/* * Copyright (c) 2012 Andrew D'Addesio * Copyright (c) 2013-2014 Mozilla Corporation * Copyright (c) 2016 Rostislav Pehlivanov * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include "opustab.h" #include "opus_pvq.h" #define CELT_PVQ_U(n, k) (ff_celt_pvq_u_row[FFMIN(n, k)][FFMAX(n, k)]) #define CELT_PVQ_V(n, k) (CELT_PVQ_U(n, k) + CELT_PVQ_U(n, (k) + 1)) static inline int16_t celt_cos(int16_t x) { x = (MUL16(x, x) + 4096) >> 13; x = (32767-x) + ROUND_MUL16(x, (-7651 + ROUND_MUL16(x, (8277 + ROUND_MUL16(-626, x))))); return 1+x; } static inline int celt_log2tan(int isin, int icos) { int lc, ls; lc = opus_ilog(icos); ls = opus_ilog(isin); icos <<= 15 - lc; isin <<= 15 - ls; return (ls << 11) - (lc << 11) + ROUND_MUL16(isin, ROUND_MUL16(isin, -2597) + 7932) - ROUND_MUL16(icos, ROUND_MUL16(icos, -2597) + 7932); } static inline int celt_bits2pulses(const uint8_t *cache, int bits) { // TODO: Find the size of cache and make it into an array in the parameters list int i, low = 0, high; high = cache[0]; bits--; for (i = 0; i < 6; i++) { int center = (low + high + 1) >> 1; if (cache[center] >= bits) high = center; else low = center; } return (bits - (low == 0 ? -1 : cache[low]) <= cache[high] - bits) ? low : high; } static inline int celt_pulses2bits(const uint8_t *cache, int pulses) { // TODO: Find the size of cache and make it into an array in the parameters list return (pulses == 0) ? 0 : cache[pulses] + 1; } static inline void celt_normalize_residual(const int * av_restrict iy, float * av_restrict X, int N, float g) { int i; for (i = 0; i < N; i++) X[i] = g * iy[i]; } static void celt_exp_rotation1(float *X, uint32_t len, uint32_t stride, float c, float s) { float *Xptr; int i; Xptr = X; for (i = 0; i < len - stride; i++) { float x1, x2; x1 = Xptr[0]; x2 = Xptr[stride]; Xptr[stride] = c * x2 + s * x1; *Xptr++ = c * x1 - s * x2; } Xptr = &X[len - 2 * stride - 1]; for (i = len - 2 * stride - 1; i >= 0; i--) { float x1, x2; x1 = Xptr[0]; x2 = Xptr[stride]; Xptr[stride] = c * x2 + s * x1; *Xptr-- = c * x1 - s * x2; } } static inline void celt_exp_rotation(float *X, uint32_t len, uint32_t stride, uint32_t K, enum CeltSpread spread) { uint32_t stride2 = 0; float c, s; float gain, theta; int i; if (2*K >= len || spread == CELT_SPREAD_NONE) return; gain = (float)len / (len + (20 - 5*spread) * K); theta = M_PI * gain * gain / 4; c = cosf(theta); s = sinf(theta); if (len >= stride << 3) { stride2 = 1; /* This is just a simple (equivalent) way of computing sqrt(len/stride) with rounding. It's basically incrementing long as (stride2+0.5)^2 < len/stride. */ while ((stride2 * stride2 + stride2) * stride + (stride >> 2) < len) stride2++; } /*NOTE: As a minor optimization, we could be passing around log2(B), not B, for both this and for extract_collapse_mask().*/ len /= stride; for (i = 0; i < stride; i++) { if (stride2) celt_exp_rotation1(X + i * len, len, stride2, s, c); celt_exp_rotation1(X + i * len, len, 1, c, s); } } static inline uint32_t celt_extract_collapse_mask(const int *iy, uint32_t N, uint32_t B) { uint32_t collapse_mask; int N0; int i, j; if (B <= 1) return 1; /*NOTE: As a minor optimization, we could be passing around log2(B), not B, for both this and for exp_rotation().*/ N0 = N/B; collapse_mask = 0; for (i = 0; i < B; i++) for (j = 0; j < N0; j++) collapse_mask |= (iy[i*N0+j]!=0)<>= 1; for (i = 0; i < stride; i++) { for (j = 0; j < N0; j++) { float x0 = X[stride * (2 * j + 0) + i]; float x1 = X[stride * (2 * j + 1) + i]; X[stride * (2 * j + 0) + i] = (x0 + x1) * M_SQRT1_2; X[stride * (2 * j + 1) + i] = (x0 - x1) * M_SQRT1_2; } } } static inline int celt_compute_qn(int N, int b, int offset, int pulse_cap, int dualstereo) { int qn, qb; int N2 = 2 * N - 1; if (dualstereo && N == 2) N2--; /* The upper limit ensures that in a stereo split with itheta==16384, we'll * always have enough bits left over to code at least one pulse in the * side; otherwise it would collapse, since it doesn't get folded. */ qb = FFMIN3(b - pulse_cap - (4 << 3), (b + N2 * offset) / N2, 8 << 3); qn = (qb < (1 << 3 >> 1)) ? 1 : ((ff_celt_qn_exp2[qb & 0x7] >> (14 - (qb >> 3))) + 1) >> 1 << 1; return qn; } // this code was adapted from libopus static inline uint64_t celt_cwrsi(uint32_t N, uint32_t K, uint32_t i, int *y) { uint64_t norm = 0; uint32_t p; int s, val; int k0; while (N > 2) { uint32_t q; /*Lots of pulses case:*/ if (K >= N) { const uint32_t *row = ff_celt_pvq_u_row[N]; /* Are the pulses in this dimension negative? */ p = row[K + 1]; s = -(i >= p); i -= p & s; /*Count how many pulses were placed in this dimension.*/ k0 = K; q = row[N]; if (q > i) { K = N; do { p = ff_celt_pvq_u_row[--K][N]; } while (p > i); } else for (p = row[K]; p > i; p = row[K]) K--; i -= p; val = (k0 - K + s) ^ s; norm += val * val; *y++ = val; } else { /*Lots of dimensions case:*/ /*Are there any pulses in this dimension at all?*/ p = ff_celt_pvq_u_row[K ][N]; q = ff_celt_pvq_u_row[K + 1][N]; if (p <= i && i < q) { i -= p; *y++ = 0; } else { /*Are the pulses in this dimension negative?*/ s = -(i >= q); i -= q & s; /*Count how many pulses were placed in this dimension.*/ k0 = K; do p = ff_celt_pvq_u_row[--K][N]; while (p > i); i -= p; val = (k0 - K + s) ^ s; norm += val * val; *y++ = val; } } N--; } /* N == 2 */ p = 2 * K + 1; s = -(i >= p); i -= p & s; k0 = K; K = (i + 1) / 2; if (K) i -= 2 * K - 1; val = (k0 - K + s) ^ s; norm += val * val; *y++ = val; /* N==1 */ s = -i; val = (K + s) ^ s; norm += val * val; *y = val; return norm; } static inline float celt_decode_pulses(OpusRangeCoder *rc, int *y, uint32_t N, uint32_t K) { const uint32_t idx = ff_opus_rc_dec_uint(rc, CELT_PVQ_V(N, K)); return celt_cwrsi(N, K, idx, y); } /** Decode pulse vector and combine the result with the pitch vector to produce the final normalised signal in the current band. */ static uint32_t celt_alg_unquant(OpusRangeCoder *rc, float *X, uint32_t N, uint32_t K, enum CeltSpread spread, uint32_t blocks, float gain) { int y[176]; gain /= sqrtf(celt_decode_pulses(rc, y, N, K)); celt_normalize_residual(y, X, N, gain); celt_exp_rotation(X, N, blocks, K, spread); return celt_extract_collapse_mask(y, N, blocks); } uint32_t ff_celt_decode_band(CeltContext *s, OpusRangeCoder *rc, const int band, float *X, float *Y, int N, int b, uint32_t blocks, float *lowband, int duration, float *lowband_out, int level, float gain, float *lowband_scratch, int fill) { const uint8_t *cache; int dualstereo, split; int imid = 0, iside = 0; uint32_t N0 = N; int N_B; int N_B0; int B0 = blocks; int time_divide = 0; int recombine = 0; int inv = 0; float mid = 0, side = 0; int longblocks = (B0 == 1); uint32_t cm = 0; N_B0 = N_B = N / blocks; split = dualstereo = (Y != NULL); if (N == 1) { /* special case for one sample */ int i; float *x = X; for (i = 0; i <= dualstereo; i++) { int sign = 0; if (s->remaining2 >= 1<<3) { sign = ff_opus_rc_get_raw(rc, 1); s->remaining2 -= 1 << 3; b -= 1 << 3; } x[0] = sign ? -1.0f : 1.0f; x = Y; } if (lowband_out) lowband_out[0] = X[0]; return 1; } if (!dualstereo && level == 0) { int tf_change = s->tf_change[band]; int k; if (tf_change > 0) recombine = tf_change; /* Band recombining to increase frequency resolution */ if (lowband && (recombine || ((N_B & 1) == 0 && tf_change < 0) || B0 > 1)) { int j; for (j = 0; j < N; j++) lowband_scratch[j] = lowband[j]; lowband = lowband_scratch; } for (k = 0; k < recombine; k++) { if (lowband) celt_haar1(lowband, N >> k, 1 << k); fill = ff_celt_bit_interleave[fill & 0xF] | ff_celt_bit_interleave[fill >> 4] << 2; } blocks >>= recombine; N_B <<= recombine; /* Increasing the time resolution */ while ((N_B & 1) == 0 && tf_change < 0) { if (lowband) celt_haar1(lowband, N_B, blocks); fill |= fill << blocks; blocks <<= 1; N_B >>= 1; time_divide++; tf_change++; } B0 = blocks; N_B0 = N_B; /* Reorganize the samples in time order instead of frequency order */ if (B0 > 1 && lowband) celt_deinterleave_hadamard(s->scratch, lowband, N_B >> recombine, B0 << recombine, longblocks); } /* If we need 1.5 more bit than we can produce, split the band in two. */ cache = ff_celt_cache_bits + ff_celt_cache_index[(duration + 1) * CELT_MAX_BANDS + band]; if (!dualstereo && duration >= 0 && b > cache[cache[0]] + 12 && N > 2) { N >>= 1; Y = X + N; split = 1; duration -= 1; if (blocks == 1) fill = (fill & 1) | (fill << 1); blocks = (blocks + 1) >> 1; } if (split) { int qn; int itheta = 0; int mbits, sbits, delta; int qalloc; int pulse_cap; int offset; int orig_fill; int tell; /* Decide on the resolution to give to the split parameter theta */ pulse_cap = ff_celt_log_freq_range[band] + duration * 8; offset = (pulse_cap >> 1) - (dualstereo && N == 2 ? CELT_QTHETA_OFFSET_TWOPHASE : CELT_QTHETA_OFFSET); qn = (dualstereo && band >= s->intensitystereo) ? 1 : celt_compute_qn(N, b, offset, pulse_cap, dualstereo); tell = opus_rc_tell_frac(rc); if (qn != 1) { /* Entropy coding of the angle. We use a uniform pdf for the time split, a step for stereo, and a triangular one for the rest. */ if (dualstereo && N > 2) itheta = ff_opus_rc_dec_uint_step(rc, qn/2); else if (dualstereo || B0 > 1) itheta = ff_opus_rc_dec_uint(rc, qn+1); else itheta = ff_opus_rc_dec_uint_tri(rc, qn); itheta = itheta * 16384 / qn; /* NOTE: Renormalising X and Y *may* help fixed-point a bit at very high rate. Let's do that at higher complexity */ } else if (dualstereo) { inv = (b > 2 << 3 && s->remaining2 > 2 << 3) ? ff_opus_rc_dec_log(rc, 2) : 0; itheta = 0; } qalloc = opus_rc_tell_frac(rc) - tell; b -= qalloc; orig_fill = fill; if (itheta == 0) { imid = 32767; iside = 0; fill = av_mod_uintp2(fill, blocks); delta = -16384; } else if (itheta == 16384) { imid = 0; iside = 32767; fill &= ((1 << blocks) - 1) << blocks; delta = 16384; } else { imid = celt_cos(itheta); iside = celt_cos(16384-itheta); /* This is the mid vs side allocation that minimizes squared error in that band. */ delta = ROUND_MUL16((N - 1) << 7, celt_log2tan(iside, imid)); } mid = imid / 32768.0f; side = iside / 32768.0f; /* This is a special case for N=2 that only works for stereo and takes advantage of the fact that mid and side are orthogonal to encode the side with just one bit. */ if (N == 2 && dualstereo) { int c; int sign = 0; float tmp; float *x2, *y2; mbits = b; /* Only need one bit for the side */ sbits = (itheta != 0 && itheta != 16384) ? 1 << 3 : 0; mbits -= sbits; c = (itheta > 8192); s->remaining2 -= qalloc+sbits; x2 = c ? Y : X; y2 = c ? X : Y; if (sbits) sign = ff_opus_rc_get_raw(rc, 1); sign = 1 - 2 * sign; /* We use orig_fill here because we want to fold the side, but if itheta==16384, we'll have cleared the low bits of fill. */ cm = ff_celt_decode_band(s, rc, band, x2, NULL, N, mbits, blocks, lowband, duration, lowband_out, level, gain, lowband_scratch, orig_fill); /* We don't split N=2 bands, so cm is either 1 or 0 (for a fold-collapse), and there's no need to worry about mixing with the other channel. */ y2[0] = -sign * x2[1]; y2[1] = sign * x2[0]; X[0] *= mid; X[1] *= mid; Y[0] *= side; Y[1] *= side; tmp = X[0]; X[0] = tmp - Y[0]; Y[0] = tmp + Y[0]; tmp = X[1]; X[1] = tmp - Y[1]; Y[1] = tmp + Y[1]; } else { /* "Normal" split code */ float *next_lowband2 = NULL; float *next_lowband_out1 = NULL; int next_level = 0; int rebalance; /* Give more bits to low-energy MDCTs than they would * otherwise deserve */ if (B0 > 1 && !dualstereo && (itheta & 0x3fff)) { if (itheta > 8192) /* Rough approximation for pre-echo masking */ delta -= delta >> (4 - duration); else /* Corresponds to a forward-masking slope of * 1.5 dB per 10 ms */ delta = FFMIN(0, delta + (N << 3 >> (5 - duration))); } mbits = av_clip((b - delta) / 2, 0, b); sbits = b - mbits; s->remaining2 -= qalloc; if (lowband && !dualstereo) next_lowband2 = lowband + N; /* >32-bit split case */ /* Only stereo needs to pass on lowband_out. * Otherwise, it's handled at the end */ if (dualstereo) next_lowband_out1 = lowband_out; else next_level = level + 1; rebalance = s->remaining2; if (mbits >= sbits) { /* In stereo mode, we do not apply a scaling to the mid * because we need the normalized mid for folding later */ cm = ff_celt_decode_band(s, rc, band, X, NULL, N, mbits, blocks, lowband, duration, next_lowband_out1, next_level, dualstereo ? 1.0f : (gain * mid), lowband_scratch, fill); rebalance = mbits - (rebalance - s->remaining2); if (rebalance > 3 << 3 && itheta != 0) sbits += rebalance - (3 << 3); /* For a stereo split, the high bits of fill are always zero, * so no folding will be done to the side. */ cm |= ff_celt_decode_band(s, rc, band, Y, NULL, N, sbits, blocks, next_lowband2, duration, NULL, next_level, gain * side, NULL, fill >> blocks) << ((B0 >> 1) & (dualstereo - 1)); } else { /* For a stereo split, the high bits of fill are always zero, * so no folding will be done to the side. */ cm = ff_celt_decode_band(s, rc, band, Y, NULL, N, sbits, blocks, next_lowband2, duration, NULL, next_level, gain * side, NULL, fill >> blocks) << ((B0 >> 1) & (dualstereo - 1)); rebalance = sbits - (rebalance - s->remaining2); if (rebalance > 3 << 3 && itheta != 16384) mbits += rebalance - (3 << 3); /* In stereo mode, we do not apply a scaling to the mid because * we need the normalized mid for folding later */ cm |= ff_celt_decode_band(s, rc, band, X, NULL, N, mbits, blocks, lowband, duration, next_lowband_out1, next_level, dualstereo ? 1.0f : (gain * mid), lowband_scratch, fill); } } } else { /* This is the basic no-split case */ uint32_t q = celt_bits2pulses(cache, b); uint32_t curr_bits = celt_pulses2bits(cache, q); s->remaining2 -= curr_bits; /* Ensures we can never bust the budget */ while (s->remaining2 < 0 && q > 0) { s->remaining2 += curr_bits; curr_bits = celt_pulses2bits(cache, --q); s->remaining2 -= curr_bits; } if (q != 0) { /* Finally do the actual quantization */ cm = celt_alg_unquant(rc, X, N, (q < 8) ? q : (8 + (q & 7)) << ((q >> 3) - 1), s->spread, blocks, gain); } else { /* If there's no pulse, fill the band anyway */ int j; uint32_t cm_mask = (1 << blocks) - 1; fill &= cm_mask; if (!fill) { for (j = 0; j < N; j++) X[j] = 0.0f; } else { if (!lowband) { /* Noise */ for (j = 0; j < N; j++) X[j] = (((int32_t)celt_rng(s)) >> 20); cm = cm_mask; } else { /* Folded spectrum */ for (j = 0; j < N; j++) { /* About 48 dB below the "normal" folding level */ X[j] = lowband[j] + (((celt_rng(s)) & 0x8000) ? 1.0f / 256 : -1.0f / 256); } cm = fill; } celt_renormalize_vector(X, N, gain); } } } /* This code is used by the decoder and by the resynthesis-enabled encoder */ if (dualstereo) { int j; if (N != 2) celt_stereo_merge(X, Y, mid, N); if (inv) { for (j = 0; j < N; j++) Y[j] *= -1; } } else if (level == 0) { int k; /* Undo the sample reorganization going from time order to frequency order */ if (B0 > 1) celt_interleave_hadamard(s->scratch, X, N_B>>recombine, B0<>= 1; N_B <<= 1; cm |= cm >> blocks; celt_haar1(X, N_B, blocks); } for (k = 0; k < recombine; k++) { cm = ff_celt_bit_deinterleave[cm]; celt_haar1(X, N0>>k, 1<