Mercurial > foo_out_sdl
diff foosdk/sdk/foobar2000/helpers/VisUtils.cpp @ 1:20d02a178406 default tip
*: check in everything else
yay
| author | Paper <paper@tflc.us> |
|---|---|
| date | Mon, 05 Jan 2026 02:15:46 -0500 |
| parents | |
| children |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/foosdk/sdk/foobar2000/helpers/VisUtils.cpp Mon Jan 05 02:15:46 2026 -0500 @@ -0,0 +1,38 @@ +#include "StdAfx.h" + +#include "VisUtils.h" + +namespace VisUtils { + void PrepareFFTChunk(audio_chunk const & source, audio_chunk & out, double centerOffset) { + const t_uint32 channels = source.get_channel_count(); + const t_uint32 sampleRate = source.get_sample_rate(); + FB2K_DYNAMIC_ASSERT( sampleRate > 0 ); + out.set_channels(channels, source.get_channel_config()); + out.set_sample_rate(sampleRate); + const t_size inSize = source.get_sample_count(); + const t_size fftSize = MatchFFTSize(inSize); + out.set_sample_count(fftSize); + out.set_data_size(fftSize * channels); + if (fftSize >= inSize) { //rare case with *REALLY* small input + pfc::memcpy_t( out.get_data(), source.get_data(), inSize * channels ); + pfc::memset_null_t( out.get_data() + inSize * channels, (fftSize - inSize) * channels ); + } else { //inSize > fftSize, we're using a subset of source chunk for the job, pick a subset around centerOffset. + const double baseOffset = pfc::max_t<double>(0, centerOffset - 0.5 * (double)fftSize / (double)sampleRate); + const t_size baseSample = pfc::min_t<t_size>( (t_size) audio_math::time_to_samples(baseOffset, sampleRate), inSize - fftSize); + pfc::memcpy_t( out.get_data(), source.get_data() + baseSample * channels, fftSize * channels); + } + } + + bool IsValidFFTSize(t_size p_size) { + return p_size >= 2 && (p_size & (p_size - 1)) == 0; + } + + t_size MatchFFTSize(t_size samples) { + if (samples <= 2) return 2; + t_size mask = 1; + while(!IsValidFFTSize(samples)) { + samples &= ~mask; mask <<= 1; + } + return samples; + } +};
