Recherche avancée

Sur d’autres sites (13585)

• Installing ffmpeg for php

  2 février 2016, par Joe Scotto

  I’ve been searching the internet for over 3 days now and cannot find anything that has a clear explanation of how to install ffmpeg for php. I currently have ffmpeg installed correctly on my Mac command line but as to how to use it in my php scripts is beyond me. How do I install ffmpeg for php ? Any help would be great. Thanks.

• c# Create NAL unit from following structure

  30 mai 2014, par user1411499

  Im wanting to send my desktop as an avc h.264 stream.

  The pseudocode would go something like :

  1) Capture screen as bitmap
  2) Encode bitmap into h.264
  3) Create NALU header
  4) Send header and payload
  5) Rinse and repeat.
  

  My questions are :
  How would I go about creating the payload ? Would I use FFMPEG to convert the Bitmap into h.264 format ?

  I have the following spec for creating the NALU :

  

  How would I go about creating this in a c# array of bytes ? (Im not that familiar with bit shifting operations) e.g ByteArray[0] = value, ByteArray1 = value

  Im fairly new to this streaming thing so any help/code samples would be great. Im not looking for references to ISO standards(I understand they are an important part), after doing a few hours of searching I found this link http://aviadr1.blogspot.co.nz/2010/05/h264-extradata-partially-explained-for.html and it was a breath of fresh air as it was someone explaining it from the beginning !

  I am also not searching for a library to do this for me as I need learn the fundamentals.

  Any help would be great thanks !

• ffmpeg using an expression for tile filter [closed]

  25 janvier, par kaarch

  Is there any way to supply the 'tile' filter of ffmpeg with an expression ? I've tried about every combination I can think of using different escape characters and quotes, but it won't accept anything other than an explicit string like '10x10'. See the example below that works :

  



  ffmpeg -i "big_buck_bunny.mp4" -vf "tile=10x10" grid_%d.jpg


  



  I'd like to be able to do something like :

  



  ffmpeg -i "big_buck_bunny.mp4" -vf "tile=expr(n*2)x10" grid_%d.jpg


  



  Where 'n' is the current frame number. This isn't the exact expression I'm looking to use, but wanted to start with a simple example that I can then adapt to a more complex expression. Everything I've tried gives me an error like the following :

  



  [tile @ 0x7facc1d000c0] Unable to parse option value "expr(n*2)x10" as image size


  



  Can tile simply not accept an expression ? Or is there some sort of concatenate function that I should be trying ?