diff options
Diffstat (limited to 'src/audio_core/codec.cpp')
| -rw-r--r-- | src/audio_core/codec.cpp | 77 |
1 files changed, 0 insertions, 77 deletions
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 @@ | |||
| 1 | // SPDX-FileCopyrightText: Copyright 2018 yuzu Emulator Project | ||
| 2 | // SPDX-License-Identifier: GPL-2.0-or-later | ||
| 3 | |||
| 4 | #include <algorithm> | ||
| 5 | |||
| 6 | #include "audio_core/codec.h" | ||
| 7 | |||
| 8 | namespace AudioCore::Codec { | ||
| 9 | |||
| 10 | std::vector<s16> DecodeADPCM(const u8* const data, std::size_t size, const ADPCM_Coeff& coeff, | ||
| 11 | ADPCMState& state) { | ||
| 12 | // GC-ADPCM with scale factor and variable coefficients. | ||
| 13 | // Frames are 8 bytes long containing 14 samples each. | ||
| 14 | // Samples are 4 bits (one nibble) long. | ||
| 15 | |||
| 16 | constexpr std::size_t FRAME_LEN = 8; | ||
| 17 | constexpr std::size_t SAMPLES_PER_FRAME = 14; | ||
| 18 | static constexpr std::array<int, 16> SIGNED_NIBBLES{ | ||
| 19 | 0, 1, 2, 3, 4, 5, 6, 7, -8, -7, -6, -5, -4, -3, -2, -1, | ||
| 20 | }; | ||
| 21 | |||
| 22 | const std::size_t sample_count = (size / FRAME_LEN) * SAMPLES_PER_FRAME; | ||
| 23 | const std::size_t ret_size = | ||
| 24 | sample_count % 2 == 0 ? sample_count : sample_count + 1; // Ensure multiple of two. | ||
| 25 | std::vector<s16> ret(ret_size); | ||
| 26 | |||
| 27 | int yn1 = state.yn1, yn2 = state.yn2; | ||
| 28 | |||
| 29 | const std::size_t NUM_FRAMES = | ||
| 30 | (sample_count + (SAMPLES_PER_FRAME - 1)) / SAMPLES_PER_FRAME; // Round up. | ||
| 31 | for (std::size_t framei = 0; framei < NUM_FRAMES; framei++) { | ||
| 32 | const int frame_header = data[framei * FRAME_LEN]; | ||
| 33 | const int scale = 1 << (frame_header & 0xF); | ||
| 34 | const int idx = (frame_header >> 4) & 0x7; | ||
| 35 | |||
| 36 | // Coefficients are fixed point with 11 bits fractional part. | ||
| 37 | const int coef1 = coeff[idx * 2 + 0]; | ||
| 38 | const int coef2 = coeff[idx * 2 + 1]; | ||
| 39 | |||
| 40 | // Decodes an audio sample. One nibble produces one sample. | ||
| 41 | const auto decode_sample = [&](const int nibble) -> s16 { | ||
| 42 | const int xn = nibble * scale; | ||
| 43 | // We first transform everything into 11 bit fixed point, perform the second order | ||
| 44 | // digital filter, then transform back. | ||
| 45 | // 0x400 == 0.5 in 11 bit fixed point. | ||
| 46 | // Filter: y[n] = x[n] + 0.5 + c1 * y[n-1] + c2 * y[n-2] | ||
| 47 | int val = ((xn << 11) + 0x400 + coef1 * yn1 + coef2 * yn2) >> 11; | ||
| 48 | // Clamp to output range. | ||
| 49 | val = std::clamp<s32>(val, -32768, 32767); | ||
| 50 | // Advance output feedback. | ||
| 51 | yn2 = yn1; | ||
| 52 | yn1 = val; | ||
| 53 | return static_cast<s16>(val); | ||
| 54 | }; | ||
| 55 | |||
| 56 | std::size_t outputi = framei * SAMPLES_PER_FRAME; | ||
| 57 | std::size_t datai = framei * FRAME_LEN + 1; | ||
| 58 | for (std::size_t i = 0; i < SAMPLES_PER_FRAME && outputi < sample_count; i += 2) { | ||
| 59 | const s16 sample1 = decode_sample(SIGNED_NIBBLES[data[datai] >> 4]); | ||
| 60 | ret[outputi] = sample1; | ||
| 61 | outputi++; | ||
| 62 | |||
| 63 | const s16 sample2 = decode_sample(SIGNED_NIBBLES[data[datai] & 0xF]); | ||
| 64 | ret[outputi] = sample2; | ||
| 65 | outputi++; | ||
| 66 | |||
| 67 | datai++; | ||
| 68 | } | ||
| 69 | } | ||
| 70 | |||
| 71 | state.yn1 = static_cast<s16>(yn1); | ||
| 72 | state.yn2 = static_cast<s16>(yn2); | ||
| 73 | |||
| 74 | return ret; | ||
| 75 | } | ||
| 76 | |||
| 77 | } // namespace AudioCore::Codec | ||