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• Révision 17407 : on avance sur le dateur :

  14 mars 2011, par b b

  * formatage + texte_script sur les chaines de langue et pas de ucfirst * ajout de quelques chaines de langue pour les abbreviations de mois cf http://fr.wikipedia.org/wiki/Mois

• Can you think of a reason why windows might not enable audio if noone is logged in ?

  3 juillet 2017, par Caius Jard

  I’m having a bizarre problem with some virtual servers created to record podcasts. They run on amazon AWS as windows server 2012 instances and a small c# app tells FFMPEG to do the heavy lifting of capturing from the virtual screen and reading from the virtual sound card (Virtual Audio Cable : https://en.wikipedia.org/wiki/Virtual_Audio_Cable) via DirectShow filters

  The problem I have is if I leave the machine to do its stuff unattended, the recordings are sometimes silent. If I log in via VNC and watch it doing its stuff the audio is recorded just fine. All other aspects of the test op are the same, and the virtual machine is shut down between successive recordings so each one should theoretically be a clean slate. The app runs under a logged in session (hence the use of VNC rather than RDP)

  I’m now wondering if there is some optimisation of the windows sound engine whereby it doesn’t bother playing audio if it thinks noone is listening. The confusing thing to me is that not every virtual machine suffers these problems ; some of them record fine (and they’re all created from the same seed virtual hard disk image) in unattended mode

  I’m asking this question with the aim of getting together a list of things I can check/look into/debug.. I don’t have much knowledge of how MME/DirectSound/WASAPI work internally...

• Replace video with jpg in ffmpeg

  14 septembre 2020, par ben158

  I am trying to convert an mkv with video and audio into an m4v with the same audio, but with the video replaced with a still jpg for the duration. I'm following the examples from https://trac.ffmpeg.org/wiki/Slideshow and not having any success. Every time I attempt any of these, it doesn't insert the jpg, and instead uses the original video from the mkv. I am testing the files in VLC. Any ideas what could be going wrong ? I'm inclined to think the documentation itself may be outdated or wrong.

  


  Attempts following the linked examples :

  


  -i input.mkv -loop 1 -i image.jpg -c:a ac3 -b:a 640K -c:v libx264 -shortest output.m4v

-i input.mkv -framerate 1 -i image.jpg -c:a ac3 -b:a 640K -c:v libx264 -r 30 -pix_fmt yuv420p output.m4v

-i input.mkv -framerate 1 -i image.jpg -c:a ac3 -b:a 640K -c:v libx264 -r 30 -vf format=yuv420p output.m4v


  


  The one thing I got semi-working (based on code from another source) was -i input.mkv -i image.jpg -filter_complex "[1][0]scale2ref[i][v];[v][i]overlay" -c:a ac3 -b:a 640K -c:v libx264 output.m4v but this stretches the image out (which I don't want, I want the resultant video to have the same aspect ratio as the image without black padding on the sides).

  


  I'm kicking myself because I eventually got something along the lines of the first examples working a few days ago, but somehow didn't save my work and am back to square one. Any help is appreciated, thanks in advance.