Go to most recent revision | Details | Last modification | View Log | RSS feed
Rev | Author | Line No. | Line |
---|---|---|---|
4680 | right-hear | 1 | #include "fitz.h" |
2 | |||
3 | #include |
||
4 | #include |
||
5 | |||
6 | typedef struct fz_dctd_s fz_dctd; |
||
7 | |||
8 | struct fz_dctd_s |
||
9 | { |
||
10 | fz_stream *chain; |
||
11 | int color_transform; |
||
12 | int init; |
||
13 | int stride; |
||
14 | unsigned char *scanline; |
||
15 | unsigned char *rp, *wp; |
||
16 | struct jpeg_decompress_struct cinfo; |
||
17 | struct jpeg_source_mgr srcmgr; |
||
18 | struct jpeg_error_mgr errmgr; |
||
19 | jmp_buf jb; |
||
20 | char msg[JMSG_LENGTH_MAX]; |
||
21 | }; |
||
22 | |||
23 | static void error_exit(j_common_ptr cinfo) |
||
24 | { |
||
25 | fz_dctd *state = cinfo->client_data; |
||
26 | cinfo->err->format_message(cinfo, state->msg); |
||
27 | longjmp(state->jb, 1); |
||
28 | } |
||
29 | |||
30 | static void init_source(j_decompress_ptr cinfo) |
||
31 | { |
||
32 | /* nothing to do */ |
||
33 | } |
||
34 | |||
35 | static void term_source(j_decompress_ptr cinfo) |
||
36 | { |
||
37 | /* nothing to do */ |
||
38 | } |
||
39 | |||
40 | static boolean fill_input_buffer(j_decompress_ptr cinfo) |
||
41 | { |
||
42 | struct jpeg_source_mgr *src = cinfo->src; |
||
43 | fz_dctd *state = cinfo->client_data; |
||
44 | fz_stream *chain = state->chain; |
||
45 | |||
46 | chain->rp = chain->wp; |
||
47 | fz_fill_buffer(chain); |
||
48 | src->next_input_byte = chain->rp; |
||
49 | src->bytes_in_buffer = chain->wp - chain->rp; |
||
50 | |||
51 | if (src->bytes_in_buffer == 0) |
||
52 | { |
||
53 | static unsigned char eoi[2] = { 0xFF, JPEG_EOI }; |
||
54 | fz_warn("premature end of file in jpeg"); |
||
55 | src->next_input_byte = eoi; |
||
56 | src->bytes_in_buffer = 2; |
||
57 | } |
||
58 | |||
59 | return 1; |
||
60 | } |
||
61 | |||
62 | static void skip_input_data(j_decompress_ptr cinfo, long num_bytes) |
||
63 | { |
||
64 | struct jpeg_source_mgr *src = cinfo->src; |
||
65 | if (num_bytes > 0) |
||
66 | { |
||
67 | while ((size_t)num_bytes > src->bytes_in_buffer) |
||
68 | { |
||
69 | num_bytes -= src->bytes_in_buffer; |
||
70 | (void) src->fill_input_buffer(cinfo); |
||
71 | } |
||
72 | src->next_input_byte += num_bytes; |
||
73 | src->bytes_in_buffer -= num_bytes; |
||
74 | } |
||
75 | } |
||
76 | |||
77 | static int |
||
78 | read_dctd(fz_stream *stm, unsigned char *buf, int len) |
||
79 | { |
||
80 | fz_dctd *state = stm->state; |
||
81 | j_decompress_ptr cinfo = &state->cinfo; |
||
82 | unsigned char *p = buf; |
||
83 | unsigned char *ep = buf + len; |
||
84 | |||
85 | if (setjmp(state->jb)) |
||
86 | { |
||
87 | if (cinfo->src) |
||
88 | state->chain->rp = state->chain->wp - cinfo->src->bytes_in_buffer; |
||
89 | return fz_throw("jpeg error: %s", state->msg); |
||
90 | } |
||
91 | |||
92 | if (!state->init) |
||
93 | { |
||
94 | cinfo->client_data = state; |
||
95 | cinfo->err = &state->errmgr; |
||
96 | jpeg_std_error(cinfo->err); |
||
97 | cinfo->err->error_exit = error_exit; |
||
98 | jpeg_create_decompress(cinfo); |
||
99 | |||
100 | cinfo->src = &state->srcmgr; |
||
101 | cinfo->src->init_source = init_source; |
||
102 | cinfo->src->fill_input_buffer = fill_input_buffer; |
||
103 | cinfo->src->skip_input_data = skip_input_data; |
||
104 | cinfo->src->resync_to_restart = jpeg_resync_to_restart; |
||
105 | cinfo->src->term_source = term_source; |
||
106 | cinfo->src->next_input_byte = state->chain->rp; |
||
107 | cinfo->src->bytes_in_buffer = state->chain->wp - state->chain->rp; |
||
108 | |||
109 | jpeg_read_header(cinfo, 1); |
||
110 | |||
111 | /* speed up jpeg decoding a bit */ |
||
112 | cinfo->dct_method = JDCT_FASTEST; |
||
113 | cinfo->do_fancy_upsampling = FALSE; |
||
114 | |||
115 | /* default value if ColorTransform is not set */ |
||
116 | if (state->color_transform == -1) |
||
117 | { |
||
118 | if (state->cinfo.num_components == 3) |
||
119 | state->color_transform = 1; |
||
120 | else |
||
121 | state->color_transform = 0; |
||
122 | } |
||
123 | |||
124 | if (cinfo->saw_Adobe_marker) |
||
125 | state->color_transform = cinfo->Adobe_transform; |
||
126 | |||
127 | /* Guess the input colorspace, and set output colorspace accordingly */ |
||
128 | switch (cinfo->num_components) |
||
129 | { |
||
130 | case 3: |
||
131 | if (state->color_transform) |
||
132 | cinfo->jpeg_color_space = JCS_YCbCr; |
||
133 | else |
||
134 | cinfo->jpeg_color_space = JCS_RGB; |
||
135 | break; |
||
136 | case 4: |
||
137 | if (state->color_transform) |
||
138 | cinfo->jpeg_color_space = JCS_YCCK; |
||
139 | else |
||
140 | cinfo->jpeg_color_space = JCS_CMYK; |
||
141 | break; |
||
142 | } |
||
143 | |||
144 | jpeg_start_decompress(cinfo); |
||
145 | |||
146 | state->stride = cinfo->output_width * cinfo->output_components; |
||
147 | state->scanline = fz_malloc(state->stride); |
||
148 | state->rp = state->scanline; |
||
149 | state->wp = state->scanline; |
||
150 | |||
151 | state->init = 1; |
||
152 | } |
||
153 | |||
154 | while (state->rp < state->wp && p < ep) |
||
155 | *p++ = *state->rp++; |
||
156 | |||
157 | while (p < ep) |
||
158 | { |
||
159 | if (cinfo->output_scanline == cinfo->output_height) |
||
160 | break; |
||
161 | |||
162 | if (p + state->stride <= ep) |
||
163 | { |
||
164 | jpeg_read_scanlines(cinfo, &p, 1); |
||
165 | p += state->stride; |
||
166 | } |
||
167 | else |
||
168 | { |
||
169 | jpeg_read_scanlines(cinfo, &state->scanline, 1); |
||
170 | state->rp = state->scanline; |
||
171 | state->wp = state->scanline + state->stride; |
||
172 | } |
||
173 | |||
174 | while (state->rp < state->wp && p < ep) |
||
175 | *p++ = *state->rp++; |
||
176 | } |
||
177 | |||
178 | return p - buf; |
||
179 | } |
||
180 | |||
181 | static void |
||
182 | close_dctd(fz_stream *stm) |
||
183 | { |
||
184 | fz_dctd *state = stm->state; |
||
185 | |||
186 | if (setjmp(state->jb)) |
||
187 | { |
||
188 | state->chain->rp = state->chain->wp - state->cinfo.src->bytes_in_buffer; |
||
189 | fz_warn("jpeg error: %s", state->msg); |
||
190 | goto skip; |
||
191 | } |
||
192 | |||
193 | if (state->init) |
||
194 | jpeg_finish_decompress(&state->cinfo); |
||
195 | |||
196 | skip: |
||
197 | state->chain->rp = state->chain->wp - state->cinfo.src->bytes_in_buffer; |
||
198 | jpeg_destroy_decompress(&state->cinfo); |
||
199 | fz_free(state->scanline); |
||
200 | fz_close(state->chain); |
||
201 | fz_free(state); |
||
202 | } |
||
203 | |||
204 | fz_stream * |
||
205 | fz_open_dctd(fz_stream *chain, fz_obj *params) |
||
206 | { |
||
207 | fz_dctd *state; |
||
208 | fz_obj *obj; |
||
209 | |||
210 | state = fz_malloc(sizeof(fz_dctd)); |
||
211 | memset(state, 0, sizeof(fz_dctd)); |
||
212 | state->chain = chain; |
||
213 | state->color_transform = -1; /* unset */ |
||
214 | state->init = 0; |
||
215 | |||
216 | obj = fz_dict_gets(params, "ColorTransform"); |
||
217 | if (obj) |
||
218 | state->color_transform = fz_to_int(obj); |
||
219 | |||
220 | return fz_new_stream(state, read_dctd, close_dctd); |
||
221 | }>>=>>>> |