LXR linux/include/media/v4l2-h264.h

   1/* SPDX-License-Identifier: GPL-2.0-or-later */
   2/*
   3 * Helper functions for H264 codecs.
   4 *
   5 * Copyright (c) 2019 Collabora, Ltd.
   6 *
   7 * Author: Boris Brezillon <boris.brezillon@collabora.com>
   8 */
   9
  10#ifndef _MEDIA_V4L2_H264_H
  11#define _MEDIA_V4L2_H264_H
  12
  13#include <media/v4l2-ctrls.h>
  14
  15/**
  16 * struct v4l2_h264_reflist_builder - Reference list builder object
  17 *
  18 * @refs.pic_order_count: reference picture order count
  19 * @refs.frame_num: reference frame number
  20 * @refs.pic_num: reference picture number
  21 * @refs.longterm: set to true for a long term reference
  22 * @refs: array of references
  23 * @cur_pic_order_count: picture order count of the frame being decoded
  24 * @unordered_reflist: unordered list of references. Will be used to generate
  25 *                     ordered P/B0/B1 lists
  26 * @num_valid: number of valid references in the refs array
  27 *
  28 * This object stores the context of the P/B0/B1 reference list builder.
  29 * This procedure is described in section '8.2.4 Decoding process for reference
  30 * picture lists construction' of the H264 spec.
  31 */
  32struct v4l2_h264_reflist_builder {
  33        struct {
  34                s32 pic_order_count;
  35                int frame_num;
  36                u32 pic_num;
  37                u16 longterm : 1;
  38        } refs[V4L2_H264_NUM_DPB_ENTRIES];
  39        s32 cur_pic_order_count;
  40        u8 unordered_reflist[V4L2_H264_NUM_DPB_ENTRIES];
  41        u8 num_valid;
  42};
  43
  44void
  45v4l2_h264_init_reflist_builder(struct v4l2_h264_reflist_builder *b,
  46                const struct v4l2_ctrl_h264_decode_params *dec_params,
  47                const struct v4l2_ctrl_h264_sps *sps,
  48                const struct v4l2_h264_dpb_entry dpb[V4L2_H264_NUM_DPB_ENTRIES]);
  49
  50/**
  51 * v4l2_h264_build_b_ref_lists() - Build the B0/B1 reference lists
  52 *
  53 * @builder: reference list builder context
  54 * @b0_reflist: 16-bytes array used to store the B0 reference list. Each entry
  55 *              is an index in the DPB
  56 * @b1_reflist: 16-bytes array used to store the B1 reference list. Each entry
  57 *              is an index in the DPB
  58 *
  59 * This functions builds the B0/B1 reference lists. This procedure is described
  60 * in section '8.2.4 Decoding process for reference picture lists construction'
  61 * of the H264 spec. This function can be used by H264 decoder drivers that
  62 * need to pass B0/B1 reference lists to the hardware.
  63 */
  64void
  65v4l2_h264_build_b_ref_lists(const struct v4l2_h264_reflist_builder *builder,
  66                            u8 *b0_reflist, u8 *b1_reflist);
  67
  68/**
  69 * v4l2_h264_build_p_ref_list() - Build the P reference list
  70 *
  71 * @builder: reference list builder context
  72 * @reflist: 16-bytes array used to store the P reference list. Each entry
  73 *           is an index in the DPB
  74 *
  75 * This functions builds the P reference lists. This procedure is describe in
  76 * section '8.2.4 Decoding process for reference picture lists construction'
  77 * of the H264 spec. This function can be used by H264 decoder drivers that
  78 * need to pass a P reference list to the hardware.
  79 */
  80void
  81v4l2_h264_build_p_ref_list(const struct v4l2_h264_reflist_builder *builder,
  82                           u8 *reflist);
  83
  84#endif /* _MEDIA_V4L2_H264_H */
  85