xref: /btstack/src/classic/hfp_codec.c (revision 0a4f399a9d2305b59c2c6b8e6c36b1618bf00571)
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 void hfp_codec_init_msbc(hfp_codec_t * hfp_codec, btstack_sbc_encoder_state_t * msbc_encoder_context){
90     memset(hfp_codec, 0, sizeof(hfp_codec_t));
91     hfp_h2_framing_init(&hfp_codec->h2_framing);
92     hfp_codec->samples_per_frame = 120;
93     hfp_codec->encode = &hfp_codec_encode_msbc;
94     hfp_codec->msbc_encoder_context = msbc_encoder_context;
95     btstack_sbc_encoder_init(hfp_codec->msbc_encoder_context, SBC_MODE_mSBC, 16, 8, SBC_ALLOCATION_METHOD_LOUDNESS, 16000, 26, SBC_CHANNEL_MODE_MONO);
96 }
97 
98 void hfp_codec_init_lc3_swb(hfp_codec_t * hfp_codec, const btstack_lc3_encoder_t * lc3_encoder, void * lc3_encoder_context){
99     memset(hfp_codec, 0, sizeof(hfp_codec_t));
100     hfp_h2_framing_init(&hfp_codec->h2_framing);
101     hfp_codec->samples_per_frame = 240;
102     hfp_codec->encode = &hfp_codec_encode_lc3swb;
103     // init lc3 encoder
104     hfp_codec->lc3_encoder = lc3_encoder;
105     hfp_codec->lc3_encoder_context = lc3_encoder_context;
106     hfp_codec->lc3_encoder->configure(&hfp_codec->lc3_encoder_context, 32000, BTSTACK_LC3_FRAME_DURATION_7500US, LC3_SWB_OCTETS_PER_FRAME);
107 }
108 
109 bool hfp_codec_can_encode_audio_frame_now(const hfp_codec_t * hfp_codec){
110     return hfp_codec->write_pos <= SCO_FRAME_SIZE;
111 }
112 
113 uint16_t hfp_codec_num_audio_samples_per_frame(const hfp_codec_t * hfp_codec){
114     return hfp_codec->samples_per_frame;
115 }
116 
117 #ifdef ENABLE_HFP_WIDE_BAND_SPEECH
118 static void hfp_codec_encode_msbc(hfp_codec_t * hfp_codec, int16_t * pcm_samples){
119     // Encode SBC Frame
120     btstack_sbc_encoder_process_data(pcm_samples);
121     (void)memcpy(&hfp_codec->sco_packet[hfp_codec->write_pos], btstack_sbc_encoder_sbc_buffer(), FRAME_SIZE_MSBC);
122     hfp_codec->write_pos += FRAME_SIZE_MSBC;
123     // Final padding to use SCO_FRAME_SIZE bytes
124     hfp_codec->sco_packet[hfp_codec->write_pos++] = 0;
125 }
126 #endif
127 
128 #ifdef ENABLE_HFP_SUPER_WIDE_BAND_SPEECH
129 static void hfp_codec_encode_lc3swb(hfp_codec_t * hfp_codec, int16_t * pcm_samples){
130     // Encode LC3 Frame
131     hfp_codec->lc3_encoder->encode_signed_16(&hfp_codec->lc3_encoder_context, pcm_samples, 1, &hfp_codec->sco_packet[hfp_codec->write_pos]);
132     hfp_codec->write_pos += LC3_SWB_OCTETS_PER_FRAME;
133 }
134 #endif
135 
136 void hfp_codec_encode_audio_frame(hfp_codec_t * hfp_codec, int16_t * pcm_samples){
137     btstack_assert(hfp_codec_can_encode_audio_frame_now(hfp_codec));
138     // Synchronization Header H2
139     hfp_h2_framing_add_header(&hfp_codec->h2_framing, &hfp_codec->sco_packet[hfp_codec->write_pos]);
140     hfp_codec->write_pos += 2;
141     // encode
142 #ifdef HFP_CODEC_TEST
143     // packet counter
144     static uint8_t counter = 0;
145     hfp_codec->sco_packet[hfp_codec->write_pos++] = counter++;
146     // test data
147     uint8_t i;
148     for (i=3;i<SCO_FRAME_SIZE;i++){
149         hfp_codec->sco_packet[hfp_codec->write_pos++] = i;
150     }
151 #else
152     hfp_codec->encode(hfp_codec, pcm_samples);
153 #endif
154     log_info("Encode frame, read %u, write %u", hfp_codec->read_pos, hfp_codec->write_pos);
155 }
156 
157 uint16_t hfp_codec_num_bytes_available(const hfp_codec_t * hfp_codec){
158     return hfp_codec->write_pos - hfp_codec->read_pos;
159 }
160 
161 void hfp_codec_read_from_stream(hfp_codec_t * hfp_codec, uint8_t * buf, uint16_t size){
162     uint16_t num_bytes_available = hfp_codec_num_bytes_available(hfp_codec);
163     btstack_assert(num_bytes_available >= size);
164 
165     uint16_t num_bytes_to_copy = btstack_min(num_bytes_available, size);
166 
167     memcpy(buf, &hfp_codec->sco_packet[hfp_codec->read_pos], num_bytes_to_copy);
168     hfp_codec->read_pos += num_bytes_to_copy;
169 
170     // reset buffer
171     if (hfp_codec->read_pos == hfp_codec->write_pos){
172         hfp_codec->read_pos = 0;
173         hfp_codec->write_pos = 0;
174     }
175 
176     log_info("Read %u from stream, read %u, write %u", size, hfp_codec->read_pos, hfp_codec->write_pos);
177 }
178 
179 void hfp_codec_deinit(hfp_codec_t * hfp_codec){
180     UNUSED(hfp_codec);
181 }
182