Can't play a note with mingus - python

I've came to use mingus to try to reproduce some notes in python. Based on what was answered here, I've tried with:
from mingus.midi import fluidsynth
fluidsynth.init('/home/btc/Escritorio/SinestesiaRCB/gfx/ViolinsLong.sf2',"alsa")
fluidsynth.play_Note(64,0,100)
#Also tried with Note("C-5") and so forth
Using among others, one of this sf2 files. But then I got the error:
fluidsynth: warning: Failed to set thread to high priority
fluidsynth: warning: No preset found on channel 9 [bank=128 prog=0]
Researching a bit, this answer said:
For General MIDI compatibility, the default sound font instrument
assignments are bank 0, program 0 ("Acoustic Grand Piano") for
channels 0–8 and 10–15, and bank 128, program 0 ("Default Drum Set")
for channel 9. Apparently, your sound font does not have the latter.
This does not matter if your MIDI file does not assume General MIDI
compatible instruments and does not try to play drum sounds on channel
9.
But aside of this, that may made things a bit clearer, I still don't know how to solve it.
Plus, if I use the same file that the answer of the very first link, then the error I get is this one (and don't know how to solve it neither):
fluidsynth: warning: Failed to set thread to high priority
fluidsynth: warning: Failed to pin the sample data to RAM; swapping is possible.
Update
Running the program with sudo permissions removes this errors, but it doesn't sound. This way, the error I get is:
QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-root'
I thought it may be a problem with the selected driver mode in fluidsynth driver, but I've tried with them all (alsa, oss, and so forth) with the same result. Just for the sake of completeness, I'm running it within a VM, and other sounds inside it are correctly reproduced in my host speakers.
However based on this answer, I guess it should be solved by passing to it the right sound environment variable. Which I don't know. I've tried with:
pkexec env DISPLAY=$DISPLAY XAUTHORITY=$XAUTHORITY python3 /home/btc/Escritorio/SinestesiaRCB/SinestesiaRCB.py
Where the complete path to the file is needed since this needs sudo permissions and changes its working directory, and in the end the same error came: XDG_RUNTIME_DIR.
Update 2
If I run it with sudo -E option, the error is replaced by a new one:
QStandardPaths: wrong ownership on runtime directory /run/user/1000, 1000 instead of 0
I'm reading in some webs, that the 1000 user is supposed to be the default user instead of root.
Therefore, I've done a:
sudo chown root:root /run/user/1000
Just to try, and then the app runs without fails, but it still doesn't sound.
Update 3
Based on this example and this Q&A, I've tried both to use time sleep with several times, and using raw_input as well after (also before) doing a play_note, but it still doesn't sound.

I'll answer my own question, but the very big part of the debug/solving process is in the question itself done with updates.
The last part was to get it to sound, when not even waiting with sleep was making it work. Not even doing it before and after the play_note function. May I say that this function always returned True, so the note was expected to sound from the very beginning. The thing is, that the SF2 file (almost 150MB) was loaded successfully, or at least it seemed like it, since it returned True as well and was for sure pretty fast.
The solution
Let's continue after reaching the point where no errors were printed when executing my script (just before Update 3 in the Question).
I wanted to check how much CPU percent usage was doing my script, so I used top on my Linux terminal and found pulseaudio running from several days ago:
Killing this process allowed it to sound finally. However, I must say that a time.sleep() with about 0.25 seconds was added after the play_Note() function, in order to let it play the note completely.

Related

Debug a Python program which seems paused for no reason

I am writing a Python program to analyze log files. So basically I have about 30000 medium-size log files and my Python script is designed to perform some simple (line-by-line) analysis of each log file. Roughly it takes less than 5 seconds to process one file.
So once I set up the processing, I just left it there and after about 14 hours when I came back, my Python script simply paused right after analyzing one log file; seems that it hasn't written into the file system for the analyzing output of this file, and that's it. No more proceeding.
I checked the memory usage, it seems fine (less than 1G), I also tried to write to the file system (touch test), it also works as normal. So my question is that, how should I proceed to debug the issue? Could anyone share some thoughts on that? I hope this is not too general. Thanks.
You may use Trace or track Python statement execution and/or The Python Debugger module.
Try this tool https://github.com/khamidou/lptrace with command:
sudo python lptrace -p <process_id>
It will print every python function your program invokes and may help you understand where your program stucks or in an infinity loop.
If it does not output anything, that's proberbly your program get stucks, so try
pstack <process_id>
to check the stack trace and find out where stucks. The output of pstack is c frames, but I believe somehow you can find something useful to solve your problem.

"sh: Error: Can't open display" when I try to start a program from python

I have this really strange problem, basically I want to start xpdf (or Libreoffice) from my Python script, that is started by a systemd-service. When I start the script from terminal everything is working fine, but when I plug in my USB device that start the Service, I'll get this Error in my syslog:
sh[2321]: Error: Can't open Display
This error has something to do with X11, that's what my Google searches tell me.
So, my question is: How can I properly run a program like xpdf or libreoffice from Python?
import subprocess
subprocess.call("/usr/bin/xpdf")
This is it, basically. I know that it has something to do with the graphical enviroment, but I don't know how I can solve it.
The X display system has very good security to stop random local processes from just displaying stuff to the local screen (It was more a problem in the old days of expensive Sun and SGI systems where computer labs would often let users telnet to other boxes. Much fun could be had!).
If the user running the xpdf is the same user as the one who's logged into the X session, then you simply need to tell xpdf where to connect it's UI to. This is usually done by exporting DISPLAY=:0 to the environment, which means "connect to the first local screen". Most X programs also support -display :0 argument.
So do:
/usr/bin/xpdf -display :0
or:
DISPLAY=:0 /usr/bin/xpdf
It's very unlikely that you have more than one X session so :0 will work 99% of the time.
Since the issue is that xpdf isn't finding a display to connect to, we have two basic options: find and authenticate with an existing display, or make a new one. The latter is usually easier, something like:
xinit /usr/bin/xpdf -fullscreen $PDFFILE -- :2
This would start a new X display :2 running only xpdf, not even a window manager.
It finally worked, after trying and going crazy for around 2 weeks.
What worked was
os.system("DISPLAY=:0 /usr/bin/xpdf)
I know that subprocess.call is the better way to call the program, but it doesn't seem to work right now.
I'll try the way that Yann suggested later on, but for now I'm just overwhelmed with joy that it just works.
Thank you all for your help, I really appreciate it!

PyCharm: After each word is typed, there is a delay where one is unable to type

In PyCharm (JetBrains), I have been having trouble with typing full statements without getting an interuption. I first thought it was due to me not having updated the software, so I updated it, but the problem remains.
So if I type any statement or word, PyCharm seems to delay before I can proceed. An example:
import csv
Even before I finish typing "import" - if I delay a keystroke - PyCharm begins to "think" and the window is not accessible for about one to two seconds (quite literally). I assume it is going to give me suggestions or show a tip/error about the code.
Any thoughts to prevent this from happening?
Edit:
Windows 8.1; PyCharm 2016.2
Code Complete turned off via Settings->Editor->General->Code Completion, but did not solve problem.
Key PC Spec:
Intel Core i5-337U
4GB Ram
64-bit
Edit2:
I receive this error when I run anything now, including simply print("test"):
Process finished with exit code -1073741511 (0xC0000139)
Will separate the question somewhere else, since this may be a separate problem altogether.
Try disabling code completion. I believe that your computer can't search through all of Python's librarys fast enough so it freezes for a bit.

How to get rid of unkillable Freeswitch channels

After upgrading from Freeswitch 1.2.9 (1.2.9+git~20130506T233047Z~7c88f35451) to Freeswitch 1.4.21 (1.4.21-35~64bit), freeswitch stopped dropping channels after they were hung up, and when we tried to do a manual uuid_kill, it gives us this lovely error:
-ERR No such channel!
Even though show channels shows that channel clearly there. From the bugs on jira.freeswitch.com that I've seen, it looks like it may be a code problem. A little more info on our environment/code:
We have a python twisted loop that connects to the client so the client can run commands on the server and vice versa. As soon as that twisted connection dies (the client is closed/disconnected) the channels are killed as well, but we need the channel to die before then as we're taking a lot of calls per second and need them to die when the other end is disconnected. We can't close and reopen the client every time a call is done, or reconnect as that would take way too much time and defeats the purpose of our use of the software.
Once again, this error only started happening when we changed to installing the freeswitch server using apt-get instead of directly from source. This lets us get a new server up and running extremely faster, and we would rather not take the extra time to use our previous method. Please tell me if there's any code you would like to look at, and ask for any clarification you need, but we would really like this to be fixed soon. Thanks in advance!
Edit: For more clarification, we're mainly using mod_callcenter, mod_conference, and mod_sofia with our software.
Edit 2: For a little more clarification, we're running this on Ubuntu 14.04 Server
We are using an ESL connection to connect and run commands in freeswitch from python, and we think that's the root of the problem. We tried exiting the connection, but that destroys both channels.
Also, all of the bugs filed already for this problem on Jira are closed for not being bugs. I thought I may have a bit more success here, as it is a programming type question.
You need to reproduce the issue in a test environment and file the bug report to Jira. At best you should also try reproducing it with the latest master branch (only Debian 8 is supported):
https://freeswitch.org/confluence/display/FREESWITCH/Debian+8+Jessie
I had a similar problem when I used mod_perl, and a Perl object was referring to a session, and it was not properly destructed (if I remember it right, I had two Perl objects attached to the same session). That resulted in channels which were impossible to kill.
I suppose you are using a ESL connection between your application and FreeSWITCH, right?

RW-locking a Windows file in Python, so that at most one test instance runs per night

I have written a custom test harness in Python (existing stuff was not a good fit due to lots of custom logic). Windows task scheduler kicks it off once per hour every day. As my tests now take more than 2 hours to run and are growing, I am running into problems. Right now I just check the system time and do nothing unless hour % 3 == 0, but I do not like that. I have a text file that contains:
# This is a comment
LatestTestedBuild = 25100
# Blank lines are skipped too
LatestTestRunStartedDate = 2011_03_26_00:01:21
# This indicates that it has not finished yet.
LatestTestRunFinishDate =
Sometimes, when I kick off a test manually, it can happen at any time, including 12:59:59.99
I want to remove race conditions as much as possible. I would rather put some extra effort once and not worry about practical probability of something happening. So, I think locking a this text file atomically is the best approach.
I am using Python 2.7, Windows Server 2008R2 Pro and Windows 7 Pro. I prefer not to install extra libraries (Python has not been "sold" to my co-workers yet, but I could copy over a file locally that implements it all, granted that the license permits it).
So, please suggest a good, bullet-proof way to solve this.
When you start running a test make a file called __LOCK__ or something. Delete it when you finish, using a try...finally block to ensure that it always gets cleared up. Don't run the test if the file exists. If the computer crashes or similar, delete the file by hand. I doubt you need more cleverness than that.
Are you sure you need 2 hours of tests?! I think 2 minutes is a more reasonable amount of time to spend, though I guess if you are running some complicated numerics you might need more.
example code:
import os
if os.path.exists("__LOCK__"):
raise RuntimeError("Already running.") # or whatever
try:
open("__LOCK__", "w").write("Put some info here if you want.")
finally:
if os.path.exists("__LOCK__"):
os.unlink("__LOCK__")

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