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
131
132
133
134
135
|
/*
Copyright (C) 2021 Carl Hetherington <cth@carlh.net>
This file is part of DCP-o-matic.
DCP-o-matic is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
DCP-o-matic is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with DCP-o-matic. If not, see <http://www.gnu.org/licenses/>.
*/
#include "dcpomatic_assert.h"
#include "exceptions.h"
#include "image.h"
#include <jpeglib.h>
#include "i18n.h"
using std::shared_ptr;
struct destination_mgr
{
jpeg_destination_mgr pub;
std::vector<uint8_t>* data;
};
static void
init_destination (j_compress_ptr)
{
}
/* Empty the output buffer (i.e. make more space for data); we'll make
* the output buffer bigger instead.
*/
static boolean
empty_output_buffer (j_compress_ptr state)
{
auto dest = reinterpret_cast<destination_mgr*> (state->dest);
auto const old_size = dest->data->size();
dest->data->resize (old_size * 2);
dest->pub.next_output_byte = dest->data->data() + old_size;
dest->pub.free_in_buffer = old_size;
return TRUE;
}
static void
term_destination (j_compress_ptr state)
{
auto dest = reinterpret_cast<destination_mgr*> (state->dest);
dest->data->resize (dest->data->size() - dest->pub.free_in_buffer);
}
void
error_exit (j_common_ptr)
{
throw EncodeError (N_("JPEG encoding error"));
}
dcp::ArrayData
image_as_jpeg (shared_ptr<const Image> image, int quality)
{
if (image->pixel_format() != AV_PIX_FMT_RGB24) {
return image_as_jpeg(
Image::ensure_alignment(image, Image::Alignment::PADDED)->convert_pixel_format(dcp::YUVToRGB::REC709, AV_PIX_FMT_RGB24, Image::Alignment::PADDED, false),
quality
);
}
struct jpeg_compress_struct compress;
struct jpeg_error_mgr error;
compress.err = jpeg_std_error (&error);
error.error_exit = error_exit;
jpeg_create_compress (&compress);
auto mgr = new destination_mgr;
compress.dest = reinterpret_cast<jpeg_destination_mgr*>(mgr);
mgr->pub.init_destination = init_destination;
mgr->pub.empty_output_buffer = empty_output_buffer;
mgr->pub.term_destination = term_destination;
std::vector<uint8_t> data(4096);
mgr->data = &data;
mgr->pub.next_output_byte = data.data();
mgr->pub.free_in_buffer = data.size();
compress.image_width = image->size().width;
compress.image_height = image->size().height;
compress.input_components = 3;
compress.in_color_space = JCS_RGB;
jpeg_set_defaults (&compress);
jpeg_set_quality (&compress, quality, TRUE);
jpeg_start_compress (&compress, TRUE);
JSAMPROW row[1];
auto const source_data = image->data()[0];
auto const source_stride = image->stride()[0];
for (auto y = 0U; y < compress.image_height; ++y) {
row[0] = source_data + y * source_stride;
jpeg_write_scanlines (&compress, row, 1);
}
jpeg_finish_compress (&compress);
delete mgr;
jpeg_destroy_compress (&compress);
return dcp::ArrayData (data.data(), data.size());
}
|
