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• Making changes on a video before a download [on hold]

  1er février 2016, par Chris Russo

  We have a website with lots of videos (>10,000) and lots of users (>50,000). Each video might be around 1,2 Gbs.

  The goal is to generate a unique video for each one of the members or users of the website making a small variation either on the audio track of the video, or the keyframes on the video itself, using low frequency beeps, or a few random pixels on specific keyframes.

  I understand that this operation can be done using SoX for the audio track, or FFmpeg in the case of the video, manipulating the keyframes.

  Here’s my question, as we have to choose between 2 options at this point :

  In terms of resources : would it be convenient or even possible to generate in real time a clone of the video and make this variations at the moment that the user’s request the download (please considerate the big volume of videos and users).

  Or it would be convenient to face this problem using HDD, pre-generating and storing the already manipulated videos ready to be served ?

  I understand that storing all this data will require a few many Tera’s but I’m not sure about how much RAM and Microprocessing could be demanded to perform this operations in real time, over videos that might be as big as 1Gbs.

• Passing processed Video from OpenCV to FFmpeg for HLS streaming (Raspberry PI)

  25 janvier 2016, par James Townsend

  Hi I a have a question I have openCV and ffmpeg on the Raspberry Pi and I am trying to stream live video from the raspberry pi. At the moment I have the output output of openCV saving as a .avi file and I have a command for ffmpeg
  ffmpeg -i out.avi -hls_segment_filename '%03d.ts' stream.m3u8
  This Command take the output creates the playlist(.m3u8) and the segments(.ts).

  At present I have openCV programmed in C++ (this can not change) I have an executable programmed from this and I have both the executable C++ and the above ffmpeg in a Bash Script.

  #!/bin/bash
  
  
  
  while true; do
  
  ./OpenCV
  
  ffmpeg -i out.avi -hls_segment_filename '%03d.ts' stream.m3u8
  
  done

  This does allow me to stream the processed openCV video my issue is as the Bash script is in a while loop it keeps resetting the playlist and the .ts files, so i have to constantly press play on the client connection.

  Is there anyway around this ?

  I tried including a variable that would increment every loop but if i replace ’%03d’ with this i get an error.

• What version of ffmpeg does libvlc use ?

  7 janvier 2016, par user3846684

  I am writing an application on linux (debian) that uses both libvlc and ffmpeg.
  Both run fine separately, but the moment I try to compile both functionalities into my app, libvlc stops working (complains about not finding the codecs).

  I have been able to isolate the problem, basically libvlc runs fine until I compile the first line of ffmpeg code (av_register_all), at which point the linker brings in my own ffmpeg compiled lib, and the moment I do that, it stops playing the file. Obviously I have 2 conflicting ffmpeg libs on my system, the one libvlc is using, and the newer one I built myself to write ffmpeg code.

  My question is, how do I make libvlc work with the newer library ? Considering there were functions deprecated in the newer ffmpeg code, would that involve recompiling libvlc ? Is the libvlc code up to date with the newest ffmpeg library(new function signatures) ?

  Any help is appreciated !