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• How do I add a custom thumbnail to a .mp4 file using ffmpeg ?

  8 avril 2020, par cooder_one

  I am trying to find the proper ffmpeg command to add a .png or .jpg image to a .mp4 video as a thumbnail. The command will eventually automatically be executed by a C# program.

  



  This is what I have so far :

  



  # This does not work. It only removes the default thumbnail.
ffmpeg -i video.mp4 -i image.png -acodec copy -vcodec copy -map 0 -map 1:0 OUTPUT.mp4


  



  Is what I want possible with ffmpeg ? If so, please guide me in the right direction.

  


• truehd_core : Miscellaneous improvements

  6 juillet 2019, par Andreas Rheinhardt

  truehd_core : Miscellaneous improvements
  1. The loop counter of the substream_directory loop is always less than
  
  the number of substreams, yet within the loop it is checked whether it
  
  is less than FFMIN(3, s->hdr.num_substreams), although the check for < 3
  
  would suffice.
  
  2. In case the packet is a major sync packet, the last two bytes of the
  
  major sync structure were initialized to 0xff and then immediately
  
  overwritten afterwards without ever making use of the values just set.
  
  3. When updating the parity_nibble during writing the new
  
  substream_directory, the parity_nibble is updated one byte at a time
  
  with bytes that might be read from the output packet's data. But one can
  
  do both bytes at the same time without resorting to the data just
  
  written by XOR'ing with the variable that contains the value that has
  
  just been written as a big endian number. This changes the intermediate
  
  value of parity_nibble, but in the end it just amounts to a reordering
  
  of the sum modulo two that will eventually be written as parity_nibble.
  
  Due to associativity and commutativity, this value is unchanged.
  
  4. init_get_bits8 already checks that no overflow happens during the
  
  conversion of its argument from bytes to bits. ff_mlp_read_major_sync
  
  makes sure not to overread (the maximum size of a major_sync_info is 60
  
  bytes anyway) and last_offset is < 2^13, so that no overflow in the
  
  calculation of size can happen, i.e. the check for whether size is >= 0
  
  is unnecessary. But then size is completely unnecessary and can be
  
  removed.
  
  5. In case the packet is just passed through, it is unnecessary to read
  
  the packet's dts. This is therefore postponed to when we know that the
  
  packet is not passed through.
  
  6. Given that it seems overkill to use a bitreader just for one
  
  variable, the size of the input access unit is now read directly.
  
  7. A substream's offset (of the end of the substream) is now stored as is
  
  (i.e. in units of words).
  These changes amount to a slight performance improvement : It improved
  
  from 5897 decicycles of ten runs with about 262144 runs each (including
  
  an insignificant amount — about 20-25 usually of skips) to 5747
  
  decicycles under the same conditions.
  Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
  

  • [DH] libavcodec/truehd_core_bsf.c

• how to install ffmpeg in cpanel

  16 mars 2012, par Rahul TS

  I heard that most probably cpanel server dont have ffmpeg preconfigured in it. Can you explain a way to install it in cpanel.

  Please if you can guide me through the installtion of ffmpeg in cpanel server in step by step process.

  Can anyone please also give me links of other servers which have ffmpeg preconfigured and set to run.