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
|
/*
* Copyright (c) 2007 Benoit Fouet <benoit.fouet@free.fr>
*
* 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 "avcodec.h"
typedef struct H264BSFContext {
uint8_t length_size;
uint8_t first_idr;
uint8_t *sps_pps_data;
uint32_t size;
} H264BSFContext;
static void alloc_and_copy(uint8_t **poutbuf, int *poutbuf_size,
const uint8_t *sps_pps, uint32_t sps_pps_size,
const uint8_t *in, uint32_t in_size) {
uint32_t offset = *poutbuf_size;
uint8_t nal_header_size = offset ? 3 : 4;
*poutbuf_size += sps_pps_size+in_size+nal_header_size;
*poutbuf = av_realloc(*poutbuf, *poutbuf_size);
if (sps_pps)
memcpy(*poutbuf+offset, sps_pps, sps_pps_size);
memcpy(*poutbuf+sps_pps_size+nal_header_size+offset, in, in_size);
if (!offset)
AV_WB32(*poutbuf+sps_pps_size, 1);
else {
(*poutbuf+offset+sps_pps_size)[0] = (*poutbuf+offset+sps_pps_size)[1] = 0;
(*poutbuf+offset+sps_pps_size)[2] = 1;
}
}
static int h264_mp4toannexb_filter(AVBitStreamFilterContext *bsfc,
AVCodecContext *avctx, const char *args,
uint8_t **poutbuf, int *poutbuf_size,
const uint8_t *buf, int buf_size,
int keyframe) {
H264BSFContext *ctx = bsfc->priv_data;
uint8_t unit_type;
uint32_t nal_size, cumul_size = 0;
/* nothing to filter */
if (!avctx->extradata || avctx->extradata_size < 6) {
*poutbuf = (uint8_t*) buf;
*poutbuf_size = buf_size;
return 0;
}
/* retrieve sps and pps NAL units from extradata */
if (!ctx->sps_pps_data) {
uint16_t unit_size;
uint32_t total_size = 0;
uint8_t *out = NULL, unit_nb, sps_done = 0;
const uint8_t *extradata = avctx->extradata+4;
static const uint8_t nalu_header[4] = {0, 0, 0, 1};
/* retrieve length coded size */
ctx->length_size = (*extradata++ & 0x3) + 1;
if (ctx->length_size == 3)
return AVERROR(EINVAL);
/* retrieve sps and pps unit(s) */
unit_nb = *extradata++ & 0x1f; /* number of sps unit(s) */
if (!unit_nb) {
unit_nb = *extradata++; /* number of pps unit(s) */
sps_done++;
}
while (unit_nb--) {
unit_size = AV_RB16(extradata);
total_size += unit_size+4;
if (extradata+2+unit_size > avctx->extradata+avctx->extradata_size) {
av_free(out);
return AVERROR(EINVAL);
}
out = av_realloc(out, total_size);
if (!out)
return AVERROR(ENOMEM);
memcpy(out+total_size-unit_size-4, nalu_header, 4);
memcpy(out+total_size-unit_size, extradata+2, unit_size);
extradata += 2+unit_size;
if (!unit_nb && !sps_done++)
unit_nb = *extradata++; /* number of pps unit(s) */
}
ctx->sps_pps_data = out;
ctx->size = total_size;
ctx->first_idr = 1;
}
*poutbuf_size = 0;
*poutbuf = NULL;
do {
if (ctx->length_size == 1)
nal_size = buf[0];
else if (ctx->length_size == 2)
nal_size = AV_RB16(buf);
else
nal_size = AV_RB32(buf);
buf += ctx->length_size;
unit_type = *buf & 0x1f;
/* prepend only to the first type 5 NAL unit of an IDR picture */
if (ctx->first_idr && unit_type == 5) {
alloc_and_copy(poutbuf, poutbuf_size,
ctx->sps_pps_data, ctx->size,
buf, nal_size);
ctx->first_idr = 0;
}
else {
alloc_and_copy(poutbuf, poutbuf_size,
NULL, 0,
buf, nal_size);
if (!ctx->first_idr && unit_type == 1)
ctx->first_idr = 1;
}
buf += nal_size;
cumul_size += nal_size + ctx->length_size;
} while (cumul_size < buf_size);
return 1;
}
static void h264_mp4toannexb_close(AVBitStreamFilterContext *bsfc)
{
H264BSFContext *ctx = bsfc->priv_data;
av_freep(&ctx->sps_pps_data);
}
AVBitStreamFilter h264_mp4toannexb_bsf = {
"h264_mp4toannexb",
sizeof(H264BSFContext),
h264_mp4toannexb_filter,
h264_mp4toannexb_close,
};
|
