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 | |