nils/shairport-sync
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Add check of drift in the source material -- i,e, divergence between calculated and actual remote clocks for frames.

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This commit is contained in:
Mike Brady
2015-06-26 15:11:21 +01:00
parent 300b4abe6f
commit 841014277e
4 changed files with 47 additions and 22 deletions
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common.h
+2
View File
@@ -121,6 +121,8 @@ shairport_cfg config;
config_t config_file_stuff;
int64_t session_corrections;
uint32_t play_segment_reference_frame;
uint64_t play_segment_reference_frame_remote_time;
void command_start(void);
void command_stop(void);
player.c
+13 -10
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@@ -492,8 +492,8 @@ static abuf_t *buffer_get_frame(void) {
// debug(1,"First frame seen, time %u, with %d
// frames...",curframe->timestamp,seq_diff(ab_read, ab_write));
uint32_t reference_timestamp;
uint64_t reference_timestamp_time;
get_reference_timestamp_stuff(&reference_timestamp, &reference_timestamp_time);
uint64_t reference_timestamp_time,remote_reference_timestamp_time;
get_reference_timestamp_stuff(&reference_timestamp, &reference_timestamp_time, &remote_reference_timestamp_time);
if (reference_timestamp) { // if we have a reference time
// debug(1,"First frame seen with timestamp...");
first_packet_timestamp = curframe->timestamp; // we will keep buffering until we are
@@ -601,12 +601,13 @@ static abuf_t *buffer_get_frame(void) {
// with %d packets.",exact_frame_gap,fs,dac_delay,seq_diff(ab_read, ab_write));
config.output->play(silence, fs);
free(silence);
#ifdef CONFIG_METADATA
if (ab_buffering == 0) {
send_ssnc_metadata('prsm', NULL, 0,
0); // "resume", but don't wait if the queue is locked
}
uint64_t reference_timestamp_time; // don't need this...
get_reference_timestamp_stuff(&play_segment_reference_frame, &reference_timestamp_time, &play_segment_reference_frame_remote_time);
#ifdef CONFIG_METADATA
send_ssnc_metadata('prsm', NULL, 0, 0); // "resume", but don't wait if the queue is locked
#endif
}
}
}
}
@@ -629,8 +630,8 @@ static abuf_t *buffer_get_frame(void) {
int do_wait = 1;
if ((ab_synced) && (curframe) && (curframe->ready) && (curframe->timestamp)) {
uint32_t reference_timestamp;
uint64_t reference_timestamp_time;
get_reference_timestamp_stuff(&reference_timestamp, &reference_timestamp_time);
uint64_t reference_timestamp_time,remote_reference_timestamp_time;
get_reference_timestamp_stuff(&reference_timestamp, &reference_timestamp_time, &remote_reference_timestamp_time);
if (reference_timestamp) { // if we have a reference time
uint32_t packet_timestamp = curframe->timestamp;
int64_t delta = ((int64_t)packet_timestamp - (int64_t)reference_timestamp);
@@ -856,6 +857,7 @@ typedef struct stats { // statistics for running averages
static void *player_thread_func(void *arg) {
session_corrections = 0;
play_segment_reference_frame = 0; // zero signals that we are not in a play segment
// check that there are enough buffers to accommodate the desired latency and the latency offset
int maximum_latency = config.latency+config.audio_backend_latency_offset;
@@ -924,8 +926,8 @@ static void *player_thread_func(void *arg) {
at_least_one_frame_seen = 1;
uint32_t reference_timestamp;
uint64_t reference_timestamp_time;
get_reference_timestamp_stuff(&reference_timestamp, &reference_timestamp_time);
uint64_t reference_timestamp_time,remote_reference_timestamp_time;
get_reference_timestamp_stuff(&reference_timestamp, &reference_timestamp_time, &remote_reference_timestamp_time);
int64_t rt, nt;
rt = reference_timestamp;
@@ -1232,6 +1234,7 @@ void player_flush(uint32_t timestamp) {
// if (timestamp!=0)
flush_rtp_timestamp = timestamp; // flush all packets up to (and including?) this
pthread_mutex_unlock(&flush_mutex);
play_segment_reference_frame = 0;
#ifdef CONFIG_METADATA
send_ssnc_metadata('pfls', NULL, 0, 1);
#endif
rtp.c
+31 -11
View File
@@ -68,6 +68,7 @@ static pthread_t rtp_audio_thread, rtp_control_thread, rtp_timing_thread;
static uint32_t reference_timestamp;
static uint64_t reference_timestamp_time;
static uint64_t remote_reference_timestamp_time;
// debug variables
static int request_sent;
@@ -199,12 +200,13 @@ static void *rtp_control_receiver(void *arg) {
// after the one whose RTP is given. Weird.
}
pthread_mutex_lock(&reference_time_mutex);
remote_reference_timestamp_time = remote_time_of_sync;
reference_timestamp_time = remote_time_of_sync - local_to_remote_time_difference;
reference_timestamp = sync_rtp_timestamp;
pthread_mutex_unlock(&reference_time_mutex);
// debug(1,"New Reference timestamp and timestamp time...");
// get estimated remote time now
remote_time_now = local_time_now + local_to_remote_time_difference;
// remote_time_now = local_time_now + local_to_remote_time_difference;
// debug(1,"Sync Time is %lld us late (remote
// times).",((remote_time_now-remote_time_of_sync)*1000000)>>32);
@@ -404,23 +406,40 @@ static void *rtp_timing_receiver(void *arg) {
first_local_to_remote_time_difference = local_to_remote_time_difference;
first_local_to_remote_time_difference_time = get_absolute_time_in_fp();
}
int64_t source_drift_usec;
if (play_segment_reference_frame!=0) {
uint32_t reference_timestamp;
uint64_t reference_timestamp_time,remote_reference_timestamp_time;
get_reference_timestamp_stuff(&reference_timestamp, &reference_timestamp_time, &remote_reference_timestamp_time);
uint64_t frame_difference = 0;
if (reference_timestamp>=play_segment_reference_frame)
frame_difference = (uint64_t)reference_timestamp-(uint64_t)play_segment_reference_frame;
else // rollover
frame_difference = (uint64_t)reference_timestamp+0x100000000-(uint64_t)play_segment_reference_frame;
uint64_t frame_time_difference_calculated = (((uint64_t)frame_difference<<32)/44100);
uint64_t frame_time_difference_specified = remote_reference_timestamp_time-play_segment_reference_frame_remote_time;
// debug(1,"%llu frames since play started, %llu usec calculated, %llu usec actual",frame_difference, (frame_time_difference_calculated*1000000)>>32, (frame_time_difference_specified*1000000)>>32);
if (frame_time_difference_specified>=frame_time_difference_calculated)
source_drift_usec = frame_time_difference_specified-frame_time_difference_calculated;
else
source_drift_usec = -(frame_time_difference_calculated-frame_time_difference_specified);
} else
source_drift_usec = 0;
source_drift_usec = (source_drift_usec*1000000)>>32; // turn it to microseconds
uint64_t clock_drift;
int64_t current_delay;
// if (config.output->delay) {
// current_delay = config.output->delay();
// }
if (config.output->delay) {
current_delay = config.output->delay();
}
if (first_local_to_remote_time_difference>=local_to_remote_time_difference) {
clock_drift = ((first_local_to_remote_time_difference - local_to_remote_time_difference) * 1000000)>>32;
// debug(1, "-%llu\t%lld\t%lld", clock_drift,(session_corrections*1000000)/44100,current_delay);
debug(1, "-%llu\t%lld", clock_drift,(session_corrections*1000000)/44100);
//debug(1,"Clock drift is -%lld usec.",clock_drift);
debug(1, "-%llu\t%lld\t%lld\t%lld", clock_drift,(session_corrections*1000000)/44100,current_delay,source_drift_usec);
}
else {
clock_drift = ((local_to_remote_time_difference - first_local_to_remote_time_difference) * 1000000) >>32;
//debug(1,"Clock drift is %lld usec.",clock_drift);
// debug(1, "%llu\t%lld\t%lld", clock_drift,(session_corrections*1000000)/44100,current_delay);
debug(1, "%llu\t%lld\t", clock_drift,(session_corrections*1000000)/44100);
debug(1, "%llu\t%lld\t%lld\t%lld", clock_drift,(session_corrections*1000000)/44100,current_delay,source_drift_usec);
}
} else {
@@ -581,10 +600,11 @@ void rtp_setup(SOCKADDR *remote, int cport, int tport, uint32_t active_remote, i
request_sent = 0;
}
void get_reference_timestamp_stuff(uint32_t *timestamp, uint64_t *timestamp_time) {
void get_reference_timestamp_stuff(uint32_t *timestamp, uint64_t *timestamp_time, uint64_t *remote_timestamp_time) {
pthread_mutex_lock(&reference_time_mutex);
*timestamp = reference_timestamp;
*timestamp_time = reference_timestamp_time;
*remote_timestamp_time = remote_reference_timestamp_time;
pthread_mutex_unlock(&reference_time_mutex);
}
rtp.h
+1 -1
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@@ -11,7 +11,7 @@ void rtp_shutdown(void);
void rtp_request_resend(seq_t first, uint32_t count);
void rtp_request_client_pause(void); // ask the client to pause
void get_reference_timestamp_stuff(uint32_t *timestamp, uint64_t *timestamp_time);
void get_reference_timestamp_stuff(uint32_t *timestamp, uint64_t *timestamp_time, uint64_t *remote_timestamp_time);
void clear_reference_timestamp(void);
uint64_t static local_to_remote_time_jitters;