| /* |
| * Copyright (c) 2012 Andrew D'Addesio |
| * Copyright (c) 2013-2014 Mozilla Corporation |
| * Copyright (c) 2016 Rostislav Pehlivanov <atomnuker@gmail.com> |
| * |
| * 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 |
| */ |
| |
| /** |
| * @file |
| * Opus CELT decoder |
| */ |
| |
| #include "opus_celt.h" |
| #include "opustab.h" |
| #include "opus_pvq.h" |
| |
| /* Use the 2D z-transform to apply prediction in both the time domain (alpha) |
| * and the frequency domain (beta) */ |
| static void celt_decode_coarse_energy(CeltFrame *f, OpusRangeCoder *rc) |
| { |
| int i, j; |
| float prev[2] = { 0 }; |
| float alpha = ff_celt_alpha_coef[f->size]; |
| float beta = ff_celt_beta_coef[f->size]; |
| const uint8_t *model = ff_celt_coarse_energy_dist[f->size][0]; |
| |
| /* intra frame */ |
| if (opus_rc_tell(rc) + 3 <= f->framebits && ff_opus_rc_dec_log(rc, 3)) { |
| alpha = 0.0f; |
| beta = 1.0f - (4915.0f/32768.0f); |
| model = ff_celt_coarse_energy_dist[f->size][1]; |
| } |
| |
| for (i = 0; i < CELT_MAX_BANDS; i++) { |
| for (j = 0; j < f->channels; j++) { |
| CeltBlock *block = &f->block[j]; |
| float value; |
| int available; |
| |
| if (i < f->start_band || i >= f->end_band) { |
| block->energy[i] = 0.0; |
| continue; |
| } |
| |
| available = f->framebits - opus_rc_tell(rc); |
| if (available >= 15) { |
| /* decode using a Laplace distribution */ |
| int k = FFMIN(i, 20) << 1; |
| value = ff_opus_rc_dec_laplace(rc, model[k] << 7, model[k+1] << 6); |
| } else if (available >= 2) { |
| int x = ff_opus_rc_dec_cdf(rc, ff_celt_model_energy_small); |
| value = (x>>1) ^ -(x&1); |
| } else if (available >= 1) { |
| value = -(float)ff_opus_rc_dec_log(rc, 1); |
| } else value = -1; |
| |
| block->energy[i] = FFMAX(-9.0f, block->energy[i]) * alpha + prev[j] + value; |
| prev[j] += beta * value; |
| } |
| } |
| } |
| |
| static void celt_decode_fine_energy(CeltFrame *f, OpusRangeCoder *rc) |
| { |
| int i; |
| for (i = f->start_band; i < f->end_band; i++) { |
| int j; |
| if (!f->fine_bits[i]) |
| continue; |
| |
| for (j = 0; j < f->channels; j++) { |
| CeltBlock *block = &f->block[j]; |
| int q2; |
| float offset; |
| q2 = ff_opus_rc_get_raw(rc, f->fine_bits[i]); |
| offset = (q2 + 0.5f) * (1 << (14 - f->fine_bits[i])) / 16384.0f - 0.5f; |
| block->energy[i] += offset; |
| } |
| } |
| } |
| |
| static void celt_decode_final_energy(CeltFrame *f, OpusRangeCoder *rc) |
| { |
| int priority, i, j; |
| int bits_left = f->framebits - opus_rc_tell(rc); |
| |
| for (priority = 0; priority < 2; priority++) { |
| for (i = f->start_band; i < f->end_band && bits_left >= f->channels; i++) { |
| if (f->fine_priority[i] != priority || f->fine_bits[i] >= CELT_MAX_FINE_BITS) |
| continue; |
| |
| for (j = 0; j < f->channels; j++) { |
| int q2; |
| float offset; |
| q2 = ff_opus_rc_get_raw(rc, 1); |
| offset = (q2 - 0.5f) * (1 << (14 - f->fine_bits[i] - 1)) / 16384.0f; |
| f->block[j].energy[i] += offset; |
| bits_left--; |
| } |
| } |
| } |
| } |
| |
| static void celt_decode_tf_changes(CeltFrame *f, OpusRangeCoder *rc) |
| { |
| int i, diff = 0, tf_select = 0, tf_changed = 0, tf_select_bit; |
| int consumed, bits = f->transient ? 2 : 4; |
| |
| consumed = opus_rc_tell(rc); |
| tf_select_bit = (f->size != 0 && consumed+bits+1 <= f->framebits); |
| |
| for (i = f->start_band; i < f->end_band; i++) { |
| if (consumed+bits+tf_select_bit <= f->framebits) { |
| diff ^= ff_opus_rc_dec_log(rc, bits); |
| consumed = opus_rc_tell(rc); |
| tf_changed |= diff; |
| } |
| f->tf_change[i] = diff; |
| bits = f->transient ? 4 : 5; |
| } |
| |
| if (tf_select_bit && ff_celt_tf_select[f->size][f->transient][0][tf_changed] != |
| ff_celt_tf_select[f->size][f->transient][1][tf_changed]) |
| tf_select = ff_opus_rc_dec_log(rc, 1); |
| |
| for (i = f->start_band; i < f->end_band; i++) { |
| f->tf_change[i] = ff_celt_tf_select[f->size][f->transient][tf_select][f->tf_change[i]]; |
| } |
| } |
| |
| static void celt_decode_allocation(CeltFrame *f, OpusRangeCoder *rc) |
| { |
| // approx. maximum bit allocation for each band before boost/trim |
| int cap[CELT_MAX_BANDS]; |
| int boost[CELT_MAX_BANDS]; |
| int threshold[CELT_MAX_BANDS]; |
| int bits1[CELT_MAX_BANDS]; |
| int bits2[CELT_MAX_BANDS]; |
| int trim_offset[CELT_MAX_BANDS]; |
| |
| int skip_start_band = f->start_band; |
| int dynalloc = 6; |
| int alloctrim = 5; |
| int extrabits = 0; |
| |
| int skip_bit = 0; |
| int intensity_stereo_bit = 0; |
| int dual_stereo_bit = 0; |
| |
| int remaining, bandbits; |
| int low, high, total, done; |
| int totalbits; |
| int consumed; |
| int i, j; |
| |
| consumed = opus_rc_tell(rc); |
| |
| /* obtain spread flag */ |
| f->spread = CELT_SPREAD_NORMAL; |
| if (consumed + 4 <= f->framebits) |
| f->spread = ff_opus_rc_dec_cdf(rc, ff_celt_model_spread); |
| |
| /* generate static allocation caps */ |
| for (i = 0; i < CELT_MAX_BANDS; i++) { |
| cap[i] = (ff_celt_static_caps[f->size][f->channels - 1][i] + 64) |
| * ff_celt_freq_range[i] << (f->channels - 1) << f->size >> 2; |
| } |
| |
| /* obtain band boost */ |
| totalbits = f->framebits << 3; // convert to 1/8 bits |
| consumed = opus_rc_tell_frac(rc); |
| for (i = f->start_band; i < f->end_band; i++) { |
| int quanta, band_dynalloc; |
| |
| boost[i] = 0; |
| |
| quanta = ff_celt_freq_range[i] << (f->channels - 1) << f->size; |
| quanta = FFMIN(quanta << 3, FFMAX(6 << 3, quanta)); |
| band_dynalloc = dynalloc; |
| while (consumed + (band_dynalloc<<3) < totalbits && boost[i] < cap[i]) { |
| int add = ff_opus_rc_dec_log(rc, band_dynalloc); |
| consumed = opus_rc_tell_frac(rc); |
| if (!add) |
| break; |
| |
| boost[i] += quanta; |
| totalbits -= quanta; |
| band_dynalloc = 1; |
| } |
| /* dynalloc is more likely to occur if it's already been used for earlier bands */ |
| if (boost[i]) |
| dynalloc = FFMAX(2, dynalloc - 1); |
| } |
| |
| /* obtain allocation trim */ |
| if (consumed + (6 << 3) <= totalbits) |
| alloctrim = ff_opus_rc_dec_cdf(rc, ff_celt_model_alloc_trim); |
| |
| /* anti-collapse bit reservation */ |
| totalbits = (f->framebits << 3) - opus_rc_tell_frac(rc) - 1; |
| f->anticollapse_needed = 0; |
| if (f->blocks > 1 && f->size >= 2 && |
| totalbits >= ((f->size + 2) << 3)) |
| f->anticollapse_needed = 1 << 3; |
| totalbits -= f->anticollapse_needed; |
| |
| /* band skip bit reservation */ |
| if (totalbits >= 1 << 3) |
| skip_bit = 1 << 3; |
| totalbits -= skip_bit; |
| |
| /* intensity/dual stereo bit reservation */ |
| if (f->channels == 2) { |
| intensity_stereo_bit = ff_celt_log2_frac[f->end_band - f->start_band]; |
| if (intensity_stereo_bit <= totalbits) { |
| totalbits -= intensity_stereo_bit; |
| if (totalbits >= 1 << 3) { |
| dual_stereo_bit = 1 << 3; |
| totalbits -= 1 << 3; |
| } |
| } else |
| intensity_stereo_bit = 0; |
| } |
| |
| for (i = f->start_band; i < f->end_band; i++) { |
| int trim = alloctrim - 5 - f->size; |
| int band = ff_celt_freq_range[i] * (f->end_band - i - 1); |
| int duration = f->size + 3; |
| int scale = duration + f->channels - 1; |
| |
| /* PVQ minimum allocation threshold, below this value the band is |
| * skipped */ |
| threshold[i] = FFMAX(3 * ff_celt_freq_range[i] << duration >> 4, |
| f->channels << 3); |
| |
| trim_offset[i] = trim * (band << scale) >> 6; |
| |
| if (ff_celt_freq_range[i] << f->size == 1) |
| trim_offset[i] -= f->channels << 3; |
| } |
| |
| /* bisection */ |
| low = 1; |
| high = CELT_VECTORS - 1; |
| while (low <= high) { |
| int center = (low + high) >> 1; |
| done = total = 0; |
| |
| for (i = f->end_band - 1; i >= f->start_band; i--) { |
| bandbits = ff_celt_freq_range[i] * ff_celt_static_alloc[center][i] |
| << (f->channels - 1) << f->size >> 2; |
| |
| if (bandbits) |
| bandbits = FFMAX(0, bandbits + trim_offset[i]); |
| bandbits += boost[i]; |
| |
| if (bandbits >= threshold[i] || done) { |
| done = 1; |
| total += FFMIN(bandbits, cap[i]); |
| } else if (bandbits >= f->channels << 3) |
| total += f->channels << 3; |
| } |
| |
| if (total > totalbits) |
| high = center - 1; |
| else |
| low = center + 1; |
| } |
| high = low--; |
| |
| for (i = f->start_band; i < f->end_band; i++) { |
| bits1[i] = ff_celt_freq_range[i] * ff_celt_static_alloc[low][i] |
| << (f->channels - 1) << f->size >> 2; |
| bits2[i] = high >= CELT_VECTORS ? cap[i] : |
| ff_celt_freq_range[i] * ff_celt_static_alloc[high][i] |
| << (f->channels - 1) << f->size >> 2; |
| |
| if (bits1[i]) |
| bits1[i] = FFMAX(0, bits1[i] + trim_offset[i]); |
| if (bits2[i]) |
| bits2[i] = FFMAX(0, bits2[i] + trim_offset[i]); |
| if (low) |
| bits1[i] += boost[i]; |
| bits2[i] += boost[i]; |
| |
| if (boost[i]) |
| skip_start_band = i; |
| bits2[i] = FFMAX(0, bits2[i] - bits1[i]); |
| } |
| |
| /* bisection */ |
| low = 0; |
| high = 1 << CELT_ALLOC_STEPS; |
| for (i = 0; i < CELT_ALLOC_STEPS; i++) { |
| int center = (low + high) >> 1; |
| done = total = 0; |
| |
| for (j = f->end_band - 1; j >= f->start_band; j--) { |
| bandbits = bits1[j] + (center * bits2[j] >> CELT_ALLOC_STEPS); |
| |
| if (bandbits >= threshold[j] || done) { |
| done = 1; |
| total += FFMIN(bandbits, cap[j]); |
| } else if (bandbits >= f->channels << 3) |
| total += f->channels << 3; |
| } |
| if (total > totalbits) |
| high = center; |
| else |
| low = center; |
| } |
| |
| done = total = 0; |
| for (i = f->end_band - 1; i >= f->start_band; i--) { |
| bandbits = bits1[i] + (low * bits2[i] >> CELT_ALLOC_STEPS); |
| |
| if (bandbits >= threshold[i] || done) |
| done = 1; |
| else |
| bandbits = (bandbits >= f->channels << 3) ? |
| f->channels << 3 : 0; |
| |
| bandbits = FFMIN(bandbits, cap[i]); |
| f->pulses[i] = bandbits; |
| total += bandbits; |
| } |
| |
| /* band skipping */ |
| for (f->coded_bands = f->end_band; ; f->coded_bands--) { |
| int allocation; |
| j = f->coded_bands - 1; |
| |
| if (j == skip_start_band) { |
| /* all remaining bands are not skipped */ |
| totalbits += skip_bit; |
| break; |
| } |
| |
| /* determine the number of bits available for coding "do not skip" markers */ |
| remaining = totalbits - total; |
| bandbits = remaining / (ff_celt_freq_bands[j+1] - ff_celt_freq_bands[f->start_band]); |
| remaining -= bandbits * (ff_celt_freq_bands[j+1] - ff_celt_freq_bands[f->start_band]); |
| allocation = f->pulses[j] + bandbits * ff_celt_freq_range[j] |
| + FFMAX(0, remaining - (ff_celt_freq_bands[j] - ff_celt_freq_bands[f->start_band])); |
| |
| /* a "do not skip" marker is only coded if the allocation is |
| above the chosen threshold */ |
| if (allocation >= FFMAX(threshold[j], (f->channels + 1) <<3 )) { |
| if (ff_opus_rc_dec_log(rc, 1)) |
| break; |
| |
| total += 1 << 3; |
| allocation -= 1 << 3; |
| } |
| |
| /* the band is skipped, so reclaim its bits */ |
| total -= f->pulses[j]; |
| if (intensity_stereo_bit) { |
| total -= intensity_stereo_bit; |
| intensity_stereo_bit = ff_celt_log2_frac[j - f->start_band]; |
| total += intensity_stereo_bit; |
| } |
| |
| total += f->pulses[j] = (allocation >= f->channels << 3) ? |
| f->channels << 3 : 0; |
| } |
| |
| /* obtain stereo flags */ |
| f->intensity_stereo = 0; |
| f->dual_stereo = 0; |
| if (intensity_stereo_bit) |
| f->intensity_stereo = f->start_band + |
| ff_opus_rc_dec_uint(rc, f->coded_bands + 1 - f->start_band); |
| if (f->intensity_stereo <= f->start_band) |
| totalbits += dual_stereo_bit; /* no intensity stereo means no dual stereo */ |
| else if (dual_stereo_bit) |
| f->dual_stereo = ff_opus_rc_dec_log(rc, 1); |
| |
| /* supply the remaining bits in this frame to lower bands */ |
| remaining = totalbits - total; |
| bandbits = remaining / (ff_celt_freq_bands[f->coded_bands] - ff_celt_freq_bands[f->start_band]); |
| remaining -= bandbits * (ff_celt_freq_bands[f->coded_bands] - ff_celt_freq_bands[f->start_band]); |
| for (i = f->start_band; i < f->coded_bands; i++) { |
| int bits = FFMIN(remaining, ff_celt_freq_range[i]); |
| |
| f->pulses[i] += bits + bandbits * ff_celt_freq_range[i]; |
| remaining -= bits; |
| } |
| |
| for (i = f->start_band; i < f->coded_bands; i++) { |
| int N = ff_celt_freq_range[i] << f->size; |
| int prev_extra = extrabits; |
| f->pulses[i] += extrabits; |
| |
| if (N > 1) { |
| int dof; // degrees of freedom |
| int temp; // dof * channels * log(dof) |
| int offset; // fine energy quantization offset, i.e. |
| // extra bits assigned over the standard |
| // totalbits/dof |
| int fine_bits, max_bits; |
| |
| extrabits = FFMAX(0, f->pulses[i] - cap[i]); |
| f->pulses[i] -= extrabits; |
| |
| /* intensity stereo makes use of an extra degree of freedom */ |
| dof = N * f->channels |
| + (f->channels == 2 && N > 2 && !f->dual_stereo && i < f->intensity_stereo); |
| temp = dof * (ff_celt_log_freq_range[i] + (f->size<<3)); |
| offset = (temp >> 1) - dof * CELT_FINE_OFFSET; |
| if (N == 2) /* dof=2 is the only case that doesn't fit the model */ |
| offset += dof<<1; |
| |
| /* grant an additional bias for the first and second pulses */ |
| if (f->pulses[i] + offset < 2 * (dof << 3)) |
| offset += temp >> 2; |
| else if (f->pulses[i] + offset < 3 * (dof << 3)) |
| offset += temp >> 3; |
| |
| fine_bits = (f->pulses[i] + offset + (dof << 2)) / (dof << 3); |
| max_bits = FFMIN((f->pulses[i]>>3) >> (f->channels - 1), |
| CELT_MAX_FINE_BITS); |
| |
| max_bits = FFMAX(max_bits, 0); |
| |
| f->fine_bits[i] = av_clip(fine_bits, 0, max_bits); |
| |
| /* if fine_bits was rounded down or capped, |
| give priority for the final fine energy pass */ |
| f->fine_priority[i] = (f->fine_bits[i] * (dof<<3) >= f->pulses[i] + offset); |
| |
| /* the remaining bits are assigned to PVQ */ |
| f->pulses[i] -= f->fine_bits[i] << (f->channels - 1) << 3; |
| } else { |
| /* all bits go to fine energy except for the sign bit */ |
| extrabits = FFMAX(0, f->pulses[i] - (f->channels << 3)); |
| f->pulses[i] -= extrabits; |
| f->fine_bits[i] = 0; |
| f->fine_priority[i] = 1; |
| } |
| |
| /* hand back a limited number of extra fine energy bits to this band */ |
| if (extrabits > 0) { |
| int fineextra = FFMIN(extrabits >> (f->channels + 2), |
| CELT_MAX_FINE_BITS - f->fine_bits[i]); |
| f->fine_bits[i] += fineextra; |
| |
| fineextra <<= f->channels + 2; |
| f->fine_priority[i] = (fineextra >= extrabits - prev_extra); |
| extrabits -= fineextra; |
| } |
| } |
| f->remaining = extrabits; |
| |
| /* skipped bands dedicate all of their bits for fine energy */ |
| for (; i < f->end_band; i++) { |
| f->fine_bits[i] = f->pulses[i] >> (f->channels - 1) >> 3; |
| f->pulses[i] = 0; |
| f->fine_priority[i] = f->fine_bits[i] < 1; |
| } |
| } |
| |
| static void celt_denormalize(CeltFrame *f, CeltBlock *block, float *data) |
| { |
| int i, j; |
| |
| for (i = f->start_band; i < f->end_band; i++) { |
| float *dst = data + (ff_celt_freq_bands[i] << f->size); |
| float norm = exp2f(block->energy[i] + ff_celt_mean_energy[i]); |
| |
| for (j = 0; j < ff_celt_freq_range[i] << f->size; j++) |
| dst[j] *= norm; |
| } |
| } |
| |
| static void celt_postfilter_apply_transition(CeltBlock *block, float *data) |
| { |
| const int T0 = block->pf_period_old; |
| const int T1 = block->pf_period; |
| |
| float g00, g01, g02; |
| float g10, g11, g12; |
| |
| float x0, x1, x2, x3, x4; |
| |
| int i; |
| |
| if (block->pf_gains[0] == 0.0 && |
| block->pf_gains_old[0] == 0.0) |
| return; |
| |
| g00 = block->pf_gains_old[0]; |
| g01 = block->pf_gains_old[1]; |
| g02 = block->pf_gains_old[2]; |
| g10 = block->pf_gains[0]; |
| g11 = block->pf_gains[1]; |
| g12 = block->pf_gains[2]; |
| |
| x1 = data[-T1 + 1]; |
| x2 = data[-T1]; |
| x3 = data[-T1 - 1]; |
| x4 = data[-T1 - 2]; |
| |
| for (i = 0; i < CELT_OVERLAP; i++) { |
| float w = ff_celt_window2[i]; |
| x0 = data[i - T1 + 2]; |
| |
| data[i] += (1.0 - w) * g00 * data[i - T0] + |
| (1.0 - w) * g01 * (data[i - T0 - 1] + data[i - T0 + 1]) + |
| (1.0 - w) * g02 * (data[i - T0 - 2] + data[i - T0 + 2]) + |
| w * g10 * x2 + |
| w * g11 * (x1 + x3) + |
| w * g12 * (x0 + x4); |
| x4 = x3; |
| x3 = x2; |
| x2 = x1; |
| x1 = x0; |
| } |
| } |
| |
| static void celt_postfilter_apply(CeltBlock *block, float *data, int len) |
| { |
| const int T = block->pf_period; |
| float g0, g1, g2; |
| float x0, x1, x2, x3, x4; |
| int i; |
| |
| if (block->pf_gains[0] == 0.0 || len <= 0) |
| return; |
| |
| g0 = block->pf_gains[0]; |
| g1 = block->pf_gains[1]; |
| g2 = block->pf_gains[2]; |
| |
| x4 = data[-T - 2]; |
| x3 = data[-T - 1]; |
| x2 = data[-T]; |
| x1 = data[-T + 1]; |
| |
| for (i = 0; i < len; i++) { |
| x0 = data[i - T + 2]; |
| data[i] += g0 * x2 + |
| g1 * (x1 + x3) + |
| g2 * (x0 + x4); |
| x4 = x3; |
| x3 = x2; |
| x2 = x1; |
| x1 = x0; |
| } |
| } |
| |
| static void celt_postfilter(CeltFrame *f, CeltBlock *block) |
| { |
| int len = f->blocksize * f->blocks; |
| |
| celt_postfilter_apply_transition(block, block->buf + 1024); |
| |
| block->pf_period_old = block->pf_period; |
| memcpy(block->pf_gains_old, block->pf_gains, sizeof(block->pf_gains)); |
| |
| block->pf_period = block->pf_period_new; |
| memcpy(block->pf_gains, block->pf_gains_new, sizeof(block->pf_gains)); |
| |
| if (len > CELT_OVERLAP) { |
| celt_postfilter_apply_transition(block, block->buf + 1024 + CELT_OVERLAP); |
| celt_postfilter_apply(block, block->buf + 1024 + 2 * CELT_OVERLAP, |
| len - 2 * CELT_OVERLAP); |
| |
| block->pf_period_old = block->pf_period; |
| memcpy(block->pf_gains_old, block->pf_gains, sizeof(block->pf_gains)); |
| } |
| |
| memmove(block->buf, block->buf + len, (1024 + CELT_OVERLAP / 2) * sizeof(float)); |
| } |
| |
| static int parse_postfilter(CeltFrame *f, OpusRangeCoder *rc, int consumed) |
| { |
| int i; |
| |
| memset(f->block[0].pf_gains_new, 0, sizeof(f->block[0].pf_gains_new)); |
| memset(f->block[1].pf_gains_new, 0, sizeof(f->block[1].pf_gains_new)); |
| |
| if (f->start_band == 0 && consumed + 16 <= f->framebits) { |
| int has_postfilter = ff_opus_rc_dec_log(rc, 1); |
| if (has_postfilter) { |
| float gain; |
| int tapset, octave, period; |
| |
| octave = ff_opus_rc_dec_uint(rc, 6); |
| period = (16 << octave) + ff_opus_rc_get_raw(rc, 4 + octave) - 1; |
| gain = 0.09375f * (ff_opus_rc_get_raw(rc, 3) + 1); |
| tapset = (opus_rc_tell(rc) + 2 <= f->framebits) ? |
| ff_opus_rc_dec_cdf(rc, ff_celt_model_tapset) : 0; |
| |
| for (i = 0; i < 2; i++) { |
| CeltBlock *block = &f->block[i]; |
| |
| block->pf_period_new = FFMAX(period, CELT_POSTFILTER_MINPERIOD); |
| block->pf_gains_new[0] = gain * ff_celt_postfilter_taps[tapset][0]; |
| block->pf_gains_new[1] = gain * ff_celt_postfilter_taps[tapset][1]; |
| block->pf_gains_new[2] = gain * ff_celt_postfilter_taps[tapset][2]; |
| } |
| } |
| |
| consumed = opus_rc_tell(rc); |
| } |
| |
| return consumed; |
| } |
| |
| static void process_anticollapse(CeltFrame *f, CeltBlock *block, float *X) |
| { |
| int i, j, k; |
| |
| for (i = f->start_band; i < f->end_band; i++) { |
| int renormalize = 0; |
| float *xptr; |
| float prev[2]; |
| float Ediff, r; |
| float thresh, sqrt_1; |
| int depth; |
| |
| /* depth in 1/8 bits */ |
| depth = (1 + f->pulses[i]) / (ff_celt_freq_range[i] << f->size); |
| thresh = exp2f(-1.0 - 0.125f * depth); |
| sqrt_1 = 1.0f / sqrtf(ff_celt_freq_range[i] << f->size); |
| |
| xptr = X + (ff_celt_freq_bands[i] << f->size); |
| |
| prev[0] = block->prev_energy[0][i]; |
| prev[1] = block->prev_energy[1][i]; |
| if (f->channels == 1) { |
| CeltBlock *block1 = &f->block[1]; |
| |
| prev[0] = FFMAX(prev[0], block1->prev_energy[0][i]); |
| prev[1] = FFMAX(prev[1], block1->prev_energy[1][i]); |
| } |
| Ediff = block->energy[i] - FFMIN(prev[0], prev[1]); |
| Ediff = FFMAX(0, Ediff); |
| |
| /* r needs to be multiplied by 2 or 2*sqrt(2) depending on LM because |
| short blocks don't have the same energy as long */ |
| r = exp2f(1 - Ediff); |
| if (f->size == 3) |
| r *= M_SQRT2; |
| r = FFMIN(thresh, r) * sqrt_1; |
| for (k = 0; k < 1 << f->size; k++) { |
| /* Detect collapse */ |
| if (!(block->collapse_masks[i] & 1 << k)) { |
| /* Fill with noise */ |
| for (j = 0; j < ff_celt_freq_range[i]; j++) |
| xptr[(j << f->size) + k] = (celt_rng(f) & 0x8000) ? r : -r; |
| renormalize = 1; |
| } |
| } |
| |
| /* We just added some energy, so we need to renormalize */ |
| if (renormalize) |
| celt_renormalize_vector(xptr, ff_celt_freq_range[i] << f->size, 1.0f); |
| } |
| } |
| |
| static void celt_decode_bands(CeltFrame *f, OpusRangeCoder *rc) |
| { |
| float lowband_scratch[8 * 22]; |
| float norm[2 * 8 * 100]; |
| |
| int totalbits = (f->framebits << 3) - f->anticollapse_needed; |
| |
| int update_lowband = 1; |
| int lowband_offset = 0; |
| |
| int i, j; |
| |
| memset(f->block[0].coeffs, 0, sizeof(f->block[0].coeffs)); |
| memset(f->block[1].coeffs, 0, sizeof(f->block[0].coeffs)); |
| |
| for (i = f->start_band; i < f->end_band; i++) { |
| uint32_t cm[2] = { (1 << f->blocks) - 1, (1 << f->blocks) - 1 }; |
| int band_offset = ff_celt_freq_bands[i] << f->size; |
| int band_size = ff_celt_freq_range[i] << f->size; |
| float *X = f->block[0].coeffs + band_offset; |
| float *Y = (f->channels == 2) ? f->block[1].coeffs + band_offset : NULL; |
| |
| int consumed = opus_rc_tell_frac(rc); |
| float *norm2 = norm + 8 * 100; |
| int effective_lowband = -1; |
| int b = 0; |
| |
| /* Compute how many bits we want to allocate to this band */ |
| if (i != f->start_band) |
| f->remaining -= consumed; |
| f->remaining2 = totalbits - consumed - 1; |
| if (i <= f->coded_bands - 1) { |
| int curr_balance = f->remaining / FFMIN(3, f->coded_bands-i); |
| b = av_clip_uintp2(FFMIN(f->remaining2 + 1, f->pulses[i] + curr_balance), 14); |
| } |
| |
| if (ff_celt_freq_bands[i] - ff_celt_freq_range[i] >= ff_celt_freq_bands[f->start_band] && |
| (update_lowband || lowband_offset == 0)) |
| lowband_offset = i; |
| |
| /* Get a conservative estimate of the collapse_mask's for the bands we're |
| going to be folding from. */ |
| if (lowband_offset != 0 && (f->spread != CELT_SPREAD_AGGRESSIVE || |
| f->blocks > 1 || f->tf_change[i] < 0)) { |
| int foldstart, foldend; |
| |
| /* This ensures we never repeat spectral content within one band */ |
| effective_lowband = FFMAX(ff_celt_freq_bands[f->start_band], |
| ff_celt_freq_bands[lowband_offset] - ff_celt_freq_range[i]); |
| foldstart = lowband_offset; |
| while (ff_celt_freq_bands[--foldstart] > effective_lowband); |
| foldend = lowband_offset - 1; |
| while (ff_celt_freq_bands[++foldend] < effective_lowband + ff_celt_freq_range[i]); |
| |
| cm[0] = cm[1] = 0; |
| for (j = foldstart; j < foldend; j++) { |
| cm[0] |= f->block[0].collapse_masks[j]; |
| cm[1] |= f->block[f->channels - 1].collapse_masks[j]; |
| } |
| } |
| |
| if (f->dual_stereo && i == f->intensity_stereo) { |
| /* Switch off dual stereo to do intensity */ |
| f->dual_stereo = 0; |
| for (j = ff_celt_freq_bands[f->start_band] << f->size; j < band_offset; j++) |
| norm[j] = (norm[j] + norm2[j]) / 2; |
| } |
| |
| if (f->dual_stereo) { |
| cm[0] = f->pvq->decode_band(f->pvq, f, rc, i, X, NULL, band_size, b / 2, f->blocks, |
| effective_lowband != -1 ? norm + (effective_lowband << f->size) : NULL, f->size, |
| norm + band_offset, 0, 1.0f, lowband_scratch, cm[0]); |
| |
| cm[1] = f->pvq->decode_band(f->pvq, f, rc, i, Y, NULL, band_size, b/2, f->blocks, |
| effective_lowband != -1 ? norm2 + (effective_lowband << f->size) : NULL, f->size, |
| norm2 + band_offset, 0, 1.0f, lowband_scratch, cm[1]); |
| } else { |
| cm[0] = f->pvq->decode_band(f->pvq, f, rc, i, X, Y, band_size, b, f->blocks, |
| effective_lowband != -1 ? norm + (effective_lowband << f->size) : NULL, f->size, |
| norm + band_offset, 0, 1.0f, lowband_scratch, cm[0]|cm[1]); |
| cm[1] = cm[0]; |
| } |
| |
| f->block[0].collapse_masks[i] = (uint8_t)cm[0]; |
| f->block[f->channels - 1].collapse_masks[i] = (uint8_t)cm[1]; |
| f->remaining += f->pulses[i] + consumed; |
| |
| /* Update the folding position only as long as we have 1 bit/sample depth */ |
| update_lowband = (b > band_size << 3); |
| } |
| } |
| |
| int ff_celt_decode_frame(CeltFrame *f, OpusRangeCoder *rc, |
| float **output, int channels, int frame_size, |
| int start_band, int end_band) |
| { |
| int i, j, downmix = 0; |
| int consumed; // bits of entropy consumed thus far for this frame |
| MDCT15Context *imdct; |
| |
| if (channels != 1 && channels != 2) { |
| av_log(f->avctx, AV_LOG_ERROR, "Invalid number of coded channels: %d\n", |
| channels); |
| return AVERROR_INVALIDDATA; |
| } |
| if (start_band < 0 || start_band > end_band || end_band > CELT_MAX_BANDS) { |
| av_log(f->avctx, AV_LOG_ERROR, "Invalid start/end band: %d %d\n", |
| start_band, end_band); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| f->silence = 0; |
| f->transient = 0; |
| f->anticollapse = 0; |
| f->flushed = 0; |
| f->channels = channels; |
| f->start_band = start_band; |
| f->end_band = end_band; |
| f->framebits = rc->rb.bytes * 8; |
| |
| f->size = av_log2(frame_size / CELT_SHORT_BLOCKSIZE); |
| if (f->size > CELT_MAX_LOG_BLOCKS || |
| frame_size != CELT_SHORT_BLOCKSIZE * (1 << f->size)) { |
| av_log(f->avctx, AV_LOG_ERROR, "Invalid CELT frame size: %d\n", |
| frame_size); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| if (!f->output_channels) |
| f->output_channels = channels; |
| |
| memset(f->block[0].collapse_masks, 0, sizeof(f->block[0].collapse_masks)); |
| memset(f->block[1].collapse_masks, 0, sizeof(f->block[1].collapse_masks)); |
| |
| consumed = opus_rc_tell(rc); |
| |
| /* obtain silence flag */ |
| if (consumed >= f->framebits) |
| f->silence = 1; |
| else if (consumed == 1) |
| f->silence = ff_opus_rc_dec_log(rc, 15); |
| |
| |
| if (f->silence) { |
| consumed = f->framebits; |
| rc->total_bits += f->framebits - opus_rc_tell(rc); |
| } |
| |
| /* obtain post-filter options */ |
| consumed = parse_postfilter(f, rc, consumed); |
| |
| /* obtain transient flag */ |
| if (f->size != 0 && consumed+3 <= f->framebits) |
| f->transient = ff_opus_rc_dec_log(rc, 3); |
| |
| f->blocks = f->transient ? 1 << f->size : 1; |
| f->blocksize = frame_size / f->blocks; |
| |
| imdct = f->imdct[f->transient ? 0 : f->size]; |
| |
| if (channels == 1) { |
| for (i = 0; i < CELT_MAX_BANDS; i++) |
| f->block[0].energy[i] = FFMAX(f->block[0].energy[i], f->block[1].energy[i]); |
| } |
| |
| celt_decode_coarse_energy(f, rc); |
| celt_decode_tf_changes (f, rc); |
| celt_decode_allocation (f, rc); |
| celt_decode_fine_energy (f, rc); |
| celt_decode_bands (f, rc); |
| |
| if (f->anticollapse_needed) |
| f->anticollapse = ff_opus_rc_get_raw(rc, 1); |
| |
| celt_decode_final_energy(f, rc); |
| |
| /* apply anti-collapse processing and denormalization to |
| * each coded channel */ |
| for (i = 0; i < f->channels; i++) { |
| CeltBlock *block = &f->block[i]; |
| |
| if (f->anticollapse) |
| process_anticollapse(f, block, f->block[i].coeffs); |
| |
| celt_denormalize(f, block, f->block[i].coeffs); |
| } |
| |
| /* stereo -> mono downmix */ |
| if (f->output_channels < f->channels) { |
| f->dsp->vector_fmac_scalar(f->block[0].coeffs, f->block[1].coeffs, 1.0, FFALIGN(frame_size, 16)); |
| downmix = 1; |
| } else if (f->output_channels > f->channels) |
| memcpy(f->block[1].coeffs, f->block[0].coeffs, frame_size * sizeof(float)); |
| |
| if (f->silence) { |
| for (i = 0; i < 2; i++) { |
| CeltBlock *block = &f->block[i]; |
| |
| for (j = 0; j < FF_ARRAY_ELEMS(block->energy); j++) |
| block->energy[j] = CELT_ENERGY_SILENCE; |
| } |
| memset(f->block[0].coeffs, 0, sizeof(f->block[0].coeffs)); |
| memset(f->block[1].coeffs, 0, sizeof(f->block[1].coeffs)); |
| } |
| |
| /* transform and output for each output channel */ |
| for (i = 0; i < f->output_channels; i++) { |
| CeltBlock *block = &f->block[i]; |
| float m = block->emph_coeff; |
| |
| /* iMDCT and overlap-add */ |
| for (j = 0; j < f->blocks; j++) { |
| float *dst = block->buf + 1024 + j * f->blocksize; |
| |
| imdct->imdct_half(imdct, dst + CELT_OVERLAP / 2, f->block[i].coeffs + j, |
| f->blocks); |
| f->dsp->vector_fmul_window(dst, dst, dst + CELT_OVERLAP / 2, |
| ff_celt_window, CELT_OVERLAP / 2); |
| } |
| |
| if (downmix) |
| f->dsp->vector_fmul_scalar(&block->buf[1024], &block->buf[1024], 0.5f, frame_size); |
| |
| /* postfilter */ |
| celt_postfilter(f, block); |
| |
| /* deemphasis and output scaling */ |
| for (j = 0; j < frame_size; j++) { |
| const float tmp = block->buf[1024 - frame_size + j] + m; |
| m = tmp * CELT_EMPH_COEFF; |
| output[i][j] = tmp; |
| } |
| |
| block->emph_coeff = m; |
| } |
| |
| if (channels == 1) |
| memcpy(f->block[1].energy, f->block[0].energy, sizeof(f->block[0].energy)); |
| |
| for (i = 0; i < 2; i++ ) { |
| CeltBlock *block = &f->block[i]; |
| |
| if (!f->transient) { |
| memcpy(block->prev_energy[1], block->prev_energy[0], sizeof(block->prev_energy[0])); |
| memcpy(block->prev_energy[0], block->energy, sizeof(block->prev_energy[0])); |
| } else { |
| for (j = 0; j < CELT_MAX_BANDS; j++) |
| block->prev_energy[0][j] = FFMIN(block->prev_energy[0][j], block->energy[j]); |
| } |
| |
| for (j = 0; j < f->start_band; j++) { |
| block->prev_energy[0][j] = CELT_ENERGY_SILENCE; |
| block->energy[j] = 0.0; |
| } |
| for (j = f->end_band; j < CELT_MAX_BANDS; j++) { |
| block->prev_energy[0][j] = CELT_ENERGY_SILENCE; |
| block->energy[j] = 0.0; |
| } |
| } |
| |
| f->seed = rc->range; |
| |
| return 0; |
| } |
| |
| void ff_celt_flush(CeltFrame *f) |
| { |
| int i, j; |
| |
| if (f->flushed) |
| return; |
| |
| for (i = 0; i < 2; i++) { |
| CeltBlock *block = &f->block[i]; |
| |
| for (j = 0; j < CELT_MAX_BANDS; j++) |
| block->prev_energy[0][j] = block->prev_energy[1][j] = CELT_ENERGY_SILENCE; |
| |
| memset(block->energy, 0, sizeof(block->energy)); |
| memset(block->buf, 0, sizeof(block->buf)); |
| |
| memset(block->pf_gains, 0, sizeof(block->pf_gains)); |
| memset(block->pf_gains_old, 0, sizeof(block->pf_gains_old)); |
| memset(block->pf_gains_new, 0, sizeof(block->pf_gains_new)); |
| |
| block->emph_coeff = 0.0; |
| } |
| f->seed = 0; |
| |
| f->flushed = 1; |
| } |
| |
| void ff_celt_free(CeltFrame **f) |
| { |
| CeltFrame *frm = *f; |
| int i; |
| |
| if (!frm) |
| return; |
| |
| for (i = 0; i < FF_ARRAY_ELEMS(frm->imdct); i++) |
| ff_mdct15_uninit(&frm->imdct[i]); |
| |
| ff_celt_pvq_uninit(&frm->pvq); |
| |
| av_freep(&frm->dsp); |
| av_freep(f); |
| } |
| |
| int ff_celt_init(AVCodecContext *avctx, CeltFrame **f, int output_channels) |
| { |
| CeltFrame *frm; |
| int i, ret; |
| |
| if (output_channels != 1 && output_channels != 2) { |
| av_log(avctx, AV_LOG_ERROR, "Invalid number of output channels: %d\n", |
| output_channels); |
| return AVERROR(EINVAL); |
| } |
| |
| frm = av_mallocz(sizeof(*frm)); |
| if (!frm) |
| return AVERROR(ENOMEM); |
| |
| frm->avctx = avctx; |
| frm->output_channels = output_channels; |
| |
| for (i = 0; i < FF_ARRAY_ELEMS(frm->imdct); i++) |
| if ((ret = ff_mdct15_init(&frm->imdct[i], 1, i + 3, -1.0f/32768)) < 0) |
| goto fail; |
| |
| if ((ret = ff_celt_pvq_init(&frm->pvq)) < 0) |
| goto fail; |
| |
| frm->dsp = avpriv_float_dsp_alloc(avctx->flags & AV_CODEC_FLAG_BITEXACT); |
| if (!frm->dsp) { |
| ret = AVERROR(ENOMEM); |
| goto fail; |
| } |
| |
| ff_celt_flush(frm); |
| |
| *f = frm; |
| |
| return 0; |
| fail: |
| ff_celt_free(&frm); |
| return ret; |
| } |
