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 */ 32 struct 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 44 void 45 v4l2_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 */ 64 void 65 v4l2_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_b_ref_lists() - Build the P reference list 70 * 71 * @builder: reference list builder context 72 * @p_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 */ 80 void 81 v4l2_h264_build_p_ref_list(const struct v4l2_h264_reflist_builder *builder, 82 u8 *reflist); 83 84 #endif /* _MEDIA_V4L2_H264_H */ 85