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
  12 struct rbsp;
  13
  14 struct 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  */
  38 struct 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
  47 extern struct nal_rbsp_ops write;
  48 extern struct nal_rbsp_ops read;
  49
  50 void rbsp_init(struct rbsp *rbsp, void *addr, size_t size,
  51                struct nal_rbsp_ops *ops);
  52 void rbsp_unsupported(struct rbsp *rbsp);
  53
  54 void rbsp_bit(struct rbsp *rbsp, int *value);
  55 void rbsp_bits(struct rbsp *rbsp, int n, int *value);
  56 void rbsp_uev(struct rbsp *rbsp, unsigned int *value);
  57 void rbsp_sev(struct rbsp *rbsp, int *value);
  58
  59 void rbsp_trailing_bits(struct rbsp *rbsp);
  60
  61 #endif /* __NAL_RBSP_H__ */