/// <summary>
/// Decode mid/side predictors
/// </summary>
/// <param name="psRangeDec">I/O Compressor data structure</param>
/// <param name="pred_Q13">O Predictors</param>
internal static void silk_stereo_decode_pred(
EntropyCoder psRangeDec,
int[] pred_Q13)
{
int n;
int[][] ix = Arrays.InitTwoDimensionalArray <int>(2, 3);
int low_Q13, step_Q13;
// Entropy decoding
n = psRangeDec.dec_icdf(Tables.silk_stereo_pred_joint_iCDF, 8);
ix[0][2] = Inlines.silk_DIV32_16(n, 5);
ix[1][2] = n - 5 * ix[0][2];
for (n = 0; n < 2; n++)
{
ix[n][0] = psRangeDec.dec_icdf(Tables.silk_uniform3_iCDF, 8);
ix[n][1] = psRangeDec.dec_icdf(Tables.silk_uniform5_iCDF, 8);
}
// Dequantize
for (n = 0; n < 2; n++)
{
ix[n][0] += 3 * ix[n][2];
low_Q13 = Tables.silk_stereo_pred_quant_Q13[ix[n][0]];
step_Q13 = Inlines.silk_SMULWB(Tables.silk_stereo_pred_quant_Q13[ix[n][0] + 1] - low_Q13,
((int)((0.5f / SilkConstants.STEREO_QUANT_SUB_STEPS) * ((long)1 << (16)) + 0.5)) /*Inlines.SILK_CONST(0.5f / SilkConstants.STEREO_QUANT_SUB_STEPS, 16)*/);
pred_Q13[n] = Inlines.silk_SMLABB(low_Q13, step_Q13, 2 * ix[n][1] + 1);
}
/* Subtract second from first predictor (helps when actually applying these) */
pred_Q13[0] -= pred_Q13[1];
}
/// <summary>
/// Decode mid-only flag
/// </summary>
/// <param name="psRangeDec">I/O Compressor data structure</param>
/// <param name="decode_only_mid">O Flag that only mid channel has been coded</param>
internal static void silk_stereo_decode_mid_only(
EntropyCoder psRangeDec,
BoxedValueInt decode_only_mid
)
{
/* Decode flag that only mid channel is coded */
decode_only_mid.Val = psRangeDec.dec_icdf(Tables.silk_stereo_only_code_mid_iCDF, 8);
}
/// <summary>
/// Decodes signs of excitation
/// </summary>
/// <param name="psRangeDec">I/O Compressor data structure</param>
/// <param name="pulses">I/O pulse signal</param>
/// <param name="length">I length of input</param>
/// <param name="signalType">I Signal type</param>
/// <param name="quantOffsetType">I Quantization offset type</param>
/// <param name="sum_pulses">I Sum of absolute pulses per block [MAX_NB_SHELL_BLOCKS]</param>
internal static void silk_decode_signs(
EntropyCoder psRangeDec,
short[] pulses,
int length,
int signalType,
int quantOffsetType,
int[] sum_pulses)
{
int i, j, p;
byte[] icdf = new byte[2];
int q_ptr;
byte[] icdf_table = Tables.silk_sign_iCDF;
int icdf_ptr;
icdf[1] = 0;
q_ptr = 0;
i = Inlines.silk_SMULBB(7, Inlines.silk_ADD_LSHIFT(quantOffsetType, signalType, 1));
icdf_ptr = i;
length = Inlines.silk_RSHIFT(length + SilkConstants.SHELL_CODEC_FRAME_LENGTH / 2, SilkConstants.LOG2_SHELL_CODEC_FRAME_LENGTH);
for (i = 0; i < length; i++)
{
p = sum_pulses[i];
if (p > 0)
{
icdf[0] = icdf_table[icdf_ptr + Inlines.silk_min(p & 0x1F, 6)];
for (j = 0; j < SilkConstants.SHELL_CODEC_FRAME_LENGTH; j++)
{
if (pulses[q_ptr + j] > 0)
{
/* attach sign */
pulses[q_ptr + j] *= (short)(silk_dec_map(psRangeDec.dec_icdf(icdf, 8)));
}
}
}
q_ptr += SilkConstants.SHELL_CODEC_FRAME_LENGTH;
}
}
/// <summary>
///
/// </summary>
/// <param name="p_child1">O pulse amplitude of first child subframe</param>
/// <param name="child1_ptr"></param>
/// <param name="p_child2">O pulse amplitude of second child subframe</param>
/// <param name="p_child2_ptr"></param>
/// <param name="psRangeDec">I/O Compressor data structure</param>
/// <param name="p">I pulse amplitude of current subframe</param>
/// <param name="shell_table">I table of shell cdfs</param>
internal static void decode_split(
short[] p_child1,
int child1_ptr,
short[] p_child2,
int p_child2_ptr,
EntropyCoder psRangeDec,
int p,
byte[] shell_table)
{
if (p > 0)
{
p_child1[child1_ptr] = (short)(psRangeDec.dec_icdf(shell_table, (Tables.silk_shell_code_table_offsets[p]), 8));
p_child2[p_child2_ptr] = (short)(p - p_child1[child1_ptr]);
}
else
{
p_child1[child1_ptr] = 0;
p_child2[p_child2_ptr] = 0;
}
}
internal static void unquant_coarse_energy(CeltMode m, int start, int end, int[] oldEBands, int intra, EntropyCoder dec, int C, int LM)
{
byte[] prob_model = Tables.e_prob_model[LM][intra];
int i, c;
int[] prev = { 0, 0 };
int coef;
int beta;
int budget;
int tell;
if (intra != 0)
{
coef = 0;
beta = beta_intra;
}
else
{
beta = beta_coef[LM];
coef = pred_coef[LM];
}
budget = (int)dec.storage * 8;
/* Decode at a fixed coarse resolution */
for (i = start; i < end; i++)
{
c = 0;
do
{
int qi;
int q;
int tmp;
/* It would be better to express this invariant as a
* test on C at function entry, but that isn't enough
* to make the static analyzer happy. */
Inlines.OpusAssert(c < 2);
tell = dec.tell();
if (budget - tell >= 15)
{
int pi;
pi = 2 * Inlines.IMIN(i, 20);
qi = Laplace.ec_laplace_decode(dec,
(uint)prob_model[pi] << 7, prob_model[pi + 1] << 6);
}
else if (budget - tell >= 2)
{
qi = dec.dec_icdf(small_energy_icdf, 2);
qi = (qi >> 1) ^ -(qi & 1);
}
else if (budget - tell >= 1)
{
qi = 0 - dec.dec_bit_logp(1);
}
else
{
qi = -1;
}
q = (int)Inlines.SHL32(qi, CeltConstants.DB_SHIFT); // opus bug: useless extend32
oldEBands[i + c * m.nbEBands] = Inlines.MAX16((0 - ((short)(0.5 + (9.0f) * (((int)1) << (CeltConstants.DB_SHIFT)))) /*Inlines.QCONST16(9.0f, CeltConstants.DB_SHIFT)*/), oldEBands[i + c * m.nbEBands]);
tmp = Inlines.PSHR32(Inlines.MULT16_16(coef, oldEBands[i + c * m.nbEBands]), 8) + prev[c] + Inlines.SHL32(q, 7);
tmp = Inlines.MAX32(-((int)(0.5 + (28.0f) * (((int)1) << (CeltConstants.DB_SHIFT + 7)))) /*Inlines.QCONST32(28.0f, CeltConstants.DB_SHIFT + 7)*/, tmp);
oldEBands[i + c * m.nbEBands] = (Inlines.PSHR32(tmp, 7));
prev[c] = prev[c] + Inlines.SHL32(q, 7) - Inlines.MULT16_16(beta, Inlines.PSHR32(q, 8));
} while (++c < C);
}
}
/* Decode a frame */
internal static int silk_Decode( /* O Returns error code */
SilkDecoder psDec, /* I/O State */
DecControlState decControl, /* I/O Control Structure */
int lostFlag, /* I 0: no loss, 1 loss, 2 decode fec */
int newPacketFlag, /* I Indicates first decoder call for this packet */
EntropyCoder psRangeDec, /* I/O Compressor data structure */
short[] samplesOut, /* O Decoded output speech vector */
int samplesOut_ptr,
out int nSamplesOut /* O Number of samples decoded */
)
{
int i, n, decode_only_middle = 0, ret = SilkError.SILK_NO_ERROR;
int LBRR_symbol;
BoxedValueInt nSamplesOutDec = new BoxedValueInt();
short[] samplesOut_tmp;
int[] samplesOut_tmp_ptrs = new int[2];
short[] samplesOut1_tmp_storage1;
short[] samplesOut1_tmp_storage2;
short[] samplesOut2_tmp;
int[] MS_pred_Q13 = new int[] { 0, 0 };
short[] resample_out;
int resample_out_ptr;
SilkChannelDecoder[] channel_state = psDec.channel_state;
int has_side;
int stereo_to_mono;
int delay_stack_alloc;
nSamplesOut = 0;
Inlines.OpusAssert(decControl.nChannelsInternal == 1 || decControl.nChannelsInternal == 2);
/**********************************/
/* Test if first frame in payload */
/**********************************/
if (newPacketFlag != 0)
{
for (n = 0; n < decControl.nChannelsInternal; n++)
{
channel_state[n].nFramesDecoded = 0; /* Used to count frames in packet */
}
}
/* If Mono . Stereo transition in bitstream: init state of second channel */
if (decControl.nChannelsInternal > psDec.nChannelsInternal)
{
ret += channel_state[1].silk_init_decoder();
}
stereo_to_mono = (decControl.nChannelsInternal == 1 && psDec.nChannelsInternal == 2 &&
(decControl.internalSampleRate == 1000 * channel_state[0].fs_kHz)) ? 1 : 0;
if (channel_state[0].nFramesDecoded == 0)
{
for (n = 0; n < decControl.nChannelsInternal; n++)
{
int fs_kHz_dec;
if (decControl.payloadSize_ms == 0)
{
/* Assuming packet loss, use 10 ms */
channel_state[n].nFramesPerPacket = 1;
channel_state[n].nb_subfr = 2;
}
else if (decControl.payloadSize_ms == 10)
{
channel_state[n].nFramesPerPacket = 1;
channel_state[n].nb_subfr = 2;
}
else if (decControl.payloadSize_ms == 20)
{
channel_state[n].nFramesPerPacket = 1;
channel_state[n].nb_subfr = 4;
}
else if (decControl.payloadSize_ms == 40)
{
channel_state[n].nFramesPerPacket = 2;
channel_state[n].nb_subfr = 4;
}
else if (decControl.payloadSize_ms == 60)
{
channel_state[n].nFramesPerPacket = 3;
channel_state[n].nb_subfr = 4;
}
else
{
Inlines.OpusAssert(false);
return(SilkError.SILK_DEC_INVALID_FRAME_SIZE);
}
fs_kHz_dec = (decControl.internalSampleRate >> 10) + 1;
if (fs_kHz_dec != 8 && fs_kHz_dec != 12 && fs_kHz_dec != 16)
{
Inlines.OpusAssert(false);
return(SilkError.SILK_DEC_INVALID_SAMPLING_FREQUENCY);
}
ret += channel_state[n].silk_decoder_set_fs(fs_kHz_dec, decControl.API_sampleRate);
}
}
if (decControl.nChannelsAPI == 2 && decControl.nChannelsInternal == 2 && (psDec.nChannelsAPI == 1 || psDec.nChannelsInternal == 1))
{
Arrays.MemSetShort(psDec.sStereo.pred_prev_Q13, 0, 2);
Arrays.MemSetShort(psDec.sStereo.sSide, 0, 2);
channel_state[1].resampler_state.Assign(channel_state[0].resampler_state);
}
psDec.nChannelsAPI = decControl.nChannelsAPI;
psDec.nChannelsInternal = decControl.nChannelsInternal;
if (decControl.API_sampleRate > (int)SilkConstants.MAX_API_FS_KHZ * 1000 || decControl.API_sampleRate < 8000)
{
ret = SilkError.SILK_DEC_INVALID_SAMPLING_FREQUENCY;
return(ret);
}
if (lostFlag != DecoderAPIFlag.FLAG_PACKET_LOST && channel_state[0].nFramesDecoded == 0)
{
/* First decoder call for this payload */
/* Decode VAD flags and LBRR flag */
for (n = 0; n < decControl.nChannelsInternal; n++)
{
for (i = 0; i < channel_state[n].nFramesPerPacket; i++)
{
channel_state[n].VAD_flags[i] = psRangeDec.dec_bit_logp(1);
}
channel_state[n].LBRR_flag = psRangeDec.dec_bit_logp(1);
}
/* Decode LBRR flags */
for (n = 0; n < decControl.nChannelsInternal; n++)
{
Arrays.MemSetInt(channel_state[n].LBRR_flags, 0, SilkConstants.MAX_FRAMES_PER_PACKET);
if (channel_state[n].LBRR_flag != 0)
{
if (channel_state[n].nFramesPerPacket == 1)
{
channel_state[n].LBRR_flags[0] = 1;
}
else
{
LBRR_symbol = psRangeDec.dec_icdf(Tables.silk_LBRR_flags_iCDF_ptr[channel_state[n].nFramesPerPacket - 2], 8) + 1;
for (i = 0; i < channel_state[n].nFramesPerPacket; i++)
{
channel_state[n].LBRR_flags[i] = Inlines.silk_RSHIFT(LBRR_symbol, i) & 1;
}
}
}
}
if (lostFlag == DecoderAPIFlag.FLAG_DECODE_NORMAL)
{
/* Regular decoding: skip all LBRR data */
for (i = 0; i < channel_state[0].nFramesPerPacket; i++)
{
for (n = 0; n < decControl.nChannelsInternal; n++)
{
if (channel_state[n].LBRR_flags[i] != 0)
{
short[] pulses = new short[SilkConstants.MAX_FRAME_LENGTH];
int condCoding;
if (decControl.nChannelsInternal == 2 && n == 0)
{
Stereo.silk_stereo_decode_pred(psRangeDec, MS_pred_Q13);
if (channel_state[1].LBRR_flags[i] == 0)
{
BoxedValueInt decodeOnlyMiddleBoxed = new BoxedValueInt(decode_only_middle);
Stereo.silk_stereo_decode_mid_only(psRangeDec, decodeOnlyMiddleBoxed);
decode_only_middle = decodeOnlyMiddleBoxed.Val;
}
}
/* Use conditional coding if previous frame available */
if (i > 0 && (channel_state[n].LBRR_flags[i - 1] != 0))
{
condCoding = SilkConstants.CODE_CONDITIONALLY;
}
else
{
condCoding = SilkConstants.CODE_INDEPENDENTLY;
}
DecodeIndices.silk_decode_indices(channel_state[n], psRangeDec, i, 1, condCoding);
DecodePulses.silk_decode_pulses(psRangeDec, pulses, channel_state[n].indices.signalType,
channel_state[n].indices.quantOffsetType, channel_state[n].frame_length);
}
}
}
}
}
/* Get MS predictor index */
if (decControl.nChannelsInternal == 2)
{
if (lostFlag == DecoderAPIFlag.FLAG_DECODE_NORMAL ||
(lostFlag == DecoderAPIFlag.FLAG_DECODE_LBRR && channel_state[0].LBRR_flags[channel_state[0].nFramesDecoded] == 1))
{
Stereo.silk_stereo_decode_pred(psRangeDec, MS_pred_Q13);
/* For LBRR data, decode mid-only flag only if side-channel's LBRR flag is false */
if ((lostFlag == DecoderAPIFlag.FLAG_DECODE_NORMAL && channel_state[1].VAD_flags[channel_state[0].nFramesDecoded] == 0) ||
(lostFlag == DecoderAPIFlag.FLAG_DECODE_LBRR && channel_state[1].LBRR_flags[channel_state[0].nFramesDecoded] == 0))
{
BoxedValueInt decodeOnlyMiddleBoxed = new BoxedValueInt(decode_only_middle);
Stereo.silk_stereo_decode_mid_only(psRangeDec, decodeOnlyMiddleBoxed);
decode_only_middle = decodeOnlyMiddleBoxed.Val;
}
else
{
decode_only_middle = 0;
}
}
else
{
for (n = 0; n < 2; n++)
{
MS_pred_Q13[n] = psDec.sStereo.pred_prev_Q13[n];
}
}
}
/* Reset side channel decoder prediction memory for first frame with side coding */
if (decControl.nChannelsInternal == 2 && decode_only_middle == 0 && psDec.prev_decode_only_middle == 1)
{
Arrays.MemSetShort(psDec.channel_state[1].outBuf, 0, SilkConstants.MAX_FRAME_LENGTH + 2 * SilkConstants.MAX_SUB_FRAME_LENGTH);
Arrays.MemSetInt(psDec.channel_state[1].sLPC_Q14_buf, 0, SilkConstants.MAX_LPC_ORDER);
psDec.channel_state[1].lagPrev = 100;
psDec.channel_state[1].LastGainIndex = 10;
psDec.channel_state[1].prevSignalType = SilkConstants.TYPE_NO_VOICE_ACTIVITY;
psDec.channel_state[1].first_frame_after_reset = 1;
}
/* Check if the temp buffer fits into the output PCM buffer. If it fits,
* we can delay allocating the temp buffer until after the SILK peak stack
* usage. We need to use a < and not a <= because of the two extra samples. */
delay_stack_alloc = (decControl.internalSampleRate * decControl.nChannelsInternal
< decControl.API_sampleRate * decControl.nChannelsAPI) ? 1 : 0;
if (delay_stack_alloc != 0)
{
samplesOut_tmp = samplesOut;
samplesOut_tmp_ptrs[0] = samplesOut_ptr;
samplesOut_tmp_ptrs[1] = samplesOut_ptr + channel_state[0].frame_length + 2;
}
else
{
samplesOut1_tmp_storage1 = new short[decControl.nChannelsInternal * (channel_state[0].frame_length + 2)];
samplesOut_tmp = samplesOut1_tmp_storage1;
samplesOut_tmp_ptrs[0] = 0;
samplesOut_tmp_ptrs[1] = channel_state[0].frame_length + 2;
}
if (lostFlag == DecoderAPIFlag.FLAG_DECODE_NORMAL)
{
has_side = (decode_only_middle == 0) ? 1 : 0;
}
else
{
has_side = (psDec.prev_decode_only_middle == 0 ||
(decControl.nChannelsInternal == 2 &&
lostFlag == DecoderAPIFlag.FLAG_DECODE_LBRR &&
channel_state[1].LBRR_flags[channel_state[1].nFramesDecoded] == 1)) ? 1 : 0;
}
/* Call decoder for one frame */
for (n = 0; n < decControl.nChannelsInternal; n++)
{
if (n == 0 || (has_side != 0))
{
int FrameIndex;
int condCoding;
FrameIndex = channel_state[0].nFramesDecoded - n;
/* Use independent coding if no previous frame available */
if (FrameIndex <= 0)
{
condCoding = SilkConstants.CODE_INDEPENDENTLY;
}
else if (lostFlag == DecoderAPIFlag.FLAG_DECODE_LBRR)
{
condCoding = (channel_state[n].LBRR_flags[FrameIndex - 1] != 0) ? SilkConstants.CODE_CONDITIONALLY : SilkConstants.CODE_INDEPENDENTLY;
}
else if (n > 0 && (psDec.prev_decode_only_middle != 0))
{
/* If we skipped a side frame in this packet, we don't
* need LTP scaling; the LTP state is well-defined. */
condCoding = SilkConstants.CODE_INDEPENDENTLY_NO_LTP_SCALING;
}
else
{
condCoding = SilkConstants.CODE_CONDITIONALLY;
}
ret += channel_state[n].silk_decode_frame(psRangeDec, samplesOut_tmp, samplesOut_tmp_ptrs[n] + 2, nSamplesOutDec, lostFlag, condCoding);
}
else
{
Arrays.MemSetWithOffset <short>(samplesOut_tmp, 0, samplesOut_tmp_ptrs[n] + 2, nSamplesOutDec.Val);
}
channel_state[n].nFramesDecoded++;
}
if (decControl.nChannelsAPI == 2 && decControl.nChannelsInternal == 2)
{
/* Convert Mid/Side to Left/Right */
Stereo.silk_stereo_MS_to_LR(psDec.sStereo, samplesOut_tmp, samplesOut_tmp_ptrs[0], samplesOut_tmp, samplesOut_tmp_ptrs[1], MS_pred_Q13, channel_state[0].fs_kHz, nSamplesOutDec.Val);
}
else
{
/* Buffering */
Array.Copy(psDec.sStereo.sMid, 0, samplesOut_tmp, samplesOut_tmp_ptrs[0], 2);
Array.Copy(samplesOut_tmp, samplesOut_tmp_ptrs[0] + nSamplesOutDec.Val, psDec.sStereo.sMid, 0, 2);
}
/* Number of output samples */
nSamplesOut = Inlines.silk_DIV32(nSamplesOutDec.Val * decControl.API_sampleRate, Inlines.silk_SMULBB(channel_state[0].fs_kHz, 1000));
/* Set up pointers to temp buffers */
if (decControl.nChannelsAPI == 2)
{
samplesOut2_tmp = new short[nSamplesOut];
resample_out = samplesOut2_tmp;
resample_out_ptr = 0;
}
else
{
resample_out = samplesOut;
resample_out_ptr = samplesOut_ptr;
}
if (delay_stack_alloc != 0)
{
samplesOut1_tmp_storage2 = new short[decControl.nChannelsInternal * (channel_state[0].frame_length + 2)];
Array.Copy(samplesOut, samplesOut_ptr, samplesOut1_tmp_storage2, 0, decControl.nChannelsInternal * (channel_state[0].frame_length + 2));
samplesOut_tmp = samplesOut1_tmp_storage2;
samplesOut_tmp_ptrs[0] = 0;
samplesOut_tmp_ptrs[1] = channel_state[0].frame_length + 2;
}
for (n = 0; n < Inlines.silk_min(decControl.nChannelsAPI, decControl.nChannelsInternal); n++)
{
/* Resample decoded signal to API_sampleRate */
ret += Resampler.silk_resampler(channel_state[n].resampler_state, resample_out, resample_out_ptr, samplesOut_tmp, samplesOut_tmp_ptrs[n] + 1, nSamplesOutDec.Val);
/* Interleave if stereo output and stereo stream */
if (decControl.nChannelsAPI == 2)
{
int nptr = samplesOut_ptr + n;
for (i = 0; i < nSamplesOut; i++)
{
samplesOut[nptr + 2 * i] = resample_out[resample_out_ptr + i];
}
}
}
/* Create two channel output from mono stream */
if (decControl.nChannelsAPI == 2 && decControl.nChannelsInternal == 1)
{
if (stereo_to_mono != 0)
{
/* Resample right channel for newly collapsed stereo just in case
* we weren't doing collapsing when switching to mono */
ret += Resampler.silk_resampler(channel_state[1].resampler_state, resample_out, resample_out_ptr, samplesOut_tmp, samplesOut_tmp_ptrs[0] + 1, nSamplesOutDec.Val);
for (i = 0; i < nSamplesOut; i++)
{
samplesOut[samplesOut_ptr + 1 + 2 * i] = resample_out[resample_out_ptr + i];
}
}
else
{
for (i = 0; i < nSamplesOut; i++)
{
samplesOut[samplesOut_ptr + 1 + 2 * i] = samplesOut[samplesOut_ptr + 2 * i];
}
}
}
/* Export pitch lag, measured at 48 kHz sampling rate */
if (channel_state[0].prevSignalType == SilkConstants.TYPE_VOICED)
{
int[] mult_tab = { 6, 4, 3 };
decControl.prevPitchLag = channel_state[0].lagPrev * mult_tab[(channel_state[0].fs_kHz - 8) >> 2];
}
else
{
decControl.prevPitchLag = 0;
}
if (lostFlag == DecoderAPIFlag.FLAG_PACKET_LOST)
{
/* On packet loss, remove the gain clamping to prevent having the energy "bounce back"
* if we lose packets when the energy is going down */
for (i = 0; i < psDec.nChannelsInternal; i++)
{
psDec.channel_state[i].LastGainIndex = 10;
}
}
else
{
psDec.prev_decode_only_middle = decode_only_middle;
}
return(ret);
}
/*********************************************/
/* Decode quantization indices of excitation */
/*********************************************/
internal static void silk_decode_pulses(
EntropyCoder psRangeDec, /* I/O Compressor data structure */
short[] pulses, /* O Excitation signal */
int signalType, /* I Sigtype */
int quantOffsetType, /* I quantOffsetType */
int frame_length /* I Frame length */
)
{
int i, j, k, iter, abs_q, nLS, RateLevelIndex;
int[] sum_pulses = new int[SilkConstants.MAX_NB_SHELL_BLOCKS];
int[] nLshifts = new int[SilkConstants.MAX_NB_SHELL_BLOCKS];
int pulses_ptr;
/*********************/
/* Decode rate level */
/*********************/
RateLevelIndex = psRangeDec.dec_icdf(Tables.silk_rate_levels_iCDF[signalType >> 1], 8);
/* Calculate number of shell blocks */
Inlines.OpusAssert(1 << SilkConstants.LOG2_SHELL_CODEC_FRAME_LENGTH == SilkConstants.SHELL_CODEC_FRAME_LENGTH);
iter = Inlines.silk_RSHIFT(frame_length, SilkConstants.LOG2_SHELL_CODEC_FRAME_LENGTH);
if (iter * SilkConstants.SHELL_CODEC_FRAME_LENGTH < frame_length)
{
Inlines.OpusAssert(frame_length == 12 * 10); /* Make sure only happens for 10 ms @ 12 kHz */
iter++;
}
/***************************************************/
/* Sum-Weighted-Pulses Decoding */
/***************************************************/
for (i = 0; i < iter; i++)
{
nLshifts[i] = 0;
sum_pulses[i] = psRangeDec.dec_icdf(Tables.silk_pulses_per_block_iCDF[RateLevelIndex], 8);
/* LSB indication */
while (sum_pulses[i] == SilkConstants.SILK_MAX_PULSES + 1)
{
nLshifts[i]++;
/* When we've already got 10 LSBs, we shift the table to not allow (SILK_MAX_PULSES + 1) */
sum_pulses[i] = psRangeDec.dec_icdf(
Tables.silk_pulses_per_block_iCDF[SilkConstants.N_RATE_LEVELS - 1], (nLshifts[i] == 10 ? 1 : 0), 8);
}
}
/***************************************************/
/* Shell decoding */
/***************************************************/
for (i = 0; i < iter; i++)
{
if (sum_pulses[i] > 0)
{
ShellCoder.silk_shell_decoder(pulses, Inlines.silk_SMULBB(i, SilkConstants.SHELL_CODEC_FRAME_LENGTH), psRangeDec, sum_pulses[i]);
}
else
{
Arrays.MemSetWithOffset <short>(pulses, 0, Inlines.silk_SMULBB(i, SilkConstants.SHELL_CODEC_FRAME_LENGTH), SilkConstants.SHELL_CODEC_FRAME_LENGTH);
}
}
/***************************************************/
/* LSB Decoding */
/***************************************************/
for (i = 0; i < iter; i++)
{
if (nLshifts[i] > 0)
{
nLS = nLshifts[i];
pulses_ptr = Inlines.silk_SMULBB(i, SilkConstants.SHELL_CODEC_FRAME_LENGTH);
for (k = 0; k < SilkConstants.SHELL_CODEC_FRAME_LENGTH; k++)
{
abs_q = pulses[pulses_ptr + k];
for (j = 0; j < nLS; j++)
{
abs_q = Inlines.silk_LSHIFT(abs_q, 1);
abs_q += psRangeDec.dec_icdf(Tables.silk_lsb_iCDF, 8);
}
pulses[pulses_ptr + k] = (short)(abs_q);
}
/* Mark the number of pulses non-zero for sign decoding. */
sum_pulses[i] |= nLS << 5;
}
}
/****************************************/
/* Decode and add signs to pulse signal */
/****************************************/
CodeSigns.silk_decode_signs(psRangeDec, pulses, frame_length, signalType, quantOffsetType, sum_pulses);
}
/* Decode side-information parameters from payload */
internal static void silk_decode_indices(
SilkChannelDecoder psDec, /* I/O State */
EntropyCoder psRangeDec, /* I/O Compressor data structure */
int FrameIndex, /* I Frame number */
int decode_LBRR, /* I Flag indicating LBRR data is being decoded */
int condCoding /* I The type of conditional coding to use */
)
{
int i, k, Ix;
int decode_absolute_lagIndex, delta_lagIndex;
short[] ec_ix = new short[psDec.LPC_order];
byte[] pred_Q8 = new byte[psDec.LPC_order];
/*******************************************/
/* Decode signal type and quantizer offset */
/*******************************************/
if (decode_LBRR != 0 || psDec.VAD_flags[FrameIndex] != 0)
{
Ix = psRangeDec.dec_icdf(Tables.silk_type_offset_VAD_iCDF, 8) + 2;
}
else
{
Ix = psRangeDec.dec_icdf(Tables.silk_type_offset_no_VAD_iCDF, 8);
}
psDec.indices.signalType = (sbyte)Inlines.silk_RSHIFT(Ix, 1);
psDec.indices.quantOffsetType = (sbyte)(Ix & 1);
/****************/
/* Decode gains */
/****************/
/* First subframe */
if (condCoding == SilkConstants.CODE_CONDITIONALLY)
{
/* Conditional coding */
psDec.indices.GainsIndices[0] = (sbyte)psRangeDec.dec_icdf(Tables.silk_delta_gain_iCDF, 8);
}
else
{
/* Independent coding, in two stages: MSB bits followed by 3 LSBs */
psDec.indices.GainsIndices[0] = (sbyte)Inlines.silk_LSHIFT(psRangeDec.dec_icdf(Tables.silk_gain_iCDF[psDec.indices.signalType], 8), 3);
psDec.indices.GainsIndices[0] += (sbyte)psRangeDec.dec_icdf(Tables.silk_uniform8_iCDF, 8);
}
/* Remaining subframes */
for (i = 1; i < psDec.nb_subfr; i++)
{
psDec.indices.GainsIndices[i] = (sbyte)psRangeDec.dec_icdf(Tables.silk_delta_gain_iCDF, 8);
}
/**********************/
/* Decode LSF Indices */
/**********************/
psDec.indices.NLSFIndices[0] = (sbyte)psRangeDec.dec_icdf(psDec.psNLSF_CB.CB1_iCDF, (psDec.indices.signalType >> 1) * psDec.psNLSF_CB.nVectors, 8);
NLSF.silk_NLSF_unpack(ec_ix, pred_Q8, psDec.psNLSF_CB, psDec.indices.NLSFIndices[0]);
Inlines.OpusAssert(psDec.psNLSF_CB.order == psDec.LPC_order);
for (i = 0; i < psDec.psNLSF_CB.order; i++)
{
Ix = psRangeDec.dec_icdf(psDec.psNLSF_CB.ec_iCDF, (ec_ix[i]), 8);
if (Ix == 0)
{
Ix -= psRangeDec.dec_icdf(Tables.silk_NLSF_EXT_iCDF, 8);
}
else if (Ix == 2 * SilkConstants.NLSF_QUANT_MAX_AMPLITUDE)
{
Ix += psRangeDec.dec_icdf(Tables.silk_NLSF_EXT_iCDF, 8);
}
psDec.indices.NLSFIndices[i + 1] = (sbyte)(Ix - SilkConstants.NLSF_QUANT_MAX_AMPLITUDE);
}
/* Decode LSF interpolation factor */
if (psDec.nb_subfr == SilkConstants.MAX_NB_SUBFR)
{
psDec.indices.NLSFInterpCoef_Q2 = (sbyte)psRangeDec.dec_icdf(Tables.silk_NLSF_interpolation_factor_iCDF, 8);
}
else
{
psDec.indices.NLSFInterpCoef_Q2 = 4;
}
if (psDec.indices.signalType == SilkConstants.TYPE_VOICED)
{
/*********************/
/* Decode pitch lags */
/*********************/
/* Get lag index */
decode_absolute_lagIndex = 1;
if (condCoding == SilkConstants.CODE_CONDITIONALLY && psDec.ec_prevSignalType == SilkConstants.TYPE_VOICED)
{
/* Decode Delta index */
delta_lagIndex = (short)psRangeDec.dec_icdf(Tables.silk_pitch_delta_iCDF, 8);
if (delta_lagIndex > 0)
{
delta_lagIndex = delta_lagIndex - 9;
psDec.indices.lagIndex = (short)(psDec.ec_prevLagIndex + delta_lagIndex);
decode_absolute_lagIndex = 0;
}
}
if (decode_absolute_lagIndex != 0)
{
/* Absolute decoding */
psDec.indices.lagIndex = (short)(psRangeDec.dec_icdf(Tables.silk_pitch_lag_iCDF, 8) * Inlines.silk_RSHIFT(psDec.fs_kHz, 1));
psDec.indices.lagIndex += (short)psRangeDec.dec_icdf(psDec.pitch_lag_low_bits_iCDF, 8);
}
psDec.ec_prevLagIndex = psDec.indices.lagIndex;
/* Get countour index */
psDec.indices.contourIndex = (sbyte)psRangeDec.dec_icdf(psDec.pitch_contour_iCDF, 8);
/********************/
/* Decode LTP gains */
/********************/
/* Decode PERIndex value */
psDec.indices.PERIndex = (sbyte)psRangeDec.dec_icdf(Tables.silk_LTP_per_index_iCDF, 8);
for (k = 0; k < psDec.nb_subfr; k++)
{
psDec.indices.LTPIndex[k] = (sbyte)psRangeDec.dec_icdf(Tables.silk_LTP_gain_iCDF_ptrs[psDec.indices.PERIndex], 8);
}
/**********************/
/* Decode LTP scaling */
/**********************/
if (condCoding == SilkConstants.CODE_INDEPENDENTLY)
{
psDec.indices.LTP_scaleIndex = (sbyte)psRangeDec.dec_icdf(Tables.silk_LTPscale_iCDF, 8);
}
else
{
psDec.indices.LTP_scaleIndex = 0;
}
}
psDec.ec_prevSignalType = psDec.indices.signalType;
/***************/
/* Decode seed */
/***************/
psDec.indices.Seed = (sbyte)psRangeDec.dec_icdf(Tables.silk_uniform4_iCDF, 8);
}
