diff options
Diffstat (limited to 'src/codecs/include')
| -rw-r--r-- | src/codecs/include/sample.hpp | 21 |
1 files changed, 12 insertions, 9 deletions
diff --git a/src/codecs/include/sample.hpp b/src/codecs/include/sample.hpp index 937b6b79..8d79a228 100644 --- a/src/codecs/include/sample.hpp +++ b/src/codecs/include/sample.hpp @@ -25,15 +25,14 @@ namespace sample { typedef int16_t Sample; constexpr auto Clip(int64_t v) -> Sample { - if (v > INT16_MAX) - return INT16_MAX; - if (v < INT16_MIN) - return INT16_MIN; - return v; + return std::clamp<int64_t>(v, INT16_MIN, INT16_MAX); } +auto applyDither(int64_t src, uint_fast8_t bits) -> int32_t; + constexpr auto FromSigned(int32_t src, uint_fast8_t bits) -> Sample { if (bits > 16) { + src = applyDither(src, bits - 16); return src >> (bits - sizeof(Sample) * 8); } else if (bits < 16) { return src << (sizeof(Sample) * 8 - bits); @@ -48,16 +47,20 @@ constexpr auto FromUnsigned(uint32_t src, uint_fast8_t bits) -> Sample { } constexpr auto FromFloat(float src) -> Sample { - return std::clamp<float>(src, -1.0f, 1.0f) * static_cast<float>(INT16_MAX); + int32_t quantised = + std::clamp<float>(src, -1.0f, 1.0f) * static_cast<float>(INT32_MAX); + return FromSigned(quantised, 32); } constexpr auto FromDouble(double src) -> Sample { - return std::clamp<double>(src, -1.0, 1.0) * static_cast<double>(INT16_MAX); + int32_t quantised = + std::clamp<double>(src, -1.0, 1.0) * static_cast<double>(INT32_MAX); + return FromSigned(quantised, 32); } constexpr auto FromMad(mad_fixed_t src) -> Sample { // Round the bottom bits. - src += (1L << (MAD_F_FRACBITS - 16)); + src += (1L << (MAD_F_FRACBITS - 24)); // Clip the leftover bits to within range. if (src >= MAD_F_ONE) @@ -66,7 +69,7 @@ constexpr auto FromMad(mad_fixed_t src) -> Sample { src = -MAD_F_ONE; // Quantize. - return FromSigned(src >> (MAD_F_FRACBITS + 1 - 16), 16); + return FromSigned(src >> (MAD_F_FRACBITS + 1 - 24), 24); } static constexpr float kFactor = 1.0f / static_cast<float>(INT16_MAX); |
