1 /*
2 * Copyright (C) 2023 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #define LOG_TAG "hfp_lc3_decoder"
18
19 #include <bluetooth/log.h>
20
21 #include <algorithm>
22
23 #include "hfp_lc3_decoder.h"
24 #include "mmc/codec_client/codec_client.h"
25 #include "mmc/proto/mmc_config.pb.h"
26
27 using namespace bluetooth;
28
29 const int HFP_LC3_H2_HEADER_LEN = 2;
30 const int HFP_LC3_PKT_FRAME_LEN = 58;
31 const int HFP_LC3_PCM_BYTES = 480;
32
33 static mmc::CodecClient* client = nullptr;
34 static const uint8_t plc_buf[HFP_LC3_H2_HEADER_LEN + HFP_LC3_PKT_FRAME_LEN] = {0};
35
hfp_lc3_decoder_init()36 bool hfp_lc3_decoder_init() {
37 hfp_lc3_decoder_cleanup();
38 client = new mmc::CodecClient;
39
40 const int dt_us = 7500;
41 const int sr_hz = 32000;
42 const int sr_pcm_hz = 32000;
43
44 mmc::Lc3Param param;
45 param.set_dt_us(dt_us);
46 param.set_sr_hz(sr_hz);
47 param.set_sr_pcm_hz(sr_pcm_hz);
48 param.set_stride(1);
49 param.set_fmt(mmc::Lc3Param::kLc3PcmFormatS16);
50
51 mmc::ConfigParam config;
52 *config.mutable_hfp_lc3_decoder_param() = param;
53
54 int ret = client->init(config);
55 if (ret < 0) {
56 log::error("Init failed with error message, {}", strerror(-ret));
57 return false;
58 }
59
60 return true;
61 }
62
hfp_lc3_decoder_cleanup()63 void hfp_lc3_decoder_cleanup() {
64 if (client) {
65 client->cleanup();
66 delete client;
67 client = nullptr;
68 }
69 }
70
hfp_lc3_decoder_decode_packet(const uint8_t * i_buf,int16_t * o_buf,size_t out_len)71 bool hfp_lc3_decoder_decode_packet(const uint8_t* i_buf, int16_t* o_buf, size_t out_len) {
72 if (o_buf == nullptr || out_len < HFP_LC3_PCM_BYTES) {
73 log::error("Output buffer size {} is less than LC3 frame size {}", out_len, HFP_LC3_PCM_BYTES);
74 return false;
75 }
76
77 if (!client) {
78 log::error("CodecClient has not been initialized");
79 return false;
80 }
81
82 // Pass zeros to MMC when i_buf is nullptr.
83 const uint8_t* frame = i_buf ? i_buf : plc_buf;
84
85 // One extra byte in the beginning to indicate whether PLC was conducted.
86 uint8_t* o_packet = new uint8_t[out_len + 1];
87
88 int rc = client->transcode((uint8_t*)frame, HFP_LC3_PKT_FRAME_LEN + HFP_LC3_H2_HEADER_LEN,
89 o_packet, out_len + 1);
90
91 if (rc < 0) {
92 log::warn("Decode failed with error message, {}", strerror(-rc));
93 return false;
94 }
95
96 bool plc_conducted = o_packet[0];
97
98 std::copy(o_packet + 1, o_packet + 1 + out_len, (uint8_t*)o_buf);
99
100 delete[] o_packet;
101 return !plc_conducted;
102 }
103