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 "SourceI24.h" 26 27 using namespace flowgraph; 28 29 constexpr int kBytesPerI24Packed = 3; 30 SourceI24(int32_t channelCount)31SourceI24::SourceI24(int32_t channelCount) 32 : AudioSource(channelCount) { 33 } 34 onProcess(int64_t framePosition,int32_t numFrames)35int32_t SourceI24::onProcess(int64_t framePosition, int32_t numFrames) { 36 float *floatData = output.getBlock(); 37 int32_t channelCount = output.getSamplesPerFrame(); 38 39 int32_t framesLeft = mSizeInFrames - mFrameIndex; 40 int32_t framesToProcess = std::min(numFrames, framesLeft); 41 int32_t numSamples = framesToProcess * channelCount; 42 43 const uint8_t *byteBase = (uint8_t *) mData; 44 const uint8_t *byteData = &byteBase[mFrameIndex * channelCount * kBytesPerI24Packed]; 45 46 #ifdef __ANDROID__ 47 memcpy_to_float_from_p24(floatData, byteData, numSamples); 48 #else 49 static const float scale = 1. / (float)(1UL << 31); 50 for (int i = 0; i < numSamples; i++) { 51 // Assemble the data assuming Little Endian format. 52 int32_t pad = byteData[2]; 53 pad <<= 8; 54 pad |= byteData[1]; 55 pad <<= 8; 56 pad |= byteData[0]; 57 pad <<= 8; // Shift to 32 bit data so the sign is correct. 58 byteData += kBytesPerI24Packed; 59 *floatData++ = pad * scale; // scale to range -1.0 to 1.0 60 } 61 #endif 62 63 mFrameIndex += framesToProcess; 64 return framesToProcess; 65 }