Answers.Body: <p>You have to use the update option.</p>
  
  <pre><code>-vf fps=1 -s 320x240 -update 1 d:\preview\out.jpg
  </code></pre>
  
  <p>This will rewrite onto the same file.</p>
  
  <p>To avoid a possible read op in the middle of the updating, you can add <code>-atomic_writing 1</code></p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2018-06-07T15:50:51.183Z
Answers.Text: Sorry to bother you again .. But with this command when i put a logo (an overlay) it stops generating the preview image any specific reason ?? i am using a filter_complex to overlay the logo as i am using a subtitle also and a banner .. but with everything the preview works except when i use the logo overlay .. it stops generating the preview or the second output
Answers.UserDisplayName: Tony Hanna
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2018-06-07T16:25:03.267Z
Answers.Text: Open a new Q with the new command
Answers.UserDisplayName: Gyan
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2018-06-07T16:37:04.780Z
Answers.Text: i did .. just did
Answers.UserDisplayName: Tony Hanna
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2018-06-07T12:30:56.510Z
Answers.LastActivityDate: 2018-06-07T12:30:56.510Z
Answers.UserDisplayName: Gyan
Body: <p>In the process of creating a preview of what ffmpeg, is streaming i came up with this command:</p>
  
  <pre><code>ffmpeg -i colony.mkv -c:v libx264 -f mpegts udp://127.0.0.1:1234 -vf fps=1 -s 320x240 d:\preview\out%d.jpg
  </code></pre>
  
  <p>This is great, but it is outputting to a series of image files that are difficult to track:out1.jpg, out2.jpg ... etc...</p>
  
  <p>When i remove the %d parameters, it throws an error saying </p>
  
  <pre><code>[image2 @ 00000162c6a3d840] Could not get frame filename number 2 from pattern 'd:\preview\out.jpg' (either set update or use a pattern like %03d within the filename pattern)
  av_interleaved_write_frame(): Invalid argument
  </code></pre>
  
  <p>Is there a way to do this please?</p>
  
Tags: <ffmpeg><preview>
Title: ffmpeg export video to 1 image
UserDisplayName: Tony Hanna
ThreadText: # ffmpeg export video to 1 image
  
  (Asked by: username_0 on 2018-06-07)
  
  In the process of creating a preview of what ffmpeg, is streaming i came up with this command:
  
  ```
  ffmpeg -i colony.mkv -c:v libx264 -f mpegts udp://127.0.0.1:1234 -vf fps=1 -s 320x240 d:\preview\out%d.jpg
  
  ```
  
  This is great, but it is outputting to a series of image files that are difficult to track:out1.jpg, out2.jpg ... etc...
  
  When i remove the %d parameters, it throws an error saying
  
  ```
  [image2 @ 00000162c6a3d840] Could not get frame filename number 2 from pattern 'd:\preview\out.jpg' (either set update or use a pattern like %03d within the filename pattern)
  av_interleaved_write_frame(): Invalid argument
  
  ```
  
  Is there a way to do this please?
  
  **Tags:** ffmpeg, preview
  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2018-06-07. Score: 2
  
  You have to use the update option.
  
  ```
  -vf fps=1 -s 320x240 -update 1 d:\preview\out.jpg
  
  ```
  
  This will rewrite onto the same file.
  
  To avoid a possible read op in the middle of the updating, you can add `-atomic_writing 1`
  
  > **Comments:**
  > **username_0**: Sorry to bother you again .. But with this command when i put a logo (an overlay) it stops generating the preview image any specific reason ?? i am using a filter_complex to overlay the logo as i am using a subtitle also and a banner .. but with everything the preview works except when i use the logo overlay .. it stops generating the preview or the second output  
  > **username_1**: Open a new Q with the new command  
  > **username_0**: i did .. just did  
  
  ---
  
  