annotate data/fileio/AudioFileSizeEstimator.cpp @ 1858:14747f24ad04

Use cancellable serialiser; add some more profiling points
author Chris Cannam
date Thu, 14 May 2020 16:36:48 +0100
parents ce185d4dd408
children
rev   line source
Chris@1098 1 /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */
Chris@1098 2
Chris@1098 3 /*
Chris@1098 4 Sonic Visualiser
Chris@1098 5 An audio file viewer and annotation editor.
Chris@1098 6 Centre for Digital Music, Queen Mary, University of London.
Chris@1098 7
Chris@1098 8 This program is free software; you can redistribute it and/or
Chris@1098 9 modify it under the terms of the GNU General Public License as
Chris@1098 10 published by the Free Software Foundation; either version 2 of the
Chris@1098 11 License, or (at your option) any later version. See the file
Chris@1098 12 COPYING included with this distribution for more information.
Chris@1098 13 */
Chris@1098 14
Chris@1098 15 #include "AudioFileSizeEstimator.h"
Chris@1098 16
Chris@1098 17 #include "WavFileReader.h"
Chris@1098 18
Chris@1098 19 #include <QFile>
Chris@1098 20
Chris@1342 21 #include "base/Debug.h"
Chris@1104 22
Chris@1098 23 sv_frame_t
Chris@1098 24 AudioFileSizeEstimator::estimate(FileSource source,
Chris@1341 25 sv_samplerate_t targetRate)
Chris@1098 26 {
Chris@1098 27 sv_frame_t estimate = 0;
Chris@1098 28
Chris@1342 29 SVDEBUG << "AudioFileSizeEstimator: Sample count estimate requested for file \""
Chris@1342 30 << source.getLocalFilename() << "\"" << endl;
Chris@1342 31
Chris@1098 32 // Most of our file readers don't know the sample count until
Chris@1098 33 // after they've finished decoding. This is an exception:
Chris@1098 34
Chris@1098 35 WavFileReader *reader = new WavFileReader(source);
Chris@1098 36 if (reader->isOK() &&
Chris@1341 37 reader->getChannelCount() > 0 &&
Chris@1341 38 reader->getFrameCount() > 0) {
Chris@1341 39 sv_frame_t samples =
Chris@1341 40 reader->getFrameCount() * reader->getChannelCount();
Chris@1341 41 sv_samplerate_t rate = reader->getSampleRate();
Chris@1341 42 if (targetRate != 0.0 && targetRate != rate) {
Chris@1341 43 samples = sv_frame_t(double(samples) * targetRate / rate);
Chris@1341 44 }
Chris@1342 45 SVDEBUG << "AudioFileSizeEstimator: WAV file reader accepts this file, reports "
Chris@1342 46 << samples << " samples" << endl;
Chris@1341 47 estimate = samples;
Chris@1342 48 } else {
Chris@1342 49 SVDEBUG << "AudioFileSizeEstimator: WAV file reader doesn't like this file, "
Chris@1342 50 << "estimating from file size and extension instead" << endl;
Chris@1098 51 }
Chris@1098 52
Chris@1402 53 delete reader;
Chris@1582 54 reader = nullptr;
Chris@1402 55
Chris@1098 56 if (estimate == 0) {
Chris@1098 57
Chris@1341 58 // The remainder just makes an estimate based on the file size
Chris@1341 59 // and extension. We don't even know its sample rate at this
Chris@1341 60 // point, so the following is a wild guess.
Chris@1341 61
Chris@1341 62 double rateRatio = 1.0;
Chris@1341 63 if (targetRate != 0.0) {
Chris@1341 64 rateRatio = targetRate / 44100.0;
Chris@1341 65 }
Chris@1098 66
Chris@1341 67 QString extension = source.getExtension();
Chris@1098 68
Chris@1341 69 source.waitForData();
Chris@1341 70 if (!source.isOK()) return 0;
Chris@1098 71
Chris@1341 72 sv_frame_t sz = 0;
Chris@1342 73
Chris@1341 74 {
Chris@1341 75 QFile f(source.getLocalFilename());
Chris@1341 76 if (f.open(QFile::ReadOnly)) {
Chris@1342 77 SVDEBUG << "AudioFileSizeEstimator: opened file, size is "
Chris@1342 78 << f.size() << endl;
Chris@1341 79 sz = f.size();
Chris@1341 80 f.close();
Chris@1341 81 }
Chris@1341 82 }
Chris@1098 83
Chris@1341 84 if (extension == "ogg" || extension == "oga" ||
Chris@1341 85 extension == "m4a" || extension == "mp3" ||
Chris@1592 86 extension == "wma" || extension == "opus") {
Chris@1098 87
Chris@1341 88 // Usually a lossy file. Compression ratios can vary
Chris@1341 89 // dramatically, but don't usually exceed about 20x compared
Chris@1341 90 // to 16-bit PCM (e.g. a 128kbps mp3 has 11x ratio over WAV at
Chris@1341 91 // 44.1kHz). We can estimate the number of samples to be file
Chris@1341 92 // size x 20, divided by 2 as we're comparing with 16-bit PCM.
Chris@1098 93
Chris@1341 94 estimate = sv_frame_t(double(sz) * 10 * rateRatio);
Chris@1341 95 }
Chris@1098 96
Chris@1341 97 if (extension == "flac") {
Chris@1341 98
Chris@1341 99 // FLAC usually takes up a bit more than half the space of
Chris@1341 100 // 16-bit PCM. So the number of 16-bit samples is roughly the
Chris@1341 101 // same as the file size in bytes. As above, let's be
Chris@1341 102 // conservative.
Chris@1098 103
Chris@1341 104 estimate = sv_frame_t(double(sz) * 1.2 * rateRatio);
Chris@1341 105 }
Chris@1098 106
Chris@1342 107 SVDEBUG << "AudioFileSizeEstimator: for extension \""
Chris@1342 108 << extension << "\", estimate = " << estimate << " samples" << endl;
Chris@1098 109 }
Chris@1098 110
Chris@1098 111 return estimate;
Chris@1098 112 }
Chris@1098 113