LXR linux/drivers/media/platform/allegro-dvt/nal-rbsp.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2/*
   3 * Copyright (C) 2019-2020 Pengutronix, Michael Tretter <kernel@pengutronix.de>
   4 */
   5
   6#ifndef __NAL_RBSP_H__
   7#define __NAL_RBSP_H__
   8
   9#include <linux/kernel.h>
  10#include <linux/types.h>
  11
  12struct rbsp;
  13
  14struct nal_rbsp_ops {
  15        int (*rbsp_bit)(struct rbsp *rbsp, int *val);
  16        int (*rbsp_bits)(struct rbsp *rbsp, int n, unsigned int *val);
  17        int (*rbsp_uev)(struct rbsp *rbsp, unsigned int *val);
  18        int (*rbsp_sev)(struct rbsp *rbsp, int *val);
  19};
  20
  21/**
  22 * struct rbsp - State object for handling a raw byte sequence payload
  23 * @data: pointer to the data of the rbsp
  24 * @size: maximum size of the data of the rbsp
  25 * @pos: current bit position inside the rbsp
  26 * @num_consecutive_zeros: number of zeros before @pos
  27 * @ops: per datatype functions for interacting with the rbsp
  28 * @error: an error occurred while handling the rbsp
  29 *
  30 * This struct is passed around the various parsing functions and tracks the
  31 * current position within the raw byte sequence payload.
  32 *
  33 * The @ops field allows to separate the operation, i.e., reading/writing a
  34 * value from/to that rbsp, from the structure of the NAL unit. This allows to
  35 * have a single function for iterating the NAL unit, while @ops has function
  36 * pointers for handling each type in the rbsp.
  37 */
  38struct rbsp {
  39        u8 *data;
  40        size_t size;
  41        unsigned int pos;
  42        unsigned int num_consecutive_zeros;
  43        struct nal_rbsp_ops *ops;
  44        int error;
  45};
  46
  47extern struct nal_rbsp_ops write;
  48extern struct nal_rbsp_ops read;
  49
  50void rbsp_init(struct rbsp *rbsp, void *addr, size_t size,
  51               struct nal_rbsp_ops *ops);
  52void rbsp_unsupported(struct rbsp *rbsp);
  53
  54void rbsp_bit(struct rbsp *rbsp, int *value);
  55void rbsp_bits(struct rbsp *rbsp, int n, int *value);
  56void rbsp_uev(struct rbsp *rbsp, unsigned int *value);
  57void rbsp_sev(struct rbsp *rbsp, int *value);
  58
  59void rbsp_trailing_bits(struct rbsp *rbsp);
  60
  61#endif /* __NAL_RBSP_H__ */
  62