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• Threads creating process in infinite loop

  10 décembre 2013, par bhupinder

  In my application a thread runs while(1){} in it so thread terminates when my app is terminated by user.

  Is it safe to do like this ? I am using while(1){} because my app continuously monitors devices on system.

  After some time I am getting "(R6016) not enough space for thread data" on ffmpeg.

  I read this but did not get solution of my problem :

  http://support.microsoft.com/kb/126709

  Thread description :
  Thread uses ffmpeg and handle utility (http://technet.microsoft.com/en-us/sysinternals/bb896655.aspx). within while(1){} loop.

  ffmpeg and handle is running through QProcess which I am deleting after process ends.

  while(1){} loop waits for 5 seconds using
  msleep(5000).

• Taking a high resolution picture with FFMPEG and Webcam

  13 mai 2016, par user2088176

  I have a Microsoft LifeCam VX-3000 and I want to capture a single image from this video source.

  I have tried DirectShow :

  ffmpeg -f dshow -video_size 1280x960 -i video="Microsoft LifeCam VX-3000" -vframes 1 file.jpg
  
  
  
  [dshow @ 01D69340] Could not set video options

  and
  Microsoft WDM Image Capture :

  ffmpeg -f vfwcap -video_size 1280x960 -i video="Microsoft LifeCam VX-3000" -vframes 1 file.jpg
  
  
  
  [vfwcap @ 01D79340] Could not set Video Format.

  If I lower the video size to 640x480, it works, but every sites tells me that 640x480 is the maximum video resolution, but the still picture maximum resolution is 1280x960. Like here

  I would like to capture the image at the highest resolution possible. Is there a way to do it with FFMPEG ? What command-line options should I give it ?

  Thank you very much.

• How to merge multiple video files into one video only

  1er août 2017, par shamaleyte

  I have multiple webm video files of a conference call.
  However, each participant joined the call at a different time which resulted in the fact that each video file has a different startTimeOffset values.

  Video Start Time

  Video1 : 00:00

  Video2 : 00:10

  Video3 : 01:40

  My purpose is to play back this conference. However, I do not record the conference as 1 video, it is recorded with multiple video files, instead.
  Is there any best practice to stitch such videos accordingly ?
  Maybe by ffmpeg library ?

  There is also a paid solution ; https://aws.amazon.com/about-aws/whats-new/2016/11/amazon-elastic-transcoder-adds-support-for-clip-stitching/ ) to merge video fragments to a single clip, this will make the client-side much simpler. But any free practice of doing it ?

  The expected outcome is to have 1 video showing 3 videos in a grid.
  When ffmpeg stitches the videos, it should consider their start time values properly so that the videos are played accordingly.