X-Git-Url: http://git.code-monkey.de/?a=blobdiff_plain;f=pv%2Fdata%2Fanalogsegment.cpp;h=b3f310a144c5cd7ce2e18fb83ed242bd10526b6c;hb=c70e34649be658e7a443d5e68abe16dd55d53bf2;hp=cfc0f2bb60a9498d9561f10c27b5e22ae84ee896;hpb=7db61e770abd2d1c7eb326a09e35cd4266664c1d;p=pulseview.git

diff --git a/pv/data/analogsegment.cpp b/pv/data/analogsegment.cpp
index cfc0f2b..b3f310a 100644
--- a/pv/data/analogsegment.cpp
+++ b/pv/data/analogsegment.cpp
@@ -106,17 +106,17 @@ const std::pair<float, float> AnalogSegment::get_min_max() const
 	return std::make_pair(min_value_, max_value_);
 }
 
-SegmentAnalogDataIterator* AnalogSegment::begin_sample_iteration(uint64_t start) const
+SegmentAnalogDataIterator* AnalogSegment::begin_sample_iteration(uint64_t start)
 {
 	return (SegmentAnalogDataIterator*)begin_raw_sample_iteration(start);
 }
 
-void AnalogSegment::continue_sample_iteration(SegmentAnalogDataIterator* it, uint64_t increase) const
+void AnalogSegment::continue_sample_iteration(SegmentAnalogDataIterator* it, uint64_t increase)
 {
 	Segment::continue_raw_sample_iteration((SegmentRawDataIterator*)it, increase);
 }
 
-void AnalogSegment::end_sample_iteration(SegmentAnalogDataIterator* it) const
+void AnalogSegment::end_sample_iteration(SegmentAnalogDataIterator* it)
 {
 	Segment::end_raw_sample_iteration((SegmentRawDataIterator*)it);
 }
@@ -167,6 +167,18 @@ void AnalogSegment::append_payload_to_envelope_levels()
 	prev_length = e0.length;
 	e0.length = sample_count_ / EnvelopeScaleFactor;
 
+	// Calculate min/max values in case we have too few samples for an envelope
+	if (sample_count_ < EnvelopeScaleFactor) {
+		it = begin_raw_sample_iteration(0);
+		for (uint64_t i = 0; i < sample_count_; i++) {
+			const float sample = *((float*)it->value);
+			if (sample < min_value_) min_value_ = sample;
+			if (sample > max_value_) max_value_ = sample;
+			continue_raw_sample_iteration(it, 1);
+		}
+		end_raw_sample_iteration(it);
+	}
+
 	// Break off if there are no new samples to compute
 	if (e0.length == prev_length)
 		return;