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