1 /* SPDX-License-Identifier: LGPL-2.1+ */ 2 /* 3 * Copyright 2016 Tom aan de Wiel 4 * Copyright 2018 Cisco Systems, Inc. and/or its affiliates. All rights reserved. 5 */ 6 7 #ifndef CODEC_FWHT_H 8 #define CODEC_FWHT_H 9 10 #include <linux/types.h> 11 #include <linux/bitops.h> 12 #include <asm/byteorder.h> 13 14 /* 15 * The compressed format consists of a fwht_cframe_hdr struct followed by the 16 * compressed frame data. The header contains the size of that data. 17 * Each Y, Cb and Cr plane is compressed separately. If the compressed 18 * size of each plane becomes larger than the uncompressed size, then 19 * that plane is stored uncompressed and the corresponding bit is set 20 * in the flags field of the header. 21 * 22 * Each compressed plane consists of macroblocks and each macroblock 23 * is run-length-encoded. Each macroblock starts with a 16 bit value. 24 * Bit 15 indicates if this is a P-coded macroblock (1) or not (0). 25 * P-coded macroblocks contain a delta against the previous frame. 26 * 27 * Bits 1-12 contain a number. If non-zero, then this same macroblock 28 * repeats that number of times. This results in a high degree of 29 * compression for generated images like colorbars. 30 * 31 * Following this macroblock header the MB coefficients are run-length 32 * encoded: the top 12 bits contain the coefficient, the bottom 4 bits 33 * tell how many times this coefficient occurs. The value 0xf indicates 34 * that the remainder of the macroblock should be filled with zeroes. 35 * 36 * All 16 and 32 bit values are stored in big-endian (network) order. 37 * 38 * Each fwht_cframe_hdr starts with an 8 byte magic header that is 39 * guaranteed not to occur in the compressed frame data. This header 40 * can be used to sync to the next frame. 41 * 42 * This codec uses the Fast Walsh Hadamard Transform. Tom aan de Wiel 43 * developed this as part of a university project, specifically for use 44 * with this driver. His project report can be found here: 45 * 46 * https://hverkuil.home.xs4all.nl/fwht.pdf 47 */ 48 49 /* 50 * This is a sequence of 8 bytes with the low 4 bits set to 0xf. 51 * 52 * This sequence cannot occur in the encoded data 53 * 54 * Note that these two magic values are symmetrical so endian issues here. 55 */ 56 #define FWHT_MAGIC1 0x4f4f4f4f 57 #define FWHT_MAGIC2 0xffffffff 58 59 /* 60 * A macro to calculate the needed padding in order to make sure 61 * both luma and chroma components resolutions are rounded up to 62 * a multiple of 8 63 */ 64 #define vic_round_dim(dim, div) (round_up((dim) / (div), 8) * (div)) 65 66 struct fwht_cframe_hdr { 67 u32 magic1; 68 u32 magic2; 69 __be32 version; 70 __be32 width, height; 71 __be32 flags; 72 __be32 colorspace; 73 __be32 xfer_func; 74 __be32 ycbcr_enc; 75 __be32 quantization; 76 __be32 size; 77 }; 78 79 struct fwht_cframe { 80 u16 i_frame_qp; 81 u16 p_frame_qp; 82 __be16 *rlc_data; 83 s16 coeffs[8 * 8]; 84 s16 de_coeffs[8 * 8]; 85 s16 de_fwht[8 * 8]; 86 u32 size; 87 }; 88 89 struct fwht_raw_frame { 90 unsigned int width_div; 91 unsigned int height_div; 92 unsigned int luma_alpha_step; 93 unsigned int chroma_step; 94 unsigned int components_num; 95 u8 *buf; 96 u8 *luma, *cb, *cr, *alpha; 97 }; 98 99 #define FWHT_FRAME_PCODED BIT(0) 100 #define FWHT_FRAME_UNENCODED BIT(1) 101 #define FWHT_LUMA_UNENCODED BIT(2) 102 #define FWHT_CB_UNENCODED BIT(3) 103 #define FWHT_CR_UNENCODED BIT(4) 104 #define FWHT_ALPHA_UNENCODED BIT(5) 105 106 u32 fwht_encode_frame(struct fwht_raw_frame *frm, 107 struct fwht_raw_frame *ref_frm, 108 struct fwht_cframe *cf, 109 bool is_intra, bool next_is_intra, 110 unsigned int width, unsigned int height, 111 unsigned int stride, unsigned int chroma_stride); 112 bool fwht_decode_frame(struct fwht_cframe *cf, u32 hdr_flags, 113 unsigned int components_num, unsigned int width, 114 unsigned int height, const struct fwht_raw_frame *ref, 115 unsigned int ref_stride, unsigned int ref_chroma_stride, 116 struct fwht_raw_frame *dst, unsigned int dst_stride, 117 unsigned int dst_chroma_stride); 118 #endif 119