1 /*
2  * Copyright (c) 2011 Apple Inc. All rights reserved.
3  *
4  * @APPLE_APACHE_LICENSE_HEADER_START@
5  *
6  * Licensed under the Apache License, Version 2.0 (the "License");
7  * you may not use this file except in compliance with the License.
8  * You may obtain a copy of the License at
9  *
10  *     http://www.apache.org/licenses/LICENSE-2.0
11  *
12  * Unless required by applicable law or agreed to in writing, software
13  * distributed under the License is distributed on an "AS IS" BASIS,
14  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15  * See the License for the specific language governing permissions and
16  * limitations under the License.
17  *
18  * @APPLE_APACHE_LICENSE_HEADER_END@
19  */
20 
21 /*
22 	File:		matrixlib.h
23 
24 	Contains:	ALAC mixing/matrixing routines to/from 32-bit predictor buffers.
25 
26 	Copyright:	Copyright (C) 2004 to 2011 Apple, Inc.
27 */
28 
29 #ifndef __MATRIXLIB_H
30 #define __MATRIXLIB_H
31 
32 #pragma once
33 
34 #include <stdint.h>
35 
36 #ifdef __cplusplus
37 extern "C" {
38 #endif
39 
40 // 16-bit routines
41 void	mix16( int16_t * in, uint32_t stride, int32_t * u, int32_t * v, int32_t numSamples, int32_t mixbits, int32_t mixres );
42 void	unmix16( int32_t * u, int32_t * v, int16_t * out, uint32_t stride, int32_t numSamples, int32_t mixbits, int32_t mixres );
43 
44 // 20-bit routines
45 void	mix20( uint8_t * in, uint32_t stride, int32_t * u, int32_t * v, int32_t numSamples, int32_t mixbits, int32_t mixres );
46 void	unmix20( int32_t * u, int32_t * v, uint8_t * out, uint32_t stride, int32_t numSamples, int32_t mixbits, int32_t mixres );
47 
48 // 24-bit routines
49 // - 24-bit data sometimes compresses better by shifting off the bottom byte so these routines deal with
50 //	 the specified "unused lower bytes" in the combined "shift" buffer
51 void	mix24( uint8_t * in, uint32_t stride, int32_t * u, int32_t * v, int32_t numSamples,
52 				int32_t mixbits, int32_t mixres, uint16_t * shiftUV, int32_t bytesShifted );
53 void	unmix24( int32_t * u, int32_t * v, uint8_t * out, uint32_t stride, int32_t numSamples,
54 				 int32_t mixbits, int32_t mixres, uint16_t * shiftUV, int32_t bytesShifted );
55 
56 // 32-bit routines
57 // - note that these really expect the internal data width to be < 32-bit but the arrays are 32-bit
58 // - otherwise, the calculations might overflow into the 33rd bit and be lost
59 // - therefore, these routines deal with the specified "unused lower" bytes in the combined "shift" buffer
60 void	mix32( int32_t * in, uint32_t stride, int32_t * u, int32_t * v, int32_t numSamples,
61 				int32_t mixbits, int32_t mixres, uint16_t * shiftUV, int32_t bytesShifted );
62 void	unmix32( int32_t * u, int32_t * v, int32_t * out, uint32_t stride, int32_t numSamples,
63 				 int32_t mixbits, int32_t mixres, uint16_t * shiftUV, int32_t bytesShifted );
64 
65 // 20/24/32-bit <-> 32-bit helper routines (not really matrixing but convenient to put here)
66 void	copy20ToPredictor( uint8_t * in, uint32_t stride, int32_t * out, int32_t numSamples );
67 void	copy24ToPredictor( uint8_t * in, uint32_t stride, int32_t * out, int32_t numSamples );
68 
69 void	copyPredictorTo24( int32_t * in, uint8_t * out, uint32_t stride, int32_t numSamples );
70 void	copyPredictorTo24Shift( int32_t * in, uint16_t * shift, uint8_t * out, uint32_t stride, int32_t numSamples, int32_t bytesShifted );
71 void	copyPredictorTo20( int32_t * in, uint8_t * out, uint32_t stride, int32_t numSamples );
72 
73 void	copyPredictorTo32( int32_t * in, int32_t * out, uint32_t stride, int32_t numSamples );
74 void	copyPredictorTo32Shift( int32_t * in, uint16_t * shift, int32_t * out, uint32_t stride, int32_t numSamples, int32_t bytesShifted );
75 
76 #ifdef __cplusplus
77 }
78 #endif
79 
80 #endif	/* __MATRIXLIB_H */
81