1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
|
/* SPDX-License-Identifier: LGPL-2.1+ */
/*
* Copyright 2016 Tom aan de Wiel
* Copyright 2018 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
*/
#ifndef CODEC_FWHT_H
#define CODEC_FWHT_H
#include <linux/types.h>
#include <linux/bitops.h>
#include <asm/byteorder.h>
/*
* The compressed format consists of a fwht_cframe_hdr struct followed by the
* compressed frame data. The header contains the size of that data.
* Each Y, Cb and Cr plane is compressed separately. If the compressed
* size of each plane becomes larger than the uncompressed size, then
* that plane is stored uncompressed and the corresponding bit is set
* in the flags field of the header.
*
* Each compressed plane consists of macroblocks and each macroblock
* is run-length-encoded. Each macroblock starts with a 16 bit value.
* Bit 15 indicates if this is a P-coded macroblock (1) or not (0).
* P-coded macroblocks contain a delta against the previous frame.
*
* Bits 1-12 contain a number. If non-zero, then this same macroblock
* repeats that number of times. This results in a high degree of
* compression for generated images like colorbars.
*
* Following this macroblock header the MB coefficients are run-length
* encoded: the top 12 bits contain the coefficient, the bottom 4 bits
* tell how many times this coefficient occurs. The value 0xf indicates
* that the remainder of the macroblock should be filled with zeroes.
*
* All 16 and 32 bit values are stored in big-endian (network) order.
*
* Each fwht_cframe_hdr starts with an 8 byte magic header that is
* guaranteed not to occur in the compressed frame data. This header
* can be used to sync to the next frame.
*
* This codec uses the Fast Walsh Hadamard Transform. Tom aan de Wiel
* developed this as part of a university project, specifically for use
* with this driver. His project report can be found here:
*
* https://hverkuil.home.xs4all.nl/fwht.pdf
*/
/*
* This is a sequence of 8 bytes with the low 4 bits set to 0xf.
*
* This sequence cannot occur in the encoded data
*
* Note that these two magic values are symmetrical so endian issues here.
*/
#define FWHT_MAGIC1 0x4f4f4f4f
#define FWHT_MAGIC2 0xffffffff
#define FWHT_VERSION 2
/* Set if this is an interlaced format */
#define FWHT_FL_IS_INTERLACED BIT(0)
/* Set if this is a bottom-first (NTSC) interlaced format */
#define FWHT_FL_IS_BOTTOM_FIRST BIT(1)
/* Set if each 'frame' contains just one field */
#define FWHT_FL_IS_ALTERNATE BIT(2)
/*
* If FWHT_FL_IS_ALTERNATE was set, then this is set if this
* 'frame' is the bottom field, else it is the top field.
*/
#define FWHT_FL_IS_BOTTOM_FIELD BIT(3)
/* Set if this frame is uncompressed */
#define FWHT_FL_LUMA_IS_UNCOMPRESSED BIT(4)
#define FWHT_FL_CB_IS_UNCOMPRESSED BIT(5)
#define FWHT_FL_CR_IS_UNCOMPRESSED BIT(6)
#define FWHT_FL_CHROMA_FULL_HEIGHT BIT(7)
#define FWHT_FL_CHROMA_FULL_WIDTH BIT(8)
/* A 4-values flag - the number of components - 1 */
#define FWHT_FL_COMPONENTS_NUM_MSK GENMASK(17, 16)
#define FWHT_FL_COMPONENTS_NUM_OFFSET 16
struct fwht_cframe_hdr {
u32 magic1;
u32 magic2;
__be32 version;
__be32 width, height;
__be32 flags;
__be32 colorspace;
__be32 xfer_func;
__be32 ycbcr_enc;
__be32 quantization;
__be32 size;
};
struct fwht_cframe {
unsigned int width, height;
u16 i_frame_qp;
u16 p_frame_qp;
__be16 *rlc_data;
s16 coeffs[8 * 8];
s16 de_coeffs[8 * 8];
s16 de_fwht[8 * 8];
u32 size;
};
struct fwht_raw_frame {
unsigned int width, height;
unsigned int width_div;
unsigned int height_div;
unsigned int luma_alpha_step;
unsigned int chroma_step;
unsigned int components_num;
u8 *luma, *cb, *cr, *alpha;
};
#define FWHT_FRAME_PCODED BIT(0)
#define FWHT_FRAME_UNENCODED BIT(1)
#define FWHT_LUMA_UNENCODED BIT(2)
#define FWHT_CB_UNENCODED BIT(3)
#define FWHT_CR_UNENCODED BIT(4)
u32 fwht_encode_frame(struct fwht_raw_frame *frm,
struct fwht_raw_frame *ref_frm,
struct fwht_cframe *cf,
bool is_intra, bool next_is_intra);
void fwht_decode_frame(struct fwht_cframe *cf, struct fwht_raw_frame *ref,
u32 hdr_flags, unsigned int components_num);
#endif
|
