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• Black screen when recording specific screen / window using ffmpeg [closed]

  16 mai, par Mark Brin

  Issue :
I'm trying to capture the specific window using ffmpeg & i've tried these below command for that :

  


  ffmpeg -f gdigrab -framerate 30 -i title="Window Title" -b:v 3M -pix_fmt yuv420p output_FILENAME.webm


  


  And also try changing output format to .mp4

  


  ffmpeg -f gdigrab -framerate 30 -i title="Window Title" -b:v 3M -pix_fmt yuv420p output_FILENAME.mp4


  


  but the output video just shows the black screen with cursor.

  


  What i've tried :

  


  


  • Tried online solutions like Recording Screen with FFmpeg, How to record a specific window using ffmpeg ?, Record specific window using ffmpeg, but none of them worked.

    


  


  • even tried some of the tweaks like removing flags like -pix_fmt yuv420p also tried -f d3d11grab but didn't work.

    


  


  • When i try desktop capture it works completely fine.

    


  


  • I'm using this command to confirm that i'm using correct window title

    


  


  


  Get-Process |
  Where-Object { $_.MainWindowTitle -ne "" } |
  Select-Object -Unique MainWindowTitle


  


  System I'm using :

  


  Windows 11

  


• Look for fastest video encoder with least lag to stream webcam streaming to ipad [closed]

  7 avril, par kelly

  I'm looking for the fastest way to encode a webcam stream that will be viewable in a html5 video tag. I'm using a Pandaboard : http://www.digikey.com/product-highlights/us/en/texas-instruments-pandaboard/686#tabs-2 for the hardware. Can use gstreamer, cvlc, ffmpeg. I'll be using it to drive a robot, so need the least amount of lag in the video stream. Quality doesn't have to be great and it doesn't need audio. Also, this is only for one client so bandwidth isn't an issue. The best solution so far is using ffmpeg with a mpjpeg gives me around 1 sec delay. Anything better ?

  


• FFmpeg : canvas and crop work separately but result in black screen when combined

  25 janvier, par didi00

  I'm working on a video processing pipeline with FFmpeg, where I :

  


  

  • Create a black canvas using the color filter.

  


  • Crop a region from my video input.

  


  • Overlay the cropped region onto the black canvas.

  


  


  Both the canvas and the crop display correctly when tested individually. However, when I attempt to combine them (overlay the crop onto the canvas), the result is a black screen.
What Works :

  


  Black Canvas Alone :

  


  ffmpeg -filter_complex "color=c=black:s=1920x1080[out]" -map "[out]" -f nut - | ffplay 
-


  


  This shows a plain black screen, as expected.

  


  Cropped Region Alone :

  


  ffmpeg -f v4l2 -input_format yuyv422 -framerate 60 -video_size 1920x1080 -i /dev/video0 
\ -vf "crop=1024:192:0:0" -f nut - | ffplay -


  


  This shows the cropped region of the video correctly.

  


  When I combine these steps to overlay the crop onto the black canvas, I get a black screen :

  


  ffmpeg -f v4l2 -input_format yuyv422 -framerate 60 -video_size 1920x1080 -i /dev/video0 
\-filter_complex "color=c=black:s=1920x1080,format=yuv420p[background]; \
[0:v]crop=1024:192:0:0,format=yuv420p[region0]; \
[background][region0]overlay=x=0:y=0[out]" \
-map "[out]" -f nut - | ffplay -


  


  Environment :

  


  

  • OS : Linux (Debian-based)

  


  • FFmpeg Version : [Insert version, e.g., 4.x or 5.x]

  


  • Capture Card Format : yuyv422

  


  


  Question :

  


  Why does the pipeline result in a black screen when combining the canvas and the crop, even though both work separately ? Is this an issue with pixel format compatibility, or is there something I'm overlooking in the overlay filter setup ?