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1 /*
2  * Copyright (c) 2018, Alliance for Open Media. All rights reserved
3  *
4  * This source code is subject to the terms of the BSD 2 Clause License and
5  * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
6  * was not distributed with this source code in the LICENSE file, you can
7  * obtain it at www.aomedia.org/license/software. If the Alliance for Open
8  * Media Patent License 1.0 was not distributed with this source code in the
9  * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
10  */
11 #ifndef AOM_COMMON_AV1_CONFIG_H_
12 #define AOM_COMMON_AV1_CONFIG_H_
13 
14 #include "aom/aom_integer.h"
15 
16 #ifdef __cplusplus
17 extern "C" {
18 #endif
19 
20 // Struct representing ISOBMFF/Matroska AV1 config. See:
21 // https://aomediacodec.github.io/av1-isobmff/#av1codecconfigurationbox-syntax
22 //
23 // The AV1 config has the following format:
24 //
25 // unsigned int (1) marker = 1;
26 // unsigned int (7) version = 1;
27 // unsigned int (3) seq_profile;
28 // unsigned int (5) seq_level_idx_0;
29 // unsigned int (1) seq_tier_0;
30 // unsigned int (1) high_bitdepth;
31 // unsigned int (1) twelve_bit;
32 // unsigned int (1) monochrome;
33 // unsigned int (1) chroma_subsampling_x;
34 // unsigned int (1) chroma_subsampling_y;
35 // unsigned int (2) chroma_sample_position;
36 // unsigned int (3) reserved = 0;
37 //
38 // unsigned int (1) initial_presentation_delay_present;
39 // if (initial_presentation_delay_present) {
40 //   unsigned int (4) initial_presentation_delay_minus_one;
41 // } else {
42 //   unsigned int (4) reserved = 0;
43 // }
44 //
45 // unsigned int (8)[] configOBUs;
46 //
47 // Note: get_av1config_from_obu() does not currently store 'configOBUs' data, so
48 // the field is omitted.
49 typedef struct _Av1Config {
50   uint8_t marker;
51   uint8_t version;
52   uint8_t seq_profile;
53   uint8_t seq_level_idx_0;
54   uint8_t seq_tier_0;
55   uint8_t high_bitdepth;
56   uint8_t twelve_bit;
57   uint8_t monochrome;
58   uint8_t chroma_subsampling_x;
59   uint8_t chroma_subsampling_y;
60   uint8_t chroma_sample_position;
61   uint8_t initial_presentation_delay_present;
62   uint8_t initial_presentation_delay_minus_one;
63 } Av1Config;
64 
65 // Attempts to parse a Sequence Header OBU and set the paramenters of 'config'.
66 // Returns 0 upon success, and -1 upon failure. 'buffer' can contain multiple
67 // OBUs, but the Sequence Header OBU must be the first OBU within the buffer.
68 int get_av1config_from_obu(const uint8_t *buffer, size_t length, int is_annexb,
69                            Av1Config *config);
70 
71 // Attempts to parse an AV1 config from 'buffer'. Returns 0 upon success.
72 // Returns -1 when 'buffer_length' is less than 4, when passed NULL pointers, or
73 // when parsing of 'buffer' fails.
74 int read_av1config(const uint8_t *buffer, size_t buffer_length,
75                    size_t *bytes_read, Av1Config *config);
76 
77 // Writes 'config' to 'buffer'. Returns 0 upon successful write to 'buffer'.
78 // Returns -1 when passed NULL pointers or when 'capacity' insufficient.
79 int write_av1config(const Av1Config *config, size_t capacity,
80                     size_t *bytes_written, uint8_t *buffer);
81 
82 #ifdef __cplusplus
83 } /* extern "C" */
84 #endif
85 
86 #endif  // AOM_COMMON_AV1_CONFIG_H_
87