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• Using only ffmpeg, is it possible to consume a source GIF image and output a video that is a set length > one loop through the input GIF ?

  23 octobre 2013, par Thomas Graft

  Let's say I have an 8 frame animated GIF that is 2 seconds long. I would like to build a video file (codec not important at this point) that is 30 seconds long that consists of the source GIF repeating over and over.

  Is it possible to do this using only ffmpeg ? Answers that use convert or some other pre-processing utility do not count [The reason being that I would like to use this on PandaStream, which does not have that utility]. Let's also assume that shell scripts are out of the question as well, though it can be multiple ffmpeg commands.

  ---

  Things I have tried that did not work (though maybe I did them wrong, I'm not terribly familiar with ffmpeg) :

  1. Using the -loop_input, -loop_output options present in the ffmpeg docs. Using both ffmpeg 1.2 and 2.0, I get a Unrecognized option 'loop_[input|output]' error message. I might be using this wrong though since the error is about not recognizing the option, though the docs say it is deprecated.

  2. -loop option. Does not seem to do anything with GIF -> Video. I think this flag and the above flag are related to generating animated GIFs as the output.

  3. Concat. Doing something like :

     ffmpeg -i "concat:image.gif|image.gif|image1.gif|image2.gif|image3.gif|image4.gif" image-long.gif

     Results in a 16 frame gif (so two gifs are concatenated) which is progress, though the output gif is of much lower quality.

  ---

  I'm a bit at my wits end here (I have tried many other permutations of the above concepts), I'm at the point now of 'poking it with a stick', hopefully someone out there has done this !

• avformat/mpegts : make sure mpegts_read_header always stops at the first pmt

  15 novembre 2020, par Marton Balint

  avformat/mpegts : make sure mpegts_read_header always stops at the first pmt
  mpegts_read_header stops parsing the file at the first PMT. However the check
  
  that ensured this was wrong because streams can also be added before the first
  
  PMT is received (e.g. EIT).
  So let's make sure we are in the header reading phase by checking if ts->pkt is
  
  unset instead of checking if the number of streams found so far is 0.
  Signed-off-by : Marton Balint <cus@passwd.hu>
  

  • [DH] libavformat/mpegts.c

• How to get FFMPEG to use more GPU when encoding

  24 mars 2023, par Entropy

  so the situation is as following

  


  Im receiging 20/30 uncompressed image per second. format is either PNG or Bitmap. Each individual photo size is between 40 and 50 mb (all have same size since uncompressed).

  


  I want to encode them to a 265 lossless video and stream them to a http server using FFMPEG.
The output video is 1920x1080, so there is some downsampling.
Compression is allowed but nothing is allowed to be lost other than the down sampling.

  


  now i m still in the testing phase. i have a 500 sample image. and i m tryng to encode them as effeciently as possible.
Im using commands such as :

  


  ffmpeg  -hwaccel cuvid -f  image2  -i "0(%01d).png" -framerate 30 / 
-pix_fmt p010le -c:v hevc_nvenc -preset lossless -rc vbr_hq /
-b:v 6M -maxrate:v 10M  -vf scale=1920:1080  -c:a aac -b:a 240k result.mp4


  


  I have a powerfull modern quadro GPU and a 6 cores intel CPU and an Nvme hard drive.

  


  The usuage of the GPU when encoding is exactly 10%, CPU is circa 30-40%

  


  How can i get GPU usuage to 80% ? The machine on which im going to run the code will have at leat a quadro 4000 (maybe stronger) and i want to use it to the fullest