1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
|
/*
* Audio Processing Technology codec for Bluetooth (aptX)
*
* Copyright (C) 2017 Aurelien Jacobs <aurel@gnuage.org>
*
* 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 "config_components.h"
#include "libavutil/channel_layout.h"
#include "aptx.h"
#include "codec_internal.h"
#include "internal.h"
/*
* Half-band QMF synthesis filter realized with a polyphase FIR filter.
* Join 2 subbands and upsample by 2.
* So for each 2 subbands sample that goes in, a pair of samples goes out.
*/
av_always_inline
static void aptx_qmf_polyphase_synthesis(FilterSignal signal[NB_FILTERS],
const int32_t coeffs[NB_FILTERS][FILTER_TAPS],
int shift,
int32_t low_subband_input,
int32_t high_subband_input,
int32_t samples[NB_FILTERS])
{
int32_t subbands[NB_FILTERS];
int i;
subbands[0] = low_subband_input + high_subband_input;
subbands[1] = low_subband_input - high_subband_input;
for (i = 0; i < NB_FILTERS; i++) {
aptx_qmf_filter_signal_push(&signal[i], subbands[1-i]);
samples[i] = aptx_qmf_convolution(&signal[i], coeffs[i], shift);
}
}
/*
* Two stage QMF synthesis tree.
* Join 4 subbands and upsample by 4.
* So for each 4 subbands sample that goes in, a group of 4 samples goes out.
*/
static void aptx_qmf_tree_synthesis(QMFAnalysis *qmf,
int32_t subband_samples[4],
int32_t samples[4])
{
int32_t intermediate_samples[4];
int i;
/* Join 4 subbands into 2 intermediate subbands upsampled to 2 samples. */
for (i = 0; i < 2; i++)
aptx_qmf_polyphase_synthesis(qmf->inner_filter_signal[i],
aptx_qmf_inner_coeffs, 22,
subband_samples[2*i+0],
subband_samples[2*i+1],
&intermediate_samples[2*i]);
/* Join 2 samples from intermediate subbands upsampled to 4 samples. */
for (i = 0; i < 2; i++)
aptx_qmf_polyphase_synthesis(qmf->outer_filter_signal,
aptx_qmf_outer_coeffs, 21,
intermediate_samples[0+i],
intermediate_samples[2+i],
&samples[2*i]);
}
static void aptx_decode_channel(Channel *channel, int32_t samples[4])
{
int32_t subband_samples[4];
int subband;
for (subband = 0; subband < NB_SUBBANDS; subband++)
subband_samples[subband] = channel->prediction[subband].previous_reconstructed_sample;
aptx_qmf_tree_synthesis(&channel->qmf, subband_samples, samples);
}
static void aptx_unpack_codeword(Channel *channel, uint16_t codeword)
{
channel->quantize[0].quantized_sample = sign_extend(codeword >> 0, 7);
channel->quantize[1].quantized_sample = sign_extend(codeword >> 7, 4);
channel->quantize[2].quantized_sample = sign_extend(codeword >> 11, 2);
channel->quantize[3].quantized_sample = sign_extend(codeword >> 13, 3);
channel->quantize[3].quantized_sample = (channel->quantize[3].quantized_sample & ~1)
| aptx_quantized_parity(channel);
}
static void aptxhd_unpack_codeword(Channel *channel, uint32_t codeword)
{
channel->quantize[0].quantized_sample = sign_extend(codeword >> 0, 9);
channel->quantize[1].quantized_sample = sign_extend(codeword >> 9, 6);
channel->quantize[2].quantized_sample = sign_extend(codeword >> 15, 4);
channel->quantize[3].quantized_sample = sign_extend(codeword >> 19, 5);
channel->quantize[3].quantized_sample = (channel->quantize[3].quantized_sample & ~1)
| aptx_quantized_parity(channel);
}
static int aptx_decode_samples(AptXContext *ctx,
const uint8_t *input,
int32_t samples[NB_CHANNELS][4])
{
int channel, ret;
for (channel = 0; channel < NB_CHANNELS; channel++) {
ff_aptx_generate_dither(&ctx->channels[channel]);
if (ctx->hd)
aptxhd_unpack_codeword(&ctx->channels[channel],
AV_RB24(input + 3*channel));
else
aptx_unpack_codeword(&ctx->channels[channel],
AV_RB16(input + 2*channel));
ff_aptx_invert_quantize_and_prediction(&ctx->channels[channel], ctx->hd);
}
ret = aptx_check_parity(ctx->channels, &ctx->sync_idx);
for (channel = 0; channel < NB_CHANNELS; channel++)
aptx_decode_channel(&ctx->channels[channel], samples[channel]);
return ret;
}
static int aptx_decode_frame(AVCodecContext *avctx, void *data,
int *got_frame_ptr, AVPacket *avpkt)
{
AptXContext *s = avctx->priv_data;
AVFrame *frame = data;
int pos, opos, channel, sample, ret;
if (avpkt->size < s->block_size) {
av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
return AVERROR_INVALIDDATA;
}
/* get output buffer */
frame->ch_layout.nb_channels = NB_CHANNELS;
frame->format = AV_SAMPLE_FMT_S32P;
frame->nb_samples = 4 * avpkt->size / s->block_size;
if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
return ret;
for (pos = 0, opos = 0; opos < frame->nb_samples; pos += s->block_size, opos += 4) {
int32_t samples[NB_CHANNELS][4];
if (aptx_decode_samples(s, &avpkt->data[pos], samples)) {
av_log(avctx, AV_LOG_ERROR, "Synchronization error\n");
return AVERROR_INVALIDDATA;
}
for (channel = 0; channel < NB_CHANNELS; channel++)
for (sample = 0; sample < 4; sample++)
AV_WN32A(&frame->data[channel][4*(opos+sample)],
samples[channel][sample] * 256);
}
*got_frame_ptr = 1;
return s->block_size * frame->nb_samples / 4;
}
#if CONFIG_APTX_DECODER
const FFCodec ff_aptx_decoder = {
.p.name = "aptx",
.p.long_name = NULL_IF_CONFIG_SMALL("aptX (Audio Processing Technology for Bluetooth)"),
.p.type = AVMEDIA_TYPE_AUDIO,
.p.id = AV_CODEC_ID_APTX,
.priv_data_size = sizeof(AptXContext),
.init = ff_aptx_init,
.decode = aptx_decode_frame,
.p.capabilities = AV_CODEC_CAP_DR1,
.caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
#if FF_API_OLD_CHANNEL_LAYOUT
.p.channel_layouts = (const uint64_t[]) { AV_CH_LAYOUT_STEREO, 0},
#endif
.p.ch_layouts = (const AVChannelLayout[]) { AV_CHANNEL_LAYOUT_STEREO, { 0 } },
.p.sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S32P,
AV_SAMPLE_FMT_NONE },
};
#endif
#if CONFIG_APTX_HD_DECODER
const FFCodec ff_aptx_hd_decoder = {
.p.name = "aptx_hd",
.p.long_name = NULL_IF_CONFIG_SMALL("aptX HD (Audio Processing Technology for Bluetooth)"),
.p.type = AVMEDIA_TYPE_AUDIO,
.p.id = AV_CODEC_ID_APTX_HD,
.priv_data_size = sizeof(AptXContext),
.init = ff_aptx_init,
.decode = aptx_decode_frame,
.p.capabilities = AV_CODEC_CAP_DR1,
.caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
#if FF_API_OLD_CHANNEL_LAYOUT
.p.channel_layouts = (const uint64_t[]) { AV_CH_LAYOUT_STEREO, 0},
#endif
.p.ch_layouts = (const AVChannelLayout[]) { AV_CHANNEL_LAYOUT_STEREO, { 0 } },
.p.sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S32P,
AV_SAMPLE_FMT_NONE },
};
#endif
|
