Slow Startup?

[maribox]

Is it just me or is the app kind of slow in startup?
Like it's about 4-5 seconds on a machine with 1 4k, 1 Full-HD, and 1 ~Full-HD (weird format) monitors, compared to 1 second with Spectacle

[dynobo]

Hi @maribox, I guess you are running on Wayland, right?

Unfortunately, the official way to take screenshots on Wayland (through dbus portal) is quite slow, because the image needs to be saved to disk and loaded again (plus some additional communication time). This is especially true for multi-display and high resolution (large image size).

I observed the same behavior as you did, that the default screenshot tools (Spectacle on KDE, Screenshot on Gnome) are a lot faster. Other 3rd party tools I tried suffer from the similar performance issue as NormCap. Honestly, I don't know why the native tools are so fast, but I could imagine that the KDE/Gnome developers allowed their default tools a direct access to the screenshot API and do not have to go through dbus portal.

Would you mind providing me the debug log of such a slow startup? This would allow me to verify, that it's indeed the dbus portal access that burns the seconds...

[maribox]

Certainly! (And yes, I am running on Wayland)

flatpak run --command=normcap com.github.dynobo.normcap -v debug
01:49:28 - INFO    - normcap:49 - Start NormCap v0.5.4
01:49:28 - DEBUG   - normcap:95 - Set XCURSOR_SIZE=24
01:49:28 - DEBUG   - normcap:100 - Set QT_QPA_PLATFORM=wayland
01:49:28 - DEBUG   - normcap.gui.tray:77 - System info:
{'normcap_version': '0.5.4', 'python_version': '3.11.9', 'cli_args': '/app/bin/normcap -v debug', 'is_briefcase_package': False, 'is_flatpak_package': True, 'is_appimage_package': False, 'platform': 'linux', 'desktop_environment': <DesktopEnvironment.KDE: 2>, 'display_manager_is_wayland': True, 'pyside6_version': '6.6.1', 'qt_version': '6.6.1', 'qt_library_path': '/usr/share/runtime/lib/plugins, /app/lib/python3.11/site-packages/PySide6/Qt/plugins, /usr/bin', 'locale': 'DEFAULT', 'config_directory': PosixPath('/home/fed/.var/app/com.github.dynobo.normcap/config/normcap'), 'resources_path': PosixPath('/app/lib/python3.11/site-packages/normcap/resources'), 'tesseract_path': PosixPath('/app/bin/tesseract'), 'tessdata_path': PosixPath('/home/fed/.var/app/com.github.dynobo.normcap/config/normcap/tessdata'), 'envs': {'TESSDATA_PREFIX': '/app/share', 'LD_LIBRARY_PATH': ''}, 'screens': [Screen(left=3760, top=400, right=5679, bottom=1599, device_pixel_ratio=1.0, index=0, screenshot=None), Screen(left=0, top=0, right=1199, bottom=1599, device_pixel_ratio=1.0, index=1, screenshot=None), Screen(left=1200, top=280, right=3759, bottom=1719, device_pixel_ratio=2.0, index=2, screenshot=None)]}
01:49:28 - DEBUG   - normcap.gui.settings:162 - Skip update of non existing setting (show_introduction: None)
01:49:28 - DEBUG   - normcap.gui.settings:162 - Skip update of non existing setting (cli_mode: False)
01:49:28 - DEBUG   - normcap.gui.settings:162 - Skip update of non existing setting (background_mode: False)
01:49:28 - DEBUG   - normcap.gui.settings:162 - Skip update of non existing setting (clipboard_handler: None)
01:49:28 - DEBUG   - normcap.gui.tray:388 - Listen on local socket v0.5.4-normcap.
01:49:28 - DEBUG   - normcap.screengrab.main:32 - Select capture method DBUS portal
01:49:28 - DEBUG   - normcap.screengrab.dbus_portal:94 - DBus request message: <PySide6.QtDBus.QDBusMessage(type=MethodReturn, service=":1.27", signature="o", contents=([ObjectPath: /org/freedesktop/portal/desktop/request/1_375/normcap_geffhehi]) ) at 0x7f9ff9177b40>
01:49:28 - DEBUG   - normcap.screengrab.dbus_portal:101 - Request accepted
01:49:28 - DEBUG   - normcap.ocr.tesseract:24 - Executing '/app/bin/tesseract --list-langs --tessdata-dir /home/fed/.var/app/com.github.dynobo.normcap/config/normcap/tessdata'
01:49:28 - DEBUG   - normcap.ocr.tesseract:37 - Tesseract command output: List of available languages in "/home/fed/.var/app/com.github.dynobo.normcap/config/normcap/tessdata/" (3): ¬ deu ¬ eng ¬ equ ¬
01:49:29 - DEBUG   - normcap.screengrab.dbus_portal:121 - DBus signal message: <PySide6.QtDBus.QDBusMessage(type=Signal, service=":1.27", path="/org/freedesktop/portal/desktop/request/1_375/normcap_geffhehi", interface="org.freedesktop.portal.Request", member="Response", signature="ua{sv}", contents=(0, [Argument: a{sv} {"uri" = [Variant(QString): "file:///run/user/1000/doc/8cd10bf8/Screenshot_20240510_014928.png"]}]) ) at 0x7f9ff97bad40>
01:49:29 - DEBUG   - normcap.screengrab.dbus_portal:139 - Parse response
01:49:29 - DEBUG   - normcap.screengrab.utils:25 - Virtual geometry width: 5680
01:49:29 - DEBUG   - normcap.screengrab.utils:26 - Image width: 8520
01:49:29 - DEBUG   - normcap.screengrab.utils:27 - Resize ratio: 1.5
01:49:29 - DEBUG   - normcap.gui.utils:22 - Save debug image as /tmp/normcap/2024-05-09_23-49-29_raw_screen0.png
01:49:30 - DEBUG   - normcap.gui.utils:22 - Save debug image as /tmp/normcap/2024-05-09_23-49-30_raw_screen1.png
01:49:30 - DEBUG   - normcap.gui.utils:22 - Save debug image as /tmp/normcap/2024-05-09_23-49-30_raw_screen2.png
01:49:30 - DEBUG   - normcap.gui.window:52 - Create window for screen 0
01:49:30 - DEBUG   - normcap.gui.window:128 - Set window of screen 0 to fullscreen
01:49:32 - DEBUG   - normcap.gui.dbus:126 - Moving window 'NormCap [0]' to (left=3760, top=400, right=5679, bottom=1599) via org.kde.kwin.Scripting
01:49:32 - WARNING - normcap.gui.dbus:156 - Failed to move window via org.kde.kwin.Scripting!
01:49:32 - DEBUG   - normcap.gui.dbus:157 - Traceback (most recent call last):
  File "/app/lib/python3.11/site-packages/normcap/gui/dbus.py", line 150, in move_window_via_kde_kwin_scripting
    raise RuntimeError(  # noqa: TRY301
RuntimeError: ('org.kde.kwin.Scripting.loadScript response: %s', (1,))
01:49:32 - DEBUG   - normcap.gui.window:52 - Create window for screen 1
01:49:32 - DEBUG   - normcap.gui.window:128 - Set window of screen 1 to fullscreen
01:49:32 - DEBUG   - normcap.gui.dbus:126 - Moving window 'NormCap [1]' to (left=0, top=0, right=1199, bottom=1599) via org.kde.kwin.Scripting
01:49:32 - WARNING - normcap.gui.dbus:156 - Failed to move window via org.kde.kwin.Scripting!
01:49:32 - DEBUG   - normcap.gui.dbus:157 - Traceback (most recent call last):
  File "/app/lib/python3.11/site-packages/normcap/gui/dbus.py", line 150, in move_window_via_kde_kwin_scripting
    raise RuntimeError(  # noqa: TRY301
RuntimeError: ('org.kde.kwin.Scripting.loadScript response: %s', (2,))
01:49:32 - DEBUG   - normcap.gui.window:52 - Create window for screen 2
01:49:32 - DEBUG   - normcap.gui.window:128 - Set window of screen 2 to fullscreen
01:49:32 - DEBUG   - normcap.gui.dbus:126 - Moving window 'NormCap [2]' to (left=1200, top=280, right=3759, bottom=1719) via org.kde.kwin.Scripting
01:49:32 - WARNING - normcap.gui.dbus:156 - Failed to move window via org.kde.kwin.Scripting!
01:49:32 - DEBUG   - normcap.gui.dbus:157 - Traceback (most recent call last):
  File "/app/lib/python3.11/site-packages/normcap/gui/dbus.py", line 150, in move_window_via_kde_kwin_scripting
    raise RuntimeError(  # noqa: TRY301
RuntimeError: ('org.kde.kwin.Scripting.loadScript response: %s', (3,))
01:49:40 - DEBUG   - normcap.gui.tray:354 - Hide 3 windows
01:49:40 - INFO    - normcap.gui.tray:246 - Crop image to region (1537, 1131, 1585, 1219)
01:49:40 - DEBUG   - normcap.gui.utils:22 - Save debug image as /tmp/normcap/2024-05-09_23-49-40_cropped.png
01:49:40 - DEBUG   - normcap.gui.tray:271 - Start OCR
01:49:40 - DEBUG   - normcap.ocr.enhance:84 - Scale image x2
01:49:40 - DEBUG   - normcap.ocr.enhance:57 - Pad image by 80px
01:49:40 - DEBUG   - normcap.ocr.recognize:35 - Run Tesseract on image of size (258, 338) with args:
TessArgs(tessdata_path=PosixPath('/home/fed/.var/app/com.github.dynobo.normcap/config/normcap/tessdata'), lang='eng', oem=<OEM.DEFAULT: 3>, psm=<PSM.AUTO: 3>)
01:49:40 - DEBUG   - normcap.ocr.tesseract:24 - Executing '/app/bin/tesseract /tmp/tmp02usg0f4/normcap_tesseract_input.png /tmp/tmp02usg0f4/normcap_tesseract_input.png -c tessedit_create_tsv=1 -l eng --oem 3 --psm 3 --tessdata-dir /home/fed/.var/app/com.github.dynobo.normcap/config/normcap/tessdata -c tessedit_write_images=1 -c tessedit_dump_pageseg_images=1'
01:49:40 - DEBUG   - normcap.ocr.tesseract:37 - Tesseract command output: 
01:49:40 - DEBUG   - normcap.ocr.tesseract:67 - Skip moving file to temp dir, it does not exist: /tmp/tmp02usg0f4/normcap_tesseract_input.png.png_debug.pdf
01:49:40 - DEBUG   - normcap.ocr.recognize:44 - OCR result:
OcrResult(tess_args=TessArgs(tessdata_path=PosixPath('/home/fed/.var/app/com.github.dynobo.normcap/config/normcap/tessdata'), lang='eng', oem=<OEM.DEFAULT: 3>, psm=<PSM.AUTO: 3>), words=[], image=<PySide6.QtGui.QImage(QSize(258, 338),format=QImage::Format_RGB32,depth=32,devicePixelRatio=1,bytesPerLine=1032,sizeInBytes=348816) at 0x7f9ff9076e40>, magic_scores={}, parsed='')
01:49:40 - INFO    - normcap.ocr.magics.email_magic:60 - 0 emails found 
01:49:40 - DEBUG   - normcap.ocr.magics.email_magic:71 - 0/0 (0) chars in emails
01:49:40 - INFO    - normcap.ocr.magics.url_magic:57 - 0 URLs found 
01:49:40 - DEBUG   - normcap.ocr.magics.url_magic:65 - 0/1 (0.0) chars in urls
01:49:40 - DEBUG   - normcap.ocr.magic:82 - Magic scores:
{'SingleLineMagic': 1, 'MultiLineMagic': 0, 'ParagraphMagic': 200.0, 'EmailMagic': 0, 'UrlMagic': 0.0}
01:49:40 - DEBUG   - normcap.ocr.recognize:48 - Parsed text:

01:49:40 - DEBUG   - normcap.gui.utils:22 - Save debug image as /tmp/normcap/2024-05-09_23-49-40_enhanced.png
01:49:40 - INFO    - normcap.gui.tray:289 - Text from OCR:

01:49:40 - DEBUG   - normcap.gui.tray:323 - Nothing there to be copied to clipboard!
01:49:40 - DEBUG   - normcap.gui.notification:170 - Send notification via QT
01:49:45 - INFO    - normcap.gui.tray:610 - Exit normcap
01:49:45 - DEBUG   - normcap.gui.tray:611 - Debug images saved in /tmp/normcap

[maribox]

Would a possible solution to this maybe be not even screenshotting everything or just screenshotting the area needed after it has been selected? Or maybe saving to disk as soon as selection has begone only? Of course this would be a lot of extra work just for Wayland users and might not even give any additional performance boost if you need to take a Screenshot of the entire screen anyways, I'm just spitballing a little here :D

[maribox]

And also may there be any performance boosts in saving in a different file format than png?

Edit: Ok I looked into this a little and I think you'd have to implement it differently for every DE and I understand that you probably do not have the time to do that.

Example from flameshot:
https://github.com/flameshot-org/flameshot/blob/master/src/utils/screengrabber.cpp#L126

Flameshot takes a little less than two seconds on my system (KDE, Fedora40, Wayland)

[dynobo]

Thanks for the log, @maribox ! Seems like the screenshot takes about 2sec, and loading it to show the window about 2sec more...

And also may there be any performance boosts in saving in a different file format than png?

Unfortunately, dbus portal doesn't allow specifying a file format, so I have no control over that.

Would a possible solution to this maybe be not even screenshotting everything or just screenshotting the area needed after it has been selected?

Unfortunately, no. The screenshot has to be taken before the area selection: It serves as background image, where the selection area is drawn upon in the first place. (In earlier versions I tried to great transparent windows to draw the selection area upon, but it turned that this approach doesn't work on some systems, e.g. macOS)

Ok I looked into this a little and I think you'd have to implement it differently for every DE and I understand that you probably do not have the time to do that.

Implementing different solutions for different DEs would actually be fine, as DE specific workarounds are already implemented for other things. Thanks for pointing to the relevant flameshot code!

Not sure, though, when I find the time to look into it, as there are some bugs of higher priority I want to tackle first.

So, if someone else wants to work on this: Implementing a new screengrab handler using the KDE specific technic from flameshot would be the way to go.