100 lines
2.6 KiB
C
100 lines
2.6 KiB
C
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/*
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* Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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/*
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* A wrapper for resampling a numerous amount of sampling combinations.
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*/
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#ifndef COMMON_AUDIO_RESAMPLER_INCLUDE_RESAMPLER_H_
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#define COMMON_AUDIO_RESAMPLER_INCLUDE_RESAMPLER_H_
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#include <stddef.h>
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#include <stdint.h>
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namespace webrtc {
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// All methods return 0 on success and -1 on failure.
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class Resampler {
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public:
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Resampler();
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Resampler(int inFreq, int outFreq, size_t num_channels);
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~Resampler();
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// Reset all states
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int Reset(int inFreq, int outFreq, size_t num_channels);
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// Reset all states if any parameter has changed
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int ResetIfNeeded(int inFreq, int outFreq, size_t num_channels);
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// Resample samplesIn to samplesOut.
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int Push(const int16_t* samplesIn,
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size_t lengthIn,
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int16_t* samplesOut,
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size_t maxLen,
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size_t& outLen); // NOLINT: to avoid changing APIs
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private:
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enum ResamplerMode {
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kResamplerMode1To1,
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kResamplerMode1To2,
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kResamplerMode1To3,
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kResamplerMode1To4,
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kResamplerMode1To6,
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kResamplerMode1To12,
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kResamplerMode2To3,
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kResamplerMode2To11,
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kResamplerMode4To11,
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kResamplerMode8To11,
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kResamplerMode11To16,
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kResamplerMode11To32,
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kResamplerMode2To1,
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kResamplerMode3To1,
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kResamplerMode4To1,
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kResamplerMode6To1,
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kResamplerMode12To1,
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kResamplerMode3To2,
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kResamplerMode11To2,
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kResamplerMode11To4,
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kResamplerMode11To8
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};
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// Computes the resampler mode for a given sampling frequency pair.
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// Returns -1 for unsupported frequency pairs.
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static int ComputeResamplerMode(int in_freq_hz,
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int out_freq_hz,
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ResamplerMode* mode);
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// Generic pointers since we don't know what states we'll need
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void* state1_;
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void* state2_;
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void* state3_;
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// Storage if needed
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int16_t* in_buffer_;
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int16_t* out_buffer_;
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size_t in_buffer_size_;
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size_t out_buffer_size_;
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size_t in_buffer_size_max_;
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size_t out_buffer_size_max_;
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int my_in_frequency_khz_;
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int my_out_frequency_khz_;
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ResamplerMode my_mode_;
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size_t num_channels_;
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// Extra instance for stereo
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Resampler* helper_left_;
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Resampler* helper_right_;
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};
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} // namespace webrtc
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#endif // COMMON_AUDIO_RESAMPLER_INCLUDE_RESAMPLER_H_
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