From 458da8a94877677f086f06cdeecf959ec4283a33 Mon Sep 17 00:00:00 2001 From: Kelebek1 Date: Sat, 16 Jul 2022 23:48:45 +0100 Subject: Project Andio --- src/audio_core/codec.cpp | 77 ------------------------------------------------ 1 file changed, 77 deletions(-) delete mode 100644 src/audio_core/codec.cpp (limited to 'src/audio_core/codec.cpp') diff --git a/src/audio_core/codec.cpp b/src/audio_core/codec.cpp deleted file mode 100644 index 868b7a173..000000000 --- a/src/audio_core/codec.cpp +++ /dev/null @@ -1,77 +0,0 @@ -// SPDX-FileCopyrightText: Copyright 2018 yuzu Emulator Project -// SPDX-License-Identifier: GPL-2.0-or-later - -#include - -#include "audio_core/codec.h" - -namespace AudioCore::Codec { - -std::vector DecodeADPCM(const u8* const data, std::size_t size, const ADPCM_Coeff& coeff, - ADPCMState& state) { - // GC-ADPCM with scale factor and variable coefficients. - // Frames are 8 bytes long containing 14 samples each. - // Samples are 4 bits (one nibble) long. - - constexpr std::size_t FRAME_LEN = 8; - constexpr std::size_t SAMPLES_PER_FRAME = 14; - static constexpr std::array SIGNED_NIBBLES{ - 0, 1, 2, 3, 4, 5, 6, 7, -8, -7, -6, -5, -4, -3, -2, -1, - }; - - const std::size_t sample_count = (size / FRAME_LEN) * SAMPLES_PER_FRAME; - const std::size_t ret_size = - sample_count % 2 == 0 ? sample_count : sample_count + 1; // Ensure multiple of two. - std::vector ret(ret_size); - - int yn1 = state.yn1, yn2 = state.yn2; - - const std::size_t NUM_FRAMES = - (sample_count + (SAMPLES_PER_FRAME - 1)) / SAMPLES_PER_FRAME; // Round up. - for (std::size_t framei = 0; framei < NUM_FRAMES; framei++) { - const int frame_header = data[framei * FRAME_LEN]; - const int scale = 1 << (frame_header & 0xF); - const int idx = (frame_header >> 4) & 0x7; - - // Coefficients are fixed point with 11 bits fractional part. - const int coef1 = coeff[idx * 2 + 0]; - const int coef2 = coeff[idx * 2 + 1]; - - // Decodes an audio sample. One nibble produces one sample. - const auto decode_sample = [&](const int nibble) -> s16 { - const int xn = nibble * scale; - // We first transform everything into 11 bit fixed point, perform the second order - // digital filter, then transform back. - // 0x400 == 0.5 in 11 bit fixed point. - // Filter: y[n] = x[n] + 0.5 + c1 * y[n-1] + c2 * y[n-2] - int val = ((xn << 11) + 0x400 + coef1 * yn1 + coef2 * yn2) >> 11; - // Clamp to output range. - val = std::clamp(val, -32768, 32767); - // Advance output feedback. - yn2 = yn1; - yn1 = val; - return static_cast(val); - }; - - std::size_t outputi = framei * SAMPLES_PER_FRAME; - std::size_t datai = framei * FRAME_LEN + 1; - for (std::size_t i = 0; i < SAMPLES_PER_FRAME && outputi < sample_count; i += 2) { - const s16 sample1 = decode_sample(SIGNED_NIBBLES[data[datai] >> 4]); - ret[outputi] = sample1; - outputi++; - - const s16 sample2 = decode_sample(SIGNED_NIBBLES[data[datai] & 0xF]); - ret[outputi] = sample2; - outputi++; - - datai++; - } - } - - state.yn1 = static_cast(yn1); - state.yn2 = static_cast(yn2); - - return ret; -} - -} // namespace AudioCore::Codec -- cgit v1.2.3