Merge pull request #1877 from heapo/audio_interp

Perf: Avoid (expensive) audio interpolation when sample rates already match
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bunnei 2018-12-11 11:45:53 -05:00 committed by GitHub
commit 2c6679bb01
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2 changed files with 8 additions and 4 deletions

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@ -54,8 +54,9 @@ std::vector<s16> Interpolate(InterpolationState& state, std::vector<s16> input,
double l = 0.0;
double r = 0.0;
for (std::size_t j = 0; j < h.size(); j++) {
l += Lanczos(taps, pos + j - taps + 1) * h[j][0];
r += Lanczos(taps, pos + j - taps + 1) * h[j][1];
const double lanczos_calc = Lanczos(taps, pos + j - taps + 1);
l += lanczos_calc * h[j][0];
r += lanczos_calc * h[j][1];
}
output.emplace_back(static_cast<s16>(std::clamp(l, -32768.0, 32767.0)));
output.emplace_back(static_cast<s16>(std::clamp(r, -32768.0, 32767.0)));

View file

@ -285,8 +285,11 @@ void AudioRenderer::VoiceState::RefreshBuffer() {
break;
}
samples =
Interpolate(interp_state, std::move(samples), GetInfo().sample_rate, STREAM_SAMPLE_RATE);
// Only interpolate when necessary, expensive.
if (GetInfo().sample_rate != STREAM_SAMPLE_RATE) {
samples = Interpolate(interp_state, std::move(samples), GetInfo().sample_rate,
STREAM_SAMPLE_RATE);
}
is_refresh_pending = false;
}