Body: <p>I would like to know if it is possible to find time stamps or frame numbers where a change of the display aspect ratio occurs in a video?</p>
  
  <p>In more detail, I recorded a TV-show from an SD-channel which resulted in a .ts file with a pixel resolution of 720x576. Since it is an old show, the show itself has a display aspect ratio (DAR) of 4:3. The commercials however are broadcast with a DAR of 16:9.</p>
  
  <p>I was wondering if it is possible to extract the positions of the video where the DAR changes since I'd like to use this information to detect the commercial breaks?</p>
  
  <p>I tried using comskip but it seems that it always assumes quadratic pixels and therefore is not able to detect the change of the aspect ratio.
  Other software is however able to respect the varying DAR.
  For example, vlc always rescales the video accordingly and projectx also displays the right DAR for the respective positions in the video.</p>
  
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-11-01T01:31:31.977Z
Comments.Text: I think it very specific software, but you can write it youself
Comments.UserDisplayName: bukkojot
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-11-01T06:42:31.707Z
Comments.Text: Do you know if the raster size also changes, or just the pixel aspect?
Comments.UserDisplayName: Gyan
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-11-01T12:04:47.293Z
Comments.Text: As far as I can see, it always stays at 720x576 pixels.
Comments.UserDisplayName: Simon L.
Tags: <video>
Title: Detect changes in display aspect ratio
UserDisplayName: Simon L.
ThreadText: # Detect changes in display aspect ratio
  
  (Asked by: username_0 on 2017-10-31)
  
  I would like to know if it is possible to find time stamps or frame numbers where a change of the display aspect ratio occurs in a video?
  
  In more detail, I recorded a TV-show from an SD-channel which resulted in a .ts file with a pixel resolution of 720x576. Since it is an old show, the show itself has a display aspect ratio (DAR) of 4:3. The commercials however are broadcast with a DAR of 16:9.
  
  I was wondering if it is possible to extract the positions of the video where the DAR changes since I'd like to use this information to detect the commercial breaks?
  
  I tried using comskip but it seems that it always assumes quadratic pixels and therefore is not able to detect the change of the aspect ratio.
  Other software is however able to respect the varying DAR.
  For example, vlc always rescales the video accordingly and projectx also displays the right DAR for the respective positions in the video.
  
  **Tags:** video
  
  > **Comments:**
  > **username_1**: I think it very specific software, but you can write it youself  
  > **username_2**: Do you know if the raster size also changes, or just the pixel aspect?  
  > **username_0**: As far as I can see, it always stays at 720x576 pixels.  
  
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  ## 0 answers
  
  