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