xref: /haiku/src/add-ons/media/media-add-ons/mixer/Interpolate.cpp (revision 553f3f2309e87d95345220463fa865d5fd8cf28d)
1 /*
2  * Copyright 2010-2014 Haiku, inc.
3  * Distributed under the terms of the MIT Licence.
4  *
5  * Author: Adrien Destugues <pulkomandy@pulkomandy.tk>
6  */
7 
8 
9 #include "Interpolate.h"
10 
11 #include <cmath>
12 
13 #include <MediaDefs.h>
14 
15 #include "MixerDebug.h"
16 
17 
18 /*! Resampling class doing linear interpolation.
19 */
20 
21 
22 template<typename inType, typename outType, int gnum, int gden,
23 	int inMiddle, int outMiddle, int32 min, int32 max> static void
24 kernel(Resampler* object, const void *_src, int32 srcSampleOffset,
25 	int32 srcSampleCount, void *_dest, int32 destSampleOffset,
26 	int32 destSampleCount, float _gain)
27 {
28 	register const char * src = (const char *)_src;
29 	register char * dest = (char *)_dest;
30 	register int32 count = destSampleCount;
31 	register float gain = _gain * gnum / gden;
32 
33 	if (srcSampleCount == destSampleCount) {
34 		// optimized case for no resampling
35 		while (count--) {
36 			float tmp = ((*(const inType*)src) - inMiddle) * gain + outMiddle;
37 			if (tmp < min) tmp = min;
38 			if (tmp > max) tmp = max;
39 			*(outType *)dest = (outType)tmp;
40 			src += srcSampleOffset;
41 			dest += destSampleOffset;
42 		}
43 		return;
44 	}
45 
46 	register float delta = float(srcSampleCount) / float(destSampleCount);
47 	register float current = 0.0f;
48 	float oldSample = ((Interpolate*)object)->fOldSample;
49 
50 	#define SRC *(const inType*)(src)
51 
52 	while (count--) {
53 		float tmp = (gain * (oldSample + (SRC - oldSample) * current - inMiddle)
54 			 + outMiddle);
55 		if (tmp < min) tmp = min;
56 		if (tmp > max) tmp = max;
57 		*(outType *)dest = (outType)tmp;
58 
59 		dest += destSampleOffset;
60 		current += delta;
61 		if (current >= 1.0f) {
62 			double ipart;
63 			current = modf(current, &ipart);
64 			oldSample = SRC;
65 			src += srcSampleOffset * (int)ipart;
66 		}
67 	}
68 
69 	((Interpolate*)object)->fOldSample = oldSample;
70 }
71 
72 
73 Interpolate::Interpolate(uint32 src_format, uint32 dst_format)
74 	:
75 	Resampler(),
76 	fOldSample(0)
77 {
78 	if (src_format == media_raw_audio_format::B_AUDIO_UCHAR)
79 		fOldSample = 128;
80 
81 	if (dst_format == media_raw_audio_format::B_AUDIO_FLOAT) {
82 		switch (src_format) {
83 			case media_raw_audio_format::B_AUDIO_FLOAT:
84 				fFunc = &kernel<float, float, 1, 1, 0, 0, -1, 1>;
85 				return;
86 			case media_raw_audio_format::B_AUDIO_INT:
87 				fFunc = &kernel<int32, float, 1, INT32_MAX, 0, 0, -1, 1>;
88 				return;
89 			case media_raw_audio_format::B_AUDIO_SHORT:
90 				fFunc = &kernel<int16, float, 1, INT16_MAX, 0, 0, -1, 1>;
91 				return;
92 			case media_raw_audio_format::B_AUDIO_CHAR:
93 				fFunc = &kernel<int8, float, 1, INT8_MAX, 0, 0, -1, 1>;
94 				return;
95 			case media_raw_audio_format::B_AUDIO_UCHAR:
96 				fFunc = &kernel<uint8, float, 2, UINT8_MAX, 128, 0, -1, 1>;
97 				return;
98 			default:
99 				ERROR("Resampler::Resampler: unknown source format 0x%x\n",
100 					src_format);
101 				return;
102 		}
103 	}
104 
105 	if (src_format == media_raw_audio_format::B_AUDIO_FLOAT) {
106 		switch (dst_format) {
107 			// float=>float already handled above
108 			case media_raw_audio_format::B_AUDIO_INT:
109 				fFunc = &kernel<float, int32, INT32_MAX, 1, 0, 0,
110 					INT32_MIN, INT32_MAX>;
111 				return;
112 			case media_raw_audio_format::B_AUDIO_SHORT:
113 				fFunc = &kernel<float, int16, INT16_MAX, 1, 0, 0,
114 					INT16_MIN, INT16_MAX>;
115 				return;
116 			case media_raw_audio_format::B_AUDIO_CHAR:
117 				fFunc = &kernel<float, int8, INT8_MAX, 1, 0, 0,
118 					INT8_MIN, INT8_MAX>;
119 				return;
120 			case media_raw_audio_format::B_AUDIO_UCHAR:
121 				fFunc = &kernel<float, uint8, UINT8_MAX, 2, 0, 128,
122 					0, UINT8_MAX>;
123 				return;
124 			default:
125 				ERROR("Resampler::Resampler: unknown destination format 0x%x\n",
126 					dst_format);
127 				return;
128 		}
129 	}
130 
131 	ERROR("Resampler::Resampler: source or destination format must be "
132 		"B_AUDIO_FLOAT\n");
133 }
134 
135 
136