1 /*
2 * Copyright (C) 2014 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_msbc.c"
39
40 // *****************************************************************************
41 //
42 // HFP mSBC encoder wrapper
43 //
44 // *****************************************************************************
45
46 #include "btstack_config.h"
47
48 #include <string.h>
49
50 #include "btstack_debug.h"
51 #include "btstack_sbc.h"
52 #include "hfp_msbc.h"
53
54 #define MSBC_FRAME_SIZE 57
55 #define MSBC_HEADER_H2_SIZE 2
56 #define MSBC_PADDING_SIZE 1
57 #define MSBC_EXTRA_SIZE (MSBC_HEADER_H2_SIZE + MSBC_PADDING_SIZE)
58
59 // const
60 static const uint8_t hfp_msbc_header_h2_byte_0 = 1;
61 static const uint8_t hfp_msbc_header_h2_byte_1_table[] = {0x08, 0x38, 0xc8, 0xf8 };
62
63 static btstack_sbc_encoder_state_t hfp_msbc_state;
64 static int hfp_msbc_msbc_sequence_number;
65
66 static uint8_t hfp_msbc_buffer[2 * (MSBC_FRAME_SIZE + MSBC_EXTRA_SIZE)];
67 static int hfp_msbc_buffer_offset = 0;
68
hfp_msbc_init(void)69 void hfp_msbc_init(void){
70 btstack_sbc_encoder_init(&hfp_msbc_state, SBC_MODE_mSBC, 16, 8, SBC_ALLOCATION_METHOD_LOUDNESS, 16000, 26, SBC_CHANNEL_MODE_MONO);
71 hfp_msbc_buffer_offset = 0;
72 hfp_msbc_msbc_sequence_number = 0;
73 }
74
hfp_msbc_deinit(void)75 void hfp_msbc_deinit(void){
76 (void) memset(&hfp_msbc_state, 0, sizeof(btstack_sbc_encoder_state_t));
77 hfp_msbc_msbc_sequence_number = 0;
78 hfp_msbc_buffer_offset = 0;
79 }
80
hfp_msbc_can_encode_audio_frame_now(void)81 int hfp_msbc_can_encode_audio_frame_now(void){
82 return (sizeof(hfp_msbc_buffer) - hfp_msbc_buffer_offset) >= (MSBC_FRAME_SIZE + MSBC_EXTRA_SIZE);
83 }
84
hfp_msbc_encode_audio_frame(int16_t * pcm_samples)85 void hfp_msbc_encode_audio_frame(int16_t * pcm_samples){
86 if (!hfp_msbc_can_encode_audio_frame_now()) return;
87
88 // Synchronization Header H2
89 hfp_msbc_buffer[hfp_msbc_buffer_offset++] = hfp_msbc_header_h2_byte_0;
90 hfp_msbc_buffer[hfp_msbc_buffer_offset++] = hfp_msbc_header_h2_byte_1_table[hfp_msbc_msbc_sequence_number];
91 hfp_msbc_msbc_sequence_number = (hfp_msbc_msbc_sequence_number + 1) & 3;
92
93 // SBC Frame
94 btstack_sbc_encoder_process_data(pcm_samples);
95 (void)memcpy(hfp_msbc_buffer + hfp_msbc_buffer_offset,
96 btstack_sbc_encoder_sbc_buffer(), MSBC_FRAME_SIZE);
97 hfp_msbc_buffer_offset += MSBC_FRAME_SIZE;
98
99 // Final padding to use 60 bytes for 120 audio samples
100 hfp_msbc_buffer[hfp_msbc_buffer_offset++] = 0;
101 }
102
hfp_msbc_read_from_stream(uint8_t * buf,int size)103 void hfp_msbc_read_from_stream(uint8_t * buf, int size){
104 int bytes_to_copy = size;
105 if (size > hfp_msbc_buffer_offset){
106 bytes_to_copy = hfp_msbc_buffer_offset;
107 log_error("sbc frame storage is smaller then the output buffer");
108 return;
109 }
110
111 (void)memcpy(buf, hfp_msbc_buffer, bytes_to_copy);
112 memmove(hfp_msbc_buffer, hfp_msbc_buffer + bytes_to_copy, sizeof(hfp_msbc_buffer) - bytes_to_copy);
113 hfp_msbc_buffer_offset -= bytes_to_copy;
114 }
115
hfp_msbc_num_bytes_in_stream(void)116 int hfp_msbc_num_bytes_in_stream(void){
117 return hfp_msbc_buffer_offset;
118 }
119
hfp_msbc_num_audio_samples_per_frame(void)120 int hfp_msbc_num_audio_samples_per_frame(void){
121 return btstack_sbc_encoder_num_audio_frames();
122 }
123
124
125