Answers.Body: <p><code>-stream_loop</code> is buggy in versions older than 4.1, so upgrade.</p>
  <p>Also, stream_loop won't work with movies opened via movie filter. Use it as a direct input.</p>
  <pre><code>ffmpeg -stream_loop -1 -re -i &quot;snail.mp4&quot; -f v4l2 /dev/video4 -report
  </code></pre>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-07-30T00:05:19.190Z
Answers.Text: ffmpeg is already the newest version (7:3.4.8-0ubuntu0.2)
Answers.UserDisplayName: ahoffer
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-07-30T00:13:31.523Z
Answers.Text: That command sort of works. However, the framerate slowly drops from 24 FPS to about 8 FPS. Then it picks back up. It repeats the pattern indefinitely. I looking in the report file. Some kind of recursive problem? A warning of over 1000 duplicated frames? I don't know.
Answers.UserDisplayName: ahoffer
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-07-30T06:02:29.837Z
Answers.Text: Distro packages are very out of date. Latest ver is 4.3; you're using 3.4.8. Get a static binary - see ffmpeg.org/download.html
Answers.UserDisplayName: Gyan
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-07-29T09:07:12.000Z
Answers.LastActivityDate: 2020-07-29T09:07:12.000Z
Answers.UserDisplayName: Gyan
Body: <p>UPDATED with info from -report</p>
  <hr>
  <p>I'm new to ffmpeg.</p>
  <p>I am trying to loop a video to a linux v4l2 device.</p>
  <pre><code>ffmpeg -stream_loop -1 -re -f lavfi  -i &quot;movie=snail.mp4&quot; -f v4l2 /dev/video4 -report
  </code></pre>
  <p>It plays the video once and then exits with the message &quot;Invalid</p>
  <pre><code>[Parsed_movie_0 @ 0x56289dec9a00] EOF timestamp not reliable=N/A speed=   1x    
  Error while filtering: Invalid argument
  frame=  391 fps= 25 q=-0.0 Lsize=N/A time=00:00:15.64 bitrate=N/A speed=0.999x    
  video:43988kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
  </code></pre>
  <p><strong>Which argument is invalid and why?</strong></p>
  <p>The output of the report file generated by ffmpeg is available here: <a href="https://gist.github.com/ahoffer/7217aa0572061e7c255cf08914be53e2" rel="nofollow noreferrer">https://gist.github.com/ahoffer/7217aa0572061e7c255cf08914be53e2</a></p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2020-07-28T05:07:33.430Z
Comments.Text: Add -report and rerun. Share report.
Comments.UserDisplayName: Gyan
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2020-07-28T16:04:55.747Z
Comments.Text: I added -report, but it provided no additional information.  
  
  ffmpeg  -stream_loop -1  -re -f lavfi  -i "movie=snail.mp4" -f v4l2 /dev/video4 -report
Comments.UserDisplayName: ahoffer
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2020-07-28T16:21:34.873Z
Comments.Text: It will have generated a report file in pwd. Share that.
Comments.UserDisplayName: Gyan
Tags: <ffmpeg>
Title: ffmpeg invalid argument. Which argument was invalid?
UserDisplayName: ahoffer
ThreadText: # ffmpeg invalid argument. Which argument was invalid?
  
  (Asked by: username_0 on 2020-07-27)
  
  UPDATED with info from -report
  
  ---
  
  I'm new to ffmpeg.
  
  I am trying to loop a video to a linux v4l2 device.
  
  ```
  ffmpeg -stream_loop -1 -re -f lavfi  -i "movie=snail.mp4" -f v4l2 /dev/video4 -report
  
  ```
  
  It plays the video once and then exits with the message "Invalid
  
  ```
  [Parsed_movie_0 @ 0x56289dec9a00] EOF timestamp not reliable=N/A speed=   1x    
  Error while filtering: Invalid argument
  frame=  391 fps= 25 q=-0.0 Lsize=N/A time=00:00:15.64 bitrate=N/A speed=0.999x    
  video:43988kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
  
  ```
  
  **Which argument is invalid and why?**
  
  The output of the report file generated by ffmpeg is available here: <https://gist.github.com/username_0/7217aa0572061e7c255cf08914be53e2>
  
  **Tags:** ffmpeg
  
  > **Comments:**
  > **username_1**: Add -report and rerun. Share report.  
  > **username_0**: I added -report, but it provided no additional information.    ffmpeg  -stream_loop -1  -re -f lavfi  -i "movie=snail.mp4" -f v4l2 /dev/video4 -report  
  > **username_1**: It will have generated a report file in pwd. Share that.  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2020-07-29. Score: 1
  
  `-stream_loop` is buggy in versions older than 4.1, so upgrade.
  
  Also, stream\_loop won't work with movies opened via movie filter. Use it as a direct input.
  
  ```
  ffmpeg -stream_loop -1 -re -i "snail.mp4" -f v4l2 /dev/video4 -report
  
  ```
  
  > **Comments:**
  > **username_0**: ffmpeg is already the newest version (7:3.4.8-0ubuntu0.2)  
  > **username_0**: That command sort of works. However, the framerate slowly drops from 24 FPS to about 8 FPS. Then it picks back up. It repeats the pattern indefinitely. I looking in the report file. Some kind of recursive problem? A warning of over 1000 duplicated frames? I don't know.  
  > **username_1**: Distro packages are very out of date. Latest ver is 4.3; you're using 3.4.8. Get a static binary - see ffmpeg.org/download.html  
  
  ---
  
  