FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavcodec/av1_parse.h
Date: 2025-04-29 22:51:50
Exec Total Coverage
Lines: 37 41 90.2%
Functions: 2 2 100.0%
Branches: 24 30 80.0%
Line Branch Exec Source
1 /*
2 * AV1 common parsing code
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21 #ifndef AVCODEC_AV1_PARSE_H
22 #define AVCODEC_AV1_PARSE_H
23
24 #include <limits.h>
25 #include <stdint.h>
26
27 #include "libavutil/error.h"
28 #include "libavutil/intmath.h"
29 #include "libavutil/macros.h"
30
31 #include "av1.h"
32 #include "get_bits.h"
33 #include "leb.h"
34
35 // OBU header fields + max leb128 length
36 #define MAX_OBU_HEADER_SIZE (2 + 8)
37
38 typedef struct AV1OBU {
39 /** Size of payload */
40 int size;
41 const uint8_t *data;
42
43 /**
44 * Size, in bits, of just the data, excluding the trailing_one_bit and
45 * any trailing padding.
46 */
47 int size_bits;
48
49 /** Size of entire OBU, including header */
50 int raw_size;
51 const uint8_t *raw_data;
52
53 int type;
54
55 int temporal_id;
56 int spatial_id;
57 } AV1OBU;
58
59 /** An input packet split into OBUs */
60 typedef struct AV1Packet {
61 AV1OBU *obus;
62 int nb_obus;
63 int obus_allocated;
64 unsigned obus_allocated_size;
65 } AV1Packet;
66
67 /**
68 * Extract an OBU from a raw bitstream.
69 *
70 * @note This function does not copy or store any bitstream data. All
71 * the pointers in the AV1OBU structure will be valid as long
72 * as the input buffer also is.
73 */
74 int ff_av1_extract_obu(AV1OBU *obu, const uint8_t *buf, int length,
75 void *logctx);
76
77 /**
78 * Split an input packet into OBUs.
79 *
80 * @note This function does not copy or store any bitstream data. All
81 * the pointers in the AV1Packet structure will be valid as
82 * long as the input buffer also is.
83 */
84 int ff_av1_packet_split(AV1Packet *pkt, const uint8_t *buf, int length,
85 void *logctx);
86
87 /**
88 * Free all the allocated memory in the packet.
89 */
90 void ff_av1_packet_uninit(AV1Packet *pkt);
91
92 1550 static inline int parse_obu_header(const uint8_t *buf, int buf_size,
93 int64_t *obu_size, int *start_pos, int *type,
94 int *temporal_id, int *spatial_id)
95 {
96 GetBitContext gb;
97 int ret, extension_flag, has_size_flag;
98 int64_t size;
99
100 1550 ret = init_get_bits8(&gb, buf, FFMIN(buf_size, MAX_OBU_HEADER_SIZE));
101
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 1550 if (ret < 0)
102 ✗ return ret;
103
104
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 1550 if (get_bits1(&gb) != 0) // obu_forbidden_bit
105 33 return AVERROR_INVALIDDATA;
106
107 1517 *type = get_bits(&gb, 4);
108 1517 extension_flag = get_bits1(&gb);
109 1517 has_size_flag = get_bits1(&gb);
110 1517 skip_bits1(&gb); // obu_reserved_1bit
111
112
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 1517 if (extension_flag) {
113 1084 *temporal_id = get_bits(&gb, 3);
114 1084 *spatial_id = get_bits(&gb, 2);
115 1084 skip_bits(&gb, 3); // extension_header_reserved_3bits
116 } else {
117 433 *temporal_id = *spatial_id = 0;
118 }
119
120 1346 *obu_size = has_size_flag ? get_leb128(&gb)
121
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 1517 : buf_size - 1 - extension_flag;
122
123
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 1517 if (get_bits_left(&gb) < 0)
124 42 return AVERROR_INVALIDDATA;
125
126 1475 *start_pos = get_bits_count(&gb) / 8;
127
128 1475 size = *obu_size + *start_pos;
129
130
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 1475 if (size > buf_size)
131 663 return AVERROR_INVALIDDATA;
132
133 812 return size;
134 }
135
136 141 static inline int get_obu_bit_length(const uint8_t *buf, int size, int type)
137 {
138 int v;
139
140 /* There are no trailing bits on these */
141
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 141 if (type == AV1_OBU_TILE_GROUP ||
142
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 128 type == AV1_OBU_TILE_LIST ||
143 type == AV1_OBU_FRAME) {
144
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 56 if (size > INT_MAX / 8)
145 ✗ return AVERROR(ERANGE);
146 else
147 56 return size * 8;
148 }
149
150
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 85 while (size > 0 && buf[size - 1] == 0)
151 ✗ size--;
152
153
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 85 if (!size)
154 44 return 0;
155
156 41 v = buf[size - 1];
157
158
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 41 if (size > INT_MAX / 8)
159 ✗ return AVERROR(ERANGE);
160 41 size *= 8;
161
162 /* Remove the trailing_one_bit and following trailing zeros */
163
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 41 if (v)
164 41 size -= ff_ctz(v) + 1;
165
166 41 return size;
167 }
168
169 AVRational ff_av1_framerate(int64_t ticks_per_frame, int64_t units_per_tick,
170 int64_t time_scale);
171
172 #endif /* AVCODEC_AV1_PARSE_H */
173