xref: /btstack/src/classic/hfp_codec.h (revision 16527ed542327730cc707f18a71eed1bb7446cd1)
1 /*
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37 
38 /**
39  * @title HFP Audio Encoder
40  * @brief Create SCO packet with H2 Synchronization Header and encoded audio samples
41  */
42 
43 #ifndef HFP_CODEC_H
44 #define HFP_CODEC_H
45 
46 #include "btstack_config.h"
47 #include "hfp.h"    // hfp_h2_framing
48 
49 #include <stdint.h>
50 
51 #ifdef ENABLE_HFP_WIDE_BAND_SPEECH
52 #include "btstack_sbc.h"
53 #endif
54 
55 #ifdef ENABLE_HFP_SUPER_WIDE_BAND_SPEECH
56 #include "btstack_lc3_google.h"
57 #endif
58 
59 #if defined __cplusplus
60 extern "C" {
61 #endif
62 
63 struct hfp_codec {
64     uint8_t sco_packet[60];
65     uint16_t read_pos;
66     uint16_t write_pos;
67     uint16_t samples_per_frame;
68     hfp_h2_framing_t h2_framing;
69     void (*encode)(struct hfp_codec * hfp_codec, int16_t * pcm_samples);
70 #ifdef ENABLE_HFP_WIDE_BAND_SPEECH
71     btstack_sbc_encoder_state_t msbc_state;
72 #endif
73 #ifdef ENABLE_HFP_SUPER_WIDE_BAND_SPEECH
74     const btstack_lc3_encoder_t * lc3_encoder;
75     btstack_lc3_encoder_google_t lc3_encoder_context;
76 #endif
77 };
78 
79 /* API_START */
80 
81 typedef struct hfp_codec hfp_codec_t;
82 
83 /**
84  * @brief Initialize HFP Audio Codec
85  * @note  btstack_assert if codec_id is not supported
86  * @param hfp_codec
87  * @param codec_id see HFP_CODEC_xxx in hfp.h
88  * @return status
89  */
90 void hfp_codec_init(hfp_codec_t * hfp_codec, uint8_t codec_id);
91 
92 /**
93  * @brief Get number of audio samples per HFP SCO frame
94  * @param hfp_codec
95  * @return num audio samples per 7.5ms SCO packet
96  */
97 uint16_t hfp_codec_num_audio_samples_per_frame(const hfp_codec_t * hfp_codec);
98 
99 /**
100  * @brief Checks if next frame can be encoded
101  * @param hfp_codec
102  */
103 bool hfp_codec_can_encode_audio_frame_now(const hfp_codec_t * hfp_codec);
104 
105 /**
106  * Get number of bytes ready for sending
107  * @param hfp_codec
108  * @return num bytes ready for current packet
109  */
110 uint16_t hfp_codec_num_bytes_available(const hfp_codec_t * hfp_codec);
111 
112 /**
113  * Encode audio samples for HFP SCO packet
114  * @param hfp_codec
115  * @param pcm_samples - complete audio frame of hfp_msbc_num_audio_samples_per_frame int16 samples
116  */
117 void hfp_codec_encode_audio_frame(hfp_codec_t * hfp_codec, int16_t * pcm_samples);
118 
119 /**
120  * Read from stream into SCO packet buffer
121  * @param hfp_codec
122  * @param buffer to store stream
123  * @param size num bytes to read from stream
124  */
125 void hfp_codec_read_from_stream(hfp_codec_t * hfp_codec, uint8_t * buffer, uint16_t size);
126 
127 /**
128  * @param hfp_codec
129  */
130 void hfp_codec_deinit(hfp_codec_t * hfp_codec);
131 
132 /* API_END */
133 
134 #if defined __cplusplus
135 }
136 #endif
137 
138 #endif
139