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
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
|
/*
* AVC helper functions for muxers
* Copyright (c) 2006 Baptiste Coudurier <baptiste.coudurier@smartjog.com>
*
* 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 "libavutil/intreadwrite.h"
#include "avformat.h"
#include "avio.h"
#include "avc.h"
static const uint8_t *ff_avc_find_startcode_internal(const uint8_t *p, const uint8_t *end)
{
const uint8_t *a = p + 4 - ((intptr_t)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*)p;
// if ((x - 0x01000100) & (~x) & 0x80008000) // little endian
// if ((x - 0x00010001) & (~x) & 0x00800080) // big endian
if ((x - 0x01010101) & (~x) & 0x80808080) { // generic
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;
}
const uint8_t *ff_avc_find_startcode(const uint8_t *p, const uint8_t *end){
const uint8_t *out= ff_avc_find_startcode_internal(p, end);
if(p<out && out<end && !out[-1]) out--;
return out;
}
int ff_avc_parse_nal_units(AVIOContext *pb, const uint8_t *buf_in, int size)
{
const uint8_t *p = buf_in;
const uint8_t *end = p + size;
const uint8_t *nal_start, *nal_end;
size = 0;
nal_start = ff_avc_find_startcode(p, end);
for (;;) {
while (nal_start < end && !*(nal_start++));
if (nal_start == end)
break;
nal_end = ff_avc_find_startcode(nal_start, end);
avio_wb32(pb, nal_end - nal_start);
avio_write(pb, nal_start, nal_end - nal_start);
size += 4 + nal_end - nal_start;
nal_start = nal_end;
}
return size;
}
int ff_avc_parse_nal_units_buf(const uint8_t *buf_in, uint8_t **buf, int *size)
{
AVIOContext *pb;
int ret = avio_open_dyn_buf(&pb);
if(ret < 0)
return ret;
ff_avc_parse_nal_units(pb, buf_in, *size);
av_freep(buf);
*size = avio_close_dyn_buf(pb, buf);
return 0;
}
int ff_isom_write_avcc(AVIOContext *pb, const uint8_t *data, int len)
{
if (len > 6) {
/* check for h264 start code */
if (AV_RB32(data) == 0x00000001 ||
AV_RB24(data) == 0x000001) {
uint8_t *buf=NULL, *end, *start;
uint32_t sps_size=0, pps_size=0;
uint8_t *sps=0, *pps=0;
int ret = ff_avc_parse_nal_units_buf(data, &buf, &len);
if (ret < 0)
return ret;
start = buf;
end = buf + len;
/* look for sps and pps */
while (end - buf > 4) {
uint32_t size;
uint8_t nal_type;
size = FFMIN(AV_RB32(buf), end - buf - 4);
buf += 4;
nal_type = buf[0] & 0x1f;
if (nal_type == 7) { /* SPS */
sps = buf;
sps_size = size;
} else if (nal_type == 8) { /* PPS */
pps = buf;
pps_size = size;
}
buf += size;
}
if (!sps || !pps || sps_size < 4 || sps_size > UINT16_MAX || pps_size > UINT16_MAX)
return AVERROR_INVALIDDATA;
avio_w8(pb, 1); /* version */
avio_w8(pb, sps[1]); /* profile */
avio_w8(pb, sps[2]); /* profile compat */
avio_w8(pb, sps[3]); /* level */
avio_w8(pb, 0xff); /* 6 bits reserved (111111) + 2 bits nal size length - 1 (11) */
avio_w8(pb, 0xe1); /* 3 bits reserved (111) + 5 bits number of sps (00001) */
avio_wb16(pb, sps_size);
avio_write(pb, sps, sps_size);
avio_w8(pb, 1); /* number of pps */
avio_wb16(pb, pps_size);
avio_write(pb, pps, pps_size);
av_free(start);
} else {
avio_write(pb, data, len);
}
}
return 0;
}
int ff_avc_write_annexb_extradata(const uint8_t *in, uint8_t **buf, int *size)
{
uint16_t sps_size, pps_size;
uint8_t *out;
int out_size;
*buf = NULL;
if (*size >= 4 && (AV_RB32(in) == 0x00000001 || AV_RB24(in) == 0x000001))
return 0;
if (*size < 11 || in[0] != 1)
return AVERROR_INVALIDDATA;
sps_size = AV_RB16(&in[6]);
if (11 + sps_size > *size)
return AVERROR_INVALIDDATA;
pps_size = AV_RB16(&in[9 + sps_size]);
if (11 + sps_size + pps_size > *size)
return AVERROR_INVALIDDATA;
out_size = 8 + sps_size + pps_size;
out = av_mallocz(out_size);
if (!out)
return AVERROR(ENOMEM);
AV_WB32(&out[0], 0x00000001);
memcpy(out + 4, &in[8], sps_size);
AV_WB32(&out[4 + sps_size], 0x00000001);
memcpy(out + 8 + sps_size, &in[11 + sps_size], pps_size);
*buf = out;
*size = out_size;
return 0;
}
const uint8_t *ff_avc_mp4_find_startcode(const uint8_t *start,
const uint8_t *end,
int nal_length_size)
{
unsigned int res = 0;
if (end - start < nal_length_size)
return NULL;
while (nal_length_size--)
res = (res << 8) | *start++;
if (res > end - start)
return NULL;
return start + res;
}
|
