pipewire/spa/plugins/bluez5/hfp-h2.h
Pauli Virtanen e6f5fb12a3 bluez5: add HFP codecs in the media codec API
Add copy of HFP codec implementations in the media codec API.
2025-06-13 17:51:16 +00:00

128 lines
2.5 KiB
C

/* Spa HFP Codecs */
/* SPDX-FileCopyrightText: Copyright © 2025 Pauli Virtanen */
/* SPDX-License-Identifier: MIT */
#ifndef SPA_BLUEZ5_HFP_H2_H
#define SPA_BLUEZ5_HFP_H2_H
#define H2_PACKET_SIZE 60
struct h2_reader {
uint8_t buf[H2_PACKET_SIZE];
uint8_t pos;
bool msbc;
uint16_t seq;
bool started;
};
struct h2_writer {
uint8_t seq;
};
static inline void h2_reader_init(struct h2_reader *this, bool msbc)
{
this->pos = 0;
this->msbc = msbc;
this->seq = 0;
this->started = false;
}
static inline void h2_reader_append_byte(struct h2_reader *this, uint8_t byte)
{
/* Parse H2 sync header */
if (this->pos == 0) {
if (byte != 0x01) {
this->pos = 0;
return;
}
} else if (this->pos == 1) {
if (!((byte & 0x0F) == 0x08 &&
((byte >> 4) & 1) == ((byte >> 5) & 1) &&
((byte >> 6) & 1) == ((byte >> 7) & 1))) {
this->pos = 0;
return;
}
} else if (this->msbc) {
/* Beginning of MSBC frame: SYNCWORD + 2 nul bytes */
if (this->pos == 2) {
if (byte != 0xAD) {
this->pos = 0;
return;
}
}
else if (this->pos == 3) {
if (byte != 0x00) {
this->pos = 0;
return;
}
}
else if (this->pos == 4) {
if (byte != 0x00) {
this->pos = 0;
return;
}
}
}
if (this->pos >= H2_PACKET_SIZE) {
/* Packet completed. Reset. */
this->pos = 0;
h2_reader_append_byte(this, byte);
return;
}
this->buf[this->pos] = byte;
++this->pos;
}
static inline void *h2_reader_read(struct h2_reader *this, const uint8_t *src, size_t src_size, size_t *consumed, size_t *avail)
{
int seq;
size_t i;
for (i = 0; i < src_size && this->pos < H2_PACKET_SIZE; ++i)
h2_reader_append_byte(this, src[i]);
*consumed = i;
*avail = 0;
if (this->pos < H2_PACKET_SIZE)
return NULL;
this->pos = 0;
seq = ((this->buf[1] >> 4) & 1) | ((this->buf[1] >> 6) & 2);
if (!this->started) {
this->seq = seq;
this->started = true;
}
this->seq++;
while (seq != this->seq % 4)
this->seq++;
*avail = H2_PACKET_SIZE - 2;
return &this->buf[2];
}
static inline void h2_write(uint8_t *buf, uint8_t seq)
{
static const uint8_t sntable[4] = { 0x08, 0x38, 0xc8, 0xf8 };
buf[0] = 0x01;
buf[1] = sntable[seq % 4];
buf[59] = 0;
}
static inline bool is_zero_packet(const uint8_t *data, size_t size)
{
size_t i;
for (i = 0; i < size; ++i)
if (data[i])
return false;
return true;
}
#endif