1 /*
2  * Copyright 2018 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include <algorithm>
18 #include <unistd.h>
19 
20 #ifdef __ANDROID__
21 #include <audio_utils/primitives.h>
22 #endif
23 
24 #include "AudioProcessorBase.h"
25 #include "SinkI24.h"
26 
27 using namespace flowgraph;
28 
29 
SinkI24(int32_t channelCount)30 SinkI24::SinkI24(int32_t channelCount)
31         : AudioSink(channelCount) {}
32 
read(void * data,int32_t numFrames)33 int32_t SinkI24::read(void *data, int32_t numFrames) {
34     uint8_t *byteData = (uint8_t *) data;
35     const int32_t channelCount = input.getSamplesPerFrame();
36 
37     int32_t framesLeft = numFrames;
38     while (framesLeft > 0) {
39         // Run the graph and pull data through the input port.
40         int32_t framesRead = pull(framesLeft);
41         if (framesRead <= 0) {
42             break;
43         }
44         const float *floatData = input.getBlock();
45         int32_t numSamples = framesRead * channelCount;
46 #ifdef __ANDROID__
47         memcpy_to_p24_from_float(byteData, floatData, numSamples);
48         static const int kBytesPerI24Packed = 3;
49         byteData += numSamples * kBytesPerI24Packed;
50         floatData += numSamples;
51 #else
52         const int32_t kI24PackedMax = 0x007FFFFF;
53         const int32_t kI24PackedMin = 0xFF800000;
54         for (int i = 0; i < numSamples; i++) {
55             int32_t n = (int32_t) (*floatData++ * 0x00800000);
56             n = std::min(kI24PackedMax, std::max(kI24PackedMin, n)); // clip
57             // Write as a packed 24-bit integer in Little Endian format.
58             *byteData++ = (uint8_t) n;
59             *byteData++ = (uint8_t) (n >> 8);
60             *byteData++ = (uint8_t) (n >> 16);
61         }
62 #endif
63         framesLeft -= framesRead;
64     }
65     return numFrames - framesLeft;
66 }
67