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 <cmath>
  24 #include <cstdlib>
  25 #include <cstring>
  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 = logf(EnvelopeScaleFactor);
  47 const uint64_t AnalogSegment::EnvelopeDataUnit = 64 * 1024;     // bytes
  48
  49 AnalogSegment::AnalogSegment(Analog& owner, uint64_t samplerate) :
  50         Segment(samplerate, sizeof(float)),
  51         owner_(owner),
  52         min_value_(0),
  53         max_value_(0)
  54 {
  55         lock_guard<recursive_mutex> lock(mutex_);
  56         memset(envelope_levels_, 0, sizeof(envelope_levels_));
  57 }
  58
  59 AnalogSegment::~AnalogSegment()
  60 {
  61         lock_guard<recursive_mutex> lock(mutex_);
  62         for (Envelope &e : envelope_levels_)
  63                 free(e.samples);
  64 }
  65
  66 void AnalogSegment::append_interleaved_samples(const float *data,
  67         size_t sample_count, size_t stride)
  68 {
  69         assert(unit_size_ == sizeof(float));
  70
  71         lock_guard<recursive_mutex> lock(mutex_);
  72
  73         uint64_t prev_sample_count = sample_count_;
  74
  75         for (uint32_t i = 0; i < sample_count; i++) {
  76                 append_single_sample((void*)data);
  77                 data += stride;
  78         }
  79
  80         // Generate the first mip-map from the data
  81         append_payload_to_envelope_levels();
  82
  83         if (sample_count > 1)
  84                 owner_.notify_samples_added(this, prev_sample_count + 1,
  85                         prev_sample_count + 1 + sample_count);
  86         else
  87                 owner_.notify_samples_added(this, prev_sample_count + 1,
  88                         prev_sample_count + 1);
  89 }
  90
  91 const float* AnalogSegment::get_samples(
  92         int64_t start_sample, int64_t end_sample) const
  93 {
  94         assert(start_sample >= 0);
  95         assert(start_sample < (int64_t)sample_count_);
  96         assert(end_sample >= 0);
  97         assert(end_sample < (int64_t)sample_count_);
  98         assert(start_sample <= end_sample);
  99
 100         lock_guard<recursive_mutex> lock(mutex_);
 101
 102         return (float*)get_raw_samples(start_sample, (end_sample - start_sample));
 103 }
 104
 105 const pair<float, float> AnalogSegment::get_min_max() const
 106 {
 107         return make_pair(min_value_, max_value_);
 108 }
 109
 110 SegmentAnalogDataIterator* AnalogSegment::begin_sample_iteration(uint64_t start)
 111 {
 112         return (SegmentAnalogDataIterator*)begin_raw_sample_iteration(start);
 113 }
 114
 115 void AnalogSegment::continue_sample_iteration(SegmentAnalogDataIterator* it, uint64_t increase)
 116 {
 117         Segment::continue_raw_sample_iteration((SegmentRawDataIterator*)it, increase);
 118 }
 119
 120 void AnalogSegment::end_sample_iteration(SegmentAnalogDataIterator* it)
 121 {
 122         Segment::end_raw_sample_iteration((SegmentRawDataIterator*)it);
 123 }
 124
 125 void AnalogSegment::get_envelope_section(EnvelopeSection &s,
 126         uint64_t start, uint64_t end, float min_length) const
 127 {
 128         assert(end <= get_sample_count());
 129         assert(start <= end);
 130         assert(min_length > 0);
 131
 132         lock_guard<recursive_mutex> lock(mutex_);
 133
 134         const unsigned int min_level = max((int)floorf(logf(min_length) /
 135                 LogEnvelopeScaleFactor) - 1, 0);
 136         const unsigned int scale_power = (min_level + 1) *
 137                 EnvelopeScalePower;
 138         start >>= scale_power;
 139         end >>= scale_power;
 140
 141         s.start = start << scale_power;
 142         s.scale = 1 << scale_power;
 143         s.length = end - start;
 144         s.samples = new EnvelopeSample[s.length];
 145         memcpy(s.samples, envelope_levels_[min_level].samples + start,
 146                 s.length * sizeof(EnvelopeSample));
 147 }
 148
 149 void AnalogSegment::reallocate_envelope(Envelope &e)
 150 {
 151         const uint64_t new_data_length = ((e.length + EnvelopeDataUnit - 1) /
 152                 EnvelopeDataUnit) * EnvelopeDataUnit;
 153         if (new_data_length > e.data_length) {
 154                 e.data_length = new_data_length;
 155                 e.samples = (EnvelopeSample*)realloc(e.samples,
 156                         new_data_length * sizeof(EnvelopeSample));
 157         }
 158 }
 159
 160 void AnalogSegment::append_payload_to_envelope_levels()
 161 {
 162         Envelope &e0 = envelope_levels_[0];
 163         uint64_t prev_length;
 164         EnvelopeSample *dest_ptr;
 165         SegmentRawDataIterator* it;
 166
 167         // Expand the data buffer to fit the new samples
 168         prev_length = e0.length;
 169         e0.length = sample_count_ / EnvelopeScaleFactor;
 170
 171         // Calculate min/max values in case we have too few samples for an envelope
 172         if (sample_count_ < EnvelopeScaleFactor) {
 173                 it = begin_raw_sample_iteration(0);
 174                 for (uint64_t i = 0; i < sample_count_; i++) {
 175                         const float sample = *((float*)it->value);
 176                         if (sample < min_value_)
 177                                 min_value_ = sample;
 178                         if (sample > max_value_)
 179                                 max_value_ = sample;
 180                         continue_raw_sample_iteration(it, 1);
 181                 }
 182                 end_raw_sample_iteration(it);
 183         }
 184
 185         // Break off if there are no new samples to compute
 186         if (e0.length == prev_length)
 187                 return;
 188
 189         reallocate_envelope(e0);
 190
 191         dest_ptr = e0.samples + prev_length;
 192
 193         // Iterate through the samples to populate the first level mipmap
 194         uint64_t start_sample = prev_length * EnvelopeScaleFactor;
 195         uint64_t end_sample = e0.length * EnvelopeScaleFactor;
 196
 197         it = begin_raw_sample_iteration(start_sample);
 198         for (uint64_t i = start_sample; i < end_sample; i += EnvelopeScaleFactor) {
 199                 const float* samples = (float*)it->value;
 200
 201                 const EnvelopeSample sub_sample = {
 202                         *min_element(samples, samples + EnvelopeScaleFactor),
 203                         *max_element(samples, samples + EnvelopeScaleFactor),
 204                 };
 205
 206                 if (sub_sample.min < min_value_)
 207                         min_value_ = sub_sample.min;
 208                 if (sub_sample.max > max_value_)
 209                         max_value_ = sub_sample.max;
 210
 211                 continue_raw_sample_iteration(it, EnvelopeScaleFactor);
 212                 *dest_ptr++ = sub_sample;
 213         }
 214         end_raw_sample_iteration(it);
 215
 216         // Compute higher level mipmaps
 217         for (unsigned int level = 1; level < ScaleStepCount; level++) {
 218                 Envelope &e = envelope_levels_[level];
 219                 const Envelope &el = envelope_levels_[level - 1];
 220
 221                 // Expand the data buffer to fit the new samples
 222                 prev_length = e.length;
 223                 e.length = el.length / EnvelopeScaleFactor;
 224
 225                 // Break off if there are no more samples to be computed
 226                 if (e.length == prev_length)
 227                         break;
 228
 229                 reallocate_envelope(e);
 230
 231                 // Subsample the lower level
 232                 const EnvelopeSample *src_ptr =
 233                         el.samples + prev_length * EnvelopeScaleFactor;
 234                 const EnvelopeSample *const end_dest_ptr = e.samples + e.length;
 235
 236                 for (dest_ptr = e.samples + prev_length;
 237                                 dest_ptr < end_dest_ptr; dest_ptr++) {
 238                         const EnvelopeSample *const end_src_ptr =
 239                                 src_ptr + EnvelopeScaleFactor;
 240
 241                         EnvelopeSample sub_sample = *src_ptr++;
 242                         while (src_ptr < end_src_ptr) {
 243                                 sub_sample.min = min(sub_sample.min, src_ptr->min);;
 244                                 sub_sample.max = max(sub_sample.max, src_ptr->max);
 245                                 src_ptr++;
 246                         }
 247
 248                         *dest_ptr = sub_sample;
 249                 }
 250         }
 251 }
 252
 253 } // namespace data
 254 } // namespace pv