c927b47752071f73718757f2c95936620fff5c6e
2 * AVC helper functions for muxers
3 * Copyright (c) 2006 Baptiste Coudurier <baptiste.coudurier@smartjog.com>
5 * This file is part of FFmpeg.
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.
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.
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
22 #include "libavutil/intreadwrite.h"
27 static const uint8_t *ff_avc_find_startcode_internal(const uint8_t *p
, const uint8_t *end
)
29 const uint8_t *a
= p
+ 4 - ((intptr_t)p
& 3);
31 for (end
-= 3; p
< a
&& p
< end
; p
++) {
32 if (p
[0] == 0 && p
[1] == 0 && p
[2] == 1)
36 for (end
-= 3; p
< end
; p
+= 4) {
37 uint32_t x
= *(const uint32_t*)p
;
38 // if ((x - 0x01000100) & (~x) & 0x80008000) // little endian
39 // if ((x - 0x00010001) & (~x) & 0x00800080) // big endian
40 if ((x
- 0x01010101) & (~x
) & 0x80808080) { // generic
42 if (p
[0] == 0 && p
[2] == 1)
44 if (p
[2] == 0 && p
[3] == 1)
48 if (p
[2] == 0 && p
[4] == 1)
50 if (p
[4] == 0 && p
[5] == 1)
56 for (end
+= 3; p
< end
; p
++) {
57 if (p
[0] == 0 && p
[1] == 0 && p
[2] == 1)
64 const uint8_t *ff_avc_find_startcode(const uint8_t *p
, const uint8_t *end
){
65 const uint8_t *out
= ff_avc_find_startcode_internal(p
, end
);
66 if(p
<out
&& out
<end
&& !out
[-1]) out
--;
70 int ff_avc_parse_nal_units(AVIOContext
*pb
, const uint8_t *buf_in
, int size
)
72 const uint8_t *p
= buf_in
;
73 const uint8_t *end
= p
+ size
;
74 const uint8_t *nal_start
, *nal_end
;
77 nal_start
= ff_avc_find_startcode(p
, end
);
79 while (nal_start
< end
&& !*(nal_start
++));
83 nal_end
= ff_avc_find_startcode(nal_start
, end
);
84 avio_wb32(pb
, nal_end
- nal_start
);
85 avio_write(pb
, nal_start
, nal_end
- nal_start
);
86 size
+= 4 + nal_end
- nal_start
;
92 int ff_avc_parse_nal_units_buf(const uint8_t *buf_in
, uint8_t **buf
, int *size
)
95 int ret
= avio_open_dyn_buf(&pb
);
99 ff_avc_parse_nal_units(pb
, buf_in
, *size
);
102 *size
= avio_close_dyn_buf(pb
, buf
);
106 int ff_isom_write_avcc(AVIOContext
*pb
, const uint8_t *data
, int len
)
109 /* check for h264 start code */
110 if (AV_RB32(data
) == 0x00000001 ||
111 AV_RB24(data
) == 0x000001) {
112 uint8_t *buf
=NULL
, *end
, *start
;
113 uint32_t sps_size
=0, pps_size
=0;
114 uint8_t *sps
=0, *pps
=0;
116 int ret
= ff_avc_parse_nal_units_buf(data
, &buf
, &len
);
122 /* look for sps and pps */
123 while (end
- buf
> 4) {
126 size
= FFMIN(AV_RB32(buf
), end
- buf
- 4);
128 nal_type
= buf
[0] & 0x1f;
130 if (nal_type
== 7) { /* SPS */
133 } else if (nal_type
== 8) { /* PPS */
141 if (!sps
|| !pps
|| sps_size
< 4 || sps_size
> UINT16_MAX
|| pps_size
> UINT16_MAX
)
142 return AVERROR_INVALIDDATA
;
144 avio_w8(pb
, 1); /* version */
145 avio_w8(pb
, sps
[1]); /* profile */
146 avio_w8(pb
, sps
[2]); /* profile compat */
147 avio_w8(pb
, sps
[3]); /* level */
148 avio_w8(pb
, 0xff); /* 6 bits reserved (111111) + 2 bits nal size length - 1 (11) */
149 avio_w8(pb
, 0xe1); /* 3 bits reserved (111) + 5 bits number of sps (00001) */
151 avio_wb16(pb
, sps_size
);
152 avio_write(pb
, sps
, sps_size
);
153 avio_w8(pb
, 1); /* number of pps */
154 avio_wb16(pb
, pps_size
);
155 avio_write(pb
, pps
, pps_size
);
158 avio_write(pb
, data
, len
);
164 int ff_avc_write_annexb_extradata(const uint8_t *in
, uint8_t **buf
, int *size
)
166 uint16_t sps_size
, pps_size
;
171 if (*size
>= 4 && (AV_RB32(in
) == 0x00000001 || AV_RB24(in
) == 0x000001))
173 if (*size
< 11 || in
[0] != 1)
174 return AVERROR_INVALIDDATA
;
176 sps_size
= AV_RB16(&in
[6]);
177 if (11 + sps_size
> *size
)
178 return AVERROR_INVALIDDATA
;
179 pps_size
= AV_RB16(&in
[9 + sps_size
]);
180 if (11 + sps_size
+ pps_size
> *size
)
181 return AVERROR_INVALIDDATA
;
182 out_size
= 8 + sps_size
+ pps_size
;
183 out
= av_mallocz(out_size
);
185 return AVERROR(ENOMEM
);
186 AV_WB32(&out
[0], 0x00000001);
187 memcpy(out
+ 4, &in
[8], sps_size
);
188 AV_WB32(&out
[4 + sps_size
], 0x00000001);
189 memcpy(out
+ 8 + sps_size
, &in
[11 + sps_size
], pps_size
);
195 const uint8_t *ff_avc_mp4_find_startcode(const uint8_t *start
,
199 unsigned int res
= 0;
201 if (end
- start
< nal_length_size
)
203 while (nal_length_size
--)
204 res
= (res
<< 8) | *start
++;
206 if (res
> end
- start
)