diff options
Diffstat (limited to 'src/audio_core')
| -rw-r--r-- | src/audio_core/algorithm/interpolate.cpp | 54 | ||||
| -rw-r--r-- | src/audio_core/algorithm/interpolate.h | 7 |
2 files changed, 38 insertions, 23 deletions
diff --git a/src/audio_core/algorithm/interpolate.cpp b/src/audio_core/algorithm/interpolate.cpp index a58f24169..49ab9d3e1 100644 --- a/src/audio_core/algorithm/interpolate.cpp +++ b/src/audio_core/algorithm/interpolate.cpp @@ -8,13 +8,14 @@ #include <climits> #include <cmath> #include <vector> + #include "audio_core/algorithm/interpolate.h" #include "common/common_types.h" #include "common/logging/log.h" namespace AudioCore { -constexpr std::array<s16, 512> curve_lut0 = { +constexpr std::array<s16, 512> curve_lut0{ 6600, 19426, 6722, 3, 6479, 19424, 6845, 9, 6359, 19419, 6968, 15, 6239, 19412, 7093, 22, 6121, 19403, 7219, 28, 6004, 19391, 7345, 34, 5888, 19377, 7472, 41, 5773, 19361, 7600, 48, 5659, 19342, 7728, 55, 5546, 19321, 7857, @@ -56,7 +57,7 @@ constexpr std::array<s16, 512> curve_lut0 = { 19403, 6121, 22, 7093, 19412, 6239, 15, 6968, 19419, 6359, 9, 6845, 19424, 6479, 3, 6722, 19426, 6600}; -constexpr std::array<s16, 512> curve_lut1 = { +constexpr std::array<s16, 512> curve_lut1{ -68, 32639, 69, -5, -200, 32630, 212, -15, -328, 32613, 359, -26, -450, 32586, 512, -36, -568, 32551, 669, -47, -680, 32507, 832, -58, -788, 32454, 1000, -69, -891, 32393, 1174, -80, -990, 32323, 1352, -92, -1084, 32244, 1536, @@ -98,7 +99,7 @@ constexpr std::array<s16, 512> curve_lut1 = { 32551, -568, -36, 512, 32586, -450, -26, 359, 32613, -328, -15, 212, 32630, -200, -5, 69, 32639, -68}; -constexpr std::array<s16, 512> curve_lut2 = { +constexpr std::array<s16, 512> curve_lut2{ 3195, 26287, 3329, -32, 3064, 26281, 3467, -34, 2936, 26270, 3608, -38, 2811, 26253, 3751, -42, 2688, 26230, 3897, -46, 2568, 26202, 4046, -50, 2451, 26169, 4199, -54, 2338, 26130, 4354, -58, 2227, 26085, 4512, -63, 2120, 26035, 4673, @@ -146,10 +147,10 @@ std::vector<s16> Interpolate(InterpolationState& state, std::vector<s16> input, if (ratio <= 0) { LOG_CRITICAL(Audio, "Nonsensical interpolation ratio {}", ratio); - ratio = 1.0; + return input; } - const int step = static_cast<int>(ratio * 0x8000); + const s32 step{static_cast<s32>(ratio * 0x8000)}; const std::array<s16, 512>& lut = [step] { if (step > 0xaaaa) { return curve_lut0; @@ -160,28 +161,37 @@ std::vector<s16> Interpolate(InterpolationState& state, std::vector<s16> input, return curve_lut2; }(); - std::vector<s16> output(static_cast<std::size_t>(input.size() / ratio)); - int in_offset = 0; - for (std::size_t out_offset = 0; out_offset < output.size(); out_offset += 2) { - const int lut_index = (state.fraction >> 8) * 4; + const std::size_t num_frames{input.size() / 2}; + + std::vector<s16> output; + output.reserve(static_cast<std::size_t>(input.size() / ratio + InterpolationState::taps)); - const int l = input[(in_offset + 0) * 2 + 0] * lut[lut_index + 0] + - input[(in_offset + 1) * 2 + 0] * lut[lut_index + 1] + - input[(in_offset + 2) * 2 + 0] * lut[lut_index + 2] + - input[(in_offset + 3) * 2 + 0] * lut[lut_index + 3]; + for (std::size_t frame{}; frame < num_frames; ++frame) { + const std::size_t lut_index{(state.fraction >> 8) * InterpolationState::taps}; - const int r = input[(in_offset + 0) * 2 + 1] * lut[lut_index + 0] + - input[(in_offset + 1) * 2 + 1] * lut[lut_index + 1] + - input[(in_offset + 2) * 2 + 1] * lut[lut_index + 2] + - input[(in_offset + 3) * 2 + 1] * lut[lut_index + 3]; + std::rotate(state.history.begin(), state.history.end() - 1, state.history.end()); + state.history[0][0] = input[frame * 2 + 0]; + state.history[0][1] = input[frame * 2 + 1]; - const int new_offset = state.fraction + step; + while (state.position <= 1.0) { + const s32 left{state.history[0][0] * lut[lut_index + 0] + + state.history[1][0] * lut[lut_index + 1] + + state.history[2][0] * lut[lut_index + 2] + + state.history[3][0] * lut[lut_index + 3]}; + const s32 right{state.history[0][1] * lut[lut_index + 0] + + state.history[1][1] * lut[lut_index + 1] + + state.history[2][1] * lut[lut_index + 2] + + state.history[3][1] * lut[lut_index + 3]}; + const s32 new_offset{state.fraction + step}; - in_offset += new_offset >> 15; - state.fraction = new_offset & 0x7fff; + state.fraction = new_offset & 0x7fff; - output[out_offset + 0] = static_cast<s16>(std::clamp(l >> 15, SHRT_MIN, SHRT_MAX)); - output[out_offset + 1] = static_cast<s16>(std::clamp(r >> 15, SHRT_MIN, SHRT_MAX)); + output.emplace_back(static_cast<s16>(std::clamp(left >> 15, SHRT_MIN, SHRT_MAX))); + output.emplace_back(static_cast<s16>(std::clamp(right >> 15, SHRT_MIN, SHRT_MAX))); + + state.position += ratio; + } + state.position -= 1.0; } return output; diff --git a/src/audio_core/algorithm/interpolate.h b/src/audio_core/algorithm/interpolate.h index 1b9831a75..ab1a31754 100644 --- a/src/audio_core/algorithm/interpolate.h +++ b/src/audio_core/algorithm/interpolate.h @@ -6,12 +6,17 @@ #include <array> #include <vector> + #include "common/common_types.h" namespace AudioCore { struct InterpolationState { - int fraction = 0; + static constexpr std::size_t taps{4}; + static constexpr std::size_t history_size{taps * 2 - 1}; + std::array<std::array<s16, 2>, history_size> history{}; + double position{}; + s32 fraction{}; }; /// Interpolates input signal to produce output signal. |