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
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
|
/**
* @file src/h264.c H.264 video codec packetization (RFC 3984)
*
* Copyright (C) 2010 - 2015 Creytiv.com
*/
#include <string.h>
#include <re.h>
#include <rem.h>
#include <baresip.h>
int h264_hdr_encode(const struct h264_hdr *hdr, struct mbuf *mb)
{
uint8_t v;
v = hdr->f<<7 | hdr->nri<<5 | hdr->type<<0;
return mbuf_write_u8(mb, v);
}
int h264_hdr_decode(struct h264_hdr *hdr, struct mbuf *mb)
{
uint8_t v;
if (mbuf_get_left(mb) < 1)
return ENOENT;
v = mbuf_read_u8(mb);
hdr->f = v>>7 & 0x1;
hdr->nri = v>>5 & 0x3;
hdr->type = v>>0 & 0x1f;
return 0;
}
int h264_fu_hdr_encode(const struct h264_fu *fu, struct mbuf *mb)
{
uint8_t v = fu->s<<7 | fu->s<<6 | fu->r<<5 | fu->type;
return mbuf_write_u8(mb, v);
}
int h264_fu_hdr_decode(struct h264_fu *fu, struct mbuf *mb)
{
uint8_t v;
if (mbuf_get_left(mb) < 1)
return ENOENT;
v = mbuf_read_u8(mb);
fu->s = v>>7 & 0x1;
fu->e = v>>6 & 0x1;
fu->r = v>>5 & 0x1;
fu->type = v>>0 & 0x1f;
return 0;
}
/*
* Find the NAL start sequence in a H.264 byte stream
*
* @note: copied from ffmpeg source
*/
const uint8_t *h264_find_startcode(const uint8_t *p, const uint8_t *end)
{
const uint8_t *a = p + 4 - ((long)p & 3);
for (end -= 3; p < a && p < end; p++ ) {
if (p[0] == 0 && p[1] == 0 && p[2] == 1)
return p;
}
for (end -= 3; p < end; p += 4) {
uint32_t x = *(const uint32_t*)(void *)p;
if ( (x - 0x01010101) & (~x) & 0x80808080 ) {
if (p[1] == 0 ) {
if ( p[0] == 0 && p[2] == 1 )
return p;
if ( p[2] == 0 && p[3] == 1 )
return p+1;
}
if ( p[3] == 0 ) {
if ( p[2] == 0 && p[4] == 1 )
return p+2;
if ( p[4] == 0 && p[5] == 1 )
return p+3;
}
}
}
for (end += 3; p < end; p++) {
if (p[0] == 0 && p[1] == 0 && p[2] == 1)
return p;
}
return end + 3;
}
static int rtp_send_data(const uint8_t *hdr, size_t hdr_sz,
const uint8_t *buf, size_t sz, bool eof,
videnc_packet_h *pkth, void *arg)
{
return pkth(eof, hdr, hdr_sz, buf, sz, arg);
}
int h264_nal_send(bool first, bool last,
bool marker, uint32_t ihdr, const uint8_t *buf,
size_t size, size_t maxsz,
videnc_packet_h *pkth, void *arg)
{
uint8_t hdr = (uint8_t)ihdr;
int err = 0;
if (first && last && size <= maxsz) {
err = rtp_send_data(&hdr, 1, buf, size, marker,
pkth, arg);
}
else {
uint8_t fu_hdr[2];
const uint8_t type = hdr & 0x1f;
const uint8_t nri = hdr & 0x60;
const size_t sz = maxsz - 2;
fu_hdr[0] = nri | H264_NAL_FU_A;
fu_hdr[1] = first ? (1<<7 | type) : type;
while (size > sz) {
err |= rtp_send_data(fu_hdr, 2, buf, sz, false,
pkth, arg);
buf += sz;
size -= sz;
fu_hdr[1] &= ~(1 << 7);
}
if (last)
fu_hdr[1] |= 1<<6; /* end bit */
err |= rtp_send_data(fu_hdr, 2, buf, size, marker && last,
pkth, arg);
}
return err;
}
int h264_packetize(const uint8_t *buf, size_t len, size_t pktsize,
videnc_packet_h *pkth, void *arg)
{
const uint8_t *start = buf;
const uint8_t *end = buf + len;
const uint8_t *r;
int err = 0;
r = h264_find_startcode(start, end);
while (r < end) {
const uint8_t *r1;
/* skip zeros */
while (!*(r++))
;
r1 = h264_find_startcode(r, end);
err |= h264_nal_send(true, true, (r1 >= end), r[0],
r+1, r1-r-1, pktsize,
pkth, arg);
r = r1;
}
return err;
}
|
