FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavcodec/aptxenc.c
Date: 2025-07-28 20:30:09
Exec Total Coverage
Lines: 109 111 98.2%
Functions: 12 12 100.0%
Branches: 39 44 88.6%
Line Branch Exec Source
1 /*
2 * Audio Processing Technology codec for Bluetooth (aptX)
3 *
4 * Copyright (C) 2017 Aurelien Jacobs <aurel@gnuage.org>
5 *
6 * This file is part of FFmpeg.
7 *
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23 #include "config_components.h"
24
25 #include "libavutil/channel_layout.h"
26 #include "aptx.h"
27 #include "audio_frame_queue.h"
28 #include "codec_internal.h"
29 #include "encode.h"
30 #include "internal.h"
31
32 typedef struct AptXEncContext {
33 AptXContext common;
34 AudioFrameQueue afq;
35 } AptXEncContext;
36
37 /*
38 * Half-band QMF analysis filter realized with a polyphase FIR filter.
39 * Split into 2 subbands and downsample by 2.
40 * So for each pair of samples that goes in, one sample goes out,
41 * split into 2 separate subbands.
42 */
43 av_always_inline
44 1675808 static void aptx_qmf_polyphase_analysis(FilterSignal signal[NB_FILTERS],
45 const int32_t coeffs[NB_FILTERS][FILTER_TAPS],
46 int shift,
47 int32_t samples[NB_FILTERS],
48 int32_t *low_subband_output,
49 int32_t *high_subband_output)
50 {
51 int32_t subbands[NB_FILTERS];
52 int i;
53
54
2/2
✓ Branch 0 taken 3351616 times.
✓ Branch 1 taken 1675808 times.
 5027424 for (i = 0; i < NB_FILTERS; i++) {
55 3351616 aptx_qmf_filter_signal_push(&signal[i], samples[NB_FILTERS-1-i]);
56 3351616 subbands[i] = aptx_qmf_convolution(&signal[i], coeffs[i], shift);
57 }
58
59 1675808 *low_subband_output = av_clip_intp2(subbands[0] + subbands[1], 23);
60 1675808 *high_subband_output = av_clip_intp2(subbands[0] - subbands[1], 23);
61 1675808 }
62
63 /*
64 * Two stage QMF analysis tree.
65 * Split 4 input samples into 4 subbands and downsample by 4.
66 * So for each group of 4 samples that goes in, one sample goes out,
67 * split into 4 separate subbands.
68 */
69 418952 static void aptx_qmf_tree_analysis(QMFAnalysis *qmf,
70 int32_t samples[4],
71 int32_t subband_samples[4])
72 {
73 int32_t intermediate_samples[4];
74 int i;
75
76 /* Split 4 input samples into 2 intermediate subbands downsampled to 2 samples */
77
2/2
✓ Branch 0 taken 837904 times.
✓ Branch 1 taken 418952 times.
 1256856 for (i = 0; i < 2; i++)
78 837904 aptx_qmf_polyphase_analysis(qmf->outer_filter_signal,
79 aptx_qmf_outer_coeffs, 23,
80 837904 &samples[2*i],
81 &intermediate_samples[0+i],
82 837904 &intermediate_samples[2+i]);
83
84 /* Split 2 intermediate subband samples into 4 final subbands downsampled to 1 sample */
85
2/2
✓ Branch 0 taken 837904 times.
✓ Branch 1 taken 418952 times.
 1256856 for (i = 0; i < 2; i++)
86 837904 aptx_qmf_polyphase_analysis(qmf->inner_filter_signal[i],
87 aptx_qmf_inner_coeffs, 23,
88 837904 &intermediate_samples[2*i],
89 837904 &subband_samples[2*i+0],
90 837904 &subband_samples[2*i+1]);
91 418952 }
92
93 av_always_inline
94 1675808 static int32_t aptx_bin_search(int32_t value, int32_t factor,
95 const int32_t *intervals, int32_t nb_intervals)
96 {
97 1675808 int32_t idx = 0;
98 int i;
99
100
2/2
✓ Branch 0 taken 6703232 times.
✓ Branch 1 taken 1675808 times.
 8379040 for (i = nb_intervals >> 1; i > 0; i >>= 1)
101
2/2
✓ Branch 0 taken 2573224 times.
✓ Branch 1 taken 4130008 times.
 6703232 if (MUL64(factor, intervals[idx + i]) <= ((int64_t)value << 24))
102 2573224 idx += i;
103
104 1675808 return idx;
105 }
106
107 1675808 static void aptx_quantize_difference(Quantize *quantize,
108 int32_t sample_difference,
109 int32_t dither,
110 int32_t quantization_factor,
111 ConstTables *tables)
112 {
113 1675808 const int32_t *intervals = tables->quantize_intervals;
114 int32_t quantized_sample, dithered_sample, parity_change;
115 int32_t d, mean, interval, inv, sample_difference_abs;
116 int64_t error;
117
118 1675808 sample_difference_abs = FFABS(sample_difference);
119 1675808 sample_difference_abs = FFMIN(sample_difference_abs, (1 << 23) - 1);
120
121 1675808 quantized_sample = aptx_bin_search(sample_difference_abs >> 4,
122 quantization_factor,
123 1675808 intervals, tables->tables_size);
124
125 1675808 d = rshift32_clip24(MULH(dither, dither), 7) - (1 << 23);
126 1675808 d = rshift64(MUL64(d, tables->quantize_dither_factors[quantized_sample]), 23);
127
128 1675808 intervals += quantized_sample;
129 1675808 mean = (intervals[1] + intervals[0]) / 2;
130 1675808 interval = (intervals[1] - intervals[0]) * (-(sample_difference < 0) | 1);
131
132 1675808 dithered_sample = rshift64_clip24(MUL64(dither, interval) + ((int64_t)av_clip_intp2(mean + d, 23) << 32), 32);
133 1675808 error = ((int64_t)sample_difference_abs << 20) - MUL64(dithered_sample, quantization_factor);
134
2/2
✓ Branch 1 taken 878803 times.
✓ Branch 2 taken 797005 times.
 1675808 quantize->error = FFABS(rshift64(error, 23));
135
136 1675808 parity_change = quantized_sample;
137
2/2
✓ Branch 0 taken 801351 times.
✓ Branch 1 taken 874457 times.
 1675808 if (error < 0)
138 801351 quantized_sample--;
139 else
140 874457 parity_change--;
141
142 1675808 inv = -(sample_difference < 0);
143 1675808 quantize->quantized_sample = quantized_sample ^ inv;
144 1675808 quantize->quantized_sample_parity_change = parity_change ^ inv;
145 1675808 }
146
147 418952 static void aptx_encode_channel(Channel *channel, int32_t samples[4], int hd)
148 {
149 int32_t subband_samples[4];
150 int subband;
151 418952 aptx_qmf_tree_analysis(&channel->qmf, samples, subband_samples);
152 418952 ff_aptx_generate_dither(channel);
153
2/2
✓ Branch 0 taken 1675808 times.
✓ Branch 1 taken 418952 times.
 2094760 for (subband = 0; subband < NB_SUBBANDS; subband++) {
154 1675808 int32_t diff = av_clip_intp2(subband_samples[subband] - channel->prediction[subband].predicted_sample, 23);
155 1675808 aptx_quantize_difference(&channel->quantize[subband], diff,
156 channel->dither[subband],
157 channel->invert_quantize[subband].quantization_factor,
158 &ff_aptx_quant_tables[hd][subband]);
159 }
160 418952 }
161
162 209476 static void aptx_insert_sync(Channel channels[NB_CHANNELS], int32_t *idx)
163 {
164
2/2
✓ Branch 1 taken 105071 times.
✓ Branch 2 taken 104405 times.
 209476 if (aptx_check_parity(channels, idx)) {
165 int i;
166 Channel *c;
167 static const int map[] = { 1, 2, 0, 3 };
168 105071 Quantize *min = &channels[NB_CHANNELS-1].quantize[map[0]];
169
2/2
✓ Branch 0 taken 210142 times.
✓ Branch 1 taken 105071 times.
 315213 for (c = &channels[NB_CHANNELS-1]; c >= channels; c--)
170
2/2
✓ Branch 0 taken 840568 times.
✓ Branch 1 taken 210142 times.
 1050710 for (i = 0; i < NB_SUBBANDS; i++)
171
2/2
✓ Branch 0 taken 199417 times.
✓ Branch 1 taken 641151 times.
 840568 if (c->quantize[map[i]].error < min->error)
172 199417 min = &c->quantize[map[i]];
173
174 /* Forcing the desired parity is done by offsetting by 1 the quantized
175 * sample from the subband featuring the smallest quantization error. */
176 105071 min->quantized_sample = min->quantized_sample_parity_change;
177 }
178 209476 }
179
180 209476 static uint16_t aptx_pack_codeword(Channel *channel)
181 {
182 209476 int32_t parity = aptx_quantized_parity(channel);
183 209476 return (((channel->quantize[3].quantized_sample & 0x06) | parity) << 13)
184 209476 | (((channel->quantize[2].quantized_sample & 0x03) ) << 11)
185 209476 | (((channel->quantize[1].quantized_sample & 0x0F) ) << 7)
186 209476 | (((channel->quantize[0].quantized_sample & 0x7F) ) << 0);
187 }
188
189 628428 static uint32_t aptxhd_pack_codeword(Channel *channel)
190 {
191 628428 int32_t parity = aptx_quantized_parity(channel);
192 628428 return (((channel->quantize[3].quantized_sample & 0x01E) | parity) << 19)
193 628428 | (((channel->quantize[2].quantized_sample & 0x00F) ) << 15)
194 628428 | (((channel->quantize[1].quantized_sample & 0x03F) ) << 9)
195 628428 | (((channel->quantize[0].quantized_sample & 0x1FF) ) << 0);
196 }
197
198 209476 static void aptx_encode_samples(AptXContext *ctx,
199 int32_t samples[NB_CHANNELS][4],
200 uint8_t *output)
201 {
202 int channel;
203
2/2
✓ Branch 0 taken 418952 times.
✓ Branch 1 taken 209476 times.
 628428 for (channel = 0; channel < NB_CHANNELS; channel++)
204 418952 aptx_encode_channel(&ctx->channels[channel], samples[channel], ctx->hd);
205
206 209476 aptx_insert_sync(ctx->channels, &ctx->sync_idx);
207
208
2/2
✓ Branch 0 taken 418952 times.
✓ Branch 1 taken 209476 times.
 628428 for (channel = 0; channel < NB_CHANNELS; channel++) {
209 418952 ff_aptx_invert_quantize_and_prediction(&ctx->channels[channel], ctx->hd);
210
2/2
✓ Branch 0 taken 209476 times.
✓ Branch 1 taken 209476 times.
 418952 if (ctx->hd)
211 209476 AV_WB24(output + 3*channel,
212 aptxhd_pack_codeword(&ctx->channels[channel]));
213 else
214 209476 AV_WB16(output + 2*channel,
215 aptx_pack_codeword(&ctx->channels[channel]));
216 }
217 209476 }
218
219 820 static int aptx_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
220 const AVFrame *frame, int *got_packet_ptr)
221 {
222 820 AptXEncContext *const s0 = avctx->priv_data;
223 820 AptXContext *const s = &s0->common;
224 int pos, ipos, channel, sample, output_size, ret;
225
226
1/2
✗ Branch 1 not taken.
✓ Branch 2 taken 820 times.
 820 if ((ret = ff_af_queue_add(&s0->afq, frame)) < 0)
227 ✗ return ret;
228
229 820 output_size = s->block_size * frame->nb_samples/4;
230
1/2
✗ Branch 1 not taken.
✓ Branch 2 taken 820 times.
 820 if ((ret = ff_get_encode_buffer(avctx, avpkt, output_size, 0)) < 0)
231 ✗ return ret;
232
233
2/2
✓ Branch 0 taken 209476 times.
✓ Branch 1 taken 820 times.
 210296 for (pos = 0, ipos = 0; pos < output_size; pos += s->block_size, ipos += 4) {
234 int32_t samples[NB_CHANNELS][4];
235
236
2/2
✓ Branch 0 taken 418952 times.
✓ Branch 1 taken 209476 times.
 628428 for (channel = 0; channel < NB_CHANNELS; channel++)
237
2/2
✓ Branch 0 taken 1675808 times.
✓ Branch 1 taken 418952 times.
 2094760 for (sample = 0; sample < 4; sample++)
238 1675808 samples[channel][sample] = (int32_t)AV_RN32A(&frame->data[channel][4*(ipos+sample)]) >> 8;
239
240 209476 aptx_encode_samples(s, samples, avpkt->data + pos);
241 }
242
243 820 ff_af_queue_remove(&s0->afq, frame->nb_samples, &avpkt->pts, &avpkt->duration);
244 820 *got_packet_ptr = 1;
245 820 return 0;
246 }
247
248 2 static av_cold int aptx_close(AVCodecContext *avctx)
249 {
250 2 AptXEncContext *const s = avctx->priv_data;
251 2 ff_af_queue_close(&s->afq);
252 2 return 0;
253 }
254
255 2 static av_cold int aptx_encode_init(AVCodecContext *avctx)
256 {
257 2 AptXEncContext *const s = avctx->priv_data;
258
259 2 ff_af_queue_init(avctx, &s->afq);
260
261
1/4
✗ Branch 0 not taken.
✓ Branch 1 taken 2 times.
✗ Branch 2 not taken.
✗ Branch 3 not taken.
 2 if (!avctx->frame_size || avctx->frame_size % 4)
262 2 avctx->frame_size = 1024;
263 2 avctx->internal->pad_samples = 4;
264
265 2 return ff_aptx_init(avctx);
266 }
267
268 #if CONFIG_APTX_ENCODER
269 const FFCodec ff_aptx_encoder = {
270 .p.name = "aptx",
271 CODEC_LONG_NAME("aptX (Audio Processing Technology for Bluetooth)"),
272 .p.type = AVMEDIA_TYPE_AUDIO,
273 .p.id = AV_CODEC_ID_APTX,
274 .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE,
275 .priv_data_size = sizeof(AptXEncContext),
276 .init = aptx_encode_init,
277 FF_CODEC_ENCODE_CB(aptx_encode_frame),
278 .close = aptx_close,
279 CODEC_CH_LAYOUTS(AV_CHANNEL_LAYOUT_STEREO),
280 CODEC_SAMPLEFMTS(AV_SAMPLE_FMT_S32P),
281 CODEC_SAMPLERATES(8000, 16000, 24000, 32000, 44100, 48000),
282 };
283 #endif
284
285 #if CONFIG_APTX_HD_ENCODER
286 const FFCodec ff_aptx_hd_encoder = {
287 .p.name = "aptx_hd",
288 CODEC_LONG_NAME("aptX HD (Audio Processing Technology for Bluetooth)"),
289 .p.type = AVMEDIA_TYPE_AUDIO,
290 .p.id = AV_CODEC_ID_APTX_HD,
291 .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE,
292 .priv_data_size = sizeof(AptXEncContext),
293 .init = aptx_encode_init,
294 FF_CODEC_ENCODE_CB(aptx_encode_frame),
295 .close = aptx_close,
296 CODEC_CH_LAYOUTS(AV_CHANNEL_LAYOUT_STEREO),
297 CODEC_SAMPLEFMTS(AV_SAMPLE_FMT_S32P),
298 CODEC_SAMPLERATES(8000, 16000, 24000, 32000, 44100, 48000),
299 };
300 #endif
301