FFmpeg `-f x11grab` captured video will stay at one or two frames, flickering

Platform

Arch Linux amd64; kernel 6.3.5

GPU, drivers, and screen setup

NVIDIA GeForce RTX 3060 Mobile / Max-Q and Intel TigerLake-H GT1 [UHD Graphics]. nvidia 530.41.03-15 intel-gpu-tools 1.27-1 intel-media-driver 23.1.0-1 mesa 23.1.1-1 xf86-video-intel 1:2.99.917+923+gb74b67f0-1 But my display is using intel, not nvidia. I'm using PRIME scheme for nvidia. Single monitor.

glxinfo -B:

name of display: :0
display: :0  screen: 0
direct rendering: Yes
Extended renderer info (GLX_MESA_query_renderer):
    Vendor: Intel (0x8086)
    Device: Mesa Intel(R) UHD Graphics (TGL GT1) (0x9a60)
    Version: 23.1.1
    Accelerated: yes
    Video memory: 64049MB
    Unified memory: yes
    Preferred profile: core (0x1)
    Max core profile version: 4.6
    Max compat profile version: 4.6
    Max GLES1 profile version: 1.1
    Max GLES[23] profile version: 3.2
OpenGL vendor string: Intel
OpenGL renderer string: Mesa Intel(R) UHD Graphics (TGL GT1)
OpenGL core profile version string: 4.6 (Core Profile) Mesa 23.1.1
OpenGL core profile shading language version string: 4.60
OpenGL core profile context flags: (none)
OpenGL core profile profile mask: core profile

OpenGL version string: 4.6 (Compatibility Profile) Mesa 23.1.1
OpenGL shading language version string: 4.60
OpenGL context flags: (none)
OpenGL profile mask: compatibility profile

OpenGL ES profile version string: OpenGL ES 3.2 Mesa 23.1.1
OpenGL ES profile shading language version string: OpenGL ES GLSL ES 3.20

Environment

i3-wm 4.22-4 alacritty 0.12.1-1

picom version

vgit-3aed5

Diagnostics

``` **Version:** vgit-3aed5 ### Extensions: * Shape: Yes * RandR: Yes * Present: Present ### Misc: * Use Overlay: No (Another compositor is already running) * Config file used: /home/bczhc/.config/picom/picom.conf ### Drivers (inaccurate): NVIDIA, Intel ### Backend: glx * Driver vendors: * GLX: Mesa Project and SGI * GL: Intel * GL renderer: Mesa Intel(R) UHD Graphics (TGL GT1) * Accelerated: 1 ### Backend: egl * Driver vendors: * EGL: Mesa Project * EGL driver: iris * GL: Intel * GL renderer: Mesa Intel(R) UHD Graphics (TGL GT1) ```

Configuration:

Configuration file

``` ################################# # Shadows # ################################# # Enabled client-side shadows on windows. Note desktop windows # (windows with '_NET_WM_WINDOW_TYPE_DESKTOP') never get shadow, # unless explicitly requested using the wintypes option. # shadow = false; # The blur radius for shadows, in pixels. (defaults to 12) shadow-radius = 12 #shadow-radius = 10; # The opacity of shadows. (0.0 - 1.0, defaults to 0.75) shadow-opacity = 0.9; # The left offset for shadows, in pixels. (defaults to -15) # shadow-offset-x = -15 shadow-offset-x = -7; # The top offset for shadows, in pixels. (defaults to -15) # shadow-offset-y = -15 shadow-offset-y = -7; # Red color value of shadow (0.0 - 1.0, defaults to 0). # shadow-red = 0 # Green color value of shadow (0.0 - 1.0, defaults to 0). # shadow-green = 0 # Blue color value of shadow (0.0 - 1.0, defaults to 0). # shadow-blue = 0 # Hex string color value of shadow (#000000 - #FFFFFF, defaults to #000000). This option will override options set shadow-(red/green/blue) # shadow-color = "#000000" # Specify a list of conditions of windows that should have no shadow. # # examples: # shadow-exclude = "n:e:Notification"; # # shadow-exclude = [] shadow-exclude = [ "name = 'Notification'", "class_g = 'Conky'", "class_g ?= 'Notify-osd'", "class_g = 'Cairo-clock'", "_GTK_FRAME_EXTENTS@:c" ]; # Specify a list of conditions of windows that should have no shadow painted over, such as a dock window. # clip-shadow-above = [] # Specify a X geometry that describes the region in which shadow should not # be painted in, such as a dock window region. Use # shadow-exclude-reg = "x10+0+0" # for example, if the 10 pixels on the bottom of the screen should not have shadows painted on. # # shadow-exclude-reg = "" # Crop shadow of a window fully on a particular Xinerama screen to the screen. # xinerama-shadow-crop = false ################################# # Fading # ################################# # Fade windows in/out when opening/closing and when opacity changes, # unless no-fading-openclose is used. # fading = false fading = true; # Opacity change between steps while fading in. (0.01 - 1.0, defaults to 0.028) # fade-in-step = 0.028 fade-in-step = 0.01; # Opacity change between steps while fading out. (0.01 - 1.0, defaults to 0.03) # fade-out-step = 0.03 fade-out-step = 0.01; # The time between steps in fade step, in milliseconds. (> 0, defaults to 10) fade-delta = 1.5 # Specify a list of conditions of windows that should not be faded. # fade-exclude = [] # Do not fade on window open/close. # no-fading-openclose = false # Do not fade destroyed ARGB windows with WM frame. Workaround of bugs in Openbox, Fluxbox, etc. # no-fading-destroyed-argb = false ################################# # Transparency / Opacity # ################################# # Opacity of inactive windows. (0.1 - 1.0, defaults to 1.0) # inactive-opacity = 1 # inactive-opacity = 0.8; # Opacity of window titlebars and borders. (0.1 - 1.0, disabled by default) # frame-opacity = 1.0 frame-opacity = 1.0; # Let inactive opacity set by -i override the '_NET_WM_WINDOW_OPACITY' values of windows. # inactive-opacity-override = true inactive-opacity-override = false; # Default opacity for active windows. (0.0 - 1.0, defaults to 1.0) # active-opacity = 1.0 # Dim inactive windows. (0.0 - 1.0, defaults to 0.0) # inactive-dim = 0.1 # Specify a list of conditions of windows that should never be considered focused. # focus-exclude = [] focus-exclude = [ "class_g = 'Cairo-clock'" ]; # Use fixed inactive dim value, instead of adjusting according to window opacity. # inactive-dim-fixed = 1.0 # Specify a list of opacity rules, in the format `PERCENT:PATTERN`, # like `50:name *= "Firefox"`. picom-trans is recommended over this. # Note we don't make any guarantee about possible conflicts with other # programs that set '_NET_WM_WINDOW_OPACITY' on frame or client windows. # example: # opacity-rule = [ "80:class_g = 'URxvt'" ]; # opacity-rule = [ "80:class_g = 'Alacritty'", "80:class_g = 'Xfce4-terminal'", "95:class_g = 'fcitx'" ] ################################# # Corners # ################################# # Sets the radius of rounded window corners. When > 0, the compositor will # round the corners of windows. Does not interact well with # `transparent-clipping`. corner-radius = 15 # Exclude conditions for rounded corners. rounded-corners-exclude = [ "window_type = 'dock'", "window_type = 'desktop'", "class_g = 'i3-frame'" ]; ################################# # Background-Blurring # ################################# # Parameters for background blurring, see the *BLUR* section for more information. # blur-method = # blur-size = 12 # # blur-deviation = false # # blur-strength = 5 # Blur background of semi-transparent / ARGB windows. # Bad in performance, with driver-dependent behavior. # The name of the switch may change without prior notifications. # blur-background = true # Blur background of windows when the window frame is not opaque. # Implies: # blur-background # Bad in performance, with driver-dependent behavior. The name may change. # # blur-background-frame = false # Use fixed blur strength rather than adjusting according to window opacity. # blur-background-fixed = false # Specify the blur convolution kernel, with the following format: # example: # blur-kern = "5,5,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1"; # # blur-kern = "" blur-kern = "3x3box"; # Exclude conditions for background blur. # blur-background-exclude = [] blur-background-exclude = [ "window_type = 'dock'", "window_type = 'desktop'", "_GTK_FRAME_EXTENTS@:c" ]; ################################# # General Settings # ################################# # Daemonize process. Fork to background after initialization. Causes issues with certain (badly-written) drivers. # daemon = false # Specify the backend to use: `xrender`, `glx`, or `xr_glx_hybrid`. # `xrender` is the default one. # backend = "glx" #backend = "xrender"; # Enable/disable VSync. # vsync = false vsync = true; # Enable remote control via D-Bus. See the *D-BUS API* section below for more details. # dbus = false # Try to detect WM windows (a non-override-redirect window with no # child that has 'WM_STATE') and mark them as active. # # mark-wmwin-focused = false mark-wmwin-focused = true; # Mark override-redirect windows that doesn't have a child window with 'WM_STATE' focused. # mark-ovredir-focused = false mark-ovredir-focused = true; # Try to detect windows with rounded corners and don't consider them # shaped windows. The accuracy is not very high, unfortunately. # # detect-rounded-corners = false detect-rounded-corners = true; # Detect '_NET_WM_WINDOW_OPACITY' on client windows, useful for window managers # not passing '_NET_WM_WINDOW_OPACITY' of client windows to frame windows. # # detect-client-opacity = false detect-client-opacity = true; # Use EWMH '_NET_ACTIVE_WINDOW' to determine currently focused window, # rather than listening to 'FocusIn'/'FocusOut' event. Might have more accuracy, # provided that the WM supports it. # # use-ewmh-active-win = false # Unredirect all windows if a full-screen opaque window is detected, # to maximize performance for full-screen windows. Known to cause flickering # when redirecting/unredirecting windows. # # unredir-if-possible = false # Delay before unredirecting the window, in milliseconds. Defaults to 0. # unredir-if-possible-delay = 0 # Conditions of windows that shouldn't be considered full-screen for unredirecting screen. # unredir-if-possible-exclude = [] # Use 'WM_TRANSIENT_FOR' to group windows, and consider windows # in the same group focused at the same time. # # detect-transient = false detect-transient = true; # Use 'WM_CLIENT_LEADER' to group windows, and consider windows in the same # group focused at the same time. This usually means windows from the same application # will be considered focused or unfocused at the same time. # 'WM_TRANSIENT_FOR' has higher priority if detect-transient is enabled, too. # # detect-client-leader = false # Resize damaged region by a specific number of pixels. # A positive value enlarges it while a negative one shrinks it. # If the value is positive, those additional pixels will not be actually painted # to screen, only used in blur calculation, and such. (Due to technical limitations, # with use-damage, those pixels will still be incorrectly painted to screen.) # Primarily used to fix the line corruption issues of blur, # in which case you should use the blur radius value here # (e.g. with a 3x3 kernel, you should use `--resize-damage 1`, # with a 5x5 one you use `--resize-damage 2`, and so on). # May or may not work with *--glx-no-stencil*. Shrinking doesn't function correctly. # # resize-damage = 1 # Specify a list of conditions of windows that should be painted with inverted color. # Resource-hogging, and is not well tested. # # invert-color-include = [] # GLX backend: Avoid using stencil buffer, useful if you don't have a stencil buffer. # Might cause incorrect opacity when rendering transparent content (but never # practically happened) and may not work with blur-background. # My tests show a 15% performance boost. Recommended. # glx-no-stencil = true; # GLX backend: Avoid rebinding pixmap on window damage. # Probably could improve performance on rapid window content changes, # but is known to break things on some drivers (LLVMpipe, xf86-video-intel, etc.). # Recommended if it works. # # glx-no-rebind-pixmap = false # Disable the use of damage information. # This cause the whole screen to be redrawn everytime, instead of the part of the screen # has actually changed. Potentially degrades the performance, but might fix some artifacts. # The opposing option is use-damage # # no-use-damage = false use-damage = true; # Use X Sync fence to sync clients' draw calls, to make sure all draw # calls are finished before picom starts drawing. Needed on nvidia-drivers # with GLX backend for some users. # # xrender-sync-fence = false # GLX backend: Use specified GLSL fragment shader for rendering window contents. # See `compton-default-fshader-win.glsl` and `compton-fake-transparency-fshader-win.glsl` # in the source tree for examples. # # glx-fshader-win = "" # Force all windows to be painted with blending. Useful if you # have a glx-fshader-win that could turn opaque pixels transparent. # # force-win-blend = false # Do not use EWMH to detect fullscreen windows. # Reverts to checking if a window is fullscreen based only on its size and coordinates. # # no-ewmh-fullscreen = false # Dimming bright windows so their brightness doesn't exceed this set value. # Brightness of a window is estimated by averaging all pixels in the window, # so this could comes with a performance hit. # Setting this to 1.0 disables this behaviour. Requires --use-damage to be disabled. (default: 1.0) # # max-brightness = 1.0 # Make transparent windows clip other windows like non-transparent windows do, # instead of blending on top of them. # # transparent-clipping = false # Set the log level. Possible values are: # "trace", "debug", "info", "warn", "error" # in increasing level of importance. Case doesn't matter. # If using the "TRACE" log level, it's better to log into a file # using *--log-file*, since it can generate a huge stream of logs. # # log-level = "debug" log-level = "warn"; # Set the log file. # If *--log-file* is never specified, logs will be written to stderr. # Otherwise, logs will to written to the given file, though some of the early # logs might still be written to the stderr. # When setting this option from the config file, it is recommended to use an absolute path. # # log-file = "/path/to/your/log/file" # Show all X errors (for debugging) # show-all-xerrors = false # Write process ID to a file. # write-pid-path = "/path/to/your/log/file" # Window type settings # # 'WINDOW_TYPE' is one of the 15 window types defined in EWMH standard: # "unknown", "desktop", "dock", "toolbar", "menu", "utility", # "splash", "dialog", "normal", "dropdown_menu", "popup_menu", # "tooltip", "notification", "combo", and "dnd". # # Following per window-type options are available: :: # # fade, shadow::: # Controls window-type-specific shadow and fade settings. # # opacity::: # Controls default opacity of the window type. # # focus::: # Controls whether the window of this type is to be always considered focused. # (By default, all window types except "normal" and "dialog" has this on.) # # full-shadow::: # Controls whether shadow is drawn under the parts of the window that you # normally won't be able to see. Useful when the window has parts of it # transparent, and you want shadows in those areas. # # clip-shadow-above::: # Controls wether shadows that would have been drawn above the window should # be clipped. Useful for dock windows that should have no shadow painted on top. # # redir-ignore::: # Controls whether this type of windows should cause screen to become # redirected again after been unredirected. If you have unredir-if-possible # set, and doesn't want certain window to cause unnecessary screen redirection, # you can set this to `true`. # wintypes: { tooltip = { fade = true; shadow = true; opacity = 0.75; focus = true; full-shadow = false; }; dock = { shadow = false; clip-shadow-above = true; } dnd = { shadow = false; } popup_menu = { opacity = 0.8; } dropdown_menu = { opacity = 0.8; } normal = {blur-background = true;}; splash = {blur-background = false;}; }; blur: { method = "dual_kawase"; strength = 4; } ```

Steps of reproduction

See the video demonstration and explanations below.

Stack trace

N/A

OpenGL trace

For some reason, apitrace will crash with SIGSEGV on Ctrl-C, but it leaves picom.trace. picom.trace picom --log-level trace

Other details

Video demonstration: Since this bug will cause screen recording problematic, I have to record it via a handcam.

rec.webm

In this video, the initial setup is: top-left terminal holding picom that has not been executed; center slim terminal: ffplay -f x11grab -framerate 30 -i $DISPLAY; this will start a window which is right to it, showing real-time screen content. Bottom-left is gedit.

First I use Fcitx5 (version 5.0.23) IME to type something in gedit, the screen-mirror video beside reflected it correctly. But when I started picom, then re-did the typing, at some point (in this video it happened instantly; actually this bug reproduces a bit randomly) the mirror video had something wrong; it didn't reflect the screen, instead it started flickering between two frames. I call this a "weird state".

In this "weird state", all screen capturing (including x0vncserver) will have problem. That is, if I use ffmpeg -f x11grab to grab a single picture, that picture won't be the current screen, but the "stagnant" frame. In the video above, I then returned to workspace 1, clicking Flameshot icon at the top-right tray, to start interactive screenshot-taking, it also shows that old frame, but not currently what the screen looks.

When I stopped picom, all went to normal.

If I do screenrecording to demonstrate this, it's like:

b.webm

With xrender backend, this issue doesn't happen.

yshui / picom