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/*
* uemis.c
*
* UEMIS SDA file importer
* AUTHOR: Dirk Hohndel - Copyright 2011
*
* Licensed under the MIT license.
*/
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <stdint.h>
#include <stdlib.h>
#define __USE_XOPEN
#include <time.h>
#include "dive.h"
#include "uemis.h"
/*
* following code is based on code found in at base64.sourceforge.net/b64.c
* AUTHOR: Bob Trower 08/04/01
* COPYRIGHT: Copyright (c) Trantor Standard Systems Inc., 2001
* NOTE: This source code may be used as you wish, subject to
* the MIT license.
*/
/*
* Translation Table to decode (created by Bob Trower)
*/
static const char cd64[]="|$$$}rstuvwxyz{$$$$$$$>?@ABCDEFGHIJKLMNOPQRSTUVW$$$$$$XYZ[\\]^_`abcdefghijklmnopq";
/*
* decodeblock -- decode 4 '6-bit' characters into 3 8-bit binary bytes
*/
static void decodeblock( unsigned char in[4], unsigned char out[3] ) {
out[ 0 ] = (unsigned char ) (in[0] << 2 | in[1] >> 4);
out[ 1 ] = (unsigned char ) (in[1] << 4 | in[2] >> 2);
out[ 2 ] = (unsigned char ) (((in[2] << 6) & 0xc0) | in[3]);
}
/*
* decode a base64 encoded stream discarding padding, line breaks and noise
*/
static void decode( uint8_t *inbuf, uint8_t *outbuf, int inbuf_len ) {
uint8_t in[4], out[3], v;
int i,len,indx_in=0,indx_out=0;
while (indx_in < inbuf_len) {
for (len = 0, i = 0; i < 4 && (indx_in < inbuf_len); i++ ) {
v = 0;
while ((indx_in < inbuf_len) && v == 0) {
v = inbuf[indx_in++];
v = ((v < 43 || v > 122) ? 0 : cd64[ v - 43 ]);
if (v)
v = ((v == '$') ? 0 : v - 61);
}
if (indx_in < inbuf_len) {
len++;
if (v)
in[i] = (v - 1);
}
else
in[i] = 0;
}
if( len ) {
decodeblock( in, out );
for( i = 0; i < len - 1; i++ )
outbuf[indx_out++] = out[i];
}
}
}
/* end code from Bob Trower */
/*
* pressure_to_depth: In centibar. And when converting to
* depth, I'm just going to always use saltwater, because I
* think "true depth" is just stupid. From a diving standpoint,
* "true depth" is pretty much completely pointless, unless
* you're doing some kind of underwater surveying work.
*
* So I give water depths in "pressure depth", always assuming
* salt water. So one atmosphere per 10m.
*/
static int pressure_to_depth(uint16_t value)
{
double atm, cm;
atm = bar_to_atm(value / 100.0);
cm = 100 * atm + 0.5;
return (cm > 0) ? 10 * (long)cm : 0;
}
/*
* convert the base64 data blog
*/
int uemis_convert_base64(char *base64, uint8_t **data) {
int len,datalen;
len = strlen(base64);
datalen = (len/4 + 1)*3;
if (datalen < 0x123+0x25) {
/* less than header + 1 sample??? */
fprintf(stderr,"suspiciously short data block\n");
}
*data = malloc(datalen);
if (! *data) {
datalen = 0;
fprintf(stderr,"Out of memory\n");
goto bail;
}
decode(base64, *data, len);
if (memcmp(*data,"Dive\01\00\00",7))
fprintf(stderr,"Missing Dive100 header\n");
bail:
return datalen;
}
/* Create events from the flag bits;
* These bits basically represent what is displayed on screen at sample time.
* Many of these 'warnings' are way hyper-active and seriously clutter the
* profile plot - so these are disabled by default
*/
void uemis_event(struct dive *dive, struct sample *sample, uemis_sample_t *u_sample)
{
uint8_t *flags = u_sample->flags;
if (flags[1] & 0x01)
add_event(dive, sample->time.seconds, 0, 0, 0, "Safety Stop Violation");
if (flags[1] & 0x08)
add_event(dive, sample->time.seconds, 0, 0, 0, "Speed Alarm");
#if WANT_CRAZY_WARNINGS
if (flags[1] & 0x06) /* both bits 1 and 2 are a warning */
add_event(dive, sample->time.seconds, 0, 0, 0, "Speed Warning");
if (flags[1] & 0x10)
add_event(dive, sample->time.seconds, 0, 0, 0, "PO2 Green Warning");
#endif
if (flags[1] & 0x20)
add_event(dive, sample->time.seconds, 0, 0, 0, "PO2 Ascend Warning");
if (flags[1] & 0x40)
add_event(dive, sample->time.seconds, 0, 0, 0, "PO2 Ascend Alarm");
/* flags[2] reflects the deco / time bar
* flags[3] reflects more display details on deco and pO2 */
if (flags[4] & 0x01)
add_event(dive, sample->time.seconds, 0, 0, 0, "Tank Pressure Info");
if (flags[4] & 0x04)
add_event(dive, sample->time.seconds, 0, 0, 0, "RGT Warning");
if (flags[4] & 0x08)
add_event(dive, sample->time.seconds, 0, 0, 0, "RGT Alert");
if (flags[4] & 0x40)
add_event(dive, sample->time.seconds, 0, 0, 0, "Tank Change Suggested");
if (flags[4] & 0x80)
add_event(dive, sample->time.seconds, 0, 0, 0, "Depth Limit Exceeded");
if (flags[5] & 0x01)
add_event(dive, sample->time.seconds, 0, 0, 0, "Max Deco Time Warning");
if (flags[5] & 0x04)
add_event(dive, sample->time.seconds, 0, 0, 0, "Dive Time Info");
if (flags[5] & 0x08)
add_event(dive, sample->time.seconds, 0, 0, 0, "Dive Time Alert");
if (flags[5] & 0x10)
add_event(dive, sample->time.seconds, 0, 0, 0, "Marker");
if (flags[6] & 0x02)
add_event(dive, sample->time.seconds, 0, 0, 0, "No Tank Data");
if (flags[6] & 0x04)
add_event(dive, sample->time.seconds, 0, 0, 0, "Low Battery Warning");
if (flags[6] & 0x08)
add_event(dive, sample->time.seconds, 0, 0, 0, "Low Battery Alert");
/* flags[7] reflects the little on screen icons that remind of previous
* warnings / alerts - not useful for events */
}
/*
* parse uemis base64 data blob into struct dive
*/
void uemis_parse_divelog_binary(char *base64, void *datap) {
int datalen;
int i;
uint8_t *data;
struct sample *sample;
uemis_sample_t *u_sample;
struct dive **divep = datap;
struct dive *dive = *divep;
int template, gasoffset;
datalen = uemis_convert_base64(base64, &data);
/* dive template in use:
0 = air
1 = nitrox (B)
2 = nitrox (B+D)
3 = nitrox (B+T+D)
uemis cylinder data is insane - it stores seven tank settings in a block
and the template tells us which of the four groups of tanks we need to look at
*/
gasoffset = template = *(uint8_t *)(data+115);
if (template == 3)
gasoffset = 4;
if (template == 0)
template = 1;
for (i = 0; i < template; i++) {
float volume = *(float *)(data+116+25*(gasoffset + i)) * 1000.0;
/* uemis always assumes a working pressure of 202.6bar (!?!?) - I first thought
* it was 3000psi, but testing against all my dives gets me that strange number.
* Still, that's of course completely bogus and shows they don't get how
* cylinders are named in non-metric parts of the world...
* we store the incorrect working pressure to get the SAC calculations "close"
* but the user will have to correct this manually
*/
dive->cylinder[i].type.size.mliter = volume;
dive->cylinder[i].type.workingpressure.mbar = 202600;
dive->cylinder[i].gasmix.o2.permille = *(uint8_t *)(data+120+25*(gasoffset + i)) * 10 + 0.5;
dive->cylinder[i].gasmix.he.permille = 0;
}
/* first byte of divelog data is at offset 0x123 */
i = 0x123;
u_sample = (uemis_sample_t *)(data + i);
while ((i < datalen) && (u_sample->dive_time)) {
/* it seems that a dive_time of 0 indicates the end of the valid readings */
/* the SDA usually records more samples after the end of the dive --
* we want to discard those, but not cut the dive short; sadly the dive
* duration in the header is a) in minutes and b) up to 3 minutes short */
if (u_sample->dive_time > dive->duration.seconds + 180)
break;
sample = prepare_sample(divep);
dive = *divep; /* prepare_sample might realloc the dive */
sample->time.seconds = u_sample->dive_time;
sample->depth.mm = pressure_to_depth(u_sample->water_pressure);
sample->temperature.mkelvin = (u_sample->dive_temperature * 100) + 273150;
sample->cylinderindex = u_sample->active_tank;
sample->cylinderpressure.mbar= u_sample->tank_pressure * 10;
uemis_event(dive, sample, u_sample);
finish_sample(dive);
i += 0x25;
u_sample++;
}
dive->duration.seconds = sample->time.seconds - 1;
return;
}
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