| /* |
| * Copyright (c) 2012 Andrew D'Addesio |
| * Copyright (c) 2013-2014 Mozilla Corporation |
| * |
| * 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 decoder/parser shared code |
| */ |
| |
| #include <stdint.h> |
| |
| #include "libavutil/error.h" |
| #include "libavutil/ffmath.h" |
| |
| #include "opus_celt.h" |
| #include "opustab.h" |
| #include "vorbis.h" |
| |
| static const uint16_t opus_frame_duration[32] = { |
| 480, 960, 1920, 2880, |
| 480, 960, 1920, 2880, |
| 480, 960, 1920, 2880, |
| 480, 960, |
| 480, 960, |
| 120, 240, 480, 960, |
| 120, 240, 480, 960, |
| 120, 240, 480, 960, |
| 120, 240, 480, 960, |
| }; |
| |
| /** |
| * Read a 1- or 2-byte frame length |
| */ |
| static inline int xiph_lacing_16bit(const uint8_t **ptr, const uint8_t *end) |
| { |
| int val; |
| |
| if (*ptr >= end) |
| return AVERROR_INVALIDDATA; |
| val = *(*ptr)++; |
| if (val >= 252) { |
| if (*ptr >= end) |
| return AVERROR_INVALIDDATA; |
| val += 4 * *(*ptr)++; |
| } |
| return val; |
| } |
| |
| /** |
| * Read a multi-byte length (used for code 3 packet padding size) |
| */ |
| static inline int xiph_lacing_full(const uint8_t **ptr, const uint8_t *end) |
| { |
| int val = 0; |
| int next; |
| |
| while (1) { |
| if (*ptr >= end || val > INT_MAX - 254) |
| return AVERROR_INVALIDDATA; |
| next = *(*ptr)++; |
| val += next; |
| if (next < 255) |
| break; |
| else |
| val--; |
| } |
| return val; |
| } |
| |
| /** |
| * Parse Opus packet info from raw packet data |
| */ |
| int ff_opus_parse_packet(OpusPacket *pkt, const uint8_t *buf, int buf_size, |
| int self_delimiting) |
| { |
| const uint8_t *ptr = buf; |
| const uint8_t *end = buf + buf_size; |
| int padding = 0; |
| int frame_bytes, i; |
| |
| if (buf_size < 1) |
| goto fail; |
| |
| /* TOC byte */ |
| i = *ptr++; |
| pkt->code = (i ) & 0x3; |
| pkt->stereo = (i >> 2) & 0x1; |
| pkt->config = (i >> 3) & 0x1F; |
| |
| /* code 2 and code 3 packets have at least 1 byte after the TOC */ |
| if (pkt->code >= 2 && buf_size < 2) |
| goto fail; |
| |
| switch (pkt->code) { |
| case 0: |
| /* 1 frame */ |
| pkt->frame_count = 1; |
| pkt->vbr = 0; |
| |
| if (self_delimiting) { |
| int len = xiph_lacing_16bit(&ptr, end); |
| if (len < 0 || len > end - ptr) |
| goto fail; |
| end = ptr + len; |
| buf_size = end - buf; |
| } |
| |
| frame_bytes = end - ptr; |
| if (frame_bytes > MAX_FRAME_SIZE) |
| goto fail; |
| pkt->frame_offset[0] = ptr - buf; |
| pkt->frame_size[0] = frame_bytes; |
| break; |
| case 1: |
| /* 2 frames, equal size */ |
| pkt->frame_count = 2; |
| pkt->vbr = 0; |
| |
| if (self_delimiting) { |
| int len = xiph_lacing_16bit(&ptr, end); |
| if (len < 0 || 2 * len > end - ptr) |
| goto fail; |
| end = ptr + 2 * len; |
| buf_size = end - buf; |
| } |
| |
| frame_bytes = end - ptr; |
| if (frame_bytes & 1 || frame_bytes >> 1 > MAX_FRAME_SIZE) |
| goto fail; |
| pkt->frame_offset[0] = ptr - buf; |
| pkt->frame_size[0] = frame_bytes >> 1; |
| pkt->frame_offset[1] = pkt->frame_offset[0] + pkt->frame_size[0]; |
| pkt->frame_size[1] = frame_bytes >> 1; |
| break; |
| case 2: |
| /* 2 frames, different sizes */ |
| pkt->frame_count = 2; |
| pkt->vbr = 1; |
| |
| /* read 1st frame size */ |
| frame_bytes = xiph_lacing_16bit(&ptr, end); |
| if (frame_bytes < 0) |
| goto fail; |
| |
| if (self_delimiting) { |
| int len = xiph_lacing_16bit(&ptr, end); |
| if (len < 0 || len + frame_bytes > end - ptr) |
| goto fail; |
| end = ptr + frame_bytes + len; |
| buf_size = end - buf; |
| } |
| |
| pkt->frame_offset[0] = ptr - buf; |
| pkt->frame_size[0] = frame_bytes; |
| |
| /* calculate 2nd frame size */ |
| frame_bytes = end - ptr - pkt->frame_size[0]; |
| if (frame_bytes < 0 || frame_bytes > MAX_FRAME_SIZE) |
| goto fail; |
| pkt->frame_offset[1] = pkt->frame_offset[0] + pkt->frame_size[0]; |
| pkt->frame_size[1] = frame_bytes; |
| break; |
| case 3: |
| /* 1 to 48 frames, can be different sizes */ |
| i = *ptr++; |
| pkt->frame_count = (i ) & 0x3F; |
| padding = (i >> 6) & 0x01; |
| pkt->vbr = (i >> 7) & 0x01; |
| |
| if (pkt->frame_count == 0 || pkt->frame_count > MAX_FRAMES) |
| goto fail; |
| |
| /* read padding size */ |
| if (padding) { |
| padding = xiph_lacing_full(&ptr, end); |
| if (padding < 0) |
| goto fail; |
| } |
| |
| /* read frame sizes */ |
| if (pkt->vbr) { |
| /* for VBR, all frames except the final one have their size coded |
| in the bitstream. the last frame size is implicit. */ |
| int total_bytes = 0; |
| for (i = 0; i < pkt->frame_count - 1; i++) { |
| frame_bytes = xiph_lacing_16bit(&ptr, end); |
| if (frame_bytes < 0) |
| goto fail; |
| pkt->frame_size[i] = frame_bytes; |
| total_bytes += frame_bytes; |
| } |
| |
| if (self_delimiting) { |
| int len = xiph_lacing_16bit(&ptr, end); |
| if (len < 0 || len + total_bytes + padding > end - ptr) |
| goto fail; |
| end = ptr + total_bytes + len + padding; |
| buf_size = end - buf; |
| } |
| |
| frame_bytes = end - ptr - padding; |
| if (total_bytes > frame_bytes) |
| goto fail; |
| pkt->frame_offset[0] = ptr - buf; |
| for (i = 1; i < pkt->frame_count; i++) |
| pkt->frame_offset[i] = pkt->frame_offset[i-1] + pkt->frame_size[i-1]; |
| pkt->frame_size[pkt->frame_count-1] = frame_bytes - total_bytes; |
| } else { |
| /* for CBR, the remaining packet bytes are divided evenly between |
| the frames */ |
| if (self_delimiting) { |
| frame_bytes = xiph_lacing_16bit(&ptr, end); |
| if (frame_bytes < 0 || pkt->frame_count * frame_bytes + padding > end - ptr) |
| goto fail; |
| end = ptr + pkt->frame_count * frame_bytes + padding; |
| buf_size = end - buf; |
| } else { |
| frame_bytes = end - ptr - padding; |
| if (frame_bytes % pkt->frame_count || |
| frame_bytes / pkt->frame_count > MAX_FRAME_SIZE) |
| goto fail; |
| frame_bytes /= pkt->frame_count; |
| } |
| |
| pkt->frame_offset[0] = ptr - buf; |
| pkt->frame_size[0] = frame_bytes; |
| for (i = 1; i < pkt->frame_count; i++) { |
| pkt->frame_offset[i] = pkt->frame_offset[i-1] + pkt->frame_size[i-1]; |
| pkt->frame_size[i] = frame_bytes; |
| } |
| } |
| } |
| |
| pkt->packet_size = buf_size; |
| pkt->data_size = pkt->packet_size - padding; |
| |
| /* total packet duration cannot be larger than 120ms */ |
| pkt->frame_duration = opus_frame_duration[pkt->config]; |
| if (pkt->frame_duration * pkt->frame_count > MAX_PACKET_DUR) |
| goto fail; |
| |
| /* set mode and bandwidth */ |
| if (pkt->config < 12) { |
| pkt->mode = OPUS_MODE_SILK; |
| pkt->bandwidth = pkt->config >> 2; |
| } else if (pkt->config < 16) { |
| pkt->mode = OPUS_MODE_HYBRID; |
| pkt->bandwidth = OPUS_BANDWIDTH_SUPERWIDEBAND + (pkt->config >= 14); |
| } else { |
| pkt->mode = OPUS_MODE_CELT; |
| pkt->bandwidth = (pkt->config - 16) >> 2; |
| /* skip medium band */ |
| if (pkt->bandwidth) |
| pkt->bandwidth++; |
| } |
| |
| return 0; |
| |
| fail: |
| memset(pkt, 0, sizeof(*pkt)); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| static int channel_reorder_vorbis(int nb_channels, int channel_idx) |
| { |
| return ff_vorbis_channel_layout_offsets[nb_channels - 1][channel_idx]; |
| } |
| |
| static int channel_reorder_unknown(int nb_channels, int channel_idx) |
| { |
| return channel_idx; |
| } |
| |
| av_cold int ff_opus_parse_extradata(AVCodecContext *avctx, |
| OpusContext *s) |
| { |
| static const uint8_t default_channel_map[2] = { 0, 1 }; |
| |
| int (*channel_reorder)(int, int) = channel_reorder_unknown; |
| |
| const uint8_t *extradata, *channel_map; |
| int extradata_size; |
| int version, channels, map_type, streams, stereo_streams, i, j; |
| uint64_t layout; |
| |
| if (!avctx->extradata) { |
| if (avctx->channels > 2) { |
| av_log(avctx, AV_LOG_ERROR, |
| "Multichannel configuration without extradata.\n"); |
| return AVERROR(EINVAL); |
| } |
| extradata = opus_default_extradata; |
| extradata_size = sizeof(opus_default_extradata); |
| } else { |
| extradata = avctx->extradata; |
| extradata_size = avctx->extradata_size; |
| } |
| |
| if (extradata_size < 19) { |
| av_log(avctx, AV_LOG_ERROR, "Invalid extradata size: %d\n", |
| extradata_size); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| version = extradata[8]; |
| if (version > 15) { |
| avpriv_request_sample(avctx, "Extradata version %d", version); |
| return AVERROR_PATCHWELCOME; |
| } |
| |
| avctx->delay = AV_RL16(extradata + 10); |
| |
| channels = avctx->extradata ? extradata[9] : (avctx->channels == 1) ? 1 : 2; |
| if (!channels) { |
| av_log(avctx, AV_LOG_ERROR, "Zero channel count specified in the extradata\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| s->gain_i = AV_RL16(extradata + 16); |
| if (s->gain_i) |
| s->gain = ff_exp10(s->gain_i / (20.0 * 256)); |
| |
| map_type = extradata[18]; |
| if (!map_type) { |
| if (channels > 2) { |
| av_log(avctx, AV_LOG_ERROR, |
| "Channel mapping 0 is only specified for up to 2 channels\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| layout = (channels == 1) ? AV_CH_LAYOUT_MONO : AV_CH_LAYOUT_STEREO; |
| streams = 1; |
| stereo_streams = channels - 1; |
| channel_map = default_channel_map; |
| } else if (map_type == 1 || map_type == 2 || map_type == 255) { |
| if (extradata_size < 21 + channels) { |
| av_log(avctx, AV_LOG_ERROR, "Invalid extradata size: %d\n", |
| extradata_size); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| streams = extradata[19]; |
| stereo_streams = extradata[20]; |
| if (!streams || stereo_streams > streams || |
| streams + stereo_streams > 255) { |
| av_log(avctx, AV_LOG_ERROR, |
| "Invalid stream/stereo stream count: %d/%d\n", streams, stereo_streams); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| if (map_type == 1) { |
| if (channels > 8) { |
| av_log(avctx, AV_LOG_ERROR, |
| "Channel mapping 1 is only specified for up to 8 channels\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| layout = ff_vorbis_channel_layouts[channels - 1]; |
| channel_reorder = channel_reorder_vorbis; |
| } else if (map_type == 2) { |
| int ambisonic_order = ff_sqrt(channels) - 1; |
| if (channels != ((ambisonic_order + 1) * (ambisonic_order + 1)) && |
| channels != ((ambisonic_order + 1) * (ambisonic_order + 1) + 2)) { |
| av_log(avctx, AV_LOG_ERROR, |
| "Channel mapping 2 is only specified for channel counts" |
| " which can be written as (n + 1)^2 or (n + 1)^2 + 2" |
| " for nonnegative integer n\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| if (channels > 227) { |
| av_log(avctx, AV_LOG_ERROR, "Too many channels\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| layout = 0; |
| } else |
| layout = 0; |
| |
| channel_map = extradata + 21; |
| } else { |
| avpriv_request_sample(avctx, "Mapping type %d", map_type); |
| return AVERROR_PATCHWELCOME; |
| } |
| |
| s->channel_maps = av_mallocz_array(channels, sizeof(*s->channel_maps)); |
| if (!s->channel_maps) |
| return AVERROR(ENOMEM); |
| |
| for (i = 0; i < channels; i++) { |
| ChannelMap *map = &s->channel_maps[i]; |
| uint8_t idx = channel_map[channel_reorder(channels, i)]; |
| |
| if (idx == 255) { |
| map->silence = 1; |
| continue; |
| } else if (idx >= streams + stereo_streams) { |
| av_log(avctx, AV_LOG_ERROR, |
| "Invalid channel map for output channel %d: %d\n", i, idx); |
| av_freep(&s->channel_maps); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| /* check that we did not see this index yet */ |
| map->copy = 0; |
| for (j = 0; j < i; j++) |
| if (channel_map[channel_reorder(channels, j)] == idx) { |
| map->copy = 1; |
| map->copy_idx = j; |
| break; |
| } |
| |
| if (idx < 2 * stereo_streams) { |
| map->stream_idx = idx / 2; |
| map->channel_idx = idx & 1; |
| } else { |
| map->stream_idx = idx - stereo_streams; |
| map->channel_idx = 0; |
| } |
| } |
| |
| avctx->channels = channels; |
| avctx->channel_layout = layout; |
| s->nb_streams = streams; |
| s->nb_stereo_streams = stereo_streams; |
| |
| return 0; |
| } |
| |
| void ff_celt_quant_bands(CeltFrame *f, OpusRangeCoder *rc) |
| { |
| float lowband_scratch[8 * 22]; |
| float norm1[2 * 8 * 100]; |
| float *norm2 = norm1 + 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; |
| float *norm_loc1, *norm_loc2; |
| |
| int consumed = opus_rc_tell_frac(rc); |
| 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] || |
| i == f->start_band + 1) && (update_lowband || lowband_offset == 0)) |
| lowband_offset = i; |
| |
| if (i == f->start_band + 1) { |
| /* Special Hybrid Folding (RFC 8251 section 9). Copy the first band into |
| the second to ensure the second band never has to use the LCG. */ |
| int count = (ff_celt_freq_range[i] - ff_celt_freq_range[i-1]) << f->size; |
| |
| memcpy(&norm1[band_offset], &norm1[band_offset - count], count * sizeof(float)); |
| |
| if (f->channels == 2) |
| memcpy(&norm2[band_offset], &norm2[band_offset - count], count * sizeof(float)); |
| } |
| |
| /* 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 (++foldend < i && 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++) |
| norm1[j] = (norm1[j] + norm2[j]) / 2; |
| } |
| |
| norm_loc1 = effective_lowband != -1 ? norm1 + (effective_lowband << f->size) : NULL; |
| norm_loc2 = effective_lowband != -1 ? norm2 + (effective_lowband << f->size) : NULL; |
| |
| if (f->dual_stereo) { |
| cm[0] = f->pvq->quant_band(f->pvq, f, rc, i, X, NULL, band_size, b >> 1, |
| f->blocks, norm_loc1, f->size, |
| norm1 + band_offset, 0, 1.0f, |
| lowband_scratch, cm[0]); |
| |
| cm[1] = f->pvq->quant_band(f->pvq, f, rc, i, Y, NULL, band_size, b >> 1, |
| f->blocks, norm_loc2, f->size, |
| norm2 + band_offset, 0, 1.0f, |
| lowband_scratch, cm[1]); |
| } else { |
| cm[0] = f->pvq->quant_band(f->pvq, f, rc, i, X, Y, band_size, b >> 0, |
| f->blocks, norm_loc1, f->size, |
| norm1 + 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); |
| } |
| } |
| |
| #define NORMC(bits) ((bits) << (f->channels - 1) << f->size >> 2) |
| |
| void ff_celt_bitalloc(CeltFrame *f, OpusRangeCoder *rc, int encode) |
| { |
| 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 boost[CELT_MAX_BANDS] = { 0 }; |
| int trim_offset[CELT_MAX_BANDS]; |
| int threshold[CELT_MAX_BANDS]; |
| int bits1[CELT_MAX_BANDS]; |
| int bits2[CELT_MAX_BANDS]; |
| |
| /* Spread */ |
| if (opus_rc_tell(rc) + 4 <= f->framebits) { |
| if (encode) |
| ff_opus_rc_enc_cdf(rc, f->spread, ff_celt_model_spread); |
| else |
| f->spread = ff_opus_rc_dec_cdf(rc, ff_celt_model_spread); |
| } else { |
| f->spread = CELT_SPREAD_NORMAL; |
| } |
| |
| /* Initialize static allocation caps */ |
| for (i = 0; i < CELT_MAX_BANDS; i++) |
| f->caps[i] = NORMC((ff_celt_static_caps[f->size][f->channels - 1][i] + 64) * ff_celt_freq_range[i]); |
| |
| /* Band boosts */ |
| tbits_8ths = f->framebits << 3; |
| for (i = f->start_band; i < f->end_band; i++) { |
| int quanta = ff_celt_freq_range[i] << (f->channels - 1) << f->size; |
| int b_dynalloc = dynalloc; |
| int boost_amount = f->alloc_boost[i]; |
| quanta = FFMIN(quanta << 3, FFMAX(6 << 3, quanta)); |
| |
| while (opus_rc_tell_frac(rc) + (b_dynalloc << 3) < tbits_8ths && boost[i] < f->caps[i]) { |
| int is_boost; |
| if (encode) { |
| is_boost = boost_amount--; |
| ff_opus_rc_enc_log(rc, is_boost, b_dynalloc); |
| } else { |
| is_boost = ff_opus_rc_dec_log(rc, b_dynalloc); |
| } |
| |
| if (!is_boost) |
| break; |
| |
| boost[i] += quanta; |
| tbits_8ths -= quanta; |
| |
| b_dynalloc = 1; |
| } |
| |
| if (boost[i]) |
| dynalloc = FFMAX(dynalloc - 1, 2); |
| } |
| |
| /* Allocation trim */ |
| if (opus_rc_tell_frac(rc) + (6 << 3) <= tbits_8ths) |
| if (encode) |
| ff_opus_rc_enc_cdf(rc, f->alloc_trim, ff_celt_model_alloc_trim); |
| else |
| f->alloc_trim = ff_opus_rc_dec_cdf(rc, 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 = NORMC(ff_celt_freq_range[i] * ff_celt_static_alloc[center][i]); |
| |
| if (bandbits) |
| bandbits = FFMAX(bandbits + trim_offset[i], 0); |
| bandbits += boost[i]; |
| |
| if (bandbits >= threshold[i] || done) { |
| done = 1; |
| total += FFMIN(bandbits, f->caps[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] = NORMC(ff_celt_freq_range[i] * ff_celt_static_alloc[low][i]); |
| bits2[i] = high >= CELT_VECTORS ? f->caps[i] : |
| NORMC(ff_celt_freq_range[i] * ff_celt_static_alloc[high][i]); |
| |
| if (bits1[i]) |
| bits1[i] = FFMAX(bits1[i] + trim_offset[i], 0); |
| if (bits2[i]) |
| bits2[i] = FFMAX(bits2[i] + trim_offset[i], 0); |
| |
| if (low) |
| bits1[i] += boost[i]; |
| bits2[i] += boost[i]; |
| |
| if (boost[i]) |
| skip_startband = i; |
| bits2[i] = FFMAX(bits2[i] - bits1[i], 0); |
| } |
| |
| /* 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, f->caps[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, f->caps[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]; |
| allocation += FFMAX(remaining - (ff_celt_freq_bands[j] - ff_celt_freq_bands[f->start_band]), 0); |
| |
| /* 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)) { |
| int do_not_skip; |
| if (encode) { |
| do_not_skip = f->coded_bands <= f->skip_band_floor; |
| ff_opus_rc_enc_log(rc, do_not_skip, 1); |
| } else { |
| do_not_skip = ff_opus_rc_dec_log(rc, 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; |
| } |
| |
| /* IS start band */ |
| if (encode) { |
| 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); |
| } |
| } else { |
| f->intensity_stereo = f->dual_stereo = 0; |
| if (intensitystereo_bit) |
| f->intensity_stereo = f->start_band + ff_opus_rc_dec_uint(rc, f->coded_bands + 1 - f->start_band); |
| } |
| |
| /* DS flag */ |
| if (f->intensity_stereo <= f->start_band) |
| tbits_8ths += dualstereo_bit; /* no intensity stereo means no dual stereo */ |
| else if (dualstereo_bit) |
| if (encode) |
| ff_opus_rc_enc_log(rc, f->dual_stereo, 1); |
| else |
| f->dual_stereo = ff_opus_rc_dec_log(rc, 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++) { |
| const 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 fine_bits; |
| int max_bits; |
| int offset; /* fine energy quantization offset, i.e. |
| * extra bits assigned over the standard |
| * totalbits/dof */ |
| |
| extrabits = FFMAX(f->pulses[i] - f->caps[i], 0); |
| 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(f->pulses[i] - (f->channels << 3), 0); |
| 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; |
| } |
| } |
