| /* |
| * Copyright (c) 2011 The WebRTC project authors. All Rights Reserved. |
| * |
| * Use of this source code is governed by a BSD-style license |
| * that can be found in the LICENSE file in the root of the source |
| * tree. An additional intellectual property rights grant can be found |
| * in the file PATENTS. All contributing project authors may |
| * be found in the AUTHORS file in the root of the source tree. |
| */ |
| |
| /* |
| * arith_routinslogist.c |
| * |
| * This C file contains arithmetic encode and decode logistic |
| * |
| */ |
| |
| #include "arith_routins.h" |
| |
| |
| /* Tables for piecewise linear cdf functions: y = k*x */ |
| |
| /* x Points for function piecewise() in Q15 */ |
| static const WebRtc_Word32 kHistEdges[51] = { |
| -327680, -314573, -301466, -288359, -275252, -262144, -249037, -235930, -222823, -209716, |
| -196608, -183501, -170394, -157287, -144180, -131072, -117965, -104858, -91751, -78644, |
| -65536, -52429, -39322, -26215, -13108, 0, 13107, 26214, 39321, 52428, |
| 65536, 78643, 91750, 104857, 117964, 131072, 144179, 157286, 170393, 183500, |
| 196608, 209715, 222822, 235929, 249036, 262144, 275251, 288358, 301465, 314572, |
| 327680 |
| }; |
| |
| |
| /* k Points for function piecewise() in Q0 */ |
| static const WebRtc_UWord16 kCdfSlope[51] = { |
| 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, |
| 5, 5, 13, 23, 47, 87, 154, 315, 700, 1088, |
| 2471, 6064, 14221, 21463, 36634, 36924, 19750, 13270, 5806, 2312, |
| 1095, 660, 316, 145, 86, 41, 32, 5, 5, 5, |
| 5, 5, 5, 5, 5, 5, 5, 5, 5, 2, |
| 0 |
| }; |
| |
| /* y Points for function piecewise() in Q0 */ |
| static const WebRtc_UWord16 kCdfLogistic[51] = { |
| 0, 2, 4, 6, 8, 10, 12, 14, 16, 18, |
| 20, 22, 24, 29, 38, 57, 92, 153, 279, 559, |
| 994, 1983, 4408, 10097, 18682, 33336, 48105, 56005, 61313, 63636, |
| 64560, 64998, 65262, 65389, 65447, 65481, 65497, 65510, 65512, 65514, |
| 65516, 65518, 65520, 65522, 65524, 65526, 65528, 65530, 65532, 65534, |
| 65535 |
| }; |
| |
| |
| /**************************************************************************** |
| * WebRtcIsacfix_Piecewise(...) |
| * |
| * Piecewise linear function |
| * |
| * Input: |
| * - xinQ15 : input value x in Q15 |
| * |
| * Return value : korresponding y-value in Q0 |
| */ |
| |
| |
| static __inline WebRtc_UWord16 WebRtcIsacfix_Piecewise(WebRtc_Word32 xinQ15) { |
| WebRtc_Word32 ind; |
| WebRtc_Word32 qtmp1; |
| WebRtc_UWord16 qtmp2; |
| |
| /* Find index for x-value */ |
| qtmp1 = WEBRTC_SPL_SAT(kHistEdges[50],xinQ15,kHistEdges[0]); |
| ind = WEBRTC_SPL_MUL(5, qtmp1 - kHistEdges[0]); |
| ind = WEBRTC_SPL_RSHIFT_W32(ind, 16); |
| |
| /* Calculate corresponding y-value ans return*/ |
| qtmp1 = qtmp1 - kHistEdges[ind]; |
| qtmp2 = (WebRtc_UWord16)WEBRTC_SPL_RSHIFT_U32( |
| WEBRTC_SPL_UMUL_32_16(qtmp1,kCdfSlope[ind]), 15); |
| return (kCdfLogistic[ind] + qtmp2); |
| } |
| |
| /**************************************************************************** |
| * WebRtcIsacfix_EncLogisticMulti2(...) |
| * |
| * Arithmetic coding of spectrum. |
| * |
| * Input: |
| * - streamData : in-/output struct containing bitstream |
| * - dataQ7 : data vector in Q7 |
| * - envQ8 : side info vector defining the width of the pdf |
| * in Q8 |
| * - lenData : data vector length |
| * |
| * Return value : 0 if ok, |
| * <0 otherwise. |
| */ |
| int WebRtcIsacfix_EncLogisticMulti2(Bitstr_enc *streamData, |
| WebRtc_Word16 *dataQ7, |
| const WebRtc_UWord16 *envQ8, |
| const WebRtc_Word16 lenData) |
| { |
| WebRtc_UWord32 W_lower; |
| WebRtc_UWord32 W_upper; |
| WebRtc_UWord16 W_upper_LSB; |
| WebRtc_UWord16 W_upper_MSB; |
| WebRtc_UWord16 *streamPtr; |
| WebRtc_UWord16 *maxStreamPtr; |
| WebRtc_UWord16 *streamPtrCarry; |
| WebRtc_UWord16 negcarry; |
| WebRtc_UWord32 cdfLo; |
| WebRtc_UWord32 cdfHi; |
| int k; |
| |
| /* point to beginning of stream buffer |
| * and set maximum streamPtr value */ |
| streamPtr = streamData->stream + streamData->stream_index; |
| maxStreamPtr = streamData->stream + STREAM_MAXW16_60MS - 1; |
| W_upper = streamData->W_upper; |
| |
| for (k = 0; k < lenData; k++) |
| { |
| /* compute cdf_lower and cdf_upper by evaluating the |
| * WebRtcIsacfix_Piecewise linear cdf */ |
| cdfLo = WebRtcIsacfix_Piecewise(WEBRTC_SPL_MUL_16_U16(*dataQ7 - 64, *envQ8)); |
| cdfHi = WebRtcIsacfix_Piecewise(WEBRTC_SPL_MUL_16_U16(*dataQ7 + 64, *envQ8)); |
| |
| /* test and clip if probability gets too small */ |
| while ((cdfLo + 1) >= cdfHi) { |
| /* clip */ |
| if (*dataQ7 > 0) { |
| *dataQ7 -= 128; |
| cdfHi = cdfLo; |
| cdfLo = WebRtcIsacfix_Piecewise( |
| WEBRTC_SPL_MUL_16_U16(*dataQ7 - 64, *envQ8)); |
| } else { |
| *dataQ7 += 128; |
| cdfLo = cdfHi; |
| cdfHi = WebRtcIsacfix_Piecewise( |
| WEBRTC_SPL_MUL_16_U16(*dataQ7 + 64, *envQ8)); |
| } |
| } |
| |
| dataQ7++; |
| /* increment only once per 4 iterations */ |
| envQ8 += (k & 1) & (k >> 1); |
| |
| |
| /* update interval */ |
| W_upper_LSB = (WebRtc_UWord16)W_upper; |
| W_upper_MSB = (WebRtc_UWord16)WEBRTC_SPL_RSHIFT_U32(W_upper, 16); |
| W_lower = WEBRTC_SPL_UMUL_32_16(cdfLo, W_upper_MSB); |
| W_lower += WEBRTC_SPL_UMUL_32_16_RSFT16(cdfLo, W_upper_LSB); |
| W_upper = WEBRTC_SPL_UMUL_32_16(cdfHi, W_upper_MSB); |
| W_upper += WEBRTC_SPL_UMUL_32_16_RSFT16(cdfHi, W_upper_LSB); |
| |
| /* shift interval such that it begins at zero */ |
| W_upper -= ++W_lower; |
| |
| /* add integer to bitstream */ |
| streamData->streamval += W_lower; |
| |
| /* handle carry */ |
| if (streamData->streamval < W_lower) |
| { |
| /* propagate carry */ |
| streamPtrCarry = streamPtr; |
| if (streamData->full == 0) { |
| negcarry = *streamPtrCarry; |
| negcarry += 0x0100; |
| *streamPtrCarry = negcarry; |
| while (!(negcarry)) |
| { |
| negcarry = *--streamPtrCarry; |
| negcarry++; |
| *streamPtrCarry = negcarry; |
| } |
| } else { |
| while (!(++(*--streamPtrCarry))); |
| } |
| } |
| |
| /* renormalize interval, store most significant byte of streamval and update streamval |
| * W_upper < 2^24 */ |
| while ( !(W_upper & 0xFF000000) ) |
| { |
| W_upper = WEBRTC_SPL_LSHIFT_U32(W_upper, 8); |
| if (streamData->full == 0) { |
| *streamPtr++ += (WebRtc_UWord16) WEBRTC_SPL_RSHIFT_U32( |
| streamData->streamval, 24); |
| streamData->full = 1; |
| } else { |
| *streamPtr = (WebRtc_UWord16) WEBRTC_SPL_LSHIFT_U32( |
| WEBRTC_SPL_RSHIFT_U32(streamData->streamval, 24), 8); |
| streamData->full = 0; |
| } |
| |
| if( streamPtr > maxStreamPtr ) |
| return -ISAC_DISALLOWED_BITSTREAM_LENGTH; |
| |
| streamData->streamval = WEBRTC_SPL_LSHIFT_U32(streamData->streamval, 8); |
| } |
| } |
| |
| /* calculate new stream_index */ |
| streamData->stream_index = streamPtr - streamData->stream; |
| streamData->W_upper = W_upper; |
| |
| return 0; |
| } |
| |
| |
| /**************************************************************************** |
| * WebRtcIsacfix_DecLogisticMulti2(...) |
| * |
| * Arithmetic decoding of spectrum. |
| * |
| * Input: |
| * - streamData : in-/output struct containing bitstream |
| * - envQ8 : side info vector defining the width of the pdf |
| * in Q8 |
| * - lenData : data vector length |
| * |
| * Input/Output: |
| * - dataQ7 : input: dither vector, output: data vector |
| * |
| * Return value : number of bytes in the stream so far |
| * -1 if error detected |
| */ |
| WebRtc_Word16 WebRtcIsacfix_DecLogisticMulti2(WebRtc_Word16 *dataQ7, |
| Bitstr_dec *streamData, |
| const WebRtc_Word32 *envQ8, |
| const WebRtc_Word16 lenData) |
| { |
| WebRtc_UWord32 W_lower; |
| WebRtc_UWord32 W_upper; |
| WebRtc_UWord32 W_tmp; |
| WebRtc_UWord16 W_upper_LSB; |
| WebRtc_UWord16 W_upper_MSB; |
| WebRtc_UWord32 streamVal; |
| WebRtc_UWord16 cdfTmp; |
| WebRtc_Word32 res; |
| WebRtc_Word32 inSqrt; |
| WebRtc_Word32 newRes; |
| const WebRtc_UWord16 *streamPtr; |
| WebRtc_Word16 candQ7; |
| WebRtc_Word16 envCount; |
| WebRtc_UWord16 tmpARSpecQ8 = 0; |
| int k, i; |
| |
| |
| /* point to beginning of stream buffer */ |
| streamPtr = streamData->stream + streamData->stream_index; |
| W_upper = streamData->W_upper; |
| |
| /* Check if it is first time decoder is called for this stream */ |
| if (streamData->stream_index == 0) |
| { |
| /* read first word from bytestream */ |
| streamVal = WEBRTC_SPL_LSHIFT_U32(*streamPtr++, 16); |
| streamVal |= *streamPtr++; |
| |
| } else { |
| streamVal = streamData->streamval; |
| } |
| |
| |
| res = WEBRTC_SPL_LSHIFT_W32((WebRtc_Word32)1, |
| WEBRTC_SPL_RSHIFT_W16(WebRtcSpl_GetSizeInBits(envQ8[0]), 1)); |
| envCount = 0; |
| |
| /* code assumes lenData%4 == 0 */ |
| for (k = 0; k < lenData; k += 4) |
| { |
| int k4; |
| |
| /* convert to magnitude spectrum, by doing square-roots (modified from SPLIB) */ |
| inSqrt = envQ8[envCount]; |
| i = 10; |
| |
| /* For safty reasons */ |
| if (inSqrt < 0) |
| inSqrt=-inSqrt; |
| |
| newRes = WEBRTC_SPL_RSHIFT_W32(WEBRTC_SPL_DIV(inSqrt, res) + res, 1); |
| do |
| { |
| res = newRes; |
| newRes = WEBRTC_SPL_RSHIFT_W32(WEBRTC_SPL_DIV(inSqrt, res) + res, 1); |
| } while (newRes != res && i-- > 0); |
| |
| tmpARSpecQ8 = (WebRtc_UWord16)newRes; |
| |
| for(k4 = 0; k4 < 4; k4++) |
| { |
| /* find the integer *data for which streamVal lies in [W_lower+1, W_upper] */ |
| W_upper_LSB = (WebRtc_UWord16) (W_upper & 0x0000FFFF); |
| W_upper_MSB = (WebRtc_UWord16) WEBRTC_SPL_RSHIFT_U32(W_upper, 16); |
| |
| /* find first candidate by inverting the logistic cdf |
| * Input dither value collected from io-stream */ |
| candQ7 = - *dataQ7 + 64; |
| cdfTmp = WebRtcIsacfix_Piecewise(WEBRTC_SPL_MUL_16_U16(candQ7, tmpARSpecQ8)); |
| |
| W_tmp = WEBRTC_SPL_UMUL_16_16(cdfTmp, W_upper_MSB); |
| W_tmp += WEBRTC_SPL_UMUL_16_16_RSFT16(cdfTmp, W_upper_LSB); |
| |
| if (streamVal > W_tmp) |
| { |
| W_lower = W_tmp; |
| candQ7 += 128; |
| cdfTmp = WebRtcIsacfix_Piecewise(WEBRTC_SPL_MUL_16_U16(candQ7, tmpARSpecQ8)); |
| |
| W_tmp = WEBRTC_SPL_UMUL_16_16(cdfTmp, W_upper_MSB); |
| W_tmp += WEBRTC_SPL_UMUL_16_16_RSFT16(cdfTmp, W_upper_LSB); |
| |
| while (streamVal > W_tmp) |
| { |
| W_lower = W_tmp; |
| candQ7 += 128; |
| cdfTmp = WebRtcIsacfix_Piecewise( |
| WEBRTC_SPL_MUL_16_U16(candQ7, tmpARSpecQ8)); |
| |
| W_tmp = WEBRTC_SPL_UMUL_16_16(cdfTmp, W_upper_MSB); |
| W_tmp += WEBRTC_SPL_UMUL_16_16_RSFT16(cdfTmp, W_upper_LSB); |
| |
| /* error check */ |
| if (W_lower == W_tmp) { |
| return -1; |
| } |
| } |
| W_upper = W_tmp; |
| |
| /* Output value put in dataQ7: another sample decoded */ |
| *dataQ7 = candQ7 - 64; |
| } |
| else |
| { |
| W_upper = W_tmp; |
| candQ7 -= 128; |
| cdfTmp = WebRtcIsacfix_Piecewise(WEBRTC_SPL_MUL_16_U16(candQ7, tmpARSpecQ8)); |
| |
| W_tmp = WEBRTC_SPL_UMUL_16_16(cdfTmp, W_upper_MSB); |
| W_tmp += WEBRTC_SPL_UMUL_16_16_RSFT16(cdfTmp, W_upper_LSB); |
| |
| while ( !(streamVal > W_tmp) ) |
| { |
| W_upper = W_tmp; |
| candQ7 -= 128; |
| cdfTmp = WebRtcIsacfix_Piecewise( |
| WEBRTC_SPL_MUL_16_U16(candQ7, tmpARSpecQ8)); |
| |
| W_tmp = WEBRTC_SPL_UMUL_16_16(cdfTmp, W_upper_MSB); |
| W_tmp += WEBRTC_SPL_UMUL_16_16_RSFT16(cdfTmp, W_upper_LSB); |
| |
| /* error check */ |
| if (W_upper == W_tmp){ |
| return -1; |
| } |
| } |
| W_lower = W_tmp; |
| |
| /* Output value put in dataQ7: another sample decoded */ |
| *dataQ7 = candQ7 + 64; |
| } |
| |
| dataQ7++; |
| |
| /* shift interval to start at zero */ |
| W_upper -= ++W_lower; |
| |
| /* add integer to bitstream */ |
| streamVal -= W_lower; |
| |
| /* renormalize interval and update streamVal |
| * W_upper < 2^24 */ |
| while ( !(W_upper & 0xFF000000) ) |
| { |
| /* read next byte from stream */ |
| if (streamData->full == 0) { |
| streamVal = WEBRTC_SPL_LSHIFT_W32(streamVal, 8) | (*streamPtr++ & 0x00FF); |
| streamData->full = 1; |
| } else { |
| streamVal = WEBRTC_SPL_LSHIFT_W32(streamVal, 8) | |
| WEBRTC_SPL_RSHIFT_U16(*streamPtr, 8); |
| streamData->full = 0; |
| } |
| W_upper = WEBRTC_SPL_LSHIFT_W32(W_upper, 8); |
| } |
| } |
| envCount++; |
| } |
| |
| streamData->stream_index = streamPtr - streamData->stream; |
| streamData->W_upper = W_upper; |
| streamData->streamval = streamVal; |
| |
| /* find number of bytes in original stream (determined by current interval width) */ |
| if ( W_upper > 0x01FFFFFF ) |
| return (streamData->stream_index*2 - 3 + !streamData->full); |
| else |
| return (streamData->stream_index*2 - 2 + !streamData->full); |
| } |
