From 2ccaaf5724fe08e63e06b677a42326d4f8e0550e Mon Sep 17 00:00:00 2001 From: jacqueline Date: Tue, 19 Dec 2023 22:45:29 +1100 Subject: Add dither when requantising >16 bit samples --- src/codecs/sample.cpp | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) create mode 100644 src/codecs/sample.cpp (limited to 'src/codecs/sample.cpp') diff --git a/src/codecs/sample.cpp b/src/codecs/sample.cpp new file mode 100644 index 00000000..c5c96fb9 --- /dev/null +++ b/src/codecs/sample.cpp @@ -0,0 +1,25 @@ +/* + * Copyright 2023 jacqueline + * + * SPDX-License-Identifier: GPL-3.0-only + */ + +#include "sample.hpp" + +#include + +#include "komihash.h" + +namespace sample { + +static uint64_t sSeed1{0}; +static uint64_t sSeed2{0}; + +auto applyDither(int64_t src, uint_fast8_t bits) -> int32_t { + uint64_t mask = 0xFFFFFFFF; // 32 ones + mask >>= 32 - bits; // `bits` ones + uint64_t noise = komirand(&sSeed1, &sSeed2) & mask; // `bits` random noise + return std::clamp(src + noise, INT32_MIN, INT32_MAX); +} + +} // namespace sample -- cgit v1.2.3