diff options
Diffstat (limited to 'src/audio_core/codec.cpp')
| -rw-r--r-- | src/audio_core/codec.cpp | 127 |
1 files changed, 0 insertions, 127 deletions
diff --git a/src/audio_core/codec.cpp b/src/audio_core/codec.cpp deleted file mode 100644 index 6fba9fdae..000000000 --- a/src/audio_core/codec.cpp +++ /dev/null | |||
| @@ -1,127 +0,0 @@ | |||
| 1 | // Copyright 2016 Citra Emulator Project | ||
| 2 | // Licensed under GPLv2 or any later version | ||
| 3 | // Refer to the license.txt file included. | ||
| 4 | |||
| 5 | #include <array> | ||
| 6 | #include <cstddef> | ||
| 7 | #include <cstring> | ||
| 8 | #include <vector> | ||
| 9 | #include "audio_core/codec.h" | ||
| 10 | #include "common/assert.h" | ||
| 11 | #include "common/common_types.h" | ||
| 12 | #include "common/math_util.h" | ||
| 13 | |||
| 14 | namespace Codec { | ||
| 15 | |||
| 16 | StereoBuffer16 DecodeADPCM(const u8* const data, const size_t sample_count, | ||
| 17 | const std::array<s16, 16>& adpcm_coeff, ADPCMState& state) { | ||
| 18 | // GC-ADPCM with scale factor and variable coefficients. | ||
| 19 | // Frames are 8 bytes long containing 14 samples each. | ||
| 20 | // Samples are 4 bits (one nibble) long. | ||
| 21 | |||
| 22 | constexpr size_t FRAME_LEN = 8; | ||
| 23 | constexpr size_t SAMPLES_PER_FRAME = 14; | ||
| 24 | constexpr std::array<int, 16> SIGNED_NIBBLES = { | ||
| 25 | {0, 1, 2, 3, 4, 5, 6, 7, -8, -7, -6, -5, -4, -3, -2, -1}}; | ||
| 26 | |||
| 27 | const size_t ret_size = | ||
| 28 | sample_count % 2 == 0 ? sample_count : sample_count + 1; // Ensure multiple of two. | ||
| 29 | StereoBuffer16 ret(ret_size); | ||
| 30 | |||
| 31 | int yn1 = state.yn1, yn2 = state.yn2; | ||
| 32 | |||
| 33 | const size_t NUM_FRAMES = | ||
| 34 | (sample_count + (SAMPLES_PER_FRAME - 1)) / SAMPLES_PER_FRAME; // Round up. | ||
| 35 | for (size_t framei = 0; framei < NUM_FRAMES; framei++) { | ||
| 36 | const int frame_header = data[framei * FRAME_LEN]; | ||
| 37 | const int scale = 1 << (frame_header & 0xF); | ||
| 38 | const int idx = (frame_header >> 4) & 0x7; | ||
| 39 | |||
| 40 | // Coefficients are fixed point with 11 bits fractional part. | ||
| 41 | const int coef1 = adpcm_coeff[idx * 2 + 0]; | ||
| 42 | const int coef2 = adpcm_coeff[idx * 2 + 1]; | ||
| 43 | |||
| 44 | // Decodes an audio sample. One nibble produces one sample. | ||
| 45 | const auto decode_sample = [&](const int nibble) -> s16 { | ||
| 46 | const int xn = nibble * scale; | ||
| 47 | // We first transform everything into 11 bit fixed point, perform the second order | ||
| 48 | // digital filter, then transform back. | ||
| 49 | // 0x400 == 0.5 in 11 bit fixed point. | ||
| 50 | // Filter: y[n] = x[n] + 0.5 + c1 * y[n-1] + c2 * y[n-2] | ||
| 51 | int val = ((xn << 11) + 0x400 + coef1 * yn1 + coef2 * yn2) >> 11; | ||
| 52 | // Clamp to output range. | ||
| 53 | val = MathUtil::Clamp(val, -32768, 32767); | ||
| 54 | // Advance output feedback. | ||
| 55 | yn2 = yn1; | ||
| 56 | yn1 = val; | ||
| 57 | return (s16)val; | ||
| 58 | }; | ||
| 59 | |||
| 60 | size_t outputi = framei * SAMPLES_PER_FRAME; | ||
| 61 | size_t datai = framei * FRAME_LEN + 1; | ||
| 62 | for (size_t i = 0; i < SAMPLES_PER_FRAME && outputi < sample_count; i += 2) { | ||
| 63 | const s16 sample1 = decode_sample(SIGNED_NIBBLES[data[datai] >> 4]); | ||
| 64 | ret[outputi].fill(sample1); | ||
| 65 | outputi++; | ||
| 66 | |||
| 67 | const s16 sample2 = decode_sample(SIGNED_NIBBLES[data[datai] & 0xF]); | ||
| 68 | ret[outputi].fill(sample2); | ||
| 69 | outputi++; | ||
| 70 | |||
| 71 | datai++; | ||
| 72 | } | ||
| 73 | } | ||
| 74 | |||
| 75 | state.yn1 = yn1; | ||
| 76 | state.yn2 = yn2; | ||
| 77 | |||
| 78 | return ret; | ||
| 79 | } | ||
| 80 | |||
| 81 | static s16 SignExtendS8(u8 x) { | ||
| 82 | // The data is actually signed PCM8. | ||
| 83 | // We sign extend this to signed PCM16. | ||
| 84 | return static_cast<s16>(static_cast<s8>(x)); | ||
| 85 | } | ||
| 86 | |||
| 87 | StereoBuffer16 DecodePCM8(const unsigned num_channels, const u8* const data, | ||
| 88 | const size_t sample_count) { | ||
| 89 | ASSERT(num_channels == 1 || num_channels == 2); | ||
| 90 | |||
| 91 | StereoBuffer16 ret(sample_count); | ||
| 92 | |||
| 93 | if (num_channels == 1) { | ||
| 94 | for (size_t i = 0; i < sample_count; i++) { | ||
| 95 | ret[i].fill(SignExtendS8(data[i])); | ||
| 96 | } | ||
| 97 | } else { | ||
| 98 | for (size_t i = 0; i < sample_count; i++) { | ||
| 99 | ret[i][0] = SignExtendS8(data[i * 2 + 0]); | ||
| 100 | ret[i][1] = SignExtendS8(data[i * 2 + 1]); | ||
| 101 | } | ||
| 102 | } | ||
| 103 | |||
| 104 | return ret; | ||
| 105 | } | ||
| 106 | |||
| 107 | StereoBuffer16 DecodePCM16(const unsigned num_channels, const u8* const data, | ||
| 108 | const size_t sample_count) { | ||
| 109 | ASSERT(num_channels == 1 || num_channels == 2); | ||
| 110 | |||
| 111 | StereoBuffer16 ret(sample_count); | ||
| 112 | |||
| 113 | if (num_channels == 1) { | ||
| 114 | for (size_t i = 0; i < sample_count; i++) { | ||
| 115 | s16 sample; | ||
| 116 | std::memcpy(&sample, data + i * sizeof(s16), sizeof(s16)); | ||
| 117 | ret[i].fill(sample); | ||
| 118 | } | ||
| 119 | } else { | ||
| 120 | for (size_t i = 0; i < sample_count; ++i) { | ||
| 121 | std::memcpy(&ret[i], data + i * sizeof(s16) * 2, 2 * sizeof(s16)); | ||
| 122 | } | ||
| 123 | } | ||
| 124 | |||
| 125 | return ret; | ||
| 126 | } | ||
| 127 | }; | ||