1616 */
1717
1818#include <stdlib.h>
19+ #include <stdio.h>
20+ #include <jpeglib.h>
1921
2022#include "pixbuf.h"
23+ #include "dither.h"
2124#include "loaders.h"
2225
2326struct pixbuf * pixbuf_load_jpeg (char * filename )
2427{
25- /* TODO */
26- return NULL ;
28+ struct pixbuf * ret ;
29+ FILE * fd ;
30+ struct jpeg_decompress_struct cinfo ;
31+ struct jpeg_error_mgr jerr ;
32+ unsigned char * pixels ;
33+ int i ;
34+ unsigned char * * row_pointers ;
35+
36+ ret = NULL ;
37+ fd = fopen (filename , "rb" );
38+ if (fd == NULL ) goto free0 ;
39+
40+ cinfo .err = jpeg_std_error (& jerr ); // TODO: get rid of the exit() code
41+ jpeg_create_decompress (& cinfo );
42+ jpeg_stdio_src (& cinfo , fd );
43+ jpeg_read_header (& cinfo , TRUE);
44+
45+ cinfo .out_color_space = JCS_RGB ;
46+ cinfo .out_color_components = 3 ;
47+ cinfo .dither_mode = JDITHER_NONE ;
48+
49+ pixels = malloc (3 * cinfo .image_width * cinfo .image_height );
50+ if (pixels == NULL ) goto free2 ;
51+ row_pointers = malloc (sizeof (char * )* cinfo .image_height );
52+ if (row_pointers == NULL ) goto free3 ;
53+ for (i = 0 ;i < cinfo .image_height ;i ++ )
54+ row_pointers [i ] = & pixels [i * 3 * cinfo .image_width ];
55+
56+ jpeg_start_decompress (& cinfo );
57+ while (cinfo .output_scanline < cinfo .output_height )
58+ jpeg_read_scanlines (& cinfo , & row_pointers [cinfo .output_scanline ], 1 );
59+ ret = pixbuf_new (cinfo .image_width , cinfo .image_height );
60+ if (ret == NULL ) goto free5 ;
61+
62+ if (!pixbuf_dither (ret -> pixels , row_pointers , cinfo .image_width , cinfo .image_height )) {
63+ pixbuf_dec_ref (ret );
64+ ret = NULL ;
65+ goto free5 ;
66+ }
67+
68+ free5 :
69+ jpeg_finish_decompress (& cinfo );
70+ free4 :
71+ free (row_pointers );
72+ free3 :
73+ free (pixels );
74+ free2 :
75+ jpeg_destroy_decompress (& cinfo );
76+ free1 :
77+ fclose (fd );
78+ free0 :
79+ return ret ;
2780}
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