1 /* 2 * Copyright (C) 2017 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 #ifndef FLAC_DECODER_H_ 18 #define FLAC_DECODER_H_ 19 20 #include <media/stagefright/foundation/ABase.h> 21 #include <utils/RefBase.h> 22 #include <utils/String8.h> 23 24 #include "FLAC/stream_decoder.h" 25 26 namespace android { 27 28 // packet based FLAC decoder, wrapps libFLAC stream decoder. 29 class FLACDecoder { 30 31 public: 32 enum { 33 kMaxChannels = 8, 34 }; 35 36 static FLACDecoder *Create(); 37 38 FLAC__StreamMetadata_StreamInfo getStreamInfo() const { 39 return mStreamInfo; 40 } 41 42 status_t parseMetadata(const uint8_t *inBuffer, size_t inBufferLen); 43 status_t decodeOneFrame(const uint8_t *inBuffer, size_t inBufferLen, 44 short *outBuffer, size_t *outBufferLen); 45 void flush(); 46 virtual ~FLACDecoder(); 47 48 protected: 49 FLACDecoder(); 50 51 private: 52 // stream properties 53 unsigned getMaxBlockSize() const { 54 return mStreamInfo.max_blocksize; 55 } 56 unsigned getSampleRate() const { 57 return mStreamInfo.sample_rate; 58 } 59 unsigned getChannels() const { 60 return mStreamInfo.channels; 61 } 62 unsigned getBitsPerSample() const { 63 return mStreamInfo.bits_per_sample; 64 } 65 FLAC__uint64 getTotalSamples() const { 66 return mStreamInfo.total_samples; 67 } 68 69 status_t addDataToBuffer(const uint8_t *inBuffer, size_t inBufferLen); 70 71 FLAC__StreamDecoder *mDecoder; 72 73 uint8_t *mBuffer; // cache input bit stream data 74 size_t mBufferLen; // the memory size of |mBuffer| 75 size_t mBufferPos; // next byte to read in |mBuffer| 76 // size of input data stored in |mBuffer|, always started at offset 0 77 size_t mBufferDataSize; 78 79 // cached when the STREAMINFO metadata is parsed by libFLAC 80 FLAC__StreamMetadata_StreamInfo mStreamInfo; 81 bool mStreamInfoValid; 82 83 // cached when a decoded PCM block is "written" by libFLAC decoder 84 bool mWriteRequested; 85 bool mWriteCompleted; 86 FLAC__FrameHeader mWriteHeader; 87 FLAC__int32 const * mWriteBuffer[kMaxChannels]; 88 89 // most recent error reported by libFLAC decoder 90 FLAC__StreamDecoderErrorStatus mErrorStatus; 91 92 void (*mCopy)(short *dst, const int *src[kMaxChannels], unsigned nSamples, unsigned nChannels); 93 94 status_t init(); 95 96 // FLAC stream decoder callbacks as C++ instance methods 97 FLAC__StreamDecoderReadStatus readCallback(FLAC__byte buffer[], size_t *bytes); 98 FLAC__StreamDecoderWriteStatus writeCallback( 99 const FLAC__Frame *frame, const FLAC__int32 * const buffer[]); 100 void metadataCallback(const FLAC__StreamMetadata *metadata); 101 void errorCallback(FLAC__StreamDecoderErrorStatus status); 102 103 DISALLOW_EVIL_CONSTRUCTORS(FLACDecoder); 104 }; 105 106 } // namespace android 107 108 #endif // FLAC_DECODER_H_ 109
