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author | The Android Open Source Project <initial-contribution@android.com> | 2009-03-03 19:31:44 -0800 |
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committer | The Android Open Source Project <initial-contribution@android.com> | 2009-03-03 19:31:44 -0800 |
commit | 9066cfe9886ac131c34d59ed0e2d287b0e3c0087 (patch) | |
tree | d88beb88001f2482911e3d28e43833b50e4b4e97 /libs/audioflinger/AudioResamplerCubic.h | |
parent | d83a98f4ce9cfa908f5c54bbd70f03eec07e7553 (diff) | |
download | frameworks_base-9066cfe9886ac131c34d59ed0e2d287b0e3c0087.zip frameworks_base-9066cfe9886ac131c34d59ed0e2d287b0e3c0087.tar.gz frameworks_base-9066cfe9886ac131c34d59ed0e2d287b0e3c0087.tar.bz2 |
auto import from //depot/cupcake/@135843
Diffstat (limited to 'libs/audioflinger/AudioResamplerCubic.h')
-rw-r--r-- | libs/audioflinger/AudioResamplerCubic.h | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/libs/audioflinger/AudioResamplerCubic.h b/libs/audioflinger/AudioResamplerCubic.h new file mode 100644 index 0000000..b72b62a --- /dev/null +++ b/libs/audioflinger/AudioResamplerCubic.h @@ -0,0 +1,68 @@ +/* + * Copyright (C) 2007 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#ifndef ANDROID_AUDIO_RESAMPLER_CUBIC_H +#define ANDROID_AUDIO_RESAMPLER_CUBIC_H + +#include <stdint.h> +#include <sys/types.h> +#include <cutils/log.h> + +#include "AudioResampler.h" + +namespace android { +// ---------------------------------------------------------------------------- + +class AudioResamplerCubic : public AudioResampler { +public: + AudioResamplerCubic(int bitDepth, int inChannelCount, int32_t sampleRate) : + AudioResampler(bitDepth, inChannelCount, sampleRate) { + } + virtual void resample(int32_t* out, size_t outFrameCount, + AudioBufferProvider* provider); +private: + // number of bits used in interpolation multiply - 14 bits avoids overflow + static const int kNumInterpBits = 14; + + // bits to shift the phase fraction down to avoid overflow + static const int kPreInterpShift = kNumPhaseBits - kNumInterpBits; + typedef struct { + int32_t a, b, c, y0, y1, y2, y3; + } state; + void init(); + void resampleMono16(int32_t* out, size_t outFrameCount, + AudioBufferProvider* provider); + void resampleStereo16(int32_t* out, size_t outFrameCount, + AudioBufferProvider* provider); + static inline int32_t interp(state* p, int32_t x) { + return (((((p->a * x >> 14) + p->b) * x >> 14) + p->c) * x >> 14) + p->y1; + } + static inline void advance(state* p, int16_t in) { + p->y0 = p->y1; + p->y1 = p->y2; + p->y2 = p->y3; + p->y3 = in; + p->a = (3 * (p->y1 - p->y2) - p->y0 + p->y3) >> 1; + p->b = (p->y2 << 1) + p->y0 - (((5 * p->y1 + p->y3)) >> 1); + p->c = (p->y2 - p->y0) >> 1; + } + state left, right; +}; + +// ---------------------------------------------------------------------------- +}; // namespace android + +#endif /*ANDROID_AUDIO_RESAMPLER_CUBIC_H*/ |