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rtpenc_h264.c
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1 /*
2  * RTP packetization for H.264 (RFC3984)
3  * Copyright (c) 2008 Luca Abeni
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 /**
23  * @file
24  * @brief H.264 packetization
25  * @author Luca Abeni <lucabe72@email.it>
26  */
27 
28 #include "avformat.h"
29 #include "avc.h"
30 #include "rtpenc.h"
31 
32 static void nal_send(AVFormatContext *s1, const uint8_t *buf, int size, int last)
33 {
34  RTPMuxContext *s = s1->priv_data;
35 
36  av_log(s1, AV_LOG_DEBUG, "Sending NAL %x of len %d M=%d\n", buf[0] & 0x1F, size, last);
37  if (size <= s->max_payload_size) {
38  ff_rtp_send_data(s1, buf, size, last);
39  } else {
40  uint8_t type = buf[0] & 0x1F;
41  uint8_t nri = buf[0] & 0x60;
42 
43  if (s->flags & FF_RTP_FLAG_H264_MODE0) {
44  av_log(s1, AV_LOG_ERROR,
45  "NAL size %d > %d, try -slice-max-size %d\n", size,
47  return;
48  }
49  av_log(s1, AV_LOG_DEBUG, "NAL size %d > %d\n", size, s->max_payload_size);
50  s->buf[0] = 28; /* FU Indicator; Type = 28 ---> FU-A */
51  s->buf[0] |= nri;
52  s->buf[1] = type;
53  s->buf[1] |= 1 << 7;
54  buf += 1;
55  size -= 1;
56  while (size + 2 > s->max_payload_size) {
57  memcpy(&s->buf[2], buf, s->max_payload_size - 2);
58  ff_rtp_send_data(s1, s->buf, s->max_payload_size, 0);
59  buf += s->max_payload_size - 2;
60  size -= s->max_payload_size - 2;
61  s->buf[1] &= ~(1 << 7);
62  }
63  s->buf[1] |= 1 << 6;
64  memcpy(&s->buf[2], buf, size);
65  ff_rtp_send_data(s1, s->buf, size + 2, last);
66  }
67 }
68 
70 {
71  const uint8_t *r, *end = buf1 + size;
72  RTPMuxContext *s = s1->priv_data;
73 
74  s->timestamp = s->cur_timestamp;
75  if (s->nal_length_size)
76  r = ff_avc_mp4_find_startcode(buf1, end, s->nal_length_size) ? buf1 : end;
77  else
78  r = ff_avc_find_startcode(buf1, end);
79  while (r < end) {
80  const uint8_t *r1;
81 
82  if (s->nal_length_size) {
84  if (!r1)
85  r1 = end;
86  r += s->nal_length_size;
87  } else {
88  while (!*(r++));
89  r1 = ff_avc_find_startcode(r, end);
90  }
91  nal_send(s1, r, r1 - r, r1 == end);
92  r = r1;
93  }
94 }