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• FFMPEG lossless simple & efficient format

  30 octobre 2016, par Adminy

  I took a sample video and ran this code for each image format like this :

  ffmpeg -i test.mkv png/%d.png
  
  ffmpeg -i test.mkv bmp/%d.bmp

  What I noted is that BMP at 1080P has a fixed size of 5.97 MB (6,266,934 bytes)

                                                             !6,220,800

  Then I did some maths :

  1 byte = 2^8 == 256 possible combinations
  
  r + g + b form a color (0-255,0-255,0-255)
  
  bmp = 3 * 1920 * 1080 = 6,220,800 bytes

  So extra is just the file headers ?! (46134 bytes for just headers ?)

  Next thing I noted that PNG size is dynamic and when the image has a lot of repetition is somewhere 2.5mb. Usually its between 10mb and 12mb.

  Also decoding BMP seemed a lot quicker compared to PNG. So there is no point in even looking at PNG. I would like to know why is it so huge over BMP if it has (zlib) compression factor.

  What is the best format to export to in terms of speed and size, preferred if its as simple as reading the file of color bytes ?

• Virtual host compared to multiple servers

  9 septembre 2011, par josiecat

  This may be dumb but has me wondering why and I know how to setup the virtual host but need to know the why or what it is good for.

  Why do you setup virtual host for local development and why not just put sub directories ?

  What are the real world uses and how do you use virtual host ?

  (my normal set up as of now)
  I use Mamp and just put more folders (speaking dummy terms here) in the htdocs folder. Is that ok what am I missing ?

  The reason why I would like to use virtual hosting is because I would like to have a few servers to try different technologies (e.g. adding ffmpeg support for streaming video and many others ) but do I use virtual hosting to be able to have more than one server or do I need to use something like virtual machine to have multiple servers with different versions of PHP, Mysql etc...?

  I understand how to set this stuff up just don't understand the difference from virtual host to multiple servers ? could I actually set up one with php just the basic and another for php with ffmpeg-php and other stuff like zend or what ever just to have different server environments to basically mock the actual server that the project will land when done ?

• kmsgrab : Fix DRM format definitions

  15 septembre 2017, par Mark Thompson

  kmsgrab : Fix DRM format definitions
  All DRM formats are defined in terms of little-endian words, so RGB formats
  
  like XRGB actually have the elements in the opposite order order in memory
  
  to the order they are in the name.
  This does not affect YUYV and similar YUV 4:2:2 formats, which are in the
  
  expected order.
  

  • [DH] libavdevice/kmsgrab.c