common/av1_config.h

   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_