def update_batch_delay(batch, factors):
"""
Given a list of factors of the form:
[(description, factor, weight)]
we calculate a new batch delay.
We use a time-weighted average of previous delays as a starting value,
then combine it with the new factors.
"""
last_updated = batch.last_updated
current_delay = batch.delay
now = time.time()
avg = 0
tv, tw = 0.0, 0.0
decay = max(1, logp(current_delay / batch.min_delay) / 5.0)
if len(batch.last_delays) > 0:
#get the weighted average
#older values matter less, we decay them according to how much we batch already
#(older values matter more when we batch a lot)
for when, delay in batch.last_delays:
#newer matter more:
w = 1.0 / (1.0 + ((now - when) / decay)**2)
d = max(batch.min_delay, min(batch.max_delay, delay))
tv += d * w
tw += w
avg = tv / tw
hist_w = tw
valid_factors = [x for x in factors if x is not None]
all_factors_weight = sum([w for _, _, w in valid_factors])
if all_factors_weight == 0:
log("update_batch_delay: no weights yet!")
return
max_factor = max([f for _, f, _ in valid_factors])
#mitigate low factors if we have some really high ones:
factor_min_limit = min(0.5, max_factor / 10.0)
for _, factor, weight in valid_factors:
actual_factor = max(factor_min_limit, factor)
target_delay = max(batch.min_delay,
min(batch.max_delay, current_delay * actual_factor))
w = max(1, hist_w) * weight / all_factors_weight
tw += w
tv += target_delay * w
batch.delay = max(batch.min_delay, min(batch.max_delay, tv / tw))
batch.last_updated = now
if DEBUG_DELAY:
decimal_delays = [dec1(x) for _, x in batch.last_delays]
if len(decimal_delays) == 0:
decimal_delays.append(0)
logfactors = [(msg, dec2(f), dec2(w)) for (msg, f, w) in valid_factors]
rec = (
"update_batch_delay: wid=%s, last updated %s ms ago, decay=%s, change factor=%s%%, delay min=%s, avg=%s, max=%s, cur=%s, w. average=%s, tot wgt=%s, hist_w=%s, new delay=%s\n %s",
batch.wid, dec2(1000.0 * now - 1000.0 * last_updated), dec2(decay),
dec1(100 * (batch.delay / current_delay - 1)), min(decimal_delays),
dec1(sum(decimal_delays) / len(decimal_delays)),
max(decimal_delays), dec1(current_delay), dec1(avg), dec1(tw),
dec1(hist_w), dec1(batch.delay),
"\n ".join([str(x) for x in logfactors]))
add_DEBUG_DELAY_MESSAGE(rec)
def update_batch_delay(batch, factors):
"""
Given a list of factors of the form:
[(description, factor, weight)]
we calculate a new batch delay.
We use a time-weighted average of previous delays as a starting value,
then combine it with the new factors.
"""
last_updated = batch.last_updated
current_delay = batch.delay
now = time.time()
avg = 0
tv, tw = 0.0, 0.0
decay = max(1, logp(current_delay/batch.min_delay)/5.0)
if len(batch.last_delays)>0:
#get the weighted average
#older values matter less, we decay them according to how much we batch already
#(older values matter more when we batch a lot)
for when, delay in batch.last_delays:
#newer matter more:
w = 1.0/(1.0+((now-when)/decay)**2)
d = max(batch.min_delay, min(batch.max_delay, delay))
tv += d*w
tw += w
avg = tv / tw
hist_w = tw
valid_factors = [x for x in factors if x is not None]
all_factors_weight = sum([w for _,_,w in valid_factors])
if all_factors_weight==0:
log("update_batch_delay: no weights yet!")
return
max_factor = max([f for _,f,_ in valid_factors])
#mitigate low factors if we have some really high ones:
factor_min_limit = min(0.5, max_factor/10.0)
for _, factor, weight in valid_factors:
actual_factor = max(factor_min_limit, factor)
target_delay = max(batch.min_delay, min(batch.max_delay, current_delay*actual_factor))
w = max(1, hist_w)*weight/all_factors_weight
tw += w
tv += target_delay*w
batch.delay = max(batch.min_delay, min(batch.max_delay, tv / tw))
batch.last_updated = now
if DEBUG_DELAY:
decimal_delays = [dec1(x) for _,x in batch.last_delays]
if len(decimal_delays)==0:
decimal_delays.append(0)
logfactors = [(msg, dec2(f), dec2(w)) for (msg, f, w) in valid_factors]
rec = ("update_batch_delay: wid=%s, last updated %s ms ago, decay=%s, change factor=%s%%, delay min=%s, avg=%s, max=%s, cur=%s, w. average=%s, tot wgt=%s, hist_w=%s, new delay=%s\n %s",
batch.wid, dec2(1000.0*now-1000.0*last_updated), dec2(decay), dec1(100*(batch.delay/current_delay-1)), min(decimal_delays), dec1(sum(decimal_delays)/len(decimal_delays)), max(decimal_delays),
dec1(current_delay), dec1(avg), dec1(tw), dec1(hist_w), dec1(batch.delay), "\n ".join([str(x) for x in logfactors]))
add_DEBUG_DELAY_MESSAGE(rec)
def calculate_batch_delay(window, wid, batch, global_statistics, statistics,
video_encoder=None, video_encoder_lock=None, video_encoder_speed=None, video_encoder_quality=None):
"""
Calculates a new batch delay.
We first gather some statistics,
then use them to calculate a number of factors.
which are then used to adjust the batch delay in 'update_batch_delay'.
"""
#the number of pixels which can be considered 'low' in terms of backlog.
#Generally, just one full frame, (more with mmap because it is so fast)
low_limit = 1024*1024
if window:
ww, wh = window.get_dimensions()
low_limit = max(8*8, ww*wh)
if global_statistics.mmap_size>0:
#mmap can accumulate much more as it is much faster
low_limit *= 4
#client latency: (how long it takes for a packet to get to the client and get the echo back)
avg_client_latency, recent_client_latency = 0.1, 0.1 #assume 100ms until we get some data
if len(global_statistics.client_latency)>0:
data = [(when, latency) for _, when, _, latency in list(global_statistics.client_latency)]
avg_client_latency, recent_client_latency = calculate_time_weighted_average(data)
#damage "in" latency: (the time it takes for damage requests to be processed only)
avg_damage_in_latency, recent_damage_in_latency = 0, 0
if len(statistics.damage_in_latency)>0:
data = [(when, latency) for when, _, _, latency in list(statistics.damage_in_latency)]
avg_damage_in_latency, recent_damage_in_latency = calculate_time_weighted_average(data)
#damage "out" latency: (the time it takes for damage requests to be processed and sent out)
avg_damage_out_latency, recent_damage_out_latency = 0, 0
if len(statistics.damage_out_latency)>0:
data = [(when, latency) for when, _, _, latency in list(statistics.damage_out_latency)]
avg_damage_out_latency, recent_damage_out_latency = calculate_time_weighted_average(data)
#client decode speed:
avg_decode_speed, recent_decode_speed = None, None
if len(statistics.client_decode_time)>0:
#the elapsed time recorded is in microseconds, so multiply by 1000*1000 to get the real value:
avg_decode_speed, recent_decode_speed = calculate_timesize_weighted_average(list(statistics.client_decode_time), sizeunit=1000*1000)
#network send speed:
avg_send_speed, recent_send_speed = None, None
if len(statistics.damage_send_speed)>0:
avg_send_speed, recent_send_speed = calculate_timesize_weighted_average(list(statistics.damage_send_speed))
#client backlog: (packets and pixels that should have been processed by now - taking into account latency)
packets_backlog, pixels_backlog = 0, 0
if len(statistics.damage_ack_pending)>0:
sent_before = time.time()-avg_client_latency
for sent_at, pixels in statistics.damage_ack_pending.values():
if sent_at>sent_before:
continue
packets_backlog += 1
pixels_backlog += pixels
max_latency = max(avg_damage_in_latency, recent_damage_in_latency, avg_damage_out_latency, recent_damage_out_latency)
#for each indicator: (description, factor, weight)
factors = []
#damage "in" latency factor:
if len(statistics.damage_in_latency)>0:
msg = "damage processing latency:"
target_latency = 0.010 + (0.050*low_limit/1024.0/1024.0)
factors.append(calculate_for_target(msg, target_latency, avg_damage_in_latency, recent_damage_in_latency, aim=0.8, slope=0.005, smoothing=sqrt))
#damage "out" latency
if len(statistics.damage_out_latency)>0:
msg = "damage send latency:"
target_latency = 0.025 + (0.060*low_limit/1024.0/1024.0)
factors.append(calculate_for_target(msg, target_latency, avg_damage_out_latency, recent_damage_out_latency, aim=0.8, slope=0.010, smoothing=sqrt))
#send speed:
if avg_send_speed is not None and recent_send_speed is not None:
#our calculate methods aims for lower values, so invert speed
#this is how long it takes to send 1MB:
avg1MB = 1.0*1024*1024/avg_send_speed
recent1MB = 1.0*1024*1024/recent_send_speed
#we only really care about this when the speed is quite low,
#so adjust the weight accordingly:
minspeed = float(128*1024)
div = logp(max(recent_send_speed, minspeed)/minspeed)
msg = "network send speed: avg=%s, recent=%s (KBytes/s), div=%s" % (int(avg_send_speed/1024), int(recent_send_speed/1024), div)
factors.append(calculate_for_average(msg, avg1MB, recent1MB, weight_offset=1.0, weight_div=div))
#client decode time:
if avg_decode_speed is not None and recent_decode_speed is not None:
msg = "client decode speed: avg=%s, recent=%s (MPixels/s)" % (dec1(avg_decode_speed/1000/1000), dec1(recent_decode_speed/1000/1000))
#our calculate methods aims for lower values, so invert speed
#this is how long it takes to send 1MB:
avg1MB = 1.0*1024*1024/avg_decode_speed
recent1MB = 1.0*1024*1024/recent_decode_speed
factors.append(calculate_for_average(msg, avg1MB, recent1MB, weight_offset=0.0))
#elapsed time without damage:
if batch.last_updated>0:
#If nothing happens for a while then we can reduce the batch delay,
#however we must ensure this is not caused by a high damage latency
#so we ignore short elapsed times.
ignore_time = max(max_latency+batch.recalculate_delay, batch.delay+batch.recalculate_delay)
ignore_count = 2 + ignore_time / batch.recalculate_delay
elapsed = time.time()-batch.last_updated
n_skipped_calcs = elapsed / batch.recalculate_delay
#the longer the elapsed time, the more we slash:
weight = logp(max(0, n_skipped_calcs-ignore_count))
msg = "delay not updated for %s ms (skipped %s times - highest latency is %s)" % (dec1(1000*elapsed), int(n_skipped_calcs), dec1(1000*max_latency))
factors.append((msg, 0, weight))
#client latency: (we want to keep client latency as low as can be)
if len(global_statistics.client_latency)>0 and avg_client_latency is not None and recent_client_latency is not None:
target_latency = 0.005
if global_statistics.min_client_latency:
target_latency = max(target_latency, global_statistics.min_client_latency)
msg = "client latency:"
factors.append(calculate_for_target(msg, target_latency, avg_client_latency, recent_client_latency, aim=0.8, slope=0.005, smoothing=sqrt, weight_multiplier=4.0))
#damage packet queue size: (includes packets from all windows)
factors.append(queue_inspect("damage packet queue size:", global_statistics.damage_packet_qsizes, smoothing=sqrt))
#damage pixels waiting in the packet queue: (extract data for our window id only)
time_values = [(event_time, value) for event_time, dwid, value in list(global_statistics.damage_packet_qpixels) if dwid==wid]
factors.append(queue_inspect("damage packet queue pixels:", time_values, div=low_limit, smoothing=sqrt))
#damage data queue: (This is an important metric since each item will consume a fair amount of memory and each will later on go through the other queues.)
factors.append(queue_inspect("damage data queue:", global_statistics.damage_data_qsizes))
last_packets_backlog, last_pixels_backlog = 0, 0
if statistics.last_packet_send_stats is not None:
#packet and pixels backlog:
last_packets_backlog, last_pixels_backlog = statistics.last_client_delta
factors.append(calculate_for_target("client packets backlog:", 0, last_packets_backlog, packets_backlog, slope=1.0, smoothing=sqrt))
factors.append(calculate_for_target("client pixels backlog:", 0, last_pixels_backlog, pixels_backlog, div=low_limit, slope=1.0, smoothing=sqrt))
if global_statistics.mmap_size>0:
#full: effective range is 0.0 to ~1.2
full = 1.0-float(global_statistics.mmap_free_size)/global_statistics.mmap_size
#aim for ~50%
factors.append(("mmap area %s%% full" % int(100*full), logp(2*full), 2*full))
#now use those factors to drive the delay change:
update_batch_delay(batch, factors)
#***************************************************************
#special hook for video encoders
if (not AUTO_QUALITY and not AUTO_SPEED) or video_encoder is None:
return
#***********************************************************
# encoding speed:
# 0 for highest compression/slower
# 100 for lowest compression/fast
# here we try to minimize damage-latency and client decoding speed
min_damage_latency = 0.010 + (0.050*low_limit/1024.0/1024.0)
target_damage_latency = min_damage_latency + batch.delay/1000.0
dam_lat = (avg_damage_in_latency or 0)/target_damage_latency
target_decode_speed = 1*1000*1000 #1 MPixels/s
dec_lat = target_decode_speed/(avg_decode_speed or target_decode_speed)
target = max(dam_lat, dec_lat, 0.0)
target_speed = 100.0 * min(1.0, target)
video_encoder_speed.append((time.time(), target_speed))
_, new_speed = calculate_time_weighted_average(video_encoder_speed)
msg = "video encoder speed factors: min_damage_latency=%s, target_damage_latency=%s, batch.delay=%s, dam_lat=%s, dec_lat=%s, target=%s, new_speed=%s", \
dec2(min_damage_latency), dec2(target_damage_latency), dec2(batch.delay), dec2(dam_lat), dec2(dec_lat), int(target_speed), int(new_speed)
log(*msg)
if DEBUG_DELAY:
add_DEBUG_DELAY_MESSAGE(msg)
#***********************************************************
# quality:
# 0 for lowest quality (low bandwidth usage)
# 100 for best quality (high bandwidth usage)
# here we try minimize client-latency, packet-backlog and batch.delay
packets_bl = 1.0 - logp(last_packets_backlog/low_limit)
batch_q = 4.0 * batch.min_delay / batch.delay
target = max(packets_bl, batch_q)
latency_q = 0.0
if len(global_statistics.client_latency)>0 and avg_client_latency is not None and recent_client_latency is not None:
target_latency = 0.005
if global_statistics.min_client_latency:
target_latency = max(target_latency, global_statistics.min_client_latency)
latency_q = 4.0 * target_latency / recent_client_latency
target = min(target, latency_q)
target_quality = 100.0*(min(1.0, max(0.0, target)))
video_encoder_quality.append((time.time(), target_quality))
new_quality, _ = calculate_time_weighted_average(video_encoder_quality)
msg = "video encoder quality factors: packets_bl=%s, batch_q=%s, latency_q=%s, target=%s, new_quality=%s", \
dec2(packets_bl), dec2(batch_q), dec2(latency_q), int(target_quality), int(new_quality)
log(*msg)
if DEBUG_DELAY:
add_DEBUG_DELAY_MESSAGE(msg)
try:
video_encoder_lock.acquire()
if AUTO_SPEED:
video_encoder.set_encoding_speed(new_speed)
if AUTO_QUALITY:
video_encoder.set_encoding_quality(new_quality)
finally:
video_encoder_lock.release()
def calculate_batch_delay(window, wid, batch, global_statistics, statistics,
video_encoder=None, video_encoder_lock=None, video_encoder_speed=None, video_encoder_quality=None,
fixed_quality=-1, fixed_speed=-1):
"""
Calculates a new batch delay.
We first gather some statistics,
then use them to calculate a number of factors.
which are then used to adjust the batch delay in 'update_batch_delay'.
"""
#the number of pixels which can be considered 'low' in terms of backlog.
#Generally, just one full frame, (more with mmap because it is so fast)
low_limit = 1024*1024
if window:
ww, wh = window.get_dimensions()
low_limit = max(8*8, ww*wh)
if global_statistics.mmap_size>0:
#mmap can accumulate much more as it is much faster
low_limit *= 4
#client latency: (how long it takes for a packet to get to the client and get the echo back)
avg_client_latency, recent_client_latency = 0.1, 0.1 #assume 100ms until we get some data
if len(global_statistics.client_latency)>0:
data = [(when, latency) for _, when, _, latency in list(global_statistics.client_latency)]
avg_client_latency, recent_client_latency = calculate_time_weighted_average(data)
global_statistics.avg_client_latency = avg_client_latency
#client ping latency: from ping packets
avg_client_ping_latency, recent_client_ping_latency = 0.1, 0.1 #assume 100ms until we get some data
if len(global_statistics.client_ping_latency)>0:
avg_client_ping_latency, recent_client_ping_latency = calculate_time_weighted_average(list(global_statistics.client_ping_latency))
#server ping latency: from ping packets
avg_server_ping_latency, recent_server_ping_latency = 0.1, 0.1 #assume 100ms until we get some data
if len(global_statistics.server_ping_latency)>0:
avg_server_ping_latency, recent_server_ping_latency = calculate_time_weighted_average(list(global_statistics.server_ping_latency))
#damage "in" latency: (the time it takes for damage requests to be processed only)
avg_damage_in_latency, recent_damage_in_latency = 0, 0
if len(statistics.damage_in_latency)>0:
data = [(when, latency) for when, _, _, latency in list(statistics.damage_in_latency)]
avg_damage_in_latency, recent_damage_in_latency = calculate_time_weighted_average(data)
#damage "out" latency: (the time it takes for damage requests to be processed and sent out)
avg_damage_out_latency, recent_damage_out_latency = 0, 0
if len(statistics.damage_out_latency)>0:
data = [(when, latency) for when, _, _, latency in list(statistics.damage_out_latency)]
avg_damage_out_latency, recent_damage_out_latency = calculate_time_weighted_average(data)
#client decode speed:
avg_decode_speed, recent_decode_speed = None, None
if len(statistics.client_decode_time)>0:
#the elapsed time recorded is in microseconds, so multiply by 1000*1000 to get the real value:
avg_decode_speed, recent_decode_speed = calculate_timesize_weighted_average(list(statistics.client_decode_time), sizeunit=1000*1000)
#network send speed:
avg_send_speed, recent_send_speed = None, None
if len(statistics.damage_send_speed)>0:
avg_send_speed, recent_send_speed = calculate_timesize_weighted_average(list(statistics.damage_send_speed))
max_latency = max(avg_damage_in_latency, recent_damage_in_latency, avg_damage_out_latency, recent_damage_out_latency)
#for each indicator: (description, factor, weight)
factors = []
#damage "in" latency factor:
if len(statistics.damage_in_latency)>0:
msg = "damage processing latency:"
target_latency = 0.010 + (0.050*low_limit/1024.0/1024.0)
factors.append(calculate_for_target(msg, target_latency, avg_damage_in_latency, recent_damage_in_latency, aim=0.8, slope=0.005, smoothing=sqrt))
#damage "out" latency
if len(statistics.damage_out_latency)>0:
msg = "damage send latency:"
target_latency = 0.025 + (0.060*low_limit/1024.0/1024.0)
factors.append(calculate_for_target(msg, target_latency, avg_damage_out_latency, recent_damage_out_latency, aim=0.8, slope=0.010, smoothing=sqrt))
#send speed:
if avg_send_speed is not None and recent_send_speed is not None:
#our calculate methods aims for lower values, so invert speed
#this is how long it takes to send 1MB:
avg1MB = 1.0*1024*1024/avg_send_speed
recent1MB = 1.0*1024*1024/recent_send_speed
#we only really care about this when the speed is quite low,
#so adjust the weight accordingly:
minspeed = float(128*1024)
div = logp(max(recent_send_speed, minspeed)/minspeed)
msg = "network send speed: avg=%s, recent=%s (KBytes/s), div=%s" % (int(avg_send_speed/1024), int(recent_send_speed/1024), div)
factors.append(calculate_for_average(msg, avg1MB, recent1MB, weight_offset=1.0, weight_div=div))
#client decode time:
if avg_decode_speed is not None and recent_decode_speed is not None:
msg = "client decode speed: avg=%s, recent=%s (MPixels/s)" % (dec1(avg_decode_speed/1000/1000), dec1(recent_decode_speed/1000/1000))
#our calculate methods aims for lower values, so invert speed
#this is how long it takes to send 1MB:
avg1MB = 1.0*1024*1024/avg_decode_speed
recent1MB = 1.0*1024*1024/recent_decode_speed
factors.append(calculate_for_average(msg, avg1MB, recent1MB, weight_offset=0.0))
#elapsed time without damage:
if batch.last_updated>0:
#If nothing happens for a while then we can reduce the batch delay,
#however we must ensure this is not caused by a high damage latency
#so we ignore short elapsed times.
ignore_time = max(max_latency+batch.recalculate_delay, batch.delay+batch.recalculate_delay)
ignore_count = 2 + ignore_time / batch.recalculate_delay
elapsed = time.time()-batch.last_updated
n_skipped_calcs = elapsed / batch.recalculate_delay
#the longer the elapsed time, the more we slash:
weight = logp(max(0, n_skipped_calcs-ignore_count))
msg = "delay not updated for %s ms (skipped %s times - highest latency is %s)" % (dec1(1000*elapsed), int(n_skipped_calcs), dec1(1000*max_latency))
factors.append((msg, 0, weight))
target_latency = statistics.get_target_client_latency(global_statistics.min_client_latency, avg_client_latency)
if len(global_statistics.client_latency)>0 and avg_client_latency is not None and recent_client_latency is not None:
#client latency: (we want to keep client latency as low as can be)
msg = "client latency:"
factors.append(calculate_for_target(msg, target_latency, avg_client_latency, recent_client_latency, aim=0.8, slope=0.005, smoothing=sqrt))
if len(global_statistics.client_ping_latency)>0:
msg = "client ping latency:"
factors.append(calculate_for_target(msg, target_latency, avg_client_ping_latency, recent_client_ping_latency, aim=0.95, slope=0.005, smoothing=sqrt, weight_multiplier=0.25))
if len(global_statistics.server_ping_latency)>0:
msg = "server ping latency:"
factors.append(calculate_for_target(msg, target_latency, avg_server_ping_latency, recent_server_ping_latency, aim=0.95, slope=0.005, smoothing=sqrt, weight_multiplier=0.25))
#damage packet queue size: (includes packets from all windows)
factors.append(queue_inspect("damage packet queue size:", global_statistics.damage_packet_qsizes, smoothing=sqrt))
#damage pixels waiting in the packet queue: (extract data for our window id only)
time_values = [(event_time, value) for event_time, dwid, value in list(global_statistics.damage_packet_qpixels) if dwid==wid]
factors.append(queue_inspect("damage packet queue pixels:", time_values, div=low_limit, smoothing=sqrt))
#damage data queue: (This is an important metric since each item will consume a fair amount of memory and each will later on go through the other queues.)
factors.append(queue_inspect("damage data queue:", global_statistics.damage_data_qsizes))
if global_statistics.mmap_size>0:
#full: effective range is 0.0 to ~1.2
full = 1.0-float(global_statistics.mmap_free_size)/global_statistics.mmap_size
#aim for ~50%
factors.append(("mmap area %s%% full" % int(100*full), logp(2*full), 2*full))
#now use those factors to drive the delay change:
update_batch_delay(batch, factors)
#***************************************************************
#special hook for video encoders
if video_encoder is None:
return
#***********************************************************
# encoding speed:
# 0 for highest compression/slower
# 100 for lowest compression/fast
# here we try to minimize damage-latency and client decoding speed
if fixed_speed>=0:
new_speed = fixed_speed
msg = "video encoder using fixed speed: %s", fixed_speed
else:
min_damage_latency = 0.010 + (0.050*low_limit/1024.0/1024.0)
target_damage_latency = min_damage_latency + batch.delay/1000.0
dam_lat = (avg_damage_in_latency or 0)/target_damage_latency
target_decode_speed = 1*1000*1000 #1 MPixels/s
dec_lat = 0.0
if avg_decode_speed:
dec_lat = target_decode_speed/(avg_decode_speed or target_decode_speed)
target = max(dam_lat, dec_lat, 0.0)
target_speed = 100.0 * min(1.0, target)
video_encoder_speed.append((time.time(), target_speed))
_, new_speed = calculate_time_weighted_average(video_encoder_speed)
msg = "video encoder speed factors: min_damage_latency=%s, target_damage_latency=%s, batch.delay=%s, dam_lat=%s, dec_lat=%s, target=%s, new_speed=%s", \
dec2(min_damage_latency), dec2(target_damage_latency), dec2(batch.delay), dec2(dam_lat), dec2(dec_lat), int(target_speed), int(new_speed)
log(*msg)
if DEBUG_DELAY:
add_DEBUG_DELAY_MESSAGE(msg)
#***********************************************************
# quality:
# 0 for lowest quality (low bandwidth usage)
# 100 for best quality (high bandwidth usage)
# here we try minimize client-latency, packet-backlog and batch.delay
if fixed_quality>=0:
new_quality = fixed_quality
msg = "video encoder using fixed quality: %s", fixed_quality
else:
packets_backlog, _, _ = statistics.get_backlog(target_latency)
packets_bl = 1.0 - logp(packets_backlog/low_limit)
batch_q = 4.0 * batch.min_delay / batch.delay
target = max(packets_bl, batch_q)
latency_q = 0.0
if len(global_statistics.client_latency)>0 and recent_client_latency>0:
latency_q = 4.0 * target_latency / recent_client_latency
target = min(target, latency_q)
target_quality = 100.0*(min(1.0, max(0.0, target)))
video_encoder_quality.append((time.time(), target_quality))
new_quality, _ = calculate_time_weighted_average(video_encoder_quality)
msg = "video encoder quality factors: packets_bl=%s, batch_q=%s, latency_q=%s, target=%s, new_quality=%s", \
dec2(packets_bl), dec2(batch_q), dec2(latency_q), int(target_quality), int(new_quality)
log(*msg)
if DEBUG_DELAY:
add_DEBUG_DELAY_MESSAGE(msg)
try:
video_encoder_lock.acquire()
video_encoder.set_encoding_speed(new_speed)
video_encoder.set_encoding_quality(new_quality)
finally:
video_encoder_lock.release()