/* * Opus encoder * Copyright (c) 2017 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 */ #include "opus_celt.h" #include "opus_pvq.h" #include "opustab.h" #include "libavutil/float_dsp.h" #include "libavutil/opt.h" #include "internal.h" #include "bytestream.h" #include "audio_frame_queue.h" /* Determines the maximum delay the psychoacoustic system will use for lookahead */ #define FF_BUFQUEUE_SIZE 145 #include "libavfilter/bufferqueue.h" #define OPUS_MAX_LOOKAHEAD ((FF_BUFQUEUE_SIZE - 1)*2.5f) #define OPUS_MAX_CHANNELS 2 /* 120 ms / 2.5 ms = 48 frames (extremely improbable, but the encoder'll work) */ #define OPUS_MAX_FRAMES_PER_PACKET 48 #define OPUS_BLOCK_SIZE(x) (2 * 15 * (1 << ((x) + 2))) #define OPUS_SAMPLES_TO_BLOCK_SIZE(x) (ff_log2((x) / (2 * 15)) - 2) typedef struct OpusEncOptions { float max_delay_ms; } OpusEncOptions; typedef struct OpusEncContext { AVClass *av_class; OpusEncOptions options; AVCodecContext *avctx; AudioFrameQueue afq; AVFloatDSPContext *dsp; MDCT15Context *mdct[CELT_BLOCK_NB]; CeltPVQ *pvq; struct FFBufQueue bufqueue; enum OpusMode mode; enum OpusBandwidth bandwidth; int pkt_framesize; int pkt_frames; int channels; CeltFrame *frame; OpusRangeCoder *rc; /* Actual energy the decoder will have */ float last_quantized_energy[OPUS_MAX_CHANNELS][CELT_MAX_BANDS]; DECLARE_ALIGNED(32, float, scratch)[2048]; } OpusEncContext; static void opus_write_extradata(AVCodecContext *avctx) { uint8_t *bs = avctx->extradata; bytestream_put_buffer(&bs, "OpusHead", 8); bytestream_put_byte (&bs, 0x1); bytestream_put_byte (&bs, avctx->channels); bytestream_put_le16 (&bs, avctx->initial_padding); bytestream_put_le32 (&bs, avctx->sample_rate); bytestream_put_le16 (&bs, 0x0); bytestream_put_byte (&bs, 0x0); /* Default layout */ } static int opus_gen_toc(OpusEncContext *s, uint8_t *toc, int *size, int *fsize_needed) { int i, tmp = 0x0, extended_toc = 0; static const int toc_cfg[][OPUS_MODE_NB][OPUS_BANDWITH_NB] = { /* Silk Hybrid Celt Layer */ /* NB MB WB SWB FB NB MB WB SWB FB NB MB WB SWB FB Bandwidth */ { { 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0 }, { 17, 0, 21, 25, 29 } }, /* 2.5 ms */ { { 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0 }, { 18, 0, 22, 26, 30 } }, /* 5 ms */ { { 1, 5, 9, 0, 0 }, { 0, 0, 0, 13, 15 }, { 19, 0, 23, 27, 31 } }, /* 10 ms */ { { 2, 6, 10, 0, 0 }, { 0, 0, 0, 14, 16 }, { 20, 0, 24, 28, 32 } }, /* 20 ms */ { { 3, 7, 11, 0, 0 }, { 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0 } }, /* 40 ms */ { { 4, 8, 12, 0, 0 }, { 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0 } }, /* 60 ms */ }; int cfg = toc_cfg[s->pkt_framesize][s->mode][s->bandwidth]; *fsize_needed = 0; if (!cfg) return 1; if (s->pkt_frames == 2) { /* 2 packets */ if (s->frame[0].framebits == s->frame[1].framebits) { /* same size */ tmp = 0x1; } else { /* different size */ tmp = 0x2; *fsize_needed = 1; /* put frame sizes in the packet */ } } else if (s->pkt_frames > 2) { tmp = 0x3; extended_toc = 1; } tmp |= (s->channels > 1) << 2; /* Stereo or mono */ tmp |= (cfg - 1) << 3; /* codec configuration */ *toc++ = tmp; if (extended_toc) { for (i = 0; i < (s->pkt_frames - 1); i++) *fsize_needed |= (s->frame[i].framebits != s->frame[i + 1].framebits); tmp = (*fsize_needed) << 7; /* vbr flag */ tmp |= s->pkt_frames; /* frame number - can be 0 as well */ *toc++ = tmp; } *size = 1 + extended_toc; return 0; } static void celt_frame_setup_input(OpusEncContext *s, CeltFrame *f) { int sf, ch; AVFrame *cur = NULL; const int subframesize = s->avctx->frame_size; int subframes = OPUS_BLOCK_SIZE(s->pkt_framesize) / subframesize; cur = ff_bufqueue_get(&s->bufqueue); for (ch = 0; ch < f->channels; ch++) { CeltBlock *b = &f->block[ch]; const void *input = cur->extended_data[ch]; size_t bps = av_get_bytes_per_sample(cur->format); memcpy(b->overlap, input, bps*cur->nb_samples); } av_frame_free(&cur); for (sf = 0; sf < subframes; sf++) { if (sf != (subframes - 1)) cur = ff_bufqueue_get(&s->bufqueue); else cur = ff_bufqueue_peek(&s->bufqueue, 0); for (ch = 0; ch < f->channels; ch++) { CeltBlock *b = &f->block[ch]; const void *input = cur->extended_data[ch]; const size_t bps = av_get_bytes_per_sample(cur->format); const size_t left = (subframesize - cur->nb_samples)*bps; const size_t len = FFMIN(subframesize, cur->nb_samples)*bps; memcpy(&b->samples[sf*subframesize], input, len); memset(&b->samples[cur->nb_samples], 0, left); } /* Last frame isn't popped off and freed yet - we need it for overlap */ if (sf != (subframes - 1)) av_frame_free(&cur); } } /* Apply the pre emphasis filter */ static void celt_apply_preemph_filter(OpusEncContext *s, CeltFrame *f) { int i, sf, ch; const int subframesize = s->avctx->frame_size; const int subframes = OPUS_BLOCK_SIZE(s->pkt_framesize) / subframesize; /* Filter overlap */ for (ch = 0; ch < f->channels; ch++) { CeltBlock *b = &f->block[ch]; float m = b->emph_coeff; for (i = 0; i < CELT_OVERLAP; i++) { float sample = b->overlap[i]; b->overlap[i] = sample - m; m = sample * CELT_EMPH_COEFF; } b->emph_coeff = m; } /* Filter the samples but do not update the last subframe's coeff - overlap ^^^ */ for (sf = 0; sf < subframes; sf++) { for (ch = 0; ch < f->channels; ch++) { CeltBlock *b = &f->block[ch]; float m = b->emph_coeff; for (i = 0; i < subframesize; i++) { float sample = b->samples[sf*subframesize + i]; b->samples[sf*subframesize + i] = sample - m; m = sample * CELT_EMPH_COEFF; } if (sf != (subframes - 1)) b->emph_coeff = m; } } } /* Create the window and do the mdct */ static void celt_frame_mdct(OpusEncContext *s, CeltFrame *f) { int i, t, ch; float *win = s->scratch; /* I think I can use s->dsp->vector_fmul_window for transients at least */ if (f->transient) { for (ch = 0; ch < f->channels; ch++) { CeltBlock *b = &f->block[ch]; float *src1 = b->overlap; for (t = 0; t < f->blocks; t++) { float *src2 = &b->samples[CELT_OVERLAP*t]; for (i = 0; i < CELT_OVERLAP; i++) { win[ i] = src1[i]*ff_celt_window[i]; win[CELT_OVERLAP + i] = src2[i]*ff_celt_window[CELT_OVERLAP - i - 1]; } src1 = src2; s->mdct[0]->mdct(s->mdct[0], b->coeffs + t, win, f->blocks); } } } else { int blk_len = OPUS_BLOCK_SIZE(f->size), wlen = OPUS_BLOCK_SIZE(f->size + 1); int rwin = blk_len - CELT_OVERLAP, lap_dst = (wlen - blk_len - CELT_OVERLAP) >> 1; for (ch = 0; ch < f->channels; ch++) { CeltBlock *b = &f->block[ch]; memset(win, 0, wlen*sizeof(float)); memcpy(&win[lap_dst + CELT_OVERLAP], b->samples, rwin*sizeof(float)); /* Alignment fucks me over */ //s->dsp->vector_fmul(&dst[lap_dst], b->overlap, ff_celt_window, CELT_OVERLAP); //s->dsp->vector_fmul_reverse(&dst[lap_dst + blk_len - CELT_OVERLAP], b->samples, ff_celt_window, CELT_OVERLAP); for (i = 0; i < CELT_OVERLAP; i++) { win[lap_dst + i] = b->overlap[i] *ff_celt_window[i]; win[lap_dst + blk_len + i] = b->samples[rwin + i]*ff_celt_window[CELT_OVERLAP - i - 1]; } s->mdct[f->size]->mdct(s->mdct[f->size], b->coeffs, win, 1); } } } /* Fills the bands and normalizes them */ static void celt_frame_map_norm_bands(OpusEncContext *s, CeltFrame *f) { int i, j, ch; for (ch = 0; ch < f->channels; ch++) { CeltBlock *block = &f->block[ch]; for (i = 0; i < CELT_MAX_BANDS; i++) { float ener = 0.0f; int band_offset = ff_celt_freq_bands[i] << f->size; int band_size = ff_celt_freq_range[i] << f->size; float *coeffs = &block->coeffs[band_offset]; for (j = 0; j < band_size; j++) ener += coeffs[j]*coeffs[j]; block->lin_energy[i] = sqrtf(ener) + FLT_EPSILON; ener = 1.0f/block->lin_energy[i]; for (j = 0; j < band_size; j++) coeffs[j] *= ener; block->energy[i] = log2f(block->lin_energy[i]) - ff_celt_mean_energy[i]; /* CELT_ENERGY_SILENCE is what the decoder uses and its not -infinity */ block->energy[i] = FFMAX(block->energy[i], CELT_ENERGY_SILENCE); } } } static void celt_enc_tf(OpusRangeCoder *rc, CeltFrame *f) { int i, tf_select = 0, diff = 0, tf_changed = 0, tf_select_needed; int bits = f->transient ? 2 : 4; tf_select_needed = ((f->size && (opus_rc_tell(rc) + bits + 1) <= f->framebits)); for (i = f->start_band; i < f->end_band; i++) { if ((opus_rc_tell(rc) + bits + tf_select_needed) <= f->framebits) { const int tbit = (diff ^ 1) == f->tf_change[i]; ff_opus_rc_enc_log(rc, tbit, bits); diff ^= tbit; tf_changed |= diff; } bits = f->transient ? 4 : 5; } if (tf_select_needed && ff_celt_tf_select[f->size][f->transient][0][tf_changed] != ff_celt_tf_select[f->size][f->transient][1][tf_changed]) { ff_opus_rc_enc_log(rc, f->tf_select, 1); tf_select = f->tf_select; } 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 ff_celt_enc_bitalloc(OpusRangeCoder *rc, CeltFrame *f) { int i, j, low, high, total, done, bandbits, remaining, tbits_8ths; int skip_startband = f->start_band; int skip_bit = 0; int intensitystereo_bit = 0; int dualstereo_bit = 0; int dynalloc = 6; int extrabits = 0; int *cap = f->caps; int boost[CELT_MAX_BANDS]; int trim_offset[CELT_MAX_BANDS]; int threshold[CELT_MAX_BANDS]; int bits1[CELT_MAX_BANDS]; int bits2[CELT_MAX_BANDS]; /* Tell the spread to the decoder */ if (opus_rc_tell(rc) + 4 <= f->framebits) ff_opus_rc_enc_cdf(rc, f->spread, 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; } /* Band boosts */ tbits_8ths = f->framebits << 3; for (i = f->start_band; i < f->end_band; i++) { int quanta, b_dynalloc, boost_amount = f->alloc_boost[i]; boost[i] = 0; quanta = ff_celt_freq_range[i] << (f->channels - 1) << f->size; quanta = FFMIN(quanta << 3, FFMAX(6 << 3, quanta)); b_dynalloc = dynalloc; while (opus_rc_tell_frac(rc) + (b_dynalloc << 3) < tbits_8ths && boost[i] < cap[i]) { int is_boost = boost_amount--; ff_opus_rc_enc_log(rc, is_boost, b_dynalloc); if (!is_boost) break; boost[i] += quanta; tbits_8ths -= quanta; b_dynalloc = 1; } if (boost[i]) dynalloc = FFMAX(2, dynalloc - 1); } /* Put allocation trim */ if (opus_rc_tell_frac(rc) + (6 << 3) <= tbits_8ths) ff_opus_rc_enc_cdf(rc, f->alloc_trim, ff_celt_model_alloc_trim); /* Anti-collapse bit reservation */ tbits_8ths = (f->framebits << 3) - opus_rc_tell_frac(rc) - 1; f->anticollapse_needed = 0; if (f->transient && f->size >= 2 && tbits_8ths >= ((f->size + 2) << 3)) f->anticollapse_needed = 1 << 3; tbits_8ths -= f->anticollapse_needed; /* Band skip bit reservation */ if (tbits_8ths >= 1 << 3) skip_bit = 1 << 3; tbits_8ths -= skip_bit; /* Intensity/dual stereo bit reservation */ if (f->channels == 2) { intensitystereo_bit = ff_celt_log2_frac[f->end_band - f->start_band]; if (intensitystereo_bit <= tbits_8ths) { tbits_8ths -= intensitystereo_bit; if (tbits_8ths >= 1 << 3) { dualstereo_bit = 1 << 3; tbits_8ths -= 1 << 3; } } else { intensitystereo_bit = 0; } } /* Trim offsets */ for (i = f->start_band; i < f->end_band; i++) { int trim = f->alloc_trim - 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 > tbits_8ths) high = center - 1; else low = center + 1; } high = low--; /* Bisection */ 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_startband = 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 > tbits_8ths) high = center; else low = center; } /* Bisection */ 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_startband) { /* all remaining bands are not skipped */ tbits_8ths += skip_bit; break; } /* determine the number of bits available for coding "do not skip" markers */ remaining = tbits_8ths - 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)) { const int do_not_skip = f->coded_bands <= f->skip_band_floor; ff_opus_rc_enc_log(rc, do_not_skip, 1); if (do_not_skip) break; total += 1 << 3; allocation -= 1 << 3; } /* the band is skipped, so reclaim its bits */ total -= f->pulses[j]; if (intensitystereo_bit) { total -= intensitystereo_bit; intensitystereo_bit = ff_celt_log2_frac[j - f->start_band]; total += intensitystereo_bit; } total += f->pulses[j] = (allocation >= f->channels << 3) ? f->channels << 3 : 0; } /* Encode stereo flags */ if (intensitystereo_bit) { f->intensity_stereo = FFMIN(f->intensity_stereo, f->coded_bands); ff_opus_rc_enc_uint(rc, f->intensity_stereo, f->coded_bands + 1 - f->start_band); } if (f->intensity_stereo <= f->start_band) tbits_8ths += dualstereo_bit; /* no intensity stereo means no dual stereo */ else if (dualstereo_bit) ff_opus_rc_enc_log(rc, f->dual_stereo, 1); /* Supply the remaining bits in this frame to lower bands */ remaining = tbits_8ths - 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; } /* Finally determine the allocation */ 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 exp_quant_coarse(OpusRangeCoder *rc, CeltFrame *f, float last_energy[][CELT_MAX_BANDS], int intra) { int i, ch; float alpha, beta, prev[2] = { 0, 0 }; const uint8_t *pmod = ff_celt_coarse_energy_dist[f->size][intra]; /* Inter is really just differential coding */ if (opus_rc_tell(rc) + 3 <= f->framebits) ff_opus_rc_enc_log(rc, intra, 3); else intra = 0; if (intra) { alpha = 0.0f; beta = 1.0f - 4915.0f/32768.0f; } else { alpha = ff_celt_alpha_coef[f->size]; beta = 1.0f - ff_celt_beta_coef[f->size]; } for (i = f->start_band; i < f->end_band; i++) { for (ch = 0; ch < f->channels; ch++) { CeltBlock *block = &f->block[ch]; const int left = f->framebits - opus_rc_tell(rc); const float last = FFMAX(-9.0f, last_energy[ch][i]); float diff = block->energy[i] - prev[ch] - last*alpha; int q_en = lrintf(diff); if (left >= 15) { ff_opus_rc_enc_laplace(rc, &q_en, pmod[i << 1] << 7, pmod[(i << 1) + 1] << 6); } else if (left >= 2) { q_en = av_clip(q_en, -1, 1); ff_opus_rc_enc_cdf(rc, 2*q_en + 3*(q_en < 0), ff_celt_model_energy_small); } else if (left >= 1) { q_en = av_clip(q_en, -1, 0); ff_opus_rc_enc_log(rc, (q_en & 1), 1); } else q_en = -1; block->error_energy[i] = q_en - diff; prev[ch] += beta * q_en; } } } static void celt_quant_coarse(OpusRangeCoder *rc, CeltFrame *f, float last_energy[][CELT_MAX_BANDS]) { uint32_t inter, intra; OPUS_RC_CHECKPOINT_SPAWN(rc); exp_quant_coarse(rc, f, last_energy, 1); intra = OPUS_RC_CHECKPOINT_BITS(rc); OPUS_RC_CHECKPOINT_ROLLBACK(rc); exp_quant_coarse(rc, f, last_energy, 0); inter = OPUS_RC_CHECKPOINT_BITS(rc); if (inter > intra) { /* Unlikely */ OPUS_RC_CHECKPOINT_ROLLBACK(rc); exp_quant_coarse(rc, f, last_energy, 1); } } static void celt_quant_fine(OpusRangeCoder *rc, CeltFrame *f) { int i, ch; for (i = f->start_band; i < f->end_band; i++) { if (!f->fine_bits[i]) continue; for (ch = 0; ch < f->channels; ch++) { CeltBlock *block = &f->block[ch]; int quant, lim = (1 << f->fine_bits[i]); float offset, diff = 0.5f - block->error_energy[i]; quant = av_clip(floor(diff*lim), 0, lim - 1); ff_opus_rc_put_raw(rc, quant, f->fine_bits[i]); offset = 0.5f - ((quant + 0.5f) * (1 << (14 - f->fine_bits[i])) / 16384.0f); block->error_energy[i] -= offset; } } } static void celt_quant_final(OpusEncContext *s, OpusRangeCoder *rc, CeltFrame *f) { int i, ch, priority; for (priority = 0; priority < 2; priority++) { for (i = f->start_band; i < f->end_band && (f->framebits - opus_rc_tell(rc)) >= f->channels; i++) { if (f->fine_priority[i] != priority || f->fine_bits[i] >= CELT_MAX_FINE_BITS) continue; for (ch = 0; ch < f->channels; ch++) { CeltBlock *block = &f->block[ch]; const float err = block->error_energy[i]; const float offset = 0.5f * (1 << (14 - f->fine_bits[i] - 1)) / 16384.0f; const int sign = FFABS(err + offset) < FFABS(err - offset); ff_opus_rc_put_raw(rc, sign, 1); block->error_energy[i] -= offset*(1 - 2*sign); } } } } static void celt_quant_bands(OpusRangeCoder *rc, CeltFrame *f) { 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; 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->encode_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->encode_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->encode_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); } } static void celt_encode_frame(OpusEncContext *s, OpusRangeCoder *rc, CeltFrame *f) { int i, ch; celt_frame_setup_input(s, f); celt_apply_preemph_filter(s, f); if (f->pfilter) { /* Not implemented */ } celt_frame_mdct(s, f); celt_frame_map_norm_bands(s, f); ff_opus_rc_enc_log(rc, f->silence, 15); if (!f->start_band && opus_rc_tell(rc) + 16 <= f->framebits) ff_opus_rc_enc_log(rc, f->pfilter, 1); if (f->pfilter) { /* Not implemented */ } if (f->size && opus_rc_tell(rc) + 3 <= f->framebits) ff_opus_rc_enc_log(rc, f->transient, 3); celt_quant_coarse(rc, f, s->last_quantized_energy); celt_enc_tf (rc, f); ff_celt_enc_bitalloc(rc, f); celt_quant_fine (rc, f); celt_quant_bands (rc, f); if (f->anticollapse_needed) ff_opus_rc_put_raw(rc, f->anticollapse, 1); celt_quant_final(s, rc, f); for (ch = 0; ch < f->channels; ch++) { CeltBlock *block = &f->block[ch]; for (i = 0; i < CELT_MAX_BANDS; i++) s->last_quantized_energy[ch][i] = block->energy[i] + block->error_energy[i]; } } static void ff_opus_psy_process(OpusEncContext *s, int end, int *need_more) { int max_delay_samples = (s->options.max_delay_ms*s->avctx->sample_rate)/1000; int max_bsize = FFMIN(OPUS_SAMPLES_TO_BLOCK_SIZE(max_delay_samples), CELT_BLOCK_960); s->pkt_frames = 1; s->pkt_framesize = max_bsize; s->mode = OPUS_MODE_CELT; s->bandwidth = OPUS_BANDWIDTH_FULLBAND; *need_more = s->bufqueue.available*s->avctx->frame_size < (max_delay_samples + CELT_OVERLAP); /* Don't request more if we start being flushed with NULL frames */ *need_more = !end && *need_more; } static void ff_opus_psy_celt_frame_setup(OpusEncContext *s, CeltFrame *f, int index) { int frame_size = OPUS_BLOCK_SIZE(s->pkt_framesize); f->avctx = s->avctx; f->dsp = s->dsp; f->pvq = s->pvq; f->start_band = (s->mode == OPUS_MODE_HYBRID) ? 17 : 0; f->end_band = ff_celt_band_end[s->bandwidth]; f->channels = s->channels; f->size = s->pkt_framesize; /* Decisions */ f->silence = 0; f->pfilter = 0; f->transient = 0; f->tf_select = 0; f->anticollapse = 0; f->alloc_trim = 5; f->skip_band_floor = f->end_band; f->intensity_stereo = f->end_band; f->dual_stereo = 0; f->spread = CELT_SPREAD_NORMAL; memset(f->tf_change, 0, sizeof(int)*CELT_MAX_BANDS); memset(f->alloc_boost, 0, sizeof(int)*CELT_MAX_BANDS); f->blocks = f->transient ? frame_size/CELT_OVERLAP : 1; f->framebits = FFALIGN(lrintf((double)s->avctx->bit_rate/(s->avctx->sample_rate/frame_size)), 8); } static void opus_packet_assembler(OpusEncContext *s, AVPacket *avpkt) { int i, offset, fsize_needed; /* Write toc */ opus_gen_toc(s, avpkt->data, &offset, &fsize_needed); for (i = 0; i < s->pkt_frames; i++) { ff_opus_rc_enc_end(&s->rc[i], avpkt->data + offset, s->frame[i].framebits >> 3); offset += s->frame[i].framebits >> 3; } avpkt->size = offset; } /* Used as overlap for the first frame and padding for the last encoded packet */ static AVFrame *spawn_empty_frame(OpusEncContext *s) { int i; AVFrame *f = av_frame_alloc(); if (!f) return NULL; f->format = s->avctx->sample_fmt; f->nb_samples = s->avctx->frame_size; f->channel_layout = s->avctx->channel_layout; if (av_frame_get_buffer(f, 4)) { av_frame_free(&f); return NULL; } for (i = 0; i < s->channels; i++) { size_t bps = av_get_bytes_per_sample(f->format); memset(f->extended_data[i], 0, bps*f->nb_samples); } return f; } static int opus_encode_frame(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame, int *got_packet_ptr) { OpusEncContext *s = avctx->priv_data; int i, ret, frame_size, need_more, alloc_size = 0; if (frame) { /* Add new frame to queue */ if ((ret = ff_af_queue_add(&s->afq, frame)) < 0) return ret; ff_bufqueue_add(avctx, &s->bufqueue, av_frame_clone(frame)); } else { if (!s->afq.remaining_samples) return 0; /* We've been flushed and there's nothing left to encode */ } /* Run the psychoacoustic system */ ff_opus_psy_process(s, !frame, &need_more); /* Get more samples for lookahead/encoding */ if (need_more) return 0; frame_size = OPUS_BLOCK_SIZE(s->pkt_framesize); if (!frame) { /* This can go negative, that's not a problem, we only pad if positive */ int pad_empty = s->pkt_frames*(frame_size/s->avctx->frame_size) - s->bufqueue.available + 1; /* Pad with empty 2.5 ms frames to whatever framesize was decided, * this should only happen at the very last flush frame. The frames * allocated here will be freed (because they have no other references) * after they get used by celt_frame_setup_input() */ for (i = 0; i < pad_empty; i++) { AVFrame *empty = spawn_empty_frame(s); if (!empty) return AVERROR(ENOMEM); ff_bufqueue_add(avctx, &s->bufqueue, empty); } } for (i = 0; i < s->pkt_frames; i++) { ff_opus_rc_enc_init(&s->rc[i]); ff_opus_psy_celt_frame_setup(s, &s->frame[i], i); celt_encode_frame(s, &s->rc[i], &s->frame[i]); alloc_size += s->frame[i].framebits >> 3; } /* Worst case toc + the frame lengths if needed */ alloc_size += 2 + s->pkt_frames*2; if ((ret = ff_alloc_packet2(avctx, avpkt, alloc_size, 0)) < 0) return ret; /* Assemble packet */ opus_packet_assembler(s, avpkt); /* Remove samples from queue and skip if needed */ ff_af_queue_remove(&s->afq, s->pkt_frames*frame_size, &avpkt->pts, &avpkt->duration); if (s->pkt_frames*frame_size > avpkt->duration) { uint8_t *side = av_packet_new_side_data(avpkt, AV_PKT_DATA_SKIP_SAMPLES, 10); if (!side) return AVERROR(ENOMEM); AV_WL32(&side[4], s->pkt_frames*frame_size - avpkt->duration + 120); } *got_packet_ptr = 1; return 0; } static av_cold int opus_encode_end(AVCodecContext *avctx) { int i; OpusEncContext *s = avctx->priv_data; for (i = 0; i < CELT_BLOCK_NB; i++) ff_mdct15_uninit(&s->mdct[i]); ff_celt_pvq_uninit(&s->pvq); av_freep(&s->dsp); av_freep(&s->frame); av_freep(&s->rc); ff_af_queue_close(&s->afq); ff_bufqueue_discard_all(&s->bufqueue); av_freep(&avctx->extradata); return 0; } static av_cold int opus_encode_init(AVCodecContext *avctx) { int i, ch, ret; OpusEncContext *s = avctx->priv_data; s->avctx = avctx; s->channels = avctx->channels; /* Opus allows us to change the framesize on each packet (and each packet may * have multiple frames in it) but we can't change the codec's frame size on * runtime, so fix it to the lowest possible number of samples and use a queue * to accumulate AVFrames until we have enough to encode whatever the encoder * decides is the best */ avctx->frame_size = 120; /* Initial padding will change if SILK is ever supported */ avctx->initial_padding = 120; avctx->cutoff = !avctx->cutoff ? 20000 : avctx->cutoff; if (!avctx->bit_rate) { int coupled = ff_opus_default_coupled_streams[s->channels - 1]; avctx->bit_rate = coupled*(96000) + (s->channels - coupled*2)*(48000); } else if (avctx->bit_rate < 6000 || avctx->bit_rate > 255000 * s->channels) { int64_t clipped_rate = av_clip(avctx->bit_rate, 6000, 255000 * s->channels); av_log(avctx, AV_LOG_ERROR, "Unsupported bitrate %"PRId64" kbps, clipping to %"PRId64" kbps\n", avctx->bit_rate/1000, clipped_rate/1000); avctx->bit_rate = clipped_rate; } /* Frame structs and range coder buffers */ s->frame = av_malloc(OPUS_MAX_FRAMES_PER_PACKET*sizeof(CeltFrame)); if (!s->frame) return AVERROR(ENOMEM); s->rc = av_malloc(OPUS_MAX_FRAMES_PER_PACKET*sizeof(OpusRangeCoder)); if (!s->rc) return AVERROR(ENOMEM); /* Extradata */ avctx->extradata_size = 19; avctx->extradata = av_malloc(avctx->extradata_size + AV_INPUT_BUFFER_PADDING_SIZE); if (!avctx->extradata) return AVERROR(ENOMEM); opus_write_extradata(avctx); ff_af_queue_init(avctx, &s->afq); if ((ret = ff_celt_pvq_init(&s->pvq)) < 0) return ret; if (!(s->dsp = avpriv_float_dsp_alloc(avctx->flags & AV_CODEC_FLAG_BITEXACT))) return AVERROR(ENOMEM); /* I have no idea why a base scaling factor of 68 works, could be the twiddles */ for (i = 0; i < CELT_BLOCK_NB; i++) if ((ret = ff_mdct15_init(&s->mdct[i], 0, i + 3, 68 << (CELT_BLOCK_NB - 1 - i)))) return AVERROR(ENOMEM); for (i = 0; i < OPUS_MAX_FRAMES_PER_PACKET; i++) { s->frame[i].block[0].emph_coeff = s->frame[i].block[1].emph_coeff = 0.0f; s->frame[i].seed = 0; } /* Zero out previous energy (matters for inter first frame) */ for (ch = 0; ch < s->channels; ch++) for (i = 0; i < CELT_MAX_BANDS; i++) s->last_quantized_energy[ch][i] = 0.0f; /* Allocate an empty frame to use as overlap for the first frame of audio */ ff_bufqueue_add(avctx, &s->bufqueue, spawn_empty_frame(s)); if (!ff_bufqueue_peek(&s->bufqueue, 0)) return AVERROR(ENOMEM); return 0; } #define OPUSENC_FLAGS AV_OPT_FLAG_ENCODING_PARAM | AV_OPT_FLAG_AUDIO_PARAM static const AVOption opusenc_options[] = { { "opus_delay", "Maximum delay (and lookahead) in milliseconds", offsetof(OpusEncContext, options.max_delay_ms), AV_OPT_TYPE_FLOAT, { .dbl = OPUS_MAX_LOOKAHEAD }, 2.5f, OPUS_MAX_LOOKAHEAD, OPUSENC_FLAGS }, { NULL }, }; static const AVClass opusenc_class = { .class_name = "Opus encoder", .item_name = av_default_item_name, .option = opusenc_options, .version = LIBAVUTIL_VERSION_INT, }; static const AVCodecDefault opusenc_defaults[] = { { "b", "0" }, { "compression_level", "10" }, { NULL }, }; AVCodec ff_opus_encoder = { .name = "opus", .long_name = NULL_IF_CONFIG_SMALL("Opus"), .type = AVMEDIA_TYPE_AUDIO, .id = AV_CODEC_ID_OPUS, .defaults = opusenc_defaults, .priv_class = &opusenc_class, .priv_data_size = sizeof(OpusEncContext), .init = opus_encode_init, .encode2 = opus_encode_frame, .close = opus_encode_end, .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP, .capabilities = AV_CODEC_CAP_EXPERIMENTAL | AV_CODEC_CAP_SMALL_LAST_FRAME | AV_CODEC_CAP_DELAY, .supported_samplerates = (const int []){ 48000, 0 }, .channel_layouts = (const uint64_t []){ AV_CH_LAYOUT_MONO, AV_CH_LAYOUT_STEREO, 0 }, .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_FLTP, AV_SAMPLE_FMT_NONE }, };