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, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <extdef.h>
  21
  22 #include <cassert>
  23 #include <cstring>
  24 #include <cstdlib>
  25 #include <cmath>
  26
  27 #include <algorithm>
  28
  29 #include "analog.hpp"
  30 #include "analogsegment.hpp"
  31
  32 using std::lock_guard;
  33 using std::recursive_mutex;
  34 using std::make_pair;
  35 using std::max;
  36 using std::max_element;
  37 using std::min;
  38 using std::min_element;
  39 using std::pair;
  40
  41 namespace pv {
  42 namespace data {
  43
  44 const int AnalogSegment::EnvelopeScalePower = 4;
  45 const int AnalogSegment::EnvelopeScaleFactor = 1 << EnvelopeScalePower;
  46 const float AnalogSegment::LogEnvelopeScaleFactor =
  47         logf(EnvelopeScaleFactor);
  48 const uint64_t AnalogSegment::EnvelopeDataUnit = 64*1024;       // bytes
  49
  50 AnalogSegment::AnalogSegment(Analog& owner, uint64_t samplerate) :
  51         Segment(samplerate, sizeof(float)),
  52         owner_(owner),
  53         min_value_(0),
  54         max_value_(0)
  55 {
  56         lock_guard<recursive_mutex> lock(mutex_);
  57         memset(envelope_levels_, 0, sizeof(envelope_levels_));
  58 }
  59
  60 AnalogSegment::~AnalogSegment()
  61 {
  62         lock_guard<recursive_mutex> lock(mutex_);
  63         for (Envelope &e : envelope_levels_)
  64                 free(e.samples);
  65 }
  66
  67 void AnalogSegment::append_interleaved_samples(const float *data,
  68         size_t sample_count, size_t stride)
  69 {
  70         assert(unit_size_ == sizeof(float));
  71
  72         lock_guard<recursive_mutex> lock(mutex_);
  73
  74         uint64_t prev_sample_count = sample_count_;
  75
  76         for (uint32_t i=0; i < sample_count; i++) {
  77                 append_single_sample((void*)data);
  78                 data += stride;
  79         }
  80
  81         // Generate the first mip-map from the data
  82         append_payload_to_envelope_levels();
  83
  84         if (sample_count > 1)
  85                 owner_.notify_samples_added(this, prev_sample_count + 1,
  86                         prev_sample_count + 1 + sample_count);
  87         else
  88                 owner_.notify_samples_added(this, prev_sample_count + 1,
  89                         prev_sample_count + 1);
  90 }
  91
  92 const float* AnalogSegment::get_samples(
  93         int64_t start_sample, int64_t end_sample) const
  94 {
  95         assert(start_sample >= 0);
  96         assert(start_sample < (int64_t)sample_count_);
  97         assert(end_sample >= 0);
  98         assert(end_sample < (int64_t)sample_count_);
  99         assert(start_sample <= end_sample);
 100
 101         lock_guard<recursive_mutex> lock(mutex_);
 102
 103         return (float*)get_raw_samples(start_sample, (end_sample - start_sample));
 104 }
 105
 106 const pair<float, float> AnalogSegment::get_min_max() const
 107 {
 108         return make_pair(min_value_, max_value_);
 109 }
 110
 111 SegmentAnalogDataIterator* AnalogSegment::begin_sample_iteration(uint64_t start)
 112 {
 113         return (SegmentAnalogDataIterator*)begin_raw_sample_iteration(start);
 114 }
 115
 116 void AnalogSegment::continue_sample_iteration(SegmentAnalogDataIterator* it, uint64_t increase)
 117 {
 118         Segment::continue_raw_sample_iteration((SegmentRawDataIterator*)it, increase);
 119 }
 120
 121 void AnalogSegment::end_sample_iteration(SegmentAnalogDataIterator* it)
 122 {
 123         Segment::end_raw_sample_iteration((SegmentRawDataIterator*)it);
 124 }
 125
 126 void AnalogSegment::get_envelope_section(EnvelopeSection &s,
 127         uint64_t start, uint64_t end, float min_length) const
 128 {
 129         assert(end <= get_sample_count());
 130         assert(start <= end);
 131         assert(min_length > 0);
 132
 133         lock_guard<recursive_mutex> lock(mutex_);
 134
 135         const unsigned int min_level = max((int)floorf(logf(min_length) /
 136                 LogEnvelopeScaleFactor) - 1, 0);
 137         const unsigned int scale_power = (min_level + 1) *
 138                 EnvelopeScalePower;
 139         start >>= scale_power;
 140         end >>= scale_power;
 141
 142         s.start = start << scale_power;
 143         s.scale = 1 << scale_power;
 144         s.length = end - start;
 145         s.samples = new EnvelopeSample[s.length];
 146         memcpy(s.samples, envelope_levels_[min_level].samples + start,
 147                 s.length * sizeof(EnvelopeSample));
 148 }
 149
 150 void AnalogSegment::reallocate_envelope(Envelope &e)
 151 {
 152         const uint64_t new_data_length = ((e.length + EnvelopeDataUnit - 1) /
 153                 EnvelopeDataUnit) * EnvelopeDataUnit;
 154         if (new_data_length > e.data_length) {
 155                 e.data_length = new_data_length;
 156                 e.samples = (EnvelopeSample*)realloc(e.samples,
 157                         new_data_length * sizeof(EnvelopeSample));
 158         }
 159 }
 160
 161 void AnalogSegment::append_payload_to_envelope_levels()
 162 {
 163         Envelope &e0 = envelope_levels_[0];
 164         uint64_t prev_length;
 165         EnvelopeSample *dest_ptr;
 166         SegmentRawDataIterator* it;
 167
 168         // Expand the data buffer to fit the new samples
 169         prev_length = e0.length;
 170         e0.length = sample_count_ / EnvelopeScaleFactor;
 171
 172         // Calculate min/max values in case we have too few samples for an envelope
 173         if (sample_count_ < EnvelopeScaleFactor) {
 174                 it = begin_raw_sample_iteration(0);
 175                 for (uint64_t i = 0; i < sample_count_; i++) {
 176                         const float sample = *((float*)it->value);
 177                         if (sample < min_value_) min_value_ = sample;
 178                         if (sample > max_value_) max_value_ = sample;
 179                         continue_raw_sample_iteration(it, 1);
 180                 }
 181                 end_raw_sample_iteration(it);
 182         }
 183
 184         // Break off if there are no new samples to compute
 185         if (e0.length == prev_length)
 186                 return;
 187
 188         reallocate_envelope(e0);
 189
 190         dest_ptr = e0.samples + prev_length;
 191
 192         // Iterate through the samples to populate the first level mipmap
 193         uint64_t start_sample = prev_length * EnvelopeScaleFactor;
 194         uint64_t end_sample   = e0.length * EnvelopeScaleFactor;
 195
 196         it = begin_raw_sample_iteration(start_sample);
 197         for (uint64_t i = start_sample; i < end_sample; i += EnvelopeScaleFactor) {
 198                 const float* samples = (float*)it->value;
 199
 200                 const EnvelopeSample sub_sample = {
 201                         *min_element(samples, samples + EnvelopeScaleFactor),
 202                         *max_element(samples, samples + EnvelopeScaleFactor),
 203                 };
 204
 205                 if (sub_sample.min < min_value_) min_value_ = sub_sample.min;
 206                 if (sub_sample.max > max_value_) max_value_ = sub_sample.max;
 207
 208                 continue_raw_sample_iteration(it, EnvelopeScaleFactor);
 209                 *dest_ptr++ = sub_sample;
 210         }
 211         end_raw_sample_iteration(it);
 212
 213         // Compute higher level mipmaps
 214         for (unsigned int level = 1; level < ScaleStepCount; level++) {
 215                 Envelope &e = envelope_levels_[level];
 216                 const Envelope &el = envelope_levels_[level-1];
 217
 218                 // Expand the data buffer to fit the new samples
 219                 prev_length = e.length;
 220                 e.length = el.length / EnvelopeScaleFactor;
 221
 222                 // Break off if there are no more samples to be computed
 223                 if (e.length == prev_length)
 224                         break;
 225
 226                 reallocate_envelope(e);
 227
 228                 // Subsample the lower level
 229                 const EnvelopeSample *src_ptr =
 230                         el.samples + prev_length * EnvelopeScaleFactor;
 231                 const EnvelopeSample *const end_dest_ptr = e.samples + e.length;
 232
 233                 for (dest_ptr = e.samples + prev_length;
 234                                 dest_ptr < end_dest_ptr; dest_ptr++) {
 235                         const EnvelopeSample *const end_src_ptr =
 236                                 src_ptr + EnvelopeScaleFactor;
 237
 238                         EnvelopeSample sub_sample = *src_ptr++;
 239                         while (src_ptr < end_src_ptr) {
 240                                 sub_sample.min = min(sub_sample.min, src_ptr->min);;
 241                                 sub_sample.max = max(sub_sample.max, src_ptr->max);
 242                                 src_ptr++;
 243                         }
 244
 245                         *dest_ptr = sub_sample;
 246                 }
 247         }
 248 }
 249
 250 } // namespace data
 251 } // namespace pv