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1 #ifndef __LIVE_VIEW_H
2 #define __LIVE_VIEW_H
3 
4 // Note: used in modules and platform independent code.
5 // Do not add platform dependent stuff in here (#ifdef/#endif compile options or camera dependent values)
6 
7 /*
8 Protocol notes:
9 - Unless otherwise specified, all structure values are packed in camera native (little
10   endian) byte order
11 - Frame buffer and palette data are in native camera formats
12   Some documentation may be found at http://chdk.wikia.com/wiki/Frame_buffers
13 - The frame buffer descriptions returned may not be correct depending on the
14   camera model and various camera settings (shooting mode, digital zoom, aspect ratio)
15   This may result in partial images, garbage in the "valid" area or incorrect position
16 - In some cases, the requested data may not be available. If this happens, the framebuffer
17   or palette data offset will be zero.
18 - The frame buffer descriptions are returned regardless of whether the data is available
19 */
20 // Live View protocol version
21 #define LIVE_VIEW_VERSION_MAJOR 2  // increase only with backwards incompatible changes (and reset minor)
22 #define LIVE_VIEW_VERSION_MINOR 1  // increase with extensions of functionality
23 
24 /*
25 protocol version history
26 < 2.0 - development versions
27 2.0 - initial release, chdk 1.1
28 2.1 - added palette type 4 - 16 entry VUYA, 2 bit alpha
29 */
30 
31 
32 // Control flags for determining which data block to transfer
33 #define LV_TFR_VIEWPORT     0x01
34 #define LV_TFR_BITMAP       0x04
35 #define LV_TFR_PALETTE      0x08
36 
37 enum lv_aspect_rato {
38     LV_ASPECT_4_3,
39     LV_ASPECT_16_9,
40 };
41 
42 /*
43 Framebuffer types
44 additional values will be added if new data formats appear
45 */
46 enum lv_fb_type {
47     LV_FB_YUV8, // 8 bit per element UYVYYY, used for live view
48     LV_FB_PAL8, // 8 bit paletted, used for bitmap overlay. Note palette data and type sent separately
49 };
50 
51 /*
52 framebuffer data description
53 NOTE YUV pixels widths are based on the number of Y elements
54 */
55 typedef struct {
56     int fb_type; // framebuffer type - note future versions might use different structures depending on type
57     int data_start; // offset of data from start of live view header
58     /*
59     buffer width in pixels
60     data size is always buffer_width*visible_height*(buffer bpp based on type)
61     */
62     int buffer_width;
63     /*
64     visible size in pixels
65     describes data within the buffer which contains image data to be displayed
66     any offsets within buffer data are added before sending, so the top left
67     pixel is always the first first byte of data.
68     width must always be <= buffer_width
69     if buffer_width is > width, the additional data should be skipped
70     visible_height also defines the number of data rows
71     */
72     int visible_width;
73     int visible_height;
74 
75     /*
76     margins
77     pixels offsets needed to replicate display position on cameras screen
78     not used for any buffer offsets
79     */
80     int margin_left;
81     int margin_top;
82 
83     int margin_right;
84     int margin_bot;
85 } lv_framebuffer_desc;
86 
87 typedef struct {
88     // live view sub-protocol version
89     int version_major;
90     int version_minor;
91     int lcd_aspect_ratio; // physical aspect ratio of LCD
92     int palette_type;
93     int palette_data_start;
94     // framebuffer descriptions are given as offsets, to allow expanding the structures in minor protocol changes
95     int vp_desc_start;
96     int bm_desc_start;
97 } lv_data_header;
98 
99 #endif // __LIVE_VIEW_H
100