1/* 2 * Copyright (c) 2011 Apple Inc. All rights reserved. 3 * Copyright (C) 2012-2014 Erik de Castro Lopo <erikd@mega-nerd.com> 4 * 5 * @APPLE_APACHE_LICENSE_HEADER_START@ 6 * 7 * Licensed under the Apache License, Version 2.0 (the "License") ; 8 * you may not use this file except in compliance with the License. 9 * You may obtain a copy of the License at 10 * 11 * http://www.apache.org/licenses/LICENSE-2.0 12 * 13 * Unless required by applicable law or agreed to in writing, software 14 * distributed under the License is distributed on an "AS IS" BASIS, 15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 16 * See the License for the specific language governing permissions and 17 * limitations under the License. 18 * 19 * @APPLE_APACHE_LICENSE_HEADER_END@ 20 */ 21 22/* 23 File: alac_codec.h 24*/ 25 26#ifndef ALAC_CODEC_H 27#define ALAC_CODEC_H 28 29#include <stdint.h> 30 31#include "ALACAudioTypes.h" 32 33#define ALAC_FRAME_LENGTH 4096 34 35struct BitBuffer ; 36 37typedef struct alac_decoder_s 38{ 39 // decoding parameters (public for use in the analyzer) 40 ALACSpecificConfig mConfig ; 41 42 uint16_t mActiveElements ; 43 44 // decoding buffers 45 int32_t mMixBufferU [ALAC_FRAME_LENGTH] ; 46 int32_t mMixBufferV [ALAC_FRAME_LENGTH] ; 47 union 48 { 49 int32_t mPredictor [ALAC_FRAME_LENGTH] ; 50 uint16_t mShiftBuffer [ALAC_FRAME_LENGTH] ; 51 } u ; 52 uint32_t mNumChannels ; 53} ALAC_DECODER ; 54 55typedef struct alac_encoder_s 56{ 57 // ALAC encoder parameters 58 int16_t mBitDepth ; 59 60 // encoding state 61 int16_t mLastMixRes [kALACMaxChannels] ; 62 63 int32_t mFastMode ; 64 65 // encoding buffers 66 int32_t mMixBufferU [ALAC_FRAME_LENGTH] ; 67 int32_t mMixBufferV [ALAC_FRAME_LENGTH] ; 68 int32_t mPredictorU [ALAC_FRAME_LENGTH] ; 69 int32_t mPredictorV [ALAC_FRAME_LENGTH] ; 70 uint16_t mShiftBufferUV [2 * ALAC_FRAME_LENGTH] ; 71 uint8_t mWorkBuffer [4 * ALAC_FRAME_LENGTH] ; 72 73 // per-channel coefficients buffers 74 int16_t mCoefsU [kALACMaxChannels][kALACMaxSearches][kALACMaxCoefs] ; 75 int16_t mCoefsV [kALACMaxChannels][kALACMaxSearches][kALACMaxCoefs] ; 76 77 // encoding statistics 78 uint32_t mTotalBytesGenerated ; 79 uint32_t mAvgBitRate ; 80 uint32_t mMaxFrameBytes ; 81 uint32_t mFrameSize ; 82 uint32_t mMaxOutputBytes ; 83 uint32_t mNumChannels ; 84 uint32_t mOutputSampleRate ; 85} ALAC_ENCODER ; 86 87 88int32_t alac_decoder_init (ALAC_DECODER *p, void * inMagicCookie, uint32_t inMagicCookieSize) ; 89int32_t alac_encoder_init (ALAC_ENCODER *p, uint32_t samplerate, uint32_t channels, uint32_t format_flags, uint32_t frameSize) ; 90 91int32_t alac_decode (ALAC_DECODER *, struct BitBuffer * bits, int32_t * sampleBuffer, 92 uint32_t numSamples, uint32_t * outNumSamples) ; 93 94int32_t alac_encode (ALAC_ENCODER *p, uint32_t numSamples, 95 const int32_t * theReadBuffer, unsigned char * theWriteBuffer, 96 uint32_t * ioNumBytes) ; 97 98void alac_set_fastmode (ALAC_ENCODER * p, int32_t fast) ; 99 100uint32_t alac_get_magic_cookie_size (uint32_t inNumChannels) ; 101void alac_get_magic_cookie (ALAC_ENCODER *p, void * config, uint32_t * ioSize) ; 102void alac_get_source_format (ALAC_ENCODER *p, const AudioFormatDescription * source, AudioFormatDescription * output) ; 103 104#endif 105