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comparison foosdk/sdk/foobar2000/helpers/VisUtils.cpp @ 1:20d02a178406 default tip

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*: check in everything else yay
author Paper <paper@tflc.us>
date Mon, 05 Jan 2026 02:15:46 -0500
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0:e9bb126753e7 1:20d02a178406
1 #include "StdAfx.h"
2
3 #include "VisUtils.h"
4
5 namespace VisUtils {
6 void PrepareFFTChunk(audio_chunk const & source, audio_chunk & out, double centerOffset) {
7 const t_uint32 channels = source.get_channel_count();
8 const t_uint32 sampleRate = source.get_sample_rate();
9 FB2K_DYNAMIC_ASSERT( sampleRate > 0 );
10 out.set_channels(channels, source.get_channel_config());
11 out.set_sample_rate(sampleRate);
12 const t_size inSize = source.get_sample_count();
13 const t_size fftSize = MatchFFTSize(inSize);
14 out.set_sample_count(fftSize);
15 out.set_data_size(fftSize * channels);
16 if (fftSize >= inSize) { //rare case with *REALLY* small input
17 pfc::memcpy_t( out.get_data(), source.get_data(), inSize * channels );
18 pfc::memset_null_t( out.get_data() + inSize * channels, (fftSize - inSize) * channels );
19 } else { //inSize > fftSize, we're using a subset of source chunk for the job, pick a subset around centerOffset.
20 const double baseOffset = pfc::max_t<double>(0, centerOffset - 0.5 * (double)fftSize / (double)sampleRate);
21 const t_size baseSample = pfc::min_t<t_size>( (t_size) audio_math::time_to_samples(baseOffset, sampleRate), inSize - fftSize);
22 pfc::memcpy_t( out.get_data(), source.get_data() + baseSample * channels, fftSize * channels);
23 }
24 }
25
26 bool IsValidFFTSize(t_size p_size) {
27 return p_size >= 2 && (p_size & (p_size - 1)) == 0;
28 }
29
30 t_size MatchFFTSize(t_size samples) {
31 if (samples <= 2) return 2;
32 t_size mask = 1;
33 while(!IsValidFFTSize(samples)) {
34 samples &= ~mask; mask <<= 1;
35 }
36 return samples;
37 }
38 };