aboutsummaryrefslogtreecommitdiff
path: root/src/backend_libjpeg.c
blob: 34dfb43705b73b62c9b6dc1a78f6ae8548282908 (plain)
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
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
#include "backend.h"
#include "source.h"

#include <assert.h>
#include <stdlib.h>
#include <stdio.h>
#include <sys/mman.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>

#include <turbojpeg.h>

struct private {
  int fd;
  void *data;
  size_t len;
  tjhandle jpeg;
};

static void source_free(struct imv_source *src)
{
  pthread_mutex_lock(&src->busy);
  free(src->name);
  src->name = NULL;

  struct private *private = src->private;
  tjDestroy(private->jpeg);
  if (private->fd >= 0) {
    munmap(private->data, private->len);
    close(private->fd);
  } else {
    free(private->data);
  }
  private->data = NULL;

  free(src->private);
  src->private = NULL;

  pthread_mutex_unlock(&src->busy);
  pthread_mutex_destroy(&src->busy);
  free(src);
}

static struct imv_image *to_image(int width, int height, void *bitmap)
{
  struct imv_bitmap *bmp = malloc(sizeof *bmp);
  bmp->width = width;
  bmp->height = height;
  bmp->format = IMV_ABGR;
  bmp->data = bitmap;
  struct imv_image *image = imv_image_create_from_bitmap(bmp);
  return image;
}

static void report_error(struct imv_source *src)
{
  assert(src->callback);

  struct imv_source_message msg;
  msg.source = src;
  msg.user_data = src->user_data;
  msg.image = NULL;
  msg.error = "Internal error";

  pthread_mutex_unlock(&src->busy);
  src->callback(&msg);
}

static void send_bitmap(struct imv_source *src, void *bitmap)
{
  assert(src->callback);

  struct imv_source_message msg;
  msg.source = src;
  msg.user_data = src->user_data;
  msg.image = to_image(src->width, src->height, bitmap);
  msg.frametime = 0;
  msg.error = NULL;

  pthread_mutex_unlock(&src->busy);
  src->callback(&msg);
}

static void *load_image(struct imv_source *src)
{
  /* Don't run if this source is already active */
  if (pthread_mutex_trylock(&src->busy)) {
    return NULL;
  }

  struct private *private = src->private;

  void *bitmap = malloc(src->height * src->width * 4);
  int rcode = tjDecompress2(private->jpeg, private->data, private->len,
      bitmap, src->width, 0, src->height, TJPF_RGBA, TJFLAG_FASTDCT);

  if (rcode) {
    free(bitmap);
    report_error(src);
    return NULL;
  }

  send_bitmap(src, bitmap);
  return NULL;
}

static enum backend_result open_path(const char *path, struct imv_source **src)
{
  struct private private;

  private.fd = open(path, O_RDONLY);
  if (private.fd < 0) {
    return BACKEND_BAD_PATH;
  }

  off_t len = lseek(private.fd, 0, SEEK_END);
  if (len < 0) {
    close(private.fd);
    return BACKEND_BAD_PATH;
  }

  private.len = len;

  private.data = mmap(NULL, private.len, PROT_READ, MAP_PRIVATE, private.fd, 0);
  if (private.data == MAP_FAILED || !private.data) {
    close(private.fd);
    return BACKEND_BAD_PATH;
  }

  private.jpeg = tjInitDecompress();
  if (!private.jpeg) {
    munmap(private.data, private.len);
    close(private.fd);
    return BACKEND_UNSUPPORTED;
  }

  int width, height;
  int rcode = tjDecompressHeader(private.jpeg, private.data, private.len,
      &width, &height);
  if (rcode) {
    tjDestroy(private.jpeg);
    munmap(private.data, private.len);
    close(private.fd);
    return BACKEND_UNSUPPORTED;
  }

  struct imv_source *source = calloc(1, sizeof *source);
  source->name = strdup(path);
  source->width = width;
  source->height = height;
  source->num_frames = 1;
  source->next_frame = 1;
  pthread_mutex_init(&source->busy, NULL);
  source->load_first_frame = &load_image;
  source->load_next_frame = NULL;
  source->free = &source_free;
  source->callback = NULL;
  source->user_data = NULL;
  source->private = malloc(sizeof private);
  memcpy(source->private, &private, sizeof private);

  *src = source;
  return BACKEND_SUCCESS;
}

static enum backend_result open_memory(void *data, size_t len, struct imv_source **src)
{
  struct private private;

  private.fd = -1;
  private.data = data;
  private.len = len;

  private.jpeg = tjInitDecompress();
  if (!private.jpeg) {
    return BACKEND_UNSUPPORTED;
  }

  int width, height;
  int rcode = tjDecompressHeader(private.jpeg, private.data, private.len,
      &width, &height);
  if (rcode) {
    tjDestroy(private.jpeg);
    return BACKEND_UNSUPPORTED;
  }

  struct imv_source *source = calloc(1, sizeof *source);
  source->name = strdup("-");
  source->width = width;
  source->height = height;
  source->num_frames = 1;
  source->next_frame = 1;
  pthread_mutex_init(&source->busy, NULL);
  source->load_first_frame = &load_image;
  source->load_next_frame = NULL;
  source->free = &source_free;
  source->callback = NULL;
  source->user_data = NULL;
  source->private = malloc(sizeof private);
  memcpy(source->private, &private, sizeof private);

  *src = source;
  return BACKEND_SUCCESS;
}

const struct imv_backend imv_backend_libjpeg = {
  .name = "libjpeg-turbo",
  .description = "Fast JPEG codec based on libjpeg. "
                 "This software is based in part on the work "
                 "of the Independent JPEG Group.",
  .website = "https://libjpeg-turbo.org/",
  .license = "The Modified BSD License",
  .open_path = &open_path,
  .open_memory = &open_memory,
};