xref: /btstack/src/classic/hfp_codec.c (revision 08a78038ba366a6a2a2df8fea05d5123880fdff2)
1 /*
2  * Copyright (C) 2023 BlueKitchen GmbH
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the copyright holders nor the names of
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  * 4. Any redistribution, use, or modification is done solely for
17  *    personal benefit and not for any commercial purpose or for
18  *    monetary gain.
19  *
20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL BLUEKITCHEN
24  * GMBH OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * Please inquire about commercial licensing options at
34  * [email protected]
35  *
36  */
37 
38 #define BTSTACK_FILE__ "hfp_codec.c"
39 
40 // *****************************************************************************
41 //
42 // HFP Codec
43 //
44 // *****************************************************************************
45 
46 #include "btstack_config.h"
47 
48 #include <string.h>
49 
50 #include "hfp_codec.h"
51 #include "btstack_debug.h"
52 
53 // enable to send test data
54 // #define HFP_CODEC_TEST
55 
56 #ifdef ENABLE_HFP_WIDE_BAND_SPEECH
57 #include "btstack_sbc.h"
58 #define FRAME_SIZE_MSBC 57
59 static void hfp_codec_encode_msbc(hfp_codec_t * hfp_codec, int16_t * pcm_samples);
60 #endif
61 
62 #ifdef ENABLE_HFP_SUPER_WIDE_BAND_SPEECH
63 #define LC3_SWB_OCTETS_PER_FRAME   58
64 static void hfp_codec_encode_lc3swb(hfp_codec_t * hfp_codec, int16_t * pcm_samples);
65 #endif
66 
67 // HFP H2 Framing - might get moved into a hfp_h2.c
68 
69 // const
70 static const uint8_t hfp_h2_header_h2_byte_0         = 1;
71 static const uint8_t hfp_h2_header_h2_byte_1_table[] = {0x08, 0x38, 0xc8, 0xf8 };
72 
73 void hfp_h2_framing_init(hfp_h2_framing_t * hfp_h2_framing){
74     hfp_h2_framing->sequence_number = 0;
75 }
76 
77 /**
78  * @brief Add next H2 Header
79  * @param hfp_h2_framing
80  * @param buffer [2]
81  */
82 void hfp_h2_framing_add_header(hfp_h2_framing_t * hfp_h2_framing, uint8_t * buffer){
83     // Synchronization Header H2
84     buffer[0] = hfp_h2_header_h2_byte_0;
85     buffer[1] = hfp_h2_header_h2_byte_1_table[hfp_h2_framing->sequence_number];
86     hfp_h2_framing->sequence_number = (hfp_h2_framing->sequence_number + 1) & 3;
87 }
88 
89 static void hfp_codec_reset_sco_buffer(hfp_codec_t *hfp_codec) {
90     hfp_codec->read_pos = 0;
91     hfp_codec->write_pos = 0;
92 }
93 
94 #ifdef ENABLE_HFP_WIDE_BAND_SPEECH
95 void hfp_codec_init_msbc(hfp_codec_t * hfp_codec, btstack_sbc_encoder_state_t * msbc_encoder_context){
96     memset(hfp_codec, 0, sizeof(hfp_codec_t));
97     hfp_h2_framing_init(&hfp_codec->h2_framing);
98     hfp_codec_reset_sco_buffer(hfp_codec);
99     hfp_codec->samples_per_frame = 120;
100     hfp_codec->encode = &hfp_codec_encode_msbc;
101     hfp_codec->msbc_encoder_context = msbc_encoder_context;
102     btstack_sbc_encoder_init(hfp_codec->msbc_encoder_context, SBC_MODE_mSBC, 16, 8, SBC_ALLOCATION_METHOD_LOUDNESS, 16000, 26, SBC_CHANNEL_MODE_MONO);
103 }
104 #endif
105 
106 #ifdef ENABLE_HFP_SUPER_WIDE_BAND_SPEECH
107 void hfp_codec_init_lc3_swb(hfp_codec_t * hfp_codec, const btstack_lc3_encoder_t * lc3_encoder, void * lc3_encoder_context){
108     memset(hfp_codec, 0, sizeof(hfp_codec_t));
109     hfp_h2_framing_init(&hfp_codec->h2_framing);
110     hfp_codec_reset_sco_buffer(hfp_codec);
111     hfp_codec->samples_per_frame = 240;
112     hfp_codec->encode = &hfp_codec_encode_lc3swb;
113     // init lc3 encoder
114     hfp_codec->lc3_encoder = lc3_encoder;
115     hfp_codec->lc3_encoder_context = lc3_encoder_context;
116     hfp_codec->lc3_encoder->configure(hfp_codec->lc3_encoder_context, 32000, BTSTACK_LC3_FRAME_DURATION_7500US, LC3_SWB_OCTETS_PER_FRAME);
117 }
118 #endif
119 
120 bool hfp_codec_can_encode_audio_frame_now(const hfp_codec_t * hfp_codec){
121     return hfp_codec->write_pos <= SCO_FRAME_SIZE;
122 }
123 
124 uint16_t hfp_codec_num_audio_samples_per_frame(const hfp_codec_t * hfp_codec){
125     return hfp_codec->samples_per_frame;
126 }
127 
128 #ifdef ENABLE_HFP_WIDE_BAND_SPEECH
129 static void hfp_codec_encode_msbc(hfp_codec_t * hfp_codec, int16_t * pcm_samples){
130     // Encode SBC Frame
131     btstack_sbc_encoder_process_data(pcm_samples);
132     (void)memcpy(&hfp_codec->sco_packet[hfp_codec->write_pos], btstack_sbc_encoder_sbc_buffer(), FRAME_SIZE_MSBC);
133     hfp_codec->write_pos += FRAME_SIZE_MSBC;
134     // Final padding to use SCO_FRAME_SIZE bytes
135     hfp_codec->sco_packet[hfp_codec->write_pos++] = 0;
136 }
137 #endif
138 
139 #ifdef ENABLE_HFP_SUPER_WIDE_BAND_SPEECH
140 static void hfp_codec_encode_lc3swb(hfp_codec_t * hfp_codec, int16_t * pcm_samples){
141     // Encode LC3 Frame
142     hfp_codec->lc3_encoder->encode_signed_16(hfp_codec->lc3_encoder_context, pcm_samples, 1, &hfp_codec->sco_packet[hfp_codec->write_pos]);
143     hfp_codec->write_pos += LC3_SWB_OCTETS_PER_FRAME;
144 }
145 #endif
146 
147 void hfp_codec_encode_audio_frame(hfp_codec_t * hfp_codec, int16_t * pcm_samples){
148     btstack_assert(hfp_codec_can_encode_audio_frame_now(hfp_codec));
149     // Synchronization Header H2
150     hfp_h2_framing_add_header(&hfp_codec->h2_framing, &hfp_codec->sco_packet[hfp_codec->write_pos]);
151     hfp_codec->write_pos += 2;
152     // encode
153 #ifdef HFP_CODEC_TEST
154     // packet counter
155     static uint8_t counter = 0;
156     hfp_codec->sco_packet[hfp_codec->write_pos++] = counter++;
157     // test data
158     uint8_t i;
159     for (i=3;i<SCO_FRAME_SIZE;i++){
160         hfp_codec->sco_packet[hfp_codec->write_pos++] = i;
161     }
162 #else
163     hfp_codec->encode(hfp_codec, pcm_samples);
164 #endif
165     log_debug("Encode frame, read %u, write %u", hfp_codec->read_pos, hfp_codec->write_pos);
166 }
167 
168 uint16_t hfp_codec_num_bytes_available(const hfp_codec_t * hfp_codec){
169     return hfp_codec->write_pos - hfp_codec->read_pos;
170 }
171 
172 void hfp_codec_read_from_stream(hfp_codec_t * hfp_codec, uint8_t * buf, uint16_t size){
173     uint16_t num_bytes_available = hfp_codec_num_bytes_available(hfp_codec);
174     btstack_assert(num_bytes_available >= size);
175 
176     uint16_t num_bytes_to_copy = btstack_min(num_bytes_available, size);
177 
178     memcpy(buf, &hfp_codec->sco_packet[hfp_codec->read_pos], num_bytes_to_copy);
179     hfp_codec->read_pos += num_bytes_to_copy;
180 
181     // reset buffer
182     if (hfp_codec->read_pos == hfp_codec->write_pos){
183         hfp_codec_reset_sco_buffer(hfp_codec);
184     }
185 
186     log_debug("Read %u from stream, read %u, write %u", size, hfp_codec->read_pos, hfp_codec->write_pos);
187 }
188 
189 void hfp_codec_deinit(hfp_codec_t * hfp_codec){
190     UNUSED(hfp_codec);
191 }
192