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