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Update to audio spectrum quality settings. The quality settings now means something slightly different (but are more sensible) and there is always a memory max enforced for the spectrum cache.

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Originally committed to SVN as r1615.
This commit is contained in:
Niels Martin Hansen 2007-10-19 03:32:53 +00:00
parent 2e57dda49e
commit eeee2aeb53
2 changed files with 61 additions and 14 deletions
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71
aegisub/audio_spectrum.cpp
View file

@ -374,7 +374,10 @@ public:
cache_root = new IntermediateSpectrumCache(provider, 0, num_lines, num_overlaps, 0);
// option is stored in megabytes, but we want number of bytes
unsigned long max_cache_size = Options.AsInt(_T("Audio Spectrum Memory Max")) * 1024 * 1024;
unsigned long max_cache_size = Options.AsInt(_T("Audio Spectrum Memory Max"));
// It can't go too low
if (max_cache_size < 5) max_cache_size = 128;
max_cache_size *= 1024 * 1024;
unsigned long line_size = sizeof(AudioSpectrumCache::CacheLine::value_type) * line_length;
max_lines_cached = max_cache_size / line_size;
}
@ -392,22 +395,66 @@ AudioSpectrum::AudioSpectrum(AudioProvider *_provider)
{
provider = _provider;
// Determine the quality of the spectrum rendering based on an index
int quality_index = Options.AsInt(_T("Audio Spectrum Quality"));
if (quality_index < 0) quality_index = 0;
if (quality_index > 5) quality_index = 5; // no need to go freaking insane
if (quality_index > 1)
line_length = 1 << (8 + quality_index - 1);
else
line_length = 1 << 8;
if (quality_index == 0)
fft_overlaps = 1;
else if (quality_index == 1)
fft_overlaps = 4;
else
fft_overlaps = 1 << quality_index;
// Line length determines the balance between resolution in the time and frequency domains.
// Larger line length gives better resolution in frequency domain,
// smaller gives better resolution in time domain.
// Any values uses the same amount of memory, but larger values takes (slightly) more CPU.
// Line lengths must be powers of 2 due to the FFT algorithm.
// 2^8 is a good compromise between time and frequency domain resolution, any smaller
// gives an unreasonably low resolution in the frequency domain.
// Increasing the number of overlaps gives better resolution in the time domain.
// Doubling the number of overlaps doubles memory and CPU use, and also
// doubles resolution in the time domain.
switch (quality_index) {
case 0:
// No overlaps, good comprimise between time/frequency resolution.
// 4 bytes used per sample.
line_length = 1<<8;
fft_overlaps = 1;
break;
case 1:
// Double frequency resolution, the resulting half time resolution
// is countered with an overlap.
// 8 bytes per sample.
line_length = 1<<9;
fft_overlaps = 2;
break;
case 2:
// Resulting double resolution in both domains.
// 16 bytes per sample.
line_length = 1<<9;
fft_overlaps = 4;
break;
case 3:
// Double frequency and quadrouble time resolution.
// 32 bytes per sample.
line_length = 1<<9;
fft_overlaps = 8;
break;
case 4:
// Quadrouble resolution in both domains.
// 64 bytes per sample.
line_length = 1<<10;
fft_overlaps = 16;
break;
case 5:
// Eight-double resolution in both domains.
// 256 bytes per sample.
line_length = 1<<11;
fft_overlaps = 64;
break;
default:
throw _T("Internal error in AudioSpectrum class - impossible quality index");
}
int64_t _num_lines = provider->GetNumSamples() / line_length / 2;
//assert (_num_lines < (1<<31)); // hope it fits into 32 bits...
num_lines = (unsigned long)_num_lines;
AudioSpectrumCache::SetLineLength(line_length);

4
aegisub/options.cpp
View file

@ -193,8 +193,8 @@ void OptionsManager::LoadDefaults(bool onlyDefaults) {
SetText(_T("Audio HD Cache Name"),_T("audio%02i.tmp"));
// Technically these can do with just the spectrum object being re-created
SetInt(_T("Audio Spectrum Cutoff"),0);
SetInt(_T("Audio Spectrum Quality"),0);
SetInt(_T("Audio Spectrum Memory Max"),0); // megabytes
SetInt(_T("Audio Spectrum Quality"),1);
SetInt(_T("Audio Spectrum Memory Max"),128); // megabytes
// Automation
// The path changes only take effect when a script is (re)loaded but Automatic should be good enough, it certainly doesn't warrart a restart