Standardize on 'event' as name for all Qt events.
[pulseview.git] / pv / data / analogsegment.cpp
1 /*
2  * This file is part of the PulseView project.
3  *
4  * Copyright (C) 2012 Joel Holdsworth <joel@airwebreathe.org.uk>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
19  */
20
21 #include <extdef.h>
22
23 #include <assert.h>
24 #include <string.h>
25 #include <stdlib.h>
26 #include <cmath>
27
28 #include <algorithm>
29
30 #include "analogsegment.hpp"
31
32 using std::lock_guard;
33 using std::recursive_mutex;
34 using std::max;
35 using std::max_element;
36 using std::min;
37 using std::min_element;
38
39 namespace pv {
40 namespace data {
41
42 const int AnalogSegment::EnvelopeScalePower = 4;
43 const int AnalogSegment::EnvelopeScaleFactor = 1 << EnvelopeScalePower;
44 const float AnalogSegment::LogEnvelopeScaleFactor =
45         logf(EnvelopeScaleFactor);
46 const uint64_t AnalogSegment::EnvelopeDataUnit = 64*1024;       // bytes
47
48 AnalogSegment::AnalogSegment(
49         uint64_t samplerate, const uint64_t expected_num_samples) :
50         Segment(samplerate, sizeof(float))
51 {
52         set_capacity(expected_num_samples);
53
54         lock_guard<recursive_mutex> lock(mutex_);
55         memset(envelope_levels_, 0, sizeof(envelope_levels_));
56 }
57
58 AnalogSegment::~AnalogSegment()
59 {
60         lock_guard<recursive_mutex> lock(mutex_);
61         for (Envelope &e : envelope_levels_)
62                 free(e.samples);
63 }
64
65 void AnalogSegment::append_interleaved_samples(const float *data,
66         size_t sample_count, size_t stride)
67 {
68         assert(unit_size_ == sizeof(float));
69
70         lock_guard<recursive_mutex> lock(mutex_);
71
72         // If we're out of memory, this will throw std::bad_alloc
73         data_.resize((sample_count_ + sample_count) * sizeof(float));
74
75         float *dst = (float*)data_.data() + sample_count_;
76         const float *dst_end = dst + sample_count;
77         while (dst != dst_end) {
78                 *dst++ = *data;
79                 data += stride;
80         }
81
82         sample_count_ += sample_count;
83
84         // Generate the first mip-map from the data
85         append_payload_to_envelope_levels();
86 }
87
88 const float* AnalogSegment::get_samples(
89         int64_t start_sample, int64_t end_sample) const
90 {
91         assert(start_sample >= 0);
92         assert(start_sample < (int64_t)sample_count_);
93         assert(end_sample >= 0);
94         assert(end_sample < (int64_t)sample_count_);
95         assert(start_sample <= end_sample);
96
97         lock_guard<recursive_mutex> lock(mutex_);
98
99         float *const data = new float[end_sample - start_sample];
100         memcpy(data, (float*)data_.data() + start_sample, sizeof(float) *
101                 (end_sample - start_sample));
102         return data;
103 }
104
105 void AnalogSegment::get_envelope_section(EnvelopeSection &s,
106         uint64_t start, uint64_t end, float min_length) const
107 {
108         assert(end <= get_sample_count());
109         assert(start <= end);
110         assert(min_length > 0);
111
112         lock_guard<recursive_mutex> lock(mutex_);
113
114         const unsigned int min_level = max((int)floorf(logf(min_length) /
115                 LogEnvelopeScaleFactor) - 1, 0);
116         const unsigned int scale_power = (min_level + 1) *
117                 EnvelopeScalePower;
118         start >>= scale_power;
119         end >>= scale_power;
120
121         s.start = start << scale_power;
122         s.scale = 1 << scale_power;
123         s.length = end - start;
124         s.samples = new EnvelopeSample[s.length];
125         memcpy(s.samples, envelope_levels_[min_level].samples + start,
126                 s.length * sizeof(EnvelopeSample));
127 }
128
129 void AnalogSegment::reallocate_envelope(Envelope &e)
130 {
131         const uint64_t new_data_length = ((e.length + EnvelopeDataUnit - 1) /
132                 EnvelopeDataUnit) * EnvelopeDataUnit;
133         if (new_data_length > e.data_length) {
134                 e.data_length = new_data_length;
135                 e.samples = (EnvelopeSample*)realloc(e.samples,
136                         new_data_length * sizeof(EnvelopeSample));
137         }
138 }
139
140 void AnalogSegment::append_payload_to_envelope_levels()
141 {
142         Envelope &e0 = envelope_levels_[0];
143         uint64_t prev_length;
144         EnvelopeSample *dest_ptr;
145
146         // Expand the data buffer to fit the new samples
147         prev_length = e0.length;
148         e0.length = sample_count_ / EnvelopeScaleFactor;
149
150         // Break off if there are no new samples to compute
151         if (e0.length == prev_length)
152                 return;
153
154         reallocate_envelope(e0);
155
156         dest_ptr = e0.samples + prev_length;
157
158         // Iterate through the samples to populate the first level mipmap
159         const float *const end_src_ptr = (float*)data_.data() +
160                 e0.length * EnvelopeScaleFactor;
161         for (const float *src_ptr = (float*)data_.data() +
162                         prev_length * EnvelopeScaleFactor;
163                         src_ptr < end_src_ptr; src_ptr += EnvelopeScaleFactor) {
164                 const EnvelopeSample sub_sample = {
165                         *min_element(src_ptr, src_ptr + EnvelopeScaleFactor),
166                         *max_element(src_ptr, src_ptr + EnvelopeScaleFactor),
167                 };
168
169                 *dest_ptr++ = sub_sample;
170         }
171
172         // Compute higher level mipmaps
173         for (unsigned int level = 1; level < ScaleStepCount; level++) {
174                 Envelope &e = envelope_levels_[level];
175                 const Envelope &el = envelope_levels_[level-1];
176
177                 // Expand the data buffer to fit the new samples
178                 prev_length = e.length;
179                 e.length = el.length / EnvelopeScaleFactor;
180
181                 // Break off if there are no more samples to computed
182                 if (e.length == prev_length)
183                         break;
184
185                 reallocate_envelope(e);
186
187                 // Subsample the level lower level
188                 const EnvelopeSample *src_ptr =
189                         el.samples + prev_length * EnvelopeScaleFactor;
190                 const EnvelopeSample *const end_dest_ptr = e.samples + e.length;
191                 for (dest_ptr = e.samples + prev_length;
192                                 dest_ptr < end_dest_ptr; dest_ptr++) {
193                         const EnvelopeSample *const end_src_ptr =
194                                 src_ptr + EnvelopeScaleFactor;
195
196                         EnvelopeSample sub_sample = *src_ptr++;
197                         while (src_ptr < end_src_ptr) {
198                                 sub_sample.min = min(sub_sample.min, src_ptr->min);
199                                 sub_sample.max = max(sub_sample.max, src_ptr->max);
200                                 src_ptr++;
201                         }
202
203                         *dest_ptr = sub_sample;
204                 }
205         }
206 }
207
208 } // namespace data
209 } // namespace pv