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pcm/Normalizer: no in-place editing, separate src/dest parameters 

This eliminates the memcpy() call from NormalizeFilter::FilterPCM().
This commit is contained in:
Max Kellermann 2023-03-13 13:17:43 +01:00
parent 8ea9b89321
commit d7f2d90fd3
4 changed files with 18 additions and 16 deletions
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13
src/filter/plugins/NormalizeFilterPlugin.cxx
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@ -8,8 +8,7 @@
#include "pcm/Buffer.hxx"
#include "pcm/AudioFormat.hxx"
#include "pcm/Normalizer.hxx"
#include <string.h>
#include "util/SpanCast.hxx"
class NormalizeFilter final : public Filter {
PcmNormalizer normalizer;
@ -49,13 +48,13 @@ PreparedNormalizeFilter::Open(AudioFormat &audio_format)
}
std::span<const std::byte>
NormalizeFilter::FilterPCM(std::span<const std::byte> src)
NormalizeFilter::FilterPCM(std::span<const std::byte> _src)
{
auto *dest = (int16_t *)buffer.Get(src.size());
memcpy(dest, src.data(), src.size());
const auto src = FromBytesStrict<const int16_t>(_src);
auto *dest = (int16_t *)buffer.GetT<int16_t>(src.size());
normalizer.ProcessS16({dest, src.size() / 2});
return { (const std::byte *)dest, src.size() };
normalizer.ProcessS16(dest, src);
return std::as_bytes(std::span{dest, src.size()});
}
const FilterPlugin normalize_filter_plugin = {

14
src/pcm/Normalizer.cxx
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@ -6,9 +6,11 @@
#include "Clamp.hxx"
#include "SampleFormat.hxx"
#include "Traits.hxx"
#include "util/Compiler.h"
void
PcmNormalizer::ProcessS16(const std::span<int16_t> audio) noexcept
PcmNormalizer::ProcessS16(int16_t *gcc_restrict dest,
const std::span<const int16_t> src) noexcept
{
constexpr SampleFormat format = SampleFormat::S16;
using Traits = SampleTraits<format>;
@ -16,8 +18,8 @@ PcmNormalizer::ProcessS16(const std::span<int16_t> audio) noexcept
const int slot = (pos + 1) % bufsz;
int peakVal = 1, peakPos = 0;
for (std::size_t i = 0; i < audio.size(); i++) {
int val = audio[i];
for (std::size_t i = 0; i < src.size(); i++) {
int val = src[i];
if (val < 0)
val = -val;
if (val > peakVal)
@ -52,7 +54,7 @@ PcmNormalizer::ProcessS16(const std::span<int16_t> audio) noexcept
newGain = 1 << 10;
//! Make sure the adjusted gain won't cause clipping
std::size_t ramp = audio.size();
std::size_t ramp = src.size();
if ((peakVal*newGain >> 10) > Traits::MAX)
{
newGain = (Traits::MAX << 10)/peakVal;
@ -69,9 +71,9 @@ PcmNormalizer::ProcessS16(const std::span<int16_t> audio) noexcept
curGain = 1 << 10;
const int delta = (newGain - curGain) / (int)ramp;
for (std::size_t i = 0; i < audio.size(); i++) {
for (std::size_t i = 0; i < src.size(); i++) {
//! Amplify the sample
audio[i] = PcmClamp<format>(audio[i] * curGain >> 10);
*dest++ = PcmClamp<format>(src[i] * curGain >> 10);
//! Adjust the gain
if (i < ramp)

2
src/pcm/Normalizer.hxx
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@ -41,7 +41,7 @@ public:
}
//! Process 16-bit signed data
void ProcessS16(std::span<int16_t> audio) noexcept;
void ProcessS16(int16_t *dest, std::span<const int16_t> src) noexcept;
};
//! TODO: Compressor_Process_int32, Compressor_Process_float, others as needed

5
test/run_normalize.cxx
View File

@ -37,8 +37,9 @@ try {
static std::byte buffer[4096];
ssize_t nbytes;
while ((nbytes = read(0, buffer, sizeof(buffer))) > 0) {
normalizer.ProcessS16(FromBytesStrict<int16_t>(std::span{buffer}.first(nbytes)));
[[maybe_unused]] ssize_t ignored = write(1, buffer, nbytes);
static int16_t dest[2048];
normalizer.ProcessS16(dest, FromBytesStrict<const int16_t>(std::span{buffer}.first(nbytes)));
[[maybe_unused]] ssize_t ignored = write(1, dest, nbytes);
}
return EXIT_SUCCESS;