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a2dp_sink_demo: extract constants for drift compenstation

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This commit is contained in:
Matthias Ringwald 2019-02-21 15:17:25 +01:00
parent e9c5f44ee8
commit c5fccf8bfc
1 changed files with 9 additions and 4 deletions
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13
example/a2dp_sink_demo.c
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@ -440,18 +440,23 @@ static void handle_l2cap_media_data_packet(uint8_t seid, uint8_t *packet, uint16
// decide on audio sync drift based on number of sbc frames in queue
int sbc_frames_in_buffer = btstack_ring_buffer_bytes_available(&sbc_frame_ring_buffer) / sbc_frame_size;
uint32_t resampling_factor;
// nomimal factor (fixed-point 2^16) and compensation offset
uint32_t nomimal_factor = 0x0FF80;
uint32_t compensation = 0x00100;
if (sbc_frames_in_buffer < OPTIMAL_FRAMES_MIN){
resampling_factor = 0x0FE00; // stretch samples
resampling_factor = nomimal_factor - compensation; // stretch samples
} else if (sbc_frames_in_buffer <= OPTIMAL_FRAMES_MAX){
resampling_factor = 0x10000; // nothing to do
resampling_factor = nomimal_factor; // nothing to do
} else {
resampling_factor = 0x10200; // compress samples
resampling_factor = nomimal_factor + compensation; // compress samples
}
btstack_resample_set_factor(&resample_instance, resampling_factor);
// dump
// printf("%6u %03u %05x\n", (int) btstack_run_loop_get_time_ms(), sbc_frames_in_buffer, resampling_factor);
printf("%6u %03u %05x\n", (int) btstack_run_loop_get_time_ms(), sbc_frames_in_buffer, resampling_factor);
// log_info("%03u %05x", sbc_frames_in_buffer, resampling_factor);
#ifdef STORE_SBC_TO_SBC_FILE