mirror/btstack
1
0
Fork 0
mirror of https://github.com/bluekitchen/btstack.git synced 2025-02-26 00:40:38 +00:00
Code Issues Packages Projects Releases Wiki Activity

a2dp-forwarding: implement greedy forwarding

Browse Source
This commit is contained in:
Matthias Ringwald 2020-07-22 16:15:27 +02:00 committed by Milanka Ringwald
parent 67badf5110
commit 8f671c58b1
1 changed files with 28 additions and 17 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

45
example/a2dp_mitm_demo.c
View File

@ -67,12 +67,11 @@
#define NUM_SBC_FRAMES_PER_PACKET 6
#define MAX_SBC_FRAME_SIZE 120
#define MAX_NUM_SBC_FRAMES 100
#define SBC_STORAGE_SIZE 1030
#define PREBUFFER_BYTES 10000
#define FILL_AUDIO_BUFFER_TIMEOUT_MS 5
#define A2DP_SAMPLE_RATE 44100
#define SBC_STORAGE_SIZE 1030
// configuration
// iPhone SE
@ -113,18 +112,18 @@ typedef struct {
uint16_t sbc_frame_size;
uint16_t num_sbc_frames_in_ring_buffer;
int max_media_payload_size;
bool headset_stream_ready;
#ifdef USE_TIMER_FOR_SENDING
bool forward_active;
bool sbc_ready_to_send;
uint32_t time_audio_data_sent; // ms
uint32_t acc_num_missed_samples;
uint32_t samples_ready;
btstack_timer_source_t fill_audio_buffer_timer;
int max_media_payload_size;
#endif
} mitm_context_t;
@ -159,6 +158,7 @@ static int ring_buffer_init(void){
return 0;
}
#ifdef USE_TIMER_FOR_SENDING
static void a2dp_fill_audio_buffer_timeout_handler(btstack_timer_source_t * timer){
mitm_context_t * context = (mitm_context_t *) btstack_run_loop_get_timer_context(timer);
btstack_run_loop_set_timer(&context->fill_audio_buffer_timer, FILL_AUDIO_BUFFER_TIMEOUT_MS);
@ -222,7 +222,23 @@ static void a2dp_fill_audio_buffer_timer_stop(mitm_context_t * context){
context->samples_ready = 0;
context->sbc_ready_to_send = false;
btstack_run_loop_remove_timer(&context->fill_audio_buffer_timer);
}
}
static void a2dp_mitm_try_send(void){
if (!mitm_context.forward_active && btstack_ring_buffer_bytes_available(&ring_buffer) > PREBUFFER_BYTES){
mitm_context.forward_active = true;
a2dp_fill_audio_buffer_timer_start(&mitm_context);
}
}
#endif
#ifndef USE_TIMER_FOR_SENDING
static void a2dp_mitm_try_send(void){
if (mitm_context.num_sbc_frames_in_ring_buffer < NUM_SBC_FRAMES_PER_PACKET) return;
// schedule sending
a2dp_source_stream_endpoint_request_can_send_now(mitm_context.a2dp_source_cid, mitm_context.a2dp_source_local_seid);
}
#endif
static void handle_l2cap_media_data_packet(uint8_t seid, uint8_t *packet, uint16_t size){
UNUSED(seid);
@ -286,7 +302,7 @@ static void handle_l2cap_media_data_packet(uint8_t seid, uint8_t *packet, uint16
// log_info("IN: Ringbuffer: %u bytes free", btstack_ring_buffer_bytes_free(&ring_buffer));
// store individual framees: { len_16, frame }
// store individual frames: { len_16, frame }
int i;
for (i=0;i<num_frames;i++){
uint16_t frame_size = mitm_context.sbc_frame_size;
@ -302,13 +318,7 @@ static void handle_l2cap_media_data_packet(uint8_t seid, uint8_t *packet, uint16
mitm_context.num_sbc_frames_in_ring_buffer++;
}
// printf("DEMO: Audio from smartphone, ringbuffer avail %u\n", btstack_ring_buffer_bytes_available(&ring_buffer));
if (!mitm_context.forward_active && btstack_ring_buffer_bytes_available(&ring_buffer) > PREBUFFER_BYTES){
mitm_context.forward_active = true;
a2dp_fill_audio_buffer_timer_start(&mitm_context);
}
a2dp_mitm_try_send();
}
static void packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
@ -434,7 +444,7 @@ static void a2dp_source_packet_handler(uint8_t packet_type, uint16_t channel, ui
// calculate max num sbc frames for outgoing earlier
uint16_t payload_max_size = a2dp_max_media_payload_size(mitm_context.a2dp_source_cid, mitm_context.a2dp_source_local_seid);
int max_sbc_frames = payload_max_size / mitm_context.sbc_frame_size;
int max_sbc_frames = btstack_min( payload_max_size / mitm_context.sbc_frame_size, NUM_SBC_FRAMES_PER_PACKET);
for (num_frames = 0 ; num_frames < max_sbc_frames && mitm_context.num_sbc_frames_in_ring_buffer > 0; num_frames++){
btstack_ring_buffer_read(&ring_buffer, (uint8_t*) &len, 2, &bytes_read);
@ -446,13 +456,13 @@ static void a2dp_source_packet_handler(uint8_t packet_type, uint16_t channel, ui
a2dp_source_stream_send_media_payload(mitm_context.a2dp_source_cid, mitm_context.a2dp_source_local_seid, sbc_storage, pos, num_frames, 0);
#ifdef USE_TIMER_FOR_SENDING
mitm_context.sbc_ready_to_send = false;
int num_samples_per_frame = 128;
int samples_consumed = num_frames * num_samples_per_frame;
mitm_context.samples_ready -= samples_consumed;
// printf("DEMO: audio packet sent, ring buffer %u\n", btstack_ring_buffer_bytes_available(&ring_buffer));
log_info("OUT: Ringbuffer: %u bytes available", btstack_ring_buffer_bytes_available(&ring_buffer));
if (btstack_ring_buffer_bytes_available(&ring_buffer) == 0){
@ -462,6 +472,7 @@ static void a2dp_source_packet_handler(uint8_t packet_type, uint16_t channel, ui
a2dp_fill_audio_buffer_timer_stop(&mitm_context);
break;
}
#endif
break;
}