Again on the Mares Smart Apnea topic.
I think I have found a problem on the current SW implementation and I need some advice. Sorry for the long message.
I have dumped my DC logbook, and some cross checking between the code and the expected results from the mares SW.
I think I have found some problem in the code. In the function "mares_iconhd_extract_dives" it seems to me that the code points to the very end of the buffer, then it starts crawling back to the beginning of the last immersion:
offset = layout->rb_profile_end - layout->rb_profile_begin;
unsigned int nbytes = 4 + headersize + nsamples * samplesize; ... // Move to the start of the dive. offset -= nbytes;
...but it seems that on the Smart Apnea there is not a constant samplesize: one immersion is a variable length (nsamples) sequence of dives , each one having one header (dive time, surface time, temperature, ...) and a stream of "dive time" depth measurements.
If this is true, the current approach can't work, as long as it is no longer possible to compute "nbytes".
Am I wrong?
Is there any reason to start from the end and not from the beginning (the "end of profile ring buffer" eop) and then move forward? I am getting familiar with the memory layout of the DC but still have many many doubts about the library code and architecture.
Any help would be very appreciated. I can provide the annotated dump, but I am not sure what the mailing list netiquette says about big attachments.
Thank you in advance
Giorgio
EXAMPLE:
*** start immersion 2015 08 31 10.08
18 25 : LEN (in bytes) 00 00 : ?? *** sample 1 *** 0c 00 : maxdepth(1.2) sample 1 13 00 : dive time (19 secs) 00 00 : surface time (0) fc 00 ?? fc 00 ?? 04 00 ?? 17 00 ?? 0b 00 depth //19 depth measurements: 1 per second 0c 00 depth 0b 00 depth 0b 00 depth 0b 00 depth 0b 00 depth 0b 00 depth 0c 00 depth 0c 00 depth 0b 00 depth 0b 00 depth 0b 00 depth 0b 00 depth 0b 00 depth 0b 00 depth 0c 00 depth 0b 00 depth 0b 00 depth 09 00 depth
**** sample 2 *** 11 00 maxdepth (1.2) 2d 00 divetime 3c 00 surftime fc 00 ?? fc 00 ?? 05 00 ?? ...