• Compression Techniques

  stream to jpeg

  Posted by Nayan Kapadia on June 3, 2010 at 5:19 am

  HI,

  I have converted image from live stream using ffmpeg -i rtsp:///main.mp4 -an -r 1 -y -s 320×240 video%d.jpg.Using this I obtain continous jpeg images. Is there any way to generate only one image and overwrite that image after each frame using ffmpeg?

  Another thing,I am using ffmpeg on windows.When i type ffmpeg.exe in command line it displays ffmpeg version message and configuration message, how can i stop display of these messages on command line?

  Thank you,
  NBK

  Michael Rampe replied 15 years, 11 months ago 2 Members · 6 Replies
• 6 Replies

• 

  Michael Rampe

  June 3, 2010 at 5:40 am

  [nayan kapadia] “Is there any way to generate only one image and overwrite that image after each frame using ffmpeg?”

  Do not use the “%d” in the image name. This is what creates sequential image numbers.
  The “-y” flag will overwrite the previous image which you are using. Try putting it just before the output filename.

  Eg.
  ffmpeg -i rtsp:///main.mp4 -an -r 1 -s 320×240 -y video.jpg

  This might work or might just create one frame and stop. Not too sure about this. Try it and see.

  [nayan kapadia] “When i type ffmpeg.exe in command line it displays ffmpeg version message and configuration message, how can i stop display of these messages on command line?”

  You cannot stop this display.

  Michael

  “half-way to world domination A.K.A. the belligerent blue bike shed”
• 

  Michael Rampe

  June 3, 2010 at 6:09 am

  Just tried to replicate it and it didn’t work. Just wrote one frame and failed.

  I will keep looking into it.

  What is the intended purpose for this process? There might be a workaround if I know what you are trying to achieve.

  Michael

  “half-way to world domination A.K.A. the belligerent blue bike shed”
• 

  Nayan Kapadia

  June 3, 2010 at 10:27 am

  Thanks for your reply. I can generate image only once not able to update image.

  Thank you,
  NBK
• 

  Michael Rampe

  June 3, 2010 at 11:57 pm

  Yes, it fails after one frame.

  What are you trying to achieve?

  Michael

  “half-way to world domination A.K.A. the belligerent blue bike shed”
• 

  Nayan Kapadia

  June 4, 2010 at 9:06 am

  I want to update and overwrite image from live stream continously and want to display in server.

  Thanks,
  NBK
• 

  Michael Rampe

  June 7, 2010 at 7:18 am

  I cannot think of a way to do what you need within FFmpeg but it could be easily solved writing a shell script.

  The command that produces the single frame takes less than a second on my setup. Seeing that you have specified the rate to be 1fps for pulling the frames, you could write a script that calls the same command from FFmpeg every second overwriting the previous frame and thus producing the desired result.

  Michael

  “half-way to world domination A.K.A. the belligerent blue bike shed”

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