Commit efef94a8 authored by pali's avatar pali
Browse files

bluetooth: Implement A2DP codec switching and backchannel support

Some A2DP codecs (like FastStream or aptX Low Latency) are bi-directional
and can be used for both music playback and audio calls. This patch
implements usage of backchannel if A2DP codec provided by pulseaudio API
supports it.

A2DP codec switching needs new version of bluez as older version does not
provide needed org.freedesktop.DBus.ObjectManager and RegisterApplication
DBus APIs.

Pulseaudio use for each A2DP codec separate pulseaudio profile, therefore
codec switching is implemented via changing pulseaudio profile and
currently used A2DP codec is visible in pulseaudio profile.

Getting list of supported codecs by remote device is supported only by new
version of bluez daemon.

If old bluez version is detected then only one SBC codec is supported.
parent 6f25f0ee
This diff is collapsed.
......@@ -54,14 +54,14 @@ typedef enum pa_bluetooth_hook {
} pa_bluetooth_hook_t;
typedef enum profile {
} pa_bluetooth_profile_t;
/* Profile index is used also for card profile priority. Higher number has higher priority.
* All A2DP profiles have higher priority as all non-A2DP profiles.
* And all A2DP sink profiles have higher priority as all A2DP source profiles. */
typedef unsigned pa_bluetooth_profile_t;
typedef enum pa_bluetooth_transport_state {
......@@ -86,8 +86,6 @@ struct pa_bluetooth_transport {
uint8_t *config;
size_t config_size;
const pa_a2dp_codec *a2dp_codec;
uint16_t microphone_gain;
uint16_t speaker_gain;
......@@ -109,6 +107,7 @@ struct pa_bluetooth_device {
bool tried_to_link_with_adapter;
bool valid;
bool autodetect_mtu;
bool change_a2dp_profile_in_progress;
/* Device information */
char *path;
......@@ -117,8 +116,10 @@ struct pa_bluetooth_device {
char *address;
uint32_t class_of_device;
pa_hashmap *uuids; /* char* -> char* (hashmap-as-a-set) */
pa_hashmap *a2dp_sink_endpoints; /* pa_a2dp_codec_id* -> pa_hashmap ( char* (remote endpoint) -> struct a2dp_codec_capabilities* ) */
pa_hashmap *a2dp_source_endpoints; /* pa_a2dp_codec_id* -> pa_hashmap ( char* (remote endpoint) -> struct a2dp_codec_capabilities* ) */
pa_bluetooth_transport *transports[PA_BLUETOOTH_PROFILE_COUNT];
pa_bluetooth_transport **transports;
pa_time_event *wait_for_profiles_timer;
......@@ -129,6 +130,7 @@ struct pa_bluetooth_adapter {
char *address;
bool valid;
bool media_application_registered;
......@@ -161,6 +163,9 @@ void pa_bluetooth_transport_put(pa_bluetooth_transport *t);
void pa_bluetooth_transport_unlink(pa_bluetooth_transport *t);
void pa_bluetooth_transport_free(pa_bluetooth_transport *t);
size_t pa_bluetooth_device_find_a2dp_endpoints_for_codec(const pa_bluetooth_device *device, const pa_a2dp_codec *a2dp_codec, bool is_a2dp_sink, const char **endpoints, size_t endpoints_max_count);
bool pa_bluetooth_device_change_a2dp_profile(pa_bluetooth_device *d, pa_bluetooth_profile_t profile, void (*cb)(bool, void *), void *userdata);
bool pa_bluetooth_device_any_transport_connected(const pa_bluetooth_device *d);
pa_bluetooth_device* pa_bluetooth_discovery_get_device_by_path(pa_bluetooth_discovery *y, const char *path);
......@@ -168,8 +173,21 @@ pa_bluetooth_device* pa_bluetooth_discovery_get_device_by_address(pa_bluetooth_d
pa_hook* pa_bluetooth_discovery_hook(pa_bluetooth_discovery *y, pa_bluetooth_hook_t hook);
unsigned pa_bluetooth_profile_count(void);
bool pa_bluetooth_profile_is_a2dp_sink(pa_bluetooth_profile_t profile);
bool pa_bluetooth_profile_is_a2dp_source(pa_bluetooth_profile_t profile);
const pa_a2dp_codec *pa_bluetooth_profile_to_a2dp_codec(pa_bluetooth_profile_t profile);
pa_bluetooth_profile_t pa_bluetooth_profile_for_a2dp_codec(const char *codec_name, bool is_a2dp_sink);
const char *pa_bluetooth_profile_to_string(pa_bluetooth_profile_t profile);
static inline bool pa_bluetooth_profile_is_a2dp(pa_bluetooth_profile_t profile) {
return pa_bluetooth_profile_is_a2dp_sink(profile) || pa_bluetooth_profile_is_a2dp_source(profile);
static inline bool pa_bluetooth_profile_support_a2dp_backchannel(pa_bluetooth_profile_t profile) {
return pa_bluetooth_profile_to_a2dp_codec(profile)->support_backchannel;
static inline bool pa_bluetooth_uuid_is_hsp_hs(const char *uuid) {
return pa_streq(uuid, PA_BLUETOOTH_UUID_HSP_HS) || pa_streq(uuid, PA_BLUETOOTH_UUID_HSP_HS_ALT);
......@@ -62,7 +62,8 @@ static pa_hook_result_t device_connection_changed_cb(pa_bluetooth_discovery *y,
module_loaded = pa_hashmap_get(u->loaded_device_paths, d->path) ? true : false;
if (module_loaded && !pa_bluetooth_device_any_transport_connected(d)) {
/* When changing A2DP profile there is no transport connected, ensure that no module is unloaded */
if (module_loaded && !pa_bluetooth_device_any_transport_connected(d) && !d->change_a2dp_profile_in_progress) {
/* disconnection, the module unloads itself */
pa_log_debug("Unregistering module for %s", d->path);
pa_hashmap_remove(u->loaded_device_paths, d->path);
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