luca Abeni
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #include "libavutil/intreadwrite.h"
22 
23 #include "avformat.h"
24 #include "rtpenc.h"
25 
26 
ff_rtp_send_aac(AVFormatContext * s1,const uint8_t * buff,int size)27 void ff_rtp_send_aac(AVFormatContext *s1, const uint8_t *buff, int size)
28 {
29     RTPMuxContext *s = s1->priv_data;
30     AVStream *st = s1->streams[0];
31     const int max_au_headers_size = 2 + 2 * s->max_frames_per_packet;
32     int len, max_packet_size = s->max_payload_size - max_au_headers_size;
33     uint8_t *p;
34 
35     /* skip ADTS header, if present */
36     if ((s1->streams[0]->codecpar->extradata_size) == 0) {
37         size -= 7;
38         buff += 7;
39     }
40 
41     /* test if the packet must be sent */
42     len = (s->buf_ptr - s->buf);
43     if (s->num_frames &&
44         (s->num_frames == s->max_frames_per_packet ||
45          (len + size) > s->max_payload_size ||
46          av_compare_ts(s->cur_timestamp - s->timestamp, st->time_base,
47                        s1->max_delay, AV_TIME_BASE_Q) >= 0)) {
48         int au_size = s->num_frames * 2;
49 
50         p = s->buf + max_au_headers_size - au_size - 2;
51         if (p != s->buf) {
52             memmove(p + 2, s->buf + 2, au_size);
53         }
54         /* Write the AU header size */
55         AV_WB16(p, au_size * 8);
56 
57         ff_rtp_send_data(s1, p, s->buf_ptr - p, 1);
58 
59         s->num_frames = 0;
60     }
61     if (s->num_frames == 0) {
62         s->buf_ptr = s->buf + max_au_headers_size;
63         s->timestamp = s->cur_timestamp;
64     }
65 
66     if (size <= max_packet_size) {
67         p = s->buf + s->num_frames++ * 2 + 2;
68         AV_WB16(p, size * 8);
69         memcpy(s->buf_ptr, buff, size);
70         s->buf_ptr += size;
71     } else {
72         int au_size = size;
73 
74         max_packet_size = s->max_payload_size - 4;
75         p = s->buf;
76         AV_WB16(p, 2 * 8);
77         while (size > 0) {
78             len = FFMIN(size, max_packet_size);
79             AV_WB16(&p[2], au_size * 8);
80             memcpy(p + 4, buff, len);
81             ff_rtp_send_data(s1, p, len + 4, len == size);
82             size -= len;
83             buff += len;
84         }
85     }
86 }
87