/*
*
* BlueZ - Bluetooth protocol stack for Linux
*
* Copyright (C) 2004-2008 Marcel Holtmann <marcel@holtmann.org>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
/*
Message sequence chart of streaming sequence for A2DP transport
Audio daemon User
on snd_pcm_open
<--BT_GETCAPABILITIES_REQ
BT_GETCAPABILITIES_RSP-->
on snd_pcm_hw_params
<--BT_SETCONFIGURATION_REQ
BT_SETCONFIGURATION_RSP-->
on snd_pcm_prepare
<--BT_STREAMSTART_REQ
<Moves to streaming state>
BT_STREAMSTART_RSP-->
BT_STREAMFD_IND -->
< streams data >
..........
on snd_pcm_drop/snd_pcm_drain
<--BT_STREAMSTOP_REQ
<Moves to open state>
BT_STREAMSTOP_RSP-->
on IPC close or appl crash
<Moves to idle>
*/
#ifndef BT_AUDIOCLIENT_H
#define BT_AUDIOCLIENT_H
#ifdef __cplusplus
extern "C" {
#endif
#include <stdint.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <errno.h>
#define BT_AUDIO_IPC_PACKET_SIZE 128
#define BT_IPC_SOCKET_NAME "\0/org/bluez/audio"
/* Generic message header definition, except for RSP messages */
typedef struct {
uint8_t msg_type;
} __attribute__ ((packed)) bt_audio_msg_header_t;
/* Generic message header definition, for all RSP messages */
typedef struct {
bt_audio_msg_header_t msg_h;
uint8_t posix_errno;
} __attribute__ ((packed)) bt_audio_rsp_msg_header_t;
/* Messages list */
#define BT_GETCAPABILITIES_REQ 0
#define BT_GETCAPABILITIES_RSP 1
#define BT_SETCONFIGURATION_REQ 2
#define BT_SETCONFIGURATION_RSP 3
#define BT_STREAMSTART_REQ 4
#define BT_STREAMSTART_RSP 5
#define BT_STREAMSTOP_REQ 6
#define BT_STREAMSTOP_RSP 7
#define BT_STREAMSUSPEND_IND 8
#define BT_STREAMRESUME_IND 9
#define BT_CONTROL_REQ 10
#define BT_CONTROL_RSP 11
#define BT_CONTROL_IND 12
#define BT_STREAMFD_IND 13
/* BT_GETCAPABILITIES_REQ */
#define BT_CAPABILITIES_TRANSPORT_A2DP 0
#define BT_CAPABILITIES_TRANSPORT_SCO 1
#define BT_CAPABILITIES_TRANSPORT_ANY 2
#define BT_CAPABILITIES_ACCESS_MODE_READ 1
#define BT_CAPABILITIES_ACCESS_MODE_WRITE 2
#define BT_CAPABILITIES_ACCESS_MODE_READWRITE 3
#define BT_FLAG_AUTOCONNECT 1
struct bt_getcapabilities_req {
bt_audio_msg_header_t h;
char device[18]; /* Address of the remote Device */
uint8_t transport; /* Requested transport */
uint8_t flags; /* Requested flags */
} __attribute__ ((packed));
/* BT_GETCAPABILITIES_RSP */
/**
* SBC Codec parameters as per A2DP profile 1.0 § 4.3
*/
#define BT_SBC_SAMPLING_FREQ_16000 (1 << 3)
#define BT_SBC_SAMPLING_FREQ_32000 (1 << 2)
#define BT_SBC_SAMPLING_FREQ_44100 (1 << 1)
#define BT_SBC_SAMPLING_FREQ_48000 1
#define BT_A2DP_CHANNEL_MODE_MONO (1 << 3)
#define BT_A2DP_CHANNEL_MODE_DUAL_CHANNEL (1 << 2)
#define BT_A2DP_CHANNEL_MODE_STEREO (1 << 1)
#define BT_A2DP_CHANNEL_MODE_JOINT_STEREO 1
#define BT_A2DP_BLOCK_LENGTH_4 (1 << 3)
#define BT_A2DP_BLOCK_LENGTH_8 (1 << 2)
#define BT_A2DP_BLOCK_LENGTH_12 (1 << 1)
#define BT_A2DP_BLOCK_LENGTH_16 1
#define BT_A2DP_SUBBANDS_4 (1 << 1)
#define BT_A2DP_SUBBANDS_8 1
#define BT_A2DP_ALLOCATION_SNR (1 << 1)
#define BT_A2DP_ALLOCATION_LOUDNESS 1
#define BT_MPEG_SAMPLING_FREQ_16000 (1 << 5)
#define BT_MPEG_SAMPLING_FREQ_22050 (1 << 4)
#define BT_MPEG_SAMPLING_FREQ_24000 (1 << 3)
#define BT_MPEG_SAMPLING_FREQ_32000 (1 << 2)
#define BT_MPEG_SAMPLING_FREQ_44100 (1 << 1)
#define BT_MPEG_SAMPLING_FREQ_48000 1
#define BT_MPEG_LAYER_1 (1 << 2)
#define BT_MPEG_LAYER_2 (1 << 1)
#define BT_MPEG_LAYER_3 1
typedef struct {
uint8_t channel_mode;
uint8_t frequency;
uint8_t allocation_method;
uint8_t subbands;
uint8_t block_length;
uint8_t min_bitpool;
uint8_t max_bitpool;
} __attribute__ ((packed)) sbc_capabilities_t;
typedef struct {
uint8_t channel_mode;
uint8_t crc;
uint8_t layer;
uint8_t frequency;
uint8_t mpf;
uint16_t bitrate;
} __attribute__ ((packed)) mpeg_capabilities_t;
struct bt_getcapabilities_rsp {
bt_audio_rsp_msg_header_t rsp_h;
uint8_t transport; /* Granted transport */
sbc_capabilities_t sbc_capabilities; /* A2DP only */
mpeg_capabilities_t mpeg_capabilities; /* A2DP only */
uint16_t sampling_rate; /* SCO only */
} __attribute__ ((packed));
/* BT_SETCONFIGURATION_REQ */
struct bt_setconfiguration_req {
bt_audio_msg_header_t h;
char device[18]; /* Address of the remote Device */
uint8_t transport; /* Requested transport */
uint8_t access_mode; /* Requested access mode */
sbc_capabilities_t sbc_capabilities; /* A2DP only - only one of this field
and next one must be filled */
mpeg_capabilities_t mpeg_capabilities; /* A2DP only */
} __attribute__ ((packed));
/* BT_SETCONFIGURATION_RSP */
struct bt_setconfiguration_rsp {
bt_audio_rsp_msg_header_t rsp_h;
uint8_t transport; /* Granted transport */
uint8_t access_mode; /* Granted access mode */
uint16_t link_mtu; /* Max length that transport supports */
} __attribute__ ((packed));
/* BT_STREAMSTART_REQ */
#define BT_STREAM_ACCESS_READ 0
#define BT_STREAM_ACCESS_WRITE 1
#define BT_STREAM_ACCESS_READWRITE 2
struct bt_streamstart_req {
bt_audio_msg_header_t h;
} __attribute__ ((packed));
/* BT_STREAMSTART_RSP */
struct bt_streamstart_rsp {
bt_audio_rsp_msg_header_t rsp_h;
} __attribute__ ((packed));
/* BT_STREAMFD_IND */
/* This message is followed by one byte of data containing the stream data fd
as ancilliary data */
struct bt_streamfd_ind {
bt_audio_msg_header_t h;
} __attribute__ ((packed));
/* BT_STREAMSTOP_REQ */
struct bt_streamstop_req {
bt_audio_msg_header_t h;
} __attribute__ ((packed));
/* BT_STREAMSTOP_RSP */
struct bt_streamstop_rsp {
bt_audio_rsp_msg_header_t rsp_h;
} __attribute__ ((packed));
/* BT_STREAMSUSPEND_IND */
struct bt_streamsuspend_ind {
bt_audio_msg_header_t h;
} __attribute__ ((packed));
/* BT_STREAMRESUME_IND */
struct bt_streamresume_ind {
bt_audio_msg_header_t h;
} __attribute__ ((packed));
/* BT_CONTROL_REQ */
#define BT_CONTROL_KEY_POWER 0x40
#define BT_CONTROL_KEY_VOL_UP 0x41
#define BT_CONTROL_KEY_VOL_DOWN 0x42
#define BT_CONTROL_KEY_MUTE 0x43
#define BT_CONTROL_KEY_PLAY 0x44
#define BT_CONTROL_KEY_STOP 0x45
#define BT_CONTROL_KEY_PAUSE 0x46
#define BT_CONTROL_KEY_RECORD 0x47
#define BT_CONTROL_KEY_REWIND 0x48
#define BT_CONTROL_KEY_FAST_FORWARD 0x49
#define BT_CONTROL_KEY_EJECT 0x4A
#define BT_CONTROL_KEY_FORWARD 0x4B
#define BT_CONTROL_KEY_BACKWARD 0x4C
struct bt_control_req {
bt_audio_msg_header_t h;
uint8_t mode; /* Control Mode */
uint8_t key; /* Control Key */
} __attribute__ ((packed));
/* BT_CONTROL_RSP */
struct bt_control_rsp {
bt_audio_rsp_msg_header_t rsp_h;
uint8_t mode; /* Control Mode */
uint8_t key; /* Control Key */
} __attribute__ ((packed));
/* BT_CONTROL_IND */
struct bt_control_ind {
bt_audio_msg_header_t h;
uint8_t mode; /* Control Mode */
uint8_t key; /* Control Key */
} __attribute__ ((packed));
/* Function declaration */
/* Opens a connection to the audio service: return a socket descriptor */
int bt_audio_service_open();
/* Closes a connection to the audio service */
int bt_audio_service_close(int sk);
/* Receives stream data file descriptor : must be called after a
BT_STREAMFD_IND message is returned */
int bt_audio_service_get_data_fd(int sk);
/* Human readable message type string */
const char *bt_audio_strmsg(int type);
#ifdef __cplusplus
}
#endif
#endif /* BT_AUDIOCLIENT_H */