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comparison foosdk/sdk/pfc/audio_sample.cpp @ 1:20d02a178406 default tip

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author Paper <paper@tflc.us>
date Mon, 05 Jan 2026 02:15:46 -0500
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0:e9bb126753e7 1:20d02a178406
1 #include "pfc-lite.h"
2 #include "audio_sample.h"
3 #include "primitives.h"
4 #include "byte_order.h"
5
6 namespace pfc {
7 float audio_math::decodeFloat24ptr(const void* sourcePtr) {
8 PFC_STATIC_ASSERT(pfc::byte_order_is_little_endian);
9 union {
10 uint8_t bytes[4];
11 float v;
12 } u;
13 const uint8_t* s = reinterpret_cast<const uint8_t*>(sourcePtr);
14 u.bytes[0] = 0;
15 u.bytes[1] = s[0];
16 u.bytes[2] = s[1];
17 u.bytes[3] = s[2];
18 return u.v;
19 }
20 float audio_math::decodeFloat24ptrbs(const void* sourcePtr) {
21 PFC_STATIC_ASSERT(pfc::byte_order_is_little_endian);
22 union {
23 uint8_t bytes[4];
24 float v;
25 } u;
26 const uint8_t* s = reinterpret_cast<const uint8_t*>(sourcePtr);
27 u.bytes[0] = 0;
28 u.bytes[1] = s[2];
29 u.bytes[2] = s[1];
30 u.bytes[3] = s[0];
31 return u.v;
32 }
33
34 float audio_math::decodeFloat16(uint16_t source) {
35 const unsigned fractionBits = 10;
36 const unsigned widthBits = 16;
37 typedef uint16_t source_t;
38
39 /* typedef uint64_t out_t; typedef double retval_t;
40 enum {
41 outExponent = 11,
42 outFraction = 52,
43 outExponentShift = (1 << (outExponent-1))-1
44 };*/
45
46 typedef uint32_t out_t; typedef float retval_t;
47 enum {
48 outExponent = 8,
49 outFraction = 23,
50 outExponentShift = (1 << (outExponent - 1)) - 1
51 };
52
53 const unsigned exponentBits = widthBits - fractionBits - 1;
54 // 1 bit sign | exponent | fraction
55 source_t fraction = source & (((source_t)1 << fractionBits) - 1);
56 source >>= fractionBits;
57 int exponent = (int)(source & (((source_t)1 << exponentBits) - 1)) - (int)((1 << (exponentBits - 1)) - 1);
58 source >>= exponentBits;
59
60 if constexpr (outExponent + outExponentShift <= 0) return 0;
61
62 out_t output = (out_t)(source & 1);
63 output <<= outExponent;
64 output |= (unsigned)(exponent + outExponentShift) & ((1 << outExponent) - 1);
65 output <<= outFraction;
66 int shift = (int)outFraction - (int)fractionBits;
67 if (shift < 0) output |= (out_t)(fraction >> -shift);
68 else output |= (out_t)(fraction << shift);
69 return *(retval_t*)&output / pfc::audio_math::float16scale;
70 }
71
72 unsigned audio_math::bitrate_kbps(uint64_t fileSize, double duration) {
73 if (fileSize > 0 && duration > 0) return (unsigned)floor((double)fileSize * 8 / (duration * 1000) + 0.5);
74 return 0;
75 }
76 }