Any idea why the playback tempo of audio files via an AVQueuePlayer is not an accurate product of the original audio file's tempo and the AVPlayers rate property? e.g. the original tempo is 100 b.p.m. and I set the rate to 0.7, expecting an output of audio playing at 70 b.p.m. But what I in fact get is a tempo around 65... (please excuse the inelegant code)
let assetQueue = [aVItem1, aVItem2, aVItem3, aVItem4, aVItem5, aVItem6, aVItem7, aVItem8, aVItem9, aVItem0]
var itemQueue: [AVPlayerItem] = []
for index in 0...9{
let nextItem: AVPlayerItem = AVPlayerItem(asset: assetQueue[index])
itemQueue.append(nextItem)
}
player = AVQueuePlayer(items: itemQueue)
player.play()
player.rate = 0.7
It plays perfectly at 100 b.p.m. when player.rate = 1.0
I need this to play accurately at all integer tempo values from 70 to 140 b.p.m. as it needs to synchronise with a tempo controlled UI element (the tempo of which is triggered using an NSTimer). Or is there maybe a simpler way to achieve this (perhaps with the setRate() method)?
Any assistance would be much appreciated :)
Related
I'm trying to find a way to check if i have any desktop audio AND what processes is producing sounds.
After some searching i found a way to list all the sink input in pipewire/pulseaudio using pactl list sink-inputs however i have no idea if that input is muted or not
example output:
Sink Input #512
Driver: protocol-native.c
Owner Module: 9
Client: 795
Sink: 1
Sample Specification: float32le 2ch 48000Hz
Channel Map: front-left,front-right
Format: pcm, format.sample_format = "\"float32le\"" format.rate = "48000" format.channels = "2" format.channel_map = "\"front-left,front-right\""
Corked: yes
Mute: no
Volume: front-left: 43565 / 66% / -10.64 dB, front-right: 43565 / 66% / -10.64 dB
balance 0.00
Buffer Latency: 165979 usec
Sink Latency: 75770 usec
Resample method: speex-float-1
Properties:
media.name = "Polish cow (English Lyrics Full Version) - YouTube"
application.name = "Firefox"
native-protocol.peer = "UNIX socket client"
native-protocol.version = "35"
application.process.id = "612271"
application.process.user = "user"
application.process.host = "host"
application.process.binary = "firefox"
application.language = "en_US.UTF-8"
window.x11.display = ":0"
application.process.machine_id = "93e71eeba04e43789f0972b7ea0e4b39"
application.process.session_id = "2"
application.icon_name = "firefox"
module-stream-restore.id = "sink-input-by-application-name:Firefox"
The obvious thing would be looking at the Mute and Volume line but that is not reliable at all, currently the youtube video is paused but Mute is show as no and Volume is still no different from when the youtube video is actually playing.
I need the solution to be script-able since I'll muting certain thing when there is another process that is making sounds, and play it again when there is no sound, using bash script. If it is not possible on pipewire/pulseaudio but it is possible with another sound server then please do tell me.
I'm recording audio with Julia and want to be able to trigger a 5 second recording after the audio signal exceeds a certain volume. This is my record script so far:
using PortAudio, SampledSignals, LibSndFile, FileIO, Dates
stream = PortAudioStream("HDA Intel PCH: ALC285 Analog (hw:0,0)")
buf = read(stream, 5s)
close(stream)
save(string("recording_", Dates.format(now(), "yyyymmdd_HHMMSS"), ".wav"), buf, Fs = 48000)
I'm new to Julia and signal processing in general. How can I tell this only to start recording once the audio exceeds a specified volume threshold?
You need to test the sound you capture for average amplitude and act on that. Save if loud enough, otherwise rinse and repeat.
using PortAudio, SampledSignals, LibSndFile, FileIO
const hassound = 10 # choose this to fit
suprathreshold(buf, thresh = hassound) = norm(buf) / sqrt(length(buf)) > thresh # power over threshold
stream = PortAudioStream("HDA Intel PCH: ALC285 Analog (hw:0,0)")
while true
buf = read(stream, 5s)
close(stream)
if suprathreshold(buf)
save("recording.wav", buf, Fs = 48000) # should really append here maybe???
end
end
I'm using AVFoundation capture session to output audio buffers through AVCaptureAudioDataOutput. The capture session is using the default application audio session. (ie. captureSession.usesApplicationAudioSession = true). I don't alter the audio session in any way.
The strange behavior is that the capture session returns audio buffers captured at a different frequency than the default audio session's sample rate.
Specifically:
print(AVAudioSession.sharedInstance().sampleRate) \\ 48000
but
func captureOutput(_ output: AVCaptureOutput, didOutput sampleBuffer: CMSampleBuffer, from connection: AVCaptureConnection) {
if connection.audioChannels.first != nil {
print(sampleBuffer.presentationTimeStamp) \\ CMTime(value: 2199812320, timescale: 44100, flags: __C.CMTimeFlags(rawValue: 3), epoch: 0)
delegate?.captureOutput(sampleBuffer: sampleBuffer, mediaType: .audio)
}
}
My expected behavior is that the sample buffer's timescale would also be 48000.
For a little extra info, if I do change the default audio session, for example, change preferred sample rate to 48000, the sample buffer's timescale will change to 48000 as expected. Is this a bug or am I misunderstanding something?
You need to set the capture session's automaticallyConfiguresApplicationAudioSession to false and do your own audio session configuration before starting the capture session.
Like this:
// use audioSession.setPreferredSampleRate() to request desired sample rate
captureSession.automaticallyConfiguresApplicationAudioSession = false
try! AVAudioSession.sharedInstance().setCategory(.playAndRecord) // or just record
try! AVAudioSession.sharedInstance().setActive(true) // worked without this, but feels wrong
I am trying to parse raw data results from a text file into an organised tuple but having trouble getting it right.
My raw data from the textfile looks something like this:
Episode Cumulative Results
EpisodeXD0281119
Date collected21/10/2019
Time collected10:00
Real time PCR for M. tuberculosis (Xpert MTB/Rif Ultra):
PCR result Mycobacterium tuberculosis complex NOT detected
Bacterial Culture:
Bottle: Type FAN Aerobic Plus
Result No growth after 5 days
EpisodeST32423457
Date collected23/02/2019
Time collected09:00
Gram Stain:
Neutrophils Occasional
Gram positive bacilli Moderate (2+)
Gram negative bacilli Numerous (3+)
Gram negative cocci Moderate (2+)
EpisodeST23423457
Date collected23/02/2019
Time collected09:00
Bacterial Culture:
A heavy growth of
1) Klebsiella pneumoniae subsp pneumoniae (KLEPP)
ensure that this organism does not spread in the ward/unit.
A heavy growth of
2) Enterococcus species (ENCSP)
Antibiotic/Culture KLEPP ENCSP
Trimethoprim-sulfam R
Ampicillin / Amoxic R S
Amoxicillin-clavula R
Ciprofloxacin R
Cefuroxime (Parente R
Cefuroxime (Oral) R
Cefotaxime / Ceftri R
Ceftazidime R
Cefepime R
Gentamicin S
Piperacillin/tazoba R
Ertapenem R
Imipenem S
Meropenem R
S - Sensitive ; I - Intermediate ; R - Resistant ; SDD - Sensitive Dose Dependant
Comment for organism KLEPP:
** Please note: this is a carbapenem-RESISTANT organism. Although some
carbapenems may appear susceptible in vitro, these agents should NOT be used as
MONOTHERAPY in the treatment of this patient. **
Please isolate this patient and practice strict contact precautions. Please
inform Infection Prevention and Control as contact screening might be
indicated.
For further advice on the treatment of this isolate, please contact.
The currently available laboratory methods for performing colistin
susceptibility results are unreliable and may not predict clinical outcome.
Based on published data and clinical experience, colistin is a suitable
therapeutic alternative for carbapenem resistant Acinetobacter spp, as well as
carbapenem resistant Enterobacteriaceae. If colistin is clinically indicated,
please carefully assess clinical response.
EpisodeST234234057
Date collected23/02/2019
Time collected09:00
Authorised by xxxx on 27/02/2019 at 10:35
MIC by E-test:
Organism Klebsiella pneumoniae (KLEPN)
Antibiotic Meropenem
MIC corrected 4 ug/mL
MIC interpretation Resistant
Antibiotic Imipenem
MIC corrected 1 ug/mL
MIC interpretation Sensitive
Antibiotic Ertapenem
MIC corrected 2 ug/mL
MIC interpretation Resistant
EpisodeST23423493
Date collected18/02/2019
Time collected03:15
Potassium 4.4 mmol/L 3.5 - 5.1
EpisodeST45445293
Date collected18/02/2019
Time collected03:15
Creatinine 32 L umol/L 49 - 90
eGFR (MDRD formula) >60 mL/min/1.73 m2
Creatinine 28 L umol/L 49 - 90
eGFR (MDRD formula) >60 mL/min/1.73 m2
Essentially the pattern is that ALL information starts with a unique EPISODE NUMBER and follows with a DATE and TIME and then the result of whatever test. This is the pattern throughout.
What I am trying to parse into my tuple is the date, time, name of the test and the result - whatever it might be. I have the following code:
with open(filename) as f:
data = f.read()
data = data.splitlines()
DS = namedtuple('DS', 'date time name value')
parsed = list()
idx_date = [i for i, r in enumerate(data) if r.strip().startswith('Date')]
for start, stop in zip(idx_date[:-1], idx_date[1:]):
chunk = data[start:stop]
date = time = name = value = None
for row in chunk:
if not row: continue
row = row.strip()
if row.startswith('Episode'): continue
if row.startswith('Date'):
_, date = row.split()
date = date.replace('collected', '')
elif row.startswith('Time'):
_, time = row.split()
time = time.replace('collected', '')
else:
name, value, *_ = row.split()
print (name)
parsed.append(DS(date, time, name, value))
print(parsed)
My error is that I am unable to find a way to parse the heterogeneity of the test RESULT in a way that I can use later, for example for the tuple DS ('DS', 'date time name value'):
DATE = 21/10/2019
TIME = 10:00
NAME = Real time PCR for M tuberculosis or Potassium
RESULT = Negative or 4.7
Any advice appreciated. I have hit a brick wall.
I am creating a Solar Array Simulator with python to simulate the voltage and current being created with different angles and intensities of sunlight as a satellite orbits around the earth. I have a very simple program that outputs the voltage and current just with the angle (no orbiting parameters yet). However, I need it to communicate the outputs generated with a E4350B model solar array simulator through a serial port, and I don't know where to start. I have installed pip and used that to install PySerial but do not know what to do from there. How do I communicate the voltage and amp outputs to the simulator through COM ports? Here is what I have for my program that runs the simulator.
from math import sin,radians,pi
import time
'''Needed information:
Voc (per one cell) = 2,680mV
Vmp (per one cell = 2,325mV
Isc (per one cell) = 453mA
Imp (per one cell) = 434mA
angular velocity = .05d/s'''
#Timer eclipse set for total eclipse tim ein seconds
timeEclipse = 1800
#total eclipse time = 30 mins
#Timer sun set for how many seconds it takes to change one degree
timeSun = 20
#Total sun exposer time = 60 mins
#Find the Vmp, Voc, Imp, and Isc from Beta angles 0 - 180
def Exposure():
tSun = timeSun
for x in range(0,181):
angle = sin(radians(x))
Voc = 2680 * angle
Vmp = 2325 * angle
#Amps are going to be a function of voltage
Isc = 453 * angle
Imp = 434 * angle
#
print('At angle ',x,' Vmp = ',Vmp,
'mV, Voc = ',Voc,'mV, Isc = ',Isc,'mA, and Imp = ',Imp,'mA')
time.sleep(tSun)
#Simulate time during eclipse
#Outputs nothing
def Eclipse():
tEclipse = timeEclipse
time.sleep(tEclipse)
#Run loop through Exposure and eclipse
def Run():
run = True
while(run):
Exposure()
Eclipse()
P.S. For anybody who dabbles in a little bit of physics, I need a way to find the current as a function of the voltage at every angle.