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Merge audio (m4s) segments into one

I recently started learning Laravel, and currently watching an online course. Online courses are fine, but I like to have local copies, so I'm trying to download/merge segmented audio from Laracasts: Laravel 8 From Scratch series.
I've written some scripts (in Python) that does the following:
Download the master.json
Read master.json and download audio segments
Merge the segments into a single file (the file is not playable yet)
Process the audio file via ffmpeg (now it's playable, but has issues)
I think there's a problem with the step 3 and/or 4.
In step/script 3, I create a new file, and add the contents of the segments to the file in binary.
Then (step/script 4), run a ffmpeg command in python: ffmpeg -i merged-file.mp4 -c copy processed-file.mp4
However, the final file doesn't work/play as expected. There's a delay in the beginning, and some parts seem to be cut off/skipped.
There are three possibilities:
Segment files are problematic (not likely?)
I'm doing the merging wrong
I'm doing the ffmpeg processing wrong
Can someone guide me here?
The issues/colored parts in the ffmpeg output are:
...
[mov,mp4,m4a,3gp,3g2,mj2 # 000001cfbc0de780] could not find corresponding track id 2
[mov,mp4,m4a,3gp,3g2,mj2 # 000001cfbc0de780] could not find corresponding trex (id 2)
...
[aac # 000001cfbc0f0380] Number of bands (31) exceeds limit (6).
...
[mp4 # 000001cfbc20ecc0] track 0: codec frame size is not set
...
[mp4 # 000001cfbc20ecc0] Non-monotonous DTS in output stream 0:0; previous: 318318, current: 286286; changing to 318319. This may result in incorrect timestamps in the output file.
...
Everything required for a test case is located in GitHub (akinuri/dump/m4s-segments/). Screenshot of the contents:
Note: there are two types/formats of audio in the master.json: mp42 and dash. dash works as expected, and seem to be used in limited videos/courses. On the other hand, mp42 appears more. So I need a way to make mp42 work.

Use imshow with Matlab Python engine

After building and installing the Python engine shipped with Matlab 2019b in Anaconda
(TestEnvironment) PS C:\Program Files\MATLAB\R2019b\extern\engines\python> C:\Users\USER\Anaconda3\envs\TestEnvironment\python.exe .\setup.py build -b C:\Users\USER\MATLAB\build_temp install
for Python 3.7 I wrote a simple script to test a couple of features I'm interested in:
import matlab.engine as ml_e
# Start Matlab engine
eng = ml_e.start_matlab()
# Load MAT file into engine. The result is a dictionary
mat_file = "samples/lena.mat"
lenaMat = eng.load("samples/lena.mat")
print("Variables found in \"" + mat_file + "\"")
for key in lenaMat.keys():
print(key)
# print(lenaMat["lena512"])
# Use the variable from the MAT file to display it as an image
eng.imshow(lenaMat["lena512"], [])
I have a problem with imshow() (or any similar function that displays a figure in the Matlab GUI on the screen) namely that it shows quickly and then disappears, which - I guess - at least confirms that it is possible to use it. The only possibility to keep it on the screen is to add an infinite loop at the end:
while True:
continue
For obvious reasons this is not a good solution. I am not looking for a conversion of Matlab data to NumPy or similar and displaying it using matplotlib or similar third party libraries (I am aware that SciPy can load MAT files for example). The reason is simple - I would like to use Matlab (including loading whole environments) and for debugging purposes I'd like to be able to show this and that result without having to go through loops and hoops of converting the data manually.

split midi file for each bar in python

I want to divide the MIDI file in python into bars and get the notes in that bars.
So I use music21 library and I can get the notes but I can't split it up by bar.
I want to know what kind of notes are in bar 1 and what are in bar 2.
I hope I can get some help with this problem.Thank you.

In recent versions of music21 (v7+ released after this question was first posted), you can just load the MIDI file and iterate on each measure, using the .measure(num) function and checking if the item returned has any measures in it:
myScore = converter.parse('filename.mid')
i = 1
while (measureStack := myScore.measure(i))[stream.Measure]:
print(len(measureStack[note.Note]))
i += 1
Prior to v7, you'll want to run myScore.makeMeasures(inPlace=True) before running this code. (Before v7, you'll also want to call .recurse().getElementsByClass(XXXX) instead of [XXXX]

Python Movie.py error on writing more than 4 videos

I've been trying to figure out this problem the entire day. I'm trying to add a image at the bottom of every video in a directory.
Here is the error that i get after writing just 4 videos out of 100
del self.reader
AttributeError: reader
Exception ignored in: <bound method VideoFileClip.__del__ of <moviepy.video.io.VideoFileClip.VideoFileClip object at 0x03D787B0>>
Here is how im trying to write the video
video = CompositeVideoClip([clip1, clip2.set_duration(clip1.duration)])
video = CompositeVideoClip("mixclip"+random.randint(999,999999)"+.mp4")
del video
del clip1
del clip2
Edit: Posted a slightly wrong code which i made while i was testing and got a instant a -1. Changed it. But i still cannot find solution to this problem.
Edit2: Tested alot and figured it out. Fixed it by declaring clip2 duration before mixing it. Rewrote entire code didn't check what other changes i made but its working as intended now.

Update to the latest version at the GitHub repo or wait until the next moviepy update is pushed to PyPI, where this is fixed. (See these commits: one, two)
However, unless you tell us what the line
video = CompositeVideoClip("mixclip"+random.randint(999,999999)"+.mp4")
means, you may be coming across an underlying problem with your usage.
Just a side note: the above line has a couple of errors; change it to this:
video = CompositeVideoClip("mixclip" + str(random.randint(999, 999999)) + ".mp4")

How to organize a Python GIS-project with multiple analysis steps?

I just started to use ArcPy to analyse geo-data with ArcGIS. The analysis has different steps, which are to be executed one after the other.
Here is some pseudo-code:
import arcpy
# create a masking variable
mask1 = "mask.shp"
# create a list of raster files
files_to_process = ["raster1.tif", "raster2.tif", "raster3.tif"]
# step 1 (e.g. clipping of each raster to study extent)
for index, item in enumerate(files_to_process):
raster_i = "temp/ras_tem_" + str(index) + ".tif"
arcpy.Clip_management(item, '#', raster_i, mask1)
# step 2 (e.g. change projection of raster files)
...
# step 3 (e.g. calculate some statistics for each raster)
...
etc.
This code works amazingly well so far. However, the raster files are big and some steps take quite long to execute (5-60 minutes). Therefore, I would like to execute those steps only if the input raster data changes. From the GIS-workflow point of view, this shouldn't be a problem, because each step saves a physical result on the hard disk which is then used as input by the next step.
I guess if I want to temporarily disable e.g. step 1, I could simply put a # in front of every line of this step. However, in the real analysis, each step might have a lot of lines of code, and I would therefore prefer to outsource the code of each step into a separate file (e.g. "step1.py", "step2.py",...), and then execute each file.
I experimented with execfile(step1.py), but received the error NameError: global name 'files_to_process' is not defined. It seems that the variables defined in the main script are not automatically passed to scripts called by execfile.
I also tried this, but I received the same error as above.
I'm a total Python newbie (as you might have figured out by the misuse of any Python-related expressions), and I would be very thankful for any advice on how to organize such a GIS project.

I think what you want to do is build each step into a function. These functions can be stored in the same script file or in their own module that gets loaded with the import statement (just like arcpy). The pseudo code would be something like this:
#file 1: steps.py
def step1(input_files):
# step 1 code goes here
print 'step 1 complete'
return
def step2(input_files):
# step 2 code goes here
print 'step 2 complete'
return output # optionally return a derivative here
#...and so on
Then in a second file in the same directory, you can import and call the functions passing the rasters as your inputs.
#file 2: analyze.py
import steps
files_to_process = ["raster1.tif", "raster2.tif", "raster3.tif"]
steps.step1(files_to_process)
#steps.step2(files_to_process) # uncomment this when you're ready for step 2
Now you can selectively call different steps of your code and it only requires commenting/excluding one line instead of a whle chunk of code. Hopefully I understood your question correctly.