xref: /aosp_15_r20/external/oboe/src/flowgraph/resampler/PolyphaseResampler.h (revision 05767d913155b055644481607e6fa1e35e2fe72c)
1*05767d91SRobert Wu /*
2*05767d91SRobert Wu  * Copyright 2019 The Android Open Source Project
3*05767d91SRobert Wu  *
4*05767d91SRobert Wu  * Licensed under the Apache License, Version 2.0 (the "License");
5*05767d91SRobert Wu  * you may not use this file except in compliance with the License.
6*05767d91SRobert Wu  * You may obtain a copy of the License at
7*05767d91SRobert Wu  *
8*05767d91SRobert Wu  *      http://www.apache.org/licenses/LICENSE-2.0
9*05767d91SRobert Wu  *
10*05767d91SRobert Wu  * Unless required by applicable law or agreed to in writing, software
11*05767d91SRobert Wu  * distributed under the License is distributed on an "AS IS" BASIS,
12*05767d91SRobert Wu  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13*05767d91SRobert Wu  * See the License for the specific language governing permissions and
14*05767d91SRobert Wu  * limitations under the License.
15*05767d91SRobert Wu  */
16*05767d91SRobert Wu 
17*05767d91SRobert Wu #ifndef RESAMPLER_POLYPHASE_RESAMPLER_H
18*05767d91SRobert Wu #define RESAMPLER_POLYPHASE_RESAMPLER_H
19*05767d91SRobert Wu 
20*05767d91SRobert Wu #include <memory>
21*05767d91SRobert Wu #include <vector>
22*05767d91SRobert Wu #include <sys/types.h>
23*05767d91SRobert Wu #include <unistd.h>
24*05767d91SRobert Wu 
25*05767d91SRobert Wu #include "MultiChannelResampler.h"
26*05767d91SRobert Wu #include "ResamplerDefinitions.h"
27*05767d91SRobert Wu 
28*05767d91SRobert Wu namespace RESAMPLER_OUTER_NAMESPACE::resampler {
29*05767d91SRobert Wu /**
30*05767d91SRobert Wu  * Resampler that is optimized for a reduced ratio of sample rates.
31*05767d91SRobert Wu  * All of the coefficients for each possible phase value are pre-calculated.
32*05767d91SRobert Wu  */
33*05767d91SRobert Wu class PolyphaseResampler : public MultiChannelResampler {
34*05767d91SRobert Wu public:
35*05767d91SRobert Wu     /**
36*05767d91SRobert Wu      *
37*05767d91SRobert Wu      * @param builder containing lots of parameters
38*05767d91SRobert Wu      */
39*05767d91SRobert Wu     explicit PolyphaseResampler(const MultiChannelResampler::Builder &builder);
40*05767d91SRobert Wu 
41*05767d91SRobert Wu     virtual ~PolyphaseResampler() = default;
42*05767d91SRobert Wu 
43*05767d91SRobert Wu     void readFrame(float *frame) override;
44*05767d91SRobert Wu 
45*05767d91SRobert Wu protected:
46*05767d91SRobert Wu 
47*05767d91SRobert Wu     int32_t                mCoefficientCursor = 0;
48*05767d91SRobert Wu 
49*05767d91SRobert Wu };
50*05767d91SRobert Wu 
51*05767d91SRobert Wu } /* namespace RESAMPLER_OUTER_NAMESPACE::resampler */
52*05767d91SRobert Wu 
53*05767d91SRobert Wu #endif //RESAMPLER_POLYPHASE_RESAMPLER_H
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