rtpenc: Allow requesting H264 RTP packetization mode 0
[libav.git] / libavformat / rtpenc_h264.c
1 /*
2 * RTP packetization for H.264 (RFC3984)
3 * Copyright (c) 2008 Luca Abeni
4 *
5 * This file is part of Libav.
6 *
7 * Libav 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 * Libav 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 Libav; 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 const uint8_t *avc_mp4_find_startcode(const uint8_t *start, const uint8_t *end, int nal_length_size)
33 {
34 int res = 0;
35
36 if (end - start < nal_length_size)
37 return NULL;
38 while (nal_length_size--)
39 res = (res << 8) | *start++;
40
41 if (start + res > end || res < 0 || start + res < start)
42 return NULL;
43
44 return start + res;
45 }
46
47 static void nal_send(AVFormatContext *s1, const uint8_t *buf, int size, int last)
48 {
49 RTPMuxContext *s = s1->priv_data;
50
51 av_log(s1, AV_LOG_DEBUG, "Sending NAL %x of len %d M=%d\n", buf[0] & 0x1F, size, last);
52 if (size <= s->max_payload_size) {
53 ff_rtp_send_data(s1, buf, size, last);
54 } else {
55 uint8_t type = buf[0] & 0x1F;
56 uint8_t nri = buf[0] & 0x60;
57
58 if (s->flags & FF_RTP_FLAG_H264_MODE0) {
59 av_log(s1, AV_LOG_ERROR,
60 "NAL size %d > %d, try -slice-max-size %d\n", size,
61 s->max_payload_size, s->max_payload_size);
62 return;
63 }
64 av_log(s1, AV_LOG_DEBUG, "NAL size %d > %d\n", size, s->max_payload_size);
65 s->buf[0] = 28; /* FU Indicator; Type = 28 ---> FU-A */
66 s->buf[0] |= nri;
67 s->buf[1] = type;
68 s->buf[1] |= 1 << 7;
69 buf += 1;
70 size -= 1;
71 while (size + 2 > s->max_payload_size) {
72 memcpy(&s->buf[2], buf, s->max_payload_size - 2);
73 ff_rtp_send_data(s1, s->buf, s->max_payload_size, 0);
74 buf += s->max_payload_size - 2;
75 size -= s->max_payload_size - 2;
76 s->buf[1] &= ~(1 << 7);
77 }
78 s->buf[1] |= 1 << 6;
79 memcpy(&s->buf[2], buf, size);
80 ff_rtp_send_data(s1, s->buf, size + 2, last);
81 }
82 }
83
84 void ff_rtp_send_h264(AVFormatContext *s1, const uint8_t *buf1, int size)
85 {
86 const uint8_t *r, *end = buf1 + size;
87 RTPMuxContext *s = s1->priv_data;
88
89 s->timestamp = s->cur_timestamp;
90 if (s->nal_length_size)
91 r = avc_mp4_find_startcode(buf1, end, s->nal_length_size) ? buf1 : end;
92 else
93 r = ff_avc_find_startcode(buf1, end);
94 while (r < end) {
95 const uint8_t *r1;
96
97 if (s->nal_length_size) {
98 r1 = avc_mp4_find_startcode(r, end, s->nal_length_size);
99 if (!r1)
100 r1 = end;
101 r += s->nal_length_size;
102 } else {
103 while (!*(r++));
104 r1 = ff_avc_find_startcode(r, end);
105 }
106 nal_send(s1, r, r1 - r, r1 == end);
107 r = r1;
108 }
109 }