Thanks in advance.
I'm trying to crop a .mp4 video using an ffmpeg binary (within the context of an electron-react-app).
(The binary is run in a child process using execFile() and outputs to a temp folder which is later deleted)
ffmpeg varies considerably in the time it takes to complete the creation of a cropped video file (1sec to 18sec) depending on the computer (mac vs Windows).
I need to read the cropped video file.
I've set up an event listener in the Main process of electron
if (!monitorCroppedFile) {
console.log(`${croppedFilePath} doesn't exist`);
} else {
console.log(`${croppedFilePath} exists !`)
...readFile...;
Once monitorCroppedFile = true I read it using fs.readfile().
The problem is that ffmpeg initally creates the cropped file path but it sometimes takes ages to complete the process of cropping.
This results in the read file often being blank (as the read is triggered on detecting the file path of the cropped file).
I've tried using -preset ultrafast in the ffmpeg arguments but this only improves things on Windows marginally.
The problem doesn't occur on Macs.
Can anybody suggest a possible solution ? Is there a way to detect when the crop is fully completed ?
Many thanks.
Add -progress FILE to your command where FILE should be a filename. ffmpeg will log processing status to that file. Search for the line progress=end in it. Once you find it, you can read the file.
I have added a feature to an application to allow the user to create a local backup on external storage. That part is working great, but I am having trouble restoring that back up.
Using the SAF, I have found an easy way for the user to select the file they are wanting to restore. The file they choose comes back to the app as a DocumentFile
How can I open the DocumentFile and read its contents on API 26 and up?
So far I tried 2 things and neither worked:
1)
new File(myDocumentFile.getUri().getPath())
2)
I've tried this answer but it didn't work. It is also so hacky and I don't really need access to the java.io.File I just need a way to read the contents.
How does Google want us to approach reading user's files?
Kotlin code to read lines from a text file (where 'file' is a DocumentFile)
val inputStream = contentResolver.openInputStream(file.uri)
val reader = BufferedReader(InputStreamReader(inputStream))
val lines = reader.readLines()
For flask web app, I know I can't read a "file" multiple times from request.files because it's a stream. So when I read it once, I'll empty it. But I need to use the "file" multiple times without saving it locally and I'm having trouble doing it.
For example, from this
image = request.files["image"]
I'd like to have something like
image2 = image.copy
and perform different operations on image and image2.
Can someone please help me with this?
image = request.files["image"]
# Seek the pointer to the beginning of the file to read again
request.files["image"].seek(0)
After reading a file just run "f.stream.seek(0)" this points to the beginning of the file stream and then you are able to read the file from beginning again, you can simply put the following snippet in a loop and see it in action.
f.stream.seek(0)
stream = io.StringIO(f.stream.read().decode("UTF8"), newline=None)
reader = csv.reader(stream)
for row in reader:
print(row)
I am trying to open a pdf to get the number of pages. I am using PyPDF2.
Here is my code:
def pdfPageReader(file_name):
try:
reader = PyPDF2.PdfReader(file_name, strict=True)
number_of_pages = len(reader.pages)
print(f"{file_name} = {number_of_pages}")
return number_of_pages
except:
return "1"
But then i run into this error:
PdfReadWarning: Xref table not zero-indexed. ID numbers for objects will be corrected. [pdf.py:1736]
I tried to use strict=True and strict=False, When it is True, it displays this message, and nothing, I waited for 30minutes, but nothing happened. When it is False, it just display nothing, and that's it, just do nothing, if I press ctrl+c on the terminal (cmd, windows 10) then it cancel that open and continues (I run this in a batch of pdf files). Only 1 in the batch got this problem.
My questions are, how do I fix this, or how do I skip this, or how can I cancel this and move on with the other pdf files?
If somebody had a similar problem and it even crashed the program with this error message
File "C:\Programy\Anaconda3\lib\site-packages\PyPDF2\pdf.py", line 1604, in getObject
% (indirectReference.idnum, indirectReference.generation, idnum, generation))
PyPDF2.utils.PdfReadError: Expected object ID (14 0) does not match actual (13 0); xref table not zero-indexed.
It helped me to add the strict argument equal to False for my pdf reader
pdf_reader = PdfReader(input_file, strict=False)
For anybody else who may be running into this problem, and found that strict=False didn't help, I was able to solve the problem by just re-saving a new copy of the file in Adobe Acrobat Reader. I just opened the PDF file inside an actual copy of Adobe Acrobat Reader (the plain ol' free version on Windows), did a "Save as...", and gave the file a new name. Then I ran my script again using the newly saved copy of my PDF file.
Apparently, the PDF file I was using, which were generated directly from my scanner, were somehow corrupt, even though I could open and view it just fine in Reader. Making a duplicate copy of the file via re-saving in Acrobat Reader somehow seemed to correct whatever was missing.
I had the same problem and looked for a way to skip it. I am not a programmer but looking at the documentation about warnings there is a piece of code that helps you avoid such hindrance.
Although I wouldn't recomend this as a solution, the piece of code that I used for my purpose is (just copied and pasted it from doc on link)
import sys
if not sys.warnoptions:
import warnings
warnings.simplefilter("ignore")
This happens to me when the file was created in a printer / scanner combo that generates PDFs. I could read in the PDF with only a warning though so I read it in, and then rewrote it as a new file. I could append that new one.
from PyPDF2 import PdfMerger, PdfReader, PdfWriter
reader = PdfReader("scanner_generated.pdf", strict=False)
writer = PdfWriter()
for page in reader.pages:
writer.add_page(page)
with open("fixedPDF.pdf", "wb") as fp:
writer.write(fp)
merger = PdfMerger()
merger.append("fixedPDF.pdf")
I had the exact same problem, and the solutions did help but didn't solve the problem completely, at least the one setting strict=False & resaving the document using Acrobat reader.
Anyway, I still got a stream error, but I was able to fix it after using an PDF online repair. I used sejda.com but please be aware that you are uploading your PDF on some website, so make sure there is nothing sensible in there.
Not sure about unix, but in windows you can add attributes to files, like a location on a photo file or a duration on a video file.
Is there a way to do this in node js. Would be very handy with my currently project. It would save me having to create separate attribute data files.
You may use the WinAttr package to do that.
See this module:
https://www.npmjs.com/package/winattr
But it's for attributes like archive, hidden, readonly, system.
I don't think you can add an attribute of of duration to the video file - the duration is written in the container/codec of the video itself. The location for images is in the EXIF data - which can be manipulated with other modules on npm - see:
https://www.npmjs.com/search?q=EXIF
For the location on a photo file or a duration on a video file you need to use whatever information is appropriate for that given image or video format.
You can run a SHELL command:
var execSync = require('child_process').execSync;
// Remove Hidden and system attributes:
execSync("attrib -h -s " + yourFolder);
// Add Hidden attribute:
execSync("attrib +h " + yourFolder);