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Slight change to NXDN audio packing and unpacking.

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This commit is contained in:
Jonathan Naylor 2018-03-06 19:23:48 +00:00
parent b9f342e962
commit 2a4d365729
1 changed files with 38 additions and 42 deletions
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80
NXDNAudio.cpp
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@ -443,9 +443,9 @@ const unsigned int PRNG_TABLE[] = {
const unsigned int A_TABLE[] = { 0U, 4U, 8U, 12U, 16U, 20U, 24U, 28U, 32U, 36U, 40U, 44U,
48U, 52U, 56U, 60U, 64U, 68U, 1U, 5U, 9U, 13U, 17U, 21U };
const unsigned int B_TABLE[] = { 25U, 29U, 33U, 37U, 41U, 45U, 49U, 53U, 57U, 61U, 65U, 69U,
2U, 6U, 10U, 14U, 18U, 22U, 26U, 30U, 34U, 38U, 42U, 46U };
const unsigned int C_TABLE[] = { 50U, 54U, 58U, 62U, 66U, 70U, 3U, 7U, 11U, 15U, 19U, 23U,
27U, 31U, 35U, 39U, 43U, 47U, 51U, 55U, 59U, 63U, 67U, 71U };
2U, 6U, 10U, 14U, 18U, 22U, 26U, 30U, 34U, 38U, 42U };
const unsigned int C_TABLE[] = { 46U, 50U, 54U, 58U, 62U, 66U, 70U, 3U, 7U, 11U, 15U, 19U,
23U, 27U, 31U, 35U, 39U, 43U, 47U, 51U, 55U, 59U, 63U, 67U, 71U };
CNXDNAudio::CNXDNAudio()
{
@ -479,51 +479,49 @@ void CNXDNAudio::decode(const unsigned char* in, unsigned char* out, unsigned in
assert(out != NULL);
unsigned int a = 0U;
unsigned int b = 0U;
unsigned int c = 0U;
unsigned int MASK = 0x800000U;
for (unsigned int i = 0U; i < 24U; i++) {
for (unsigned int i = 0U; i < 24U; i++, MASK >>= 1) {
unsigned int aPos = A_TABLE[i];
unsigned int bPos = B_TABLE[i];
unsigned int cPos = C_TABLE[i];
if (READ_BIT(in, aPos))
a |= MASK;
}
unsigned int b = 0U;
MASK = 0x400000U;
for (unsigned int i = 0U; i < 23U; i++, MASK >>= 1) {
unsigned int bPos = B_TABLE[i];
if (READ_BIT(in, bPos))
b |= MASK;
}
unsigned int c = 0U;
MASK = 0x1000000U;
for (unsigned int i = 0U; i < 25U; i++, MASK >>= 1) {
unsigned int cPos = C_TABLE[i];
if (READ_BIT(in, cPos))
c |= MASK;
MASK >>= 1;
}
unsigned int data = CGolay24128::decode24128(a);
// The PRNG
unsigned int p = PRNG_TABLE[data];
unsigned int p = PRNG_TABLE[data] >> 1;
b ^= p;
unsigned int datb = CGolay24128::decode24128(b);
unsigned int datb = CGolay24128::decode23127(b);
MASK = 0x000800U;
for (unsigned int i = 0U; i < 12U; i++) {
for (unsigned int i = 0U; i < 12U; i++, MASK >>= 1) {
unsigned int aPos = i + offset + 0U;
unsigned int bPos = i + offset + 12U;
WRITE_BIT(out, aPos, data & MASK);
WRITE_BIT(out, bPos, datb & MASK);
MASK >>= 1;
}
MASK = 0x800000U;
for (unsigned int i = 0U; i < 24U; i++) {
MASK = 0x1000000U;
for (unsigned int i = 0U; i < 25U; i++, MASK >>= 1) {
unsigned int cPos = i + offset + 24U;
WRITE_BIT(out, cPos, c & MASK);
MASK >>= 1;
}
}
@ -537,47 +535,45 @@ void CNXDNAudio::encode(const unsigned char* in, unsigned char* out, unsigned in
unsigned int cOrig = 0U;
unsigned int MASK = 0x000800U;
for (unsigned int i = 0U; i < 12U; i++) {
for (unsigned int i = 0U; i < 12U; i++, MASK >>= 1) {
unsigned int n1 = i + offset + 0U;
unsigned int n2 = i + offset + 12U;
if (READ_BIT(in, n1))
aOrig |= MASK;
if (READ_BIT(in, n2))
bOrig |= MASK;
MASK >>= 1;
}
MASK = 0x1000000U;
for (unsigned int i = 0U; i < 25U; i++) {
for (unsigned int i = 0U; i < 25U; i++, MASK >>= 1) {
unsigned int n = i + offset + 24U;
if (READ_BIT(in, n))
cOrig |= MASK;
MASK >>= 1;
}
unsigned int a = CGolay24128::encode24128(aOrig);
// The PRNG
unsigned int p = PRNG_TABLE[aOrig];
unsigned int b = CGolay24128::encode24128(bOrig);
unsigned int p = PRNG_TABLE[aOrig] >> 1;
unsigned int b = CGolay24128::encode23127(bOrig);
b ^= p;
unsigned int c = cOrig;
MASK = 0x800000U;
for (unsigned int i = 0U; i < 24U; i++) {
for (unsigned int i = 0U; i < 24U; i++, MASK >>= 1) {
unsigned int aPos = A_TABLE[i];
unsigned int bPos = B_TABLE[i];
unsigned int cPos = C_TABLE[i];
WRITE_BIT(out, aPos, a & MASK);
WRITE_BIT(out, bPos, b & MASK);
WRITE_BIT(out, cPos, c & MASK);
}
MASK >>= 1;
MASK = 0x400000U;
for (unsigned int i = 0U; i < 23U; i++, MASK >>= 1) {
unsigned int bPos = B_TABLE[i];
WRITE_BIT(out, bPos, b & MASK);
}
MASK = 0x1000000U;
for (unsigned int i = 0U; i < 25U; i++, MASK >>= 1) {
unsigned int cPos = C_TABLE[i];
WRITE_BIT(out, cPos, cOrig & MASK);
}
}