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c0d483cecb
Currently the APTX (HD) codecs set frame_size if unset and check whether it is divisible by block_size (corresponding to block_align as used by other codecs). But this is based upon a misunderstanding of the API: frame_size is not in bytes, but in samples. Said value is also not intended to be set by the user at all, but set by encoders and (possibly) decoders if the number of channels in a frame is constant. The latter condition is not fulfilled here, so only set it for encoders. Given that the encoder can handle any number of samples as long as it is divisible by four and given that it worked to set a custom frame size before, the encoders accept any multiple of four; otherwise the value is set to the value that it already had for APTX: 1024 samples (per channel). Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
307 lines
12 KiB
C
307 lines
12 KiB
C
/*
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* Audio Processing Technology codec for Bluetooth (aptX)
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*
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* Copyright (C) 2017 Aurelien Jacobs <aurel@gnuage.org>
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "config_components.h"
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#include "libavutil/channel_layout.h"
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#include "aptx.h"
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#include "audio_frame_queue.h"
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#include "codec_internal.h"
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#include "encode.h"
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typedef struct AptXEncContext {
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AptXContext common;
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AudioFrameQueue afq;
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} AptXEncContext;
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/*
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* Half-band QMF analysis filter realized with a polyphase FIR filter.
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* Split into 2 subbands and downsample by 2.
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* So for each pair of samples that goes in, one sample goes out,
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* split into 2 separate subbands.
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*/
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av_always_inline
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static void aptx_qmf_polyphase_analysis(FilterSignal signal[NB_FILTERS],
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const int32_t coeffs[NB_FILTERS][FILTER_TAPS],
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int shift,
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int32_t samples[NB_FILTERS],
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int32_t *low_subband_output,
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int32_t *high_subband_output)
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{
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int32_t subbands[NB_FILTERS];
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int i;
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for (i = 0; i < NB_FILTERS; i++) {
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aptx_qmf_filter_signal_push(&signal[i], samples[NB_FILTERS-1-i]);
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subbands[i] = aptx_qmf_convolution(&signal[i], coeffs[i], shift);
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}
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*low_subband_output = av_clip_intp2(subbands[0] + subbands[1], 23);
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*high_subband_output = av_clip_intp2(subbands[0] - subbands[1], 23);
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}
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/*
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* Two stage QMF analysis tree.
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* Split 4 input samples into 4 subbands and downsample by 4.
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* So for each group of 4 samples that goes in, one sample goes out,
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* split into 4 separate subbands.
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*/
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static void aptx_qmf_tree_analysis(QMFAnalysis *qmf,
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int32_t samples[4],
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int32_t subband_samples[4])
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{
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int32_t intermediate_samples[4];
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int i;
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/* Split 4 input samples into 2 intermediate subbands downsampled to 2 samples */
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for (i = 0; i < 2; i++)
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aptx_qmf_polyphase_analysis(qmf->outer_filter_signal,
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aptx_qmf_outer_coeffs, 23,
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&samples[2*i],
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&intermediate_samples[0+i],
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&intermediate_samples[2+i]);
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/* Split 2 intermediate subband samples into 4 final subbands downsampled to 1 sample */
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for (i = 0; i < 2; i++)
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aptx_qmf_polyphase_analysis(qmf->inner_filter_signal[i],
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aptx_qmf_inner_coeffs, 23,
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&intermediate_samples[2*i],
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&subband_samples[2*i+0],
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&subband_samples[2*i+1]);
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}
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av_always_inline
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static int32_t aptx_bin_search(int32_t value, int32_t factor,
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const int32_t *intervals, int32_t nb_intervals)
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{
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int32_t idx = 0;
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int i;
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for (i = nb_intervals >> 1; i > 0; i >>= 1)
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if (MUL64(factor, intervals[idx + i]) <= ((int64_t)value << 24))
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idx += i;
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return idx;
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}
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static void aptx_quantize_difference(Quantize *quantize,
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int32_t sample_difference,
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int32_t dither,
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int32_t quantization_factor,
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ConstTables *tables)
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{
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const int32_t *intervals = tables->quantize_intervals;
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int32_t quantized_sample, dithered_sample, parity_change;
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int32_t d, mean, interval, inv, sample_difference_abs;
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int64_t error;
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sample_difference_abs = FFABS(sample_difference);
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sample_difference_abs = FFMIN(sample_difference_abs, (1 << 23) - 1);
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quantized_sample = aptx_bin_search(sample_difference_abs >> 4,
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quantization_factor,
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intervals, tables->tables_size);
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d = rshift32_clip24(MULH(dither, dither), 7) - (1 << 23);
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d = rshift64(MUL64(d, tables->quantize_dither_factors[quantized_sample]), 23);
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intervals += quantized_sample;
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mean = (intervals[1] + intervals[0]) / 2;
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interval = (intervals[1] - intervals[0]) * (-(sample_difference < 0) | 1);
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dithered_sample = rshift64_clip24(MUL64(dither, interval) + ((int64_t)av_clip_intp2(mean + d, 23) << 32), 32);
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error = ((int64_t)sample_difference_abs << 20) - MUL64(dithered_sample, quantization_factor);
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quantize->error = FFABS(rshift64(error, 23));
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parity_change = quantized_sample;
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if (error < 0)
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quantized_sample--;
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else
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parity_change--;
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inv = -(sample_difference < 0);
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quantize->quantized_sample = quantized_sample ^ inv;
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quantize->quantized_sample_parity_change = parity_change ^ inv;
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}
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static void aptx_encode_channel(Channel *channel, int32_t samples[4], int hd)
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{
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int32_t subband_samples[4];
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int subband;
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aptx_qmf_tree_analysis(&channel->qmf, samples, subband_samples);
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ff_aptx_generate_dither(channel);
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for (subband = 0; subband < NB_SUBBANDS; subband++) {
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int32_t diff = av_clip_intp2(subband_samples[subband] - channel->prediction[subband].predicted_sample, 23);
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aptx_quantize_difference(&channel->quantize[subband], diff,
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channel->dither[subband],
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channel->invert_quantize[subband].quantization_factor,
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&ff_aptx_quant_tables[hd][subband]);
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}
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}
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static void aptx_insert_sync(Channel channels[NB_CHANNELS], int32_t *idx)
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{
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if (aptx_check_parity(channels, idx)) {
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int i;
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Channel *c;
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static const int map[] = { 1, 2, 0, 3 };
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Quantize *min = &channels[NB_CHANNELS-1].quantize[map[0]];
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for (c = &channels[NB_CHANNELS-1]; c >= channels; c--)
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for (i = 0; i < NB_SUBBANDS; i++)
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if (c->quantize[map[i]].error < min->error)
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min = &c->quantize[map[i]];
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/* Forcing the desired parity is done by offsetting by 1 the quantized
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* sample from the subband featuring the smallest quantization error. */
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min->quantized_sample = min->quantized_sample_parity_change;
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}
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}
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static uint16_t aptx_pack_codeword(Channel *channel)
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{
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int32_t parity = aptx_quantized_parity(channel);
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return (((channel->quantize[3].quantized_sample & 0x06) | parity) << 13)
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| (((channel->quantize[2].quantized_sample & 0x03) ) << 11)
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| (((channel->quantize[1].quantized_sample & 0x0F) ) << 7)
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| (((channel->quantize[0].quantized_sample & 0x7F) ) << 0);
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}
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static uint32_t aptxhd_pack_codeword(Channel *channel)
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{
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int32_t parity = aptx_quantized_parity(channel);
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return (((channel->quantize[3].quantized_sample & 0x01E) | parity) << 19)
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| (((channel->quantize[2].quantized_sample & 0x00F) ) << 15)
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| (((channel->quantize[1].quantized_sample & 0x03F) ) << 9)
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| (((channel->quantize[0].quantized_sample & 0x1FF) ) << 0);
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}
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static void aptx_encode_samples(AptXContext *ctx,
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int32_t samples[NB_CHANNELS][4],
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uint8_t *output)
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{
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int channel;
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for (channel = 0; channel < NB_CHANNELS; channel++)
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aptx_encode_channel(&ctx->channels[channel], samples[channel], ctx->hd);
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aptx_insert_sync(ctx->channels, &ctx->sync_idx);
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for (channel = 0; channel < NB_CHANNELS; channel++) {
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ff_aptx_invert_quantize_and_prediction(&ctx->channels[channel], ctx->hd);
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if (ctx->hd)
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AV_WB24(output + 3*channel,
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aptxhd_pack_codeword(&ctx->channels[channel]));
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else
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AV_WB16(output + 2*channel,
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aptx_pack_codeword(&ctx->channels[channel]));
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}
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}
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static int aptx_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
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const AVFrame *frame, int *got_packet_ptr)
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{
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AptXEncContext *const s0 = avctx->priv_data;
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AptXContext *const s = &s0->common;
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int pos, ipos, channel, sample, output_size, ret;
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if ((ret = ff_af_queue_add(&s0->afq, frame)) < 0)
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return ret;
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output_size = s->block_size * frame->nb_samples/4;
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if ((ret = ff_get_encode_buffer(avctx, avpkt, output_size, 0)) < 0)
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return ret;
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for (pos = 0, ipos = 0; pos < output_size; pos += s->block_size, ipos += 4) {
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int32_t samples[NB_CHANNELS][4];
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for (channel = 0; channel < NB_CHANNELS; channel++)
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for (sample = 0; sample < 4; sample++)
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samples[channel][sample] = (int32_t)AV_RN32A(&frame->data[channel][4*(ipos+sample)]) >> 8;
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aptx_encode_samples(s, samples, avpkt->data + pos);
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}
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ff_af_queue_remove(&s0->afq, frame->nb_samples, &avpkt->pts, &avpkt->duration);
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*got_packet_ptr = 1;
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return 0;
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}
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static av_cold int aptx_close(AVCodecContext *avctx)
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{
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AptXEncContext *const s = avctx->priv_data;
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ff_af_queue_close(&s->afq);
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return 0;
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}
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static av_cold int aptx_encode_init(AVCodecContext *avctx)
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{
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AptXEncContext *const s = avctx->priv_data;
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ff_af_queue_init(avctx, &s->afq);
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if (!avctx->frame_size || avctx->frame_size % 4)
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avctx->frame_size = 1024;
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return ff_aptx_init(avctx);
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}
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#if CONFIG_APTX_ENCODER
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const FFCodec ff_aptx_encoder = {
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.p.name = "aptx",
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CODEC_LONG_NAME("aptX (Audio Processing Technology for Bluetooth)"),
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.p.type = AVMEDIA_TYPE_AUDIO,
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.p.id = AV_CODEC_ID_APTX,
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.p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_SMALL_LAST_FRAME,
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.priv_data_size = sizeof(AptXEncContext),
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.init = aptx_encode_init,
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FF_CODEC_ENCODE_CB(aptx_encode_frame),
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.close = aptx_close,
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#if FF_API_OLD_CHANNEL_LAYOUT
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.p.channel_layouts = (const uint64_t[]) { AV_CH_LAYOUT_STEREO, 0},
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#endif
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.p.ch_layouts = (const AVChannelLayout[]) { AV_CHANNEL_LAYOUT_STEREO, { 0 } },
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.p.sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S32P,
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AV_SAMPLE_FMT_NONE },
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.p.supported_samplerates = (const int[]) {8000, 16000, 24000, 32000, 44100, 48000, 0},
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};
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#endif
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#if CONFIG_APTX_HD_ENCODER
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const FFCodec ff_aptx_hd_encoder = {
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.p.name = "aptx_hd",
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CODEC_LONG_NAME("aptX HD (Audio Processing Technology for Bluetooth)"),
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.p.type = AVMEDIA_TYPE_AUDIO,
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.p.id = AV_CODEC_ID_APTX_HD,
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.p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_SMALL_LAST_FRAME,
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.priv_data_size = sizeof(AptXEncContext),
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.init = aptx_encode_init,
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FF_CODEC_ENCODE_CB(aptx_encode_frame),
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.close = aptx_close,
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#if FF_API_OLD_CHANNEL_LAYOUT
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.p.channel_layouts = (const uint64_t[]) { AV_CH_LAYOUT_STEREO, 0},
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#endif
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.p.ch_layouts = (const AVChannelLayout[]) { AV_CHANNEL_LAYOUT_STEREO, { 0 } },
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.p.sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S32P,
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AV_SAMPLE_FMT_NONE },
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.p.supported_samplerates = (const int[]) {8000, 16000, 24000, 32000, 44100, 48000, 0},
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};
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#endif
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