/// <summary>
/// Encodes a buffer of G722
/// </summary>
/// <param name="state">Codec state</param>
/// <param name="outputBuffer">Output buffer (to contain encoded G722)</param>
/// <param name="inputBuffer">PCM 16 bit samples to encode</param>
/// <param name="inputBufferCount">Number of samples in the input buffer to encode</param>
/// <returns>Number of encoded bytes written into output buffer</returns>
public int Encode(G722CodecState state, byte[] outputBuffer, short[] inputBuffer, int inputBufferCount)
{
int dlow;
int dhigh;
int el;
int wd;
int wd1;
int ril;
int wd2;
int il4;
int ih2;
int wd3;
int eh;
int mih;
int i;
int j;
// Low and high band PCM from the QMF
int xlow;
int xhigh;
int g722_bytes;
// Even and odd tap accumulators
int sumeven;
int sumodd;
int ihigh;
int ilow;
int code;
g722_bytes = 0;
xhigh = 0;
for (j = 0; j < inputBufferCount;)
{
if (state.ItuTestMode)
{
xlow =
xhigh = inputBuffer[j++] >> 1;
}
else
{
if (state.EncodeFrom8000Hz)
{
xlow = inputBuffer[j++] >> 1;
}
else
{
// Apply the transmit QMF
// Shuffle the buffer down
for (i = 0; i < 22; i++)
{
state.QmfSignalHistory[i] = state.QmfSignalHistory[i + 2];
}
state.QmfSignalHistory[22] = inputBuffer[j++];
state.QmfSignalHistory[23] = inputBuffer[j++];
// Discard every other QMF output
sumeven = 0;
sumodd = 0;
for (i = 0; i < 12; i++)
{
sumodd += state.QmfSignalHistory[2 * i] * qmf_coeffs[i];
sumeven += state.QmfSignalHistory[2 * i + 1] * qmf_coeffs[11 - i];
}
xlow = (sumeven + sumodd) >> 14;
xhigh = (sumeven - sumodd) >> 14;
}
}
// Block 1L, SUBTRA
el = Saturate(xlow - state.Band[0].s);
// Block 1L, QUANTL
wd = (el >= 0) ? el : -(el + 1);
for (i = 1; i < 30; i++)
{
wd1 = (q6[i] * state.Band[0].det) >> 12;
if (wd < wd1)
{
break;
}
}
ilow = (el < 0) ? iln[i] : ilp[i];
// Block 2L, INVQAL
ril = ilow >> 2;
wd2 = qm4[ril];
dlow = (state.Band[0].det * wd2) >> 15;
// Block 3L, LOGSCL
il4 = rl42[ril];
wd = (state.Band[0].nb * 127) >> 7;
state.Band[0].nb = wd + wl[il4];
if (state.Band[0].nb < 0)
{
state.Band[0].nb = 0;
}
else if (state.Band[0].nb > 18432)
{
state.Band[0].nb = 18432;
}
// Block 3L, SCALEL
wd1 = (state.Band[0].nb >> 6) & 31;
wd2 = 8 - (state.Band[0].nb >> 11);
wd3 = (wd2 < 0) ? (ilb[wd1] << -wd2) : (ilb[wd1] >> wd2);
state.Band[0].det = wd3 << 2;
Block4(state, 0, dlow);
if (state.EncodeFrom8000Hz)
{
// Just leave the high bits as zero
code = (0xC0 | ilow) >> (8 - state.BitsPerSample);
}
else
{
// Block 1H, SUBTRA
eh = Saturate(xhigh - state.Band[1].s);
// Block 1H, QUANTH
wd = (eh >= 0) ? eh : -(eh + 1);
wd1 = (564 * state.Band[1].det) >> 12;
mih = (wd >= wd1) ? 2 : 1;
ihigh = (eh < 0) ? ihn[mih] : ihp[mih];
// Block 2H, INVQAH
wd2 = qm2[ihigh];
dhigh = (state.Band[1].det * wd2) >> 15;
// Block 3H, LOGSCH
ih2 = rh2[ihigh];
wd = (state.Band[1].nb * 127) >> 7;
state.Band[1].nb = wd + wh[ih2];
if (state.Band[1].nb < 0)
{
state.Band[1].nb = 0;
}
else if (state.Band[1].nb > 22528)
{
state.Band[1].nb = 22528;
}
// Block 3H, SCALEH
wd1 = (state.Band[1].nb >> 6) & 31;
wd2 = 10 - (state.Band[1].nb >> 11);
wd3 = (wd2 < 0) ? (ilb[wd1] << -wd2) : (ilb[wd1] >> wd2);
state.Band[1].det = wd3 << 2;
Block4(state, 1, dhigh);
code = ((ihigh << 6) | ilow) >> (8 - state.BitsPerSample);
}
if (state.Packed)
{
// Pack the code bits
state.OutBuffer |= (uint)(code << state.OutBits);
state.OutBits += state.BitsPerSample;
if (state.OutBits >= 8)
{
outputBuffer[g722_bytes++] = (byte)(state.OutBuffer & 0xFF);
state.OutBits -= 8;
state.OutBuffer >>= 8;
}
}
else
{
outputBuffer[g722_bytes++] = (byte)code;
}
}
return(g722_bytes);
}
static void Block4(G722CodecState s, int band, int d)
{
int wd1;
int wd2;
int wd3;
int i;
// Block 4, RECONS
s.Band[band].d[0] = d;
s.Band[band].r[0] = Saturate(s.Band[band].s + d);
// Block 4, PARREC
s.Band[band].p[0] = Saturate(s.Band[band].sz + d);
// Block 4, UPPOL2
for (i = 0; i < 3; i++)
{
s.Band[band].sg[i] = s.Band[band].p[i] >> 15;
}
wd1 = Saturate(s.Band[band].a[1] << 2);
wd2 = (s.Band[band].sg[0] == s.Band[band].sg[1]) ? -wd1 : wd1;
if (wd2 > 32767)
{
wd2 = 32767;
}
wd3 = (s.Band[band].sg[0] == s.Band[band].sg[2]) ? 128 : -128;
wd3 += (wd2 >> 7);
wd3 += (s.Band[band].a[2] * 32512) >> 15;
if (wd3 > 12288)
{
wd3 = 12288;
}
else if (wd3 < -12288)
{
wd3 = -12288;
}
s.Band[band].ap[2] = wd3;
// Block 4, UPPOL1
s.Band[band].sg[0] = s.Band[band].p[0] >> 15;
s.Band[band].sg[1] = s.Band[band].p[1] >> 15;
wd1 = (s.Band[band].sg[0] == s.Band[band].sg[1]) ? 192 : -192;
wd2 = (s.Band[band].a[1] * 32640) >> 15;
s.Band[band].ap[1] = Saturate(wd1 + wd2);
wd3 = Saturate(15360 - s.Band[band].ap[2]);
if (s.Band[band].ap[1] > wd3)
{
s.Band[band].ap[1] = wd3;
}
else if (s.Band[band].ap[1] < -wd3)
{
s.Band[band].ap[1] = -wd3;
}
// Block 4, UPZERO
wd1 = (d == 0) ? 0 : 128;
s.Band[band].sg[0] = d >> 15;
for (i = 1; i < 7; i++)
{
s.Band[band].sg[i] = s.Band[band].d[i] >> 15;
wd2 = (s.Band[band].sg[i] == s.Band[band].sg[0]) ? wd1 : -wd1;
wd3 = (s.Band[band].b[i] * 32640) >> 15;
s.Band[band].bp[i] = Saturate(wd2 + wd3);
}
// Block 4, DELAYA
for (i = 6; i > 0; i--)
{
s.Band[band].d[i] = s.Band[band].d[i - 1];
s.Band[band].b[i] = s.Band[band].bp[i];
}
for (i = 2; i > 0; i--)
{
s.Band[band].r[i] = s.Band[band].r[i - 1];
s.Band[band].p[i] = s.Band[band].p[i - 1];
s.Band[band].a[i] = s.Band[band].ap[i];
}
// Block 4, FILTEP
wd1 = Saturate(s.Band[band].r[1] + s.Band[band].r[1]);
wd1 = (s.Band[band].a[1] * wd1) >> 15;
wd2 = Saturate(s.Band[band].r[2] + s.Band[band].r[2]);
wd2 = (s.Band[band].a[2] * wd2) >> 15;
s.Band[band].sp = Saturate(wd1 + wd2);
// Block 4, FILTEZ
s.Band[band].sz = 0;
for (i = 6; i > 0; i--)
{
wd1 = Saturate(s.Band[band].d[i] + s.Band[band].d[i]);
s.Band[band].sz += (s.Band[band].b[i] * wd1) >> 15;
}
s.Band[band].sz = Saturate(s.Band[band].sz);
// Block 4, PREDIC
s.Band[band].s = Saturate(s.Band[band].sp + s.Band[band].sz);
}
/// <summary>
/// Decodes a buffer of G722
/// </summary>
/// <param name="state">Codec state</param>
/// <param name="outputBuffer">Output buffer (to contain decompressed PCM samples)</param>
/// <param name="inputG722Data"></param>
/// <param name="inputLength">Number of bytes in input G722 data to decode</param>
/// <returns>Number of samples written into output buffer</returns>
public int Decode(G722CodecState state, short[] outputBuffer, byte[] inputG722Data, int inputLength)
{
int dlowt;
int rlow;
int ihigh;
int dhigh;
int rhigh;
int xout1;
int xout2;
int wd1;
int wd2;
int wd3;
int code;
int outlen;
int i;
int j;
outlen = 0;
rhigh = 0;
for (j = 0; j < inputLength;)
{
if (state.Packed)
{
// Unpack the code bits
if (state.InBits < state.BitsPerSample)
{
state.InBuffer |= (uint)(inputG722Data[j++] << state.InBits);
state.InBits += 8;
}
code = (int)state.InBuffer & ((1 << state.BitsPerSample) - 1);
state.InBuffer >>= state.BitsPerSample;
state.InBits -= state.BitsPerSample;
}
else
{
code = inputG722Data[j++];
}
switch (state.BitsPerSample)
{
default:
case 8:
wd1 = code & 0x3F;
ihigh = (code >> 6) & 0x03;
wd2 = qm6[wd1];
wd1 >>= 2;
break;
case 7:
wd1 = code & 0x1F;
ihigh = (code >> 5) & 0x03;
wd2 = qm5[wd1];
wd1 >>= 1;
break;
case 6:
wd1 = code & 0x0F;
ihigh = (code >> 4) & 0x03;
wd2 = qm4[wd1];
break;
}
// Block 5L, LOW BAND INVQBL
wd2 = (state.Band[0].det * wd2) >> 15;
// Block 5L, RECONS
rlow = state.Band[0].s + wd2;
// Block 6L, LIMIT
if (rlow > 16383)
{
rlow = 16383;
}
else if (rlow < -16384)
{
rlow = -16384;
}
// Block 2L, INVQAL
wd2 = qm4[wd1];
dlowt = (state.Band[0].det * wd2) >> 15;
// Block 3L, LOGSCL
wd2 = rl42[wd1];
wd1 = (state.Band[0].nb * 127) >> 7;
wd1 += wl[wd2];
if (wd1 < 0)
{
wd1 = 0;
}
else if (wd1 > 18432)
{
wd1 = 18432;
}
state.Band[0].nb = wd1;
// Block 3L, SCALEL
wd1 = (state.Band[0].nb >> 6) & 31;
wd2 = 8 - (state.Band[0].nb >> 11);
wd3 = (wd2 < 0) ? (ilb[wd1] << -wd2) : (ilb[wd1] >> wd2);
state.Band[0].det = wd3 << 2;
Block4(state, 0, dlowt);
if (!state.EncodeFrom8000Hz)
{
// Block 2H, INVQAH
wd2 = qm2[ihigh];
dhigh = (state.Band[1].det * wd2) >> 15;
// Block 5H, RECONS
rhigh = dhigh + state.Band[1].s;
// Block 6H, LIMIT
if (rhigh > 16383)
{
rhigh = 16383;
}
else if (rhigh < -16384)
{
rhigh = -16384;
}
// Block 2H, INVQAH
wd2 = rh2[ihigh];
wd1 = (state.Band[1].nb * 127) >> 7;
wd1 += wh[wd2];
if (wd1 < 0)
{
wd1 = 0;
}
else if (wd1 > 22528)
{
wd1 = 22528;
}
state.Band[1].nb = wd1;
// Block 3H, SCALEH
wd1 = (state.Band[1].nb >> 6) & 31;
wd2 = 10 - (state.Band[1].nb >> 11);
wd3 = (wd2 < 0) ? (ilb[wd1] << -wd2) : (ilb[wd1] >> wd2);
state.Band[1].det = wd3 << 2;
Block4(state, 1, dhigh);
}
if (state.ItuTestMode)
{
outputBuffer[outlen++] = (short)(rlow << 1);
outputBuffer[outlen++] = (short)(rhigh << 1);
}
else
{
if (state.EncodeFrom8000Hz)
{
outputBuffer[outlen++] = (short)(rlow << 1);
}
else
{
// Apply the receive QMF
for (i = 0; i < 22; i++)
{
state.QmfSignalHistory[i] = state.QmfSignalHistory[i + 2];
}
state.QmfSignalHistory[22] = rlow + rhigh;
state.QmfSignalHistory[23] = rlow - rhigh;
xout1 = 0;
xout2 = 0;
for (i = 0; i < 12; i++)
{
xout2 += state.QmfSignalHistory[2 * i] * qmf_coeffs[i];
xout1 += state.QmfSignalHistory[2 * i + 1] * qmf_coeffs[11 - i];
}
outputBuffer[outlen++] = (short)(xout1 >> 11);
outputBuffer[outlen++] = (short)(xout2 >> 11);
}
}
}
return(outlen);
}