From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Thu, 17 Nov 2011 14:03:11 +0000 (-0200)
Subject: Remove redundant duplicate pressure samples
X-Git-Url: http://git.tdb.fi/?a=commitdiff_plain;h=c486a9ee81de77faba90b5aa0b2e63eb11ec47f8;p=ext%2Fsubsurface.git

Remove redundant duplicate pressure samples

At least the Suunto pressure transmitter seems to be pretty
"quantisized", and it will send identical samples for a while until the
pressure changes enough.  Then subsurface gives this silly flat line
with a sudden jump downwards, which *could* be you suddenly taking a
deep breath after holding it for a while, but almost certainly it's a
sensor issue.

So just remove successive identical pressure readings.  They aren't
interesting, and subsurface will actually do a good job of interpolating
it according to SAC rate instead.  And they just make the XML look
worse.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/dive.c b/dive.c
index dad0e23..cd797d2 100644
--- a/dive.c
+++ b/dive.c
@@ -239,16 +239,26 @@ struct dive *fixup_dive(struct dive *dive)
 	int i;
 	double depthtime = 0;
 	int lasttime = 0;
+	int lastindex = -1;
 	int start = -1, end = -1;
 	int maxdepth = 0, mintemp = 0;
 	int lastdepth = 0;
-	int lasttemp = 0;
+	int lasttemp = 0, lastpressure = 0;
 
 	for (i = 0; i < dive->samples; i++) {
 		struct sample *sample = dive->sample + i;
 		int time = sample->time.seconds;
 		int depth = sample->depth.mm;
 		int temp = sample->temperature.mkelvin;
+		int pressure = sample->cylinderpressure.mbar;
+		int index = sample->cylinderindex;
+
+		/* Remove duplicate redundant pressure information */
+		if (pressure == lastpressure && index == lastindex)
+			sample->cylinderpressure.mbar = 0;
+
+		lastindex = index;
+		lastpressure = pressure;
 
 		if (lastdepth)
 			end = time;