| /* | |
| * 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 <float.h> | |
| #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_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 log_norm = block->energy[i] + ff_celt_mean_energy[i]; | |
| float norm = exp2f(FFMIN(log_norm, 32.0f)); | |
| 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(CeltFrame *f, CeltBlock *block) | |
| { | |
| int len = f->blocksize * f->blocks; | |
| const int filter_len = len - 2 * CELT_OVERLAP; | |
| 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); | |
| if (block->pf_gains[0] > FLT_EPSILON && filter_len > 0) | |
| f->opusdsp.postfilter(block->buf + 1024 + 2 * CELT_OVERLAP, | |
| block->pf_period, block->pf_gains, | |
| filter_len); | |
| 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); | |
| } | |
| } | |
| 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 | |
| AVTXContext *imdct; | |
| av_tx_fn imdct_fn; | |
| 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; | |
| for (i = 0; i < f->channels; i++) { | |
| memset(f->block[i].coeffs, 0, sizeof(f->block[i].coeffs)); | |
| memset(f->block[i].collapse_masks, 0, sizeof(f->block[i].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->tx[f->transient ? 0 : f->size]; | |
| imdct_fn = f->tx_fn[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); | |
| ff_celt_bitalloc (f, rc, 0); | |
| celt_decode_fine_energy (f, rc); | |
| ff_celt_quant_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]; | |
| /* iMDCT and overlap-add */ | |
| for (j = 0; j < f->blocks; j++) { | |
| float *dst = block->buf + 1024 + j * f->blocksize; | |
| imdct_fn(imdct, dst + CELT_OVERLAP / 2, f->block[i].coeffs + j, | |
| sizeof(float)*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 */ | |
| block->emph_coeff = f->opusdsp.deemphasis(output[i], | |
| &block->buf[1024 - frame_size], | |
| block->emph_coeff, frame_size); | |
| } | |
| 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)); | |
| /* libopus uses CELT_EMPH_COEFF on init, but 0 is better since there's | |
| * a lesser discontinuity when seeking. | |
| * The deemphasis functions differ from libopus in that they require | |
| * an initial state divided by the coefficient. */ | |
| block->emph_coeff = 0.0f / CELT_EMPH_COEFF; | |
| } | |
| 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->tx); i++) | |
| av_tx_uninit(&frm->tx[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, | |
| int apply_phase_inv) | |
| { | |
| 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; | |
| frm->apply_phase_inv = apply_phase_inv; | |
| for (i = 0; i < FF_ARRAY_ELEMS(frm->tx); i++) { | |
| const float scale = -1.0f/32768; | |
| if ((ret = av_tx_init(&frm->tx[i], &frm->tx_fn[i], AV_TX_FLOAT_MDCT, 1, 15 << (i + 3), &scale, 0)) < 0) | |
| goto fail; | |
| } | |
| if ((ret = ff_celt_pvq_init(&frm->pvq, 0)) < 0) | |
| goto fail; | |
| frm->dsp = avpriv_float_dsp_alloc(avctx->flags & AV_CODEC_FLAG_BITEXACT); | |
| if (!frm->dsp) { | |
| ret = AVERROR(ENOMEM); | |
| goto fail; | |
| } | |
| ff_opus_dsp_init(&frm->opusdsp); | |
| ff_celt_flush(frm); | |
| *f = frm; | |
| return 0; | |
| fail: | |
| ff_celt_free(&frm); | |
| return ret; | |
| } |