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.top_field_order_cnt: top field order count 19 * @refs.bottom_field_order_cnt: bottom field order count 20 * @refs.frame_num: reference frame 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 * @cur_pic_fields: fields present in the frame being decoded 25 * @unordered_reflist: unordered list of references. Will be used to generate 26 * ordered P/B0/B1 lists 27 * @num_valid: number of valid references in the refs array 28 * 29 * This object stores the context of the P/B0/B1 reference list builder. 30 * This procedure is described in section '8.2.4 Decoding process for reference 31 * picture lists construction' of the H264 spec. 32 */ 33 struct v4l2_h264_reflist_builder { 34 struct { 35 s32 top_field_order_cnt; 36 s32 bottom_field_order_cnt; 37 int frame_num; 38 u16 longterm : 1; 39 } refs[V4L2_H264_NUM_DPB_ENTRIES]; 40 41 s32 cur_pic_order_count; 42 u8 cur_pic_fields; 43 44 struct v4l2_h264_reference unordered_reflist[V4L2_H264_REF_LIST_LEN]; 45 u8 num_valid; 46 }; 47 48 void 49 v4l2_h264_init_reflist_builder(struct v4l2_h264_reflist_builder *b, 50 const struct v4l2_ctrl_h264_decode_params *dec_params, 51 const struct v4l2_ctrl_h264_sps *sps, 52 const struct v4l2_h264_dpb_entry dpb[V4L2_H264_NUM_DPB_ENTRIES]); 53 54 /** 55 * v4l2_h264_build_b_ref_lists() - Build the B0/B1 reference lists 56 * 57 * @builder: reference list builder context 58 * @b0_reflist: 32 sized array used to store the B0 reference list. Each entry 59 * is a v4l2_h264_reference structure 60 * @b1_reflist: 32 sized array used to store the B1 reference list. Each entry 61 * is a v4l2_h264_reference structure 62 * 63 * This functions builds the B0/B1 reference lists. This procedure is described 64 * in section '8.2.4 Decoding process for reference picture lists construction' 65 * of the H264 spec. This function can be used by H264 decoder drivers that 66 * need to pass B0/B1 reference lists to the hardware. 67 */ 68 void 69 v4l2_h264_build_b_ref_lists(const struct v4l2_h264_reflist_builder *builder, 70 struct v4l2_h264_reference *b0_reflist, 71 struct v4l2_h264_reference *b1_reflist); 72 73 /** 74 * v4l2_h264_build_p_ref_list() - Build the P reference list 75 * 76 * @builder: reference list builder context 77 * @reflist: 32 sized array used to store the P reference list. Each entry 78 * is a v4l2_h264_reference structure 79 * 80 * This functions builds the P reference lists. This procedure is describe in 81 * section '8.2.4 Decoding process for reference picture lists construction' 82 * of the H264 spec. This function can be used by H264 decoder drivers that 83 * need to pass a P reference list to the hardware. 84 */ 85 void 86 v4l2_h264_build_p_ref_list(const struct v4l2_h264_reflist_builder *builder, 87 struct v4l2_h264_reference *reflist); 88 89 #endif /* _MEDIA_V4L2_H264_H */ 90