blob: 094a95821f396327ff0a3398aef53ca4f10a7bcd
1 | /* |
2 | * AVC helper functions for muxers |
3 | * Copyright (c) 2006 Baptiste Coudurier <baptiste.coudurier@smartjog.com> |
4 | * |
5 | * This file is part of FFmpeg. |
6 | * |
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. |
11 | * |
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. |
16 | * |
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 |
20 | */ |
21 | |
22 | #include "libavutil/intreadwrite.h" |
23 | #include "avformat.h" |
24 | #include "avio.h" |
25 | #include "avc.h" |
26 | |
27 | static const uint8_t *ff_avc_find_startcode_internal(const uint8_t *p, const uint8_t *end) |
28 | { |
29 | const uint8_t *a = p + 4 - ((intptr_t)p & 3); |
30 | |
31 | for (end -= 3; p < a && p < end; p++) { |
32 | if (p[0] == 0 && p[1] == 0 && p[2] == 1) |
33 | return p; |
34 | } |
35 | |
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 |
41 | if (p[1] == 0) { |
42 | if (p[0] == 0 && p[2] == 1) |
43 | return p; |
44 | if (p[2] == 0 && p[3] == 1) |
45 | return p+1; |
46 | } |
47 | if (p[3] == 0) { |
48 | if (p[2] == 0 && p[4] == 1) |
49 | return p+2; |
50 | if (p[4] == 0 && p[5] == 1) |
51 | return p+3; |
52 | } |
53 | } |
54 | } |
55 | |
56 | for (end += 3; p < end; p++) { |
57 | if (p[0] == 0 && p[1] == 0 && p[2] == 1) |
58 | return p; |
59 | } |
60 | |
61 | return end + 3; |
62 | } |
63 | |
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--; |
67 | return out; |
68 | } |
69 | |
70 | int ff_avc_parse_nal_units(AVIOContext *pb, const uint8_t *buf_in, int size) |
71 | { |
72 | const uint8_t *p = buf_in; |
73 | const uint8_t *end = p + size; |
74 | const uint8_t *nal_start, *nal_end; |
75 | |
76 | size = 0; |
77 | nal_start = ff_avc_find_startcode(p, end); |
78 | for (;;) { |
79 | while (nal_start < end && !*(nal_start++)); |
80 | if (nal_start == end) |
81 | break; |
82 | |
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; |
87 | nal_start = nal_end; |
88 | } |
89 | return size; |
90 | } |
91 | |
92 | int ff_avc_parse_nal_units_buf(const uint8_t *buf_in, uint8_t **buf, int *size) |
93 | { |
94 | AVIOContext *pb; |
95 | int ret = avio_open_dyn_buf(&pb); |
96 | if(ret < 0) |
97 | return ret; |
98 | |
99 | ff_avc_parse_nal_units(pb, buf_in, *size); |
100 | |
101 | av_freep(buf); |
102 | *size = avio_close_dyn_buf(pb, buf); |
103 | return 0; |
104 | } |
105 | |
106 | int ff_isom_write_avcc(AVIOContext *pb, const uint8_t *data, int len) |
107 | { |
108 | if (len > 6) { |
109 | /* check for H.264 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; |
115 | |
116 | int ret = ff_avc_parse_nal_units_buf(data, &buf, &len); |
117 | if (ret < 0) |
118 | return ret; |
119 | start = buf; |
120 | end = buf + len; |
121 | |
122 | /* look for sps and pps */ |
123 | while (end - buf > 4) { |
124 | uint32_t size; |
125 | uint8_t nal_type; |
126 | size = FFMIN(AV_RB32(buf), end - buf - 4); |
127 | buf += 4; |
128 | nal_type = buf[0] & 0x1f; |
129 | |
130 | if (nal_type == 7) { /* SPS */ |
131 | sps = buf; |
132 | sps_size = size; |
133 | } else if (nal_type == 8) { /* PPS */ |
134 | pps = buf; |
135 | pps_size = size; |
136 | } |
137 | |
138 | buf += size; |
139 | } |
140 | |
141 | if (!sps || !pps || sps_size < 4 || sps_size > UINT16_MAX || pps_size > UINT16_MAX) |
142 | return AVERROR_INVALIDDATA; |
143 | |
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) */ |
150 | |
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); |
156 | av_free(start); |
157 | } else { |
158 | avio_write(pb, data, len); |
159 | } |
160 | } |
161 | return 0; |
162 | } |
163 | |
164 | int ff_avc_write_annexb_extradata(const uint8_t *in, uint8_t **buf, int *size) |
165 | { |
166 | uint16_t sps_size, pps_size; |
167 | uint8_t *out; |
168 | int out_size; |
169 | |
170 | *buf = NULL; |
171 | if (*size >= 4 && (AV_RB32(in) == 0x00000001 || AV_RB24(in) == 0x000001)) |
172 | return 0; |
173 | if (*size < 11 || in[0] != 1) |
174 | return AVERROR_INVALIDDATA; |
175 | |
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 + AV_INPUT_BUFFER_PADDING_SIZE); |
184 | if (!out) |
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); |
190 | *buf = out; |
191 | *size = out_size; |
192 | return 0; |
193 | } |
194 | |
195 | const uint8_t *ff_avc_mp4_find_startcode(const uint8_t *start, |
196 | const uint8_t *end, |
197 | int nal_length_size) |
198 | { |
199 | unsigned int res = 0; |
200 | |
201 | if (end - start < nal_length_size) |
202 | return NULL; |
203 | while (nal_length_size--) |
204 | res = (res << 8) | *start++; |
205 | |
206 | if (res > end - start) |
207 | return NULL; |
208 | |
209 | return start + res; |
210 | } |
211 |