]> git.sesse.net Git - kdenlive/blob - src/v4l/dec_jpeg.c
Stopmotion widget: Improved webcam support, taken from the fswebcam project
[kdenlive] / src / v4l / dec_jpeg.c
1 /* fswebcam - Small and simple webcam for *nix                */
2 /*============================================================*/
3 /* Copyright (C)2005-2010 Philip Heron <phil@sanslogic.co.uk> */
4 /*                                                            */
5 /* This program is distributed under the terms of the GNU     */
6 /* General Public License, version 2. You may use, modify,    */
7 /* and redistribute it under the terms of this license. A     */
8 /* copy should be included with this source.                  */
9
10 #ifdef HAVE_CONFIG_H
11 #include "config.h"
12 #endif
13
14 #include <string.h>
15 #include <stdlib.h>
16 #include <stdint.h>
17 #include <gd.h>
18 #include "src.h"
19
20 int verify_jpeg_dht(uint8_t *src,  uint32_t lsrc,
21                     uint8_t **dst, uint32_t *ldst)
22 {
23         /* This function is based on a patch provided by Scott J. Bertin. */
24         
25         static unsigned char dht[] =
26         {
27                 0xff, 0xc4, 0x01, 0xa2, 0x00, 0x00, 0x01, 0x05, 0x01, 0x01,
28                 0x01, 0x01, 0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
29                 0x00, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
30                 0x09, 0x0a, 0x0b, 0x10, 0x00, 0x02, 0x01, 0x03, 0x03, 0x02,
31                 0x04, 0x03, 0x05, 0x05, 0x04, 0x04, 0x00, 0x00, 0x01, 0x7d,
32                 0x01, 0x02, 0x03, 0x00, 0x04, 0x11, 0x05, 0x12, 0x21, 0x31,
33                 0x41, 0x06, 0x13, 0x51, 0x61, 0x07, 0x22, 0x71, 0x14, 0x32,
34                 0x81, 0x91, 0xa1, 0x08, 0x23, 0x42, 0xb1, 0xc1, 0x15, 0x52,
35                 0xd1, 0xf0, 0x24, 0x33, 0x62, 0x72, 0x82, 0x09, 0x0a, 0x16,
36                 0x17, 0x18, 0x19, 0x1a, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a,
37                 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x43, 0x44, 0x45,
38                 0x46, 0x47, 0x48, 0x49, 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57,
39                 0x58, 0x59, 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69,
40                 0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x83,
41                 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x92, 0x93, 0x94,
42                 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5,
43                 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6,
44                 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7,
45                 0xc8, 0xc9, 0xca, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8,
46                 0xd9, 0xda, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8,
47                 0xe9, 0xea, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8,
48                 0xf9, 0xfa, 0x01, 0x00, 0x03, 0x01, 0x01, 0x01, 0x01, 0x01,
49                 0x01, 0x01, 0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
50                 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a,
51                 0x0b, 0x11, 0x00, 0x02, 0x01, 0x02, 0x04, 0x04, 0x03, 0x04,
52                 0x07, 0x05, 0x04, 0x04, 0x00, 0x01, 0x02, 0x77, 0x00, 0x01,
53                 0x02, 0x03, 0x11, 0x04, 0x05, 0x21, 0x31, 0x06, 0x12, 0x41,
54                 0x51, 0x07, 0x61, 0x71, 0x13, 0x22, 0x32, 0x81, 0x08, 0x14,
55                 0x42, 0x91, 0xa1, 0xb1, 0xc1, 0x09, 0x23, 0x33, 0x52, 0xf0,
56                 0x15, 0x62, 0x72, 0xd1, 0x0a, 0x16, 0x24, 0x34, 0xe1, 0x25,
57                 0xf1, 0x17, 0x18, 0x19, 0x1a, 0x26, 0x27, 0x28, 0x29, 0x2a,
58                 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x43, 0x44, 0x45, 0x46,
59                 0x47, 0x48, 0x49, 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58,
60                 0x59, 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a,
61                 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x82, 0x83,
62                 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x92, 0x93, 0x94,
63                 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5,
64                 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6,
65                 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7,
66                 0xc8, 0xc9, 0xca, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8,
67                 0xd9, 0xda, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9,
68                 0xea, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa
69         };
70         uint8_t *p, *i = NULL;
71         
72         /* By default we simply return the source image. */
73         *dst = src;
74         *ldst = lsrc;
75         
76         /* Scan for an existing DHT segment or the first SOS segment. */
77         for(p = src + 2; p - src < lsrc - 3 && i == NULL; )
78         {
79                 if(*(p++) != 0xFF) continue;
80                 
81                 if(*p == 0xD9) break;           /* JPEG_EOI */
82                 if(*p == 0xC4) return(0);       /* JPEG_DHT */
83                 if(*p == 0xDA && !i) i = p - 1; /* JPEG_SOS */
84                 
85                 /* Move to next segment. */
86                 p += (p[1] << 8) + p[2];
87         }
88         
89         /* If no SOS was found, insert the DHT directly after the SOI. */
90         if(i == NULL) i = src + 2;
91         
92         
93         *ldst = lsrc + sizeof(dht);
94         *dst  = malloc(*ldst);
95         if(!*dst)
96         {
97                 return(-1);
98         }
99         
100         /* Copy the JPEG data, inserting the DHT segment. */
101         memcpy((p  = *dst), src, i - src);
102         memcpy((p += i - src), dht, sizeof(dht));
103         memcpy((p += sizeof(dht)), i, lsrc - (i - src));
104         
105         return(1);
106 }
107
108
109