xref: /btstack/src/classic/hfp_msbc.c (revision 5b4ff0f76de63bc37890a49a94815f4f09ac38e3)
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
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7  *
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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
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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 MATTHIAS
24  * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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36  */
37 
38 // *****************************************************************************
39 //
40 // HFP mSBC encoder wrapper
41 //
42 // *****************************************************************************
43 
44 #include "btstack_config.h"
45 
46 #include <string.h>
47 
48 #include "btstack_debug.h"
49 #include "btstack_sbc_encoder.h"
50 #include "hfp_msbc.h"
51 
52 #define MSBC_FRAME_SIZE 57
53 
54 static btstack_sbc_encoder_state_t state;
55 static uint8_t msbc_padding[] = {0,0,0};
56 
57 static uint8_t msbc_buffer[2*(MSBC_FRAME_SIZE + sizeof(msbc_padding))];
58 static int msbc_buffer_offset = 0;
59 
60 void hfp_msbc_init(void){
61     btstack_sbc_encoder_init(&state, SBC_MODE_mSBC, 16, 8, 0, 16000, 26);
62     msbc_buffer_offset = 0;
63 }
64 
65 int hfp_msbc_can_encode_audio_frame_now(void){
66     return sizeof(msbc_buffer) - msbc_buffer_offset >= MSBC_FRAME_SIZE + sizeof(msbc_padding);
67 }
68 
69 void hfp_msbc_encode_audio_frame(int16_t * pcm_samples){
70     if (!hfp_msbc_can_encode_audio_frame_now()) return;
71 
72     btstack_sbc_encoder_process_data(pcm_samples);
73 
74     memcpy(msbc_buffer + msbc_buffer_offset, msbc_padding, sizeof(msbc_padding));
75     msbc_buffer_offset += sizeof(msbc_padding);
76 
77     memcpy(msbc_buffer + msbc_buffer_offset, btstack_sbc_encoder_sbc_buffer(), MSBC_FRAME_SIZE);
78     msbc_buffer_offset += MSBC_FRAME_SIZE;
79 }
80 
81 void hfp_msbc_read_from_stream(uint8_t * buf, int size){
82     int bytes_to_copy = size;
83     if (size > msbc_buffer_offset){
84         bytes_to_copy = msbc_buffer_offset;
85         log_error("sbc frame storage is smaller then the output buffer");
86         return;
87     }
88 
89     memcpy(buf, msbc_buffer, bytes_to_copy);
90     memmove(msbc_buffer, msbc_buffer + bytes_to_copy, sizeof(msbc_buffer) - bytes_to_copy);
91     msbc_buffer_offset -= bytes_to_copy;
92 }
93 
94 int hfp_msbc_num_bytes_in_stream(void){
95     return msbc_buffer_offset;
96 }
97 
98 int hfp_msbc_num_audio_samples_per_frame(void){
99     return btstack_sbc_encoder_num_audio_samples();
100 }
101 
102 
103