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• Image sequence to video stream ?

  22 août 2015, par Hauns TM

  Like many people already seem to have (there are several threads on this subject here) I am looking for ways to create video from a sequence of images.

  I want to implement my functionality in C# !

  Here is what I wan’t to do :

  /*Pseudo code*/
  
  void CreateVideo(List<image> imageSequence, long durationOfEachImageMs, string outputVideoFileName, string outputFormat)
  
  {
  
      // Info: imageSequence.Count will be > 30 000 images
  
      // Info: durationOfEachImageMs will be &lt; 300 ms
  
  
  
      if (outputFormat = "mpeg")
  
      {
  
      }
  
      else if (outputFormat = "avi")
  
      {      
  
      }
  
      else
  
      {
  
      }
  
  
  
      //Save video file do disk
  
  }
  
  </image>

  I know there’s a project called Splicer (http://splicer.codeplex.com/) but I can’t find suitable documentation or clear examples that I can follow (these are the examples that I found).

  The closest I want to do, which I find here on CodePlex is this :
  How can I create a video from a directory of images in C# ?

  I have also read a few threads about ffmpeg (for example this : C# and FFmpeg preferably without shell commands ? and this : convert image sequence using ffmpeg) but I find no one to help me with my problem and I don’t think ffmpeg-command-line-style is the best solution for me (because of the amount of images).

  I believe that I can use the Splicer-project in some way (?).

  In my case, it is about about > 30 000 images where each image should be displayed for about 200 ms (in the videostream that I want to create).

  (What the video is about ? Plants growing ...)

  Can anyone help me complete my function ?

• Compiling ffmpeg with emscripten

  18 septembre 2018, par noel

  I’m trying to compile ffmpeg into javascript so that I can decode H264 video streams using node. The streams are H264 frames packed into RTP NALUs so any solution has to be able to accept H264 frames rather than a whole file name.

  I found the Broadway.js library, but I couldn’t get it working and it doesn’t handle P-frames which I need. I also found ffmpeg.js, but could get that to work and it needs a whole file not a stream. Likewise, fluent-ffmpeg doesn’t appear to support file streams ; all of the examples show a filename being passed to the constructor. So I decided to write my own API.

  I have been able to compile ffmpeg into one big js file, but I can’t use it like that. I want to write an API around ffmpeg and then expose those functions to JS. So it seems to me like I need to do the following :

  1. Compile ffmpeg components (avcodec, avutil, etc.) into llvm bitcode.
  2. Write a C wrapper that exposes the decoding functionality and uses EMSCRIPTEN_KEEPALIVE.
  3. Use emcc to compile the wrapper and link it to the bitcode created in step 1.

  I found WASM+ffmpeg, but it’s in Chinese and some of the steps aren’t clear. In particular there is this step :

  emcc web.c process.c ../lib/libavformat.bc ../lib/libavcodec.bc ../lib/libswscale.bc ../lib/libswresample.bc ../lib/libavutil.bc \

  I don’t understand how all the ffmpeg components get compiled into separate *.bc files. I followed the emmake commands in that article and I end up with one big .bc file.

  Does anyone know the steps to compile ffmpeg using emscripten so that I can expose some API to javascript ?

  Is there a better way (with decent documentation) to decode h264 video streams using node ?

• Image sequence to video stream ?

  15 novembre 2020, par Hauns TM

  Like many people already seem to have (there are several threads on this subject here) I am looking for ways to create video from a sequence of images.

  



  I want to implement my functionality in C# !

  



  Here is what I wan't to do :

  



  /*Pseudo code*/&#xA;void CreateVideo(List<image> imageSequence, long durationOfEachImageMs, string outputVideoFileName, string outputFormat)&#xA;{&#xA;    // Info: imageSequence.Count will be > 30 000 images&#xA;    // Info: durationOfEachImageMs will be &lt; 300 ms&#xA;&#xA;    if (outputFormat = "mpeg")&#xA;    {&#xA;    }&#xA;    else if (outputFormat = "avi")&#xA;    {      &#xA;    }&#xA;    else&#xA;    {&#xA;    }&#xA;&#xA;    //Save video file do disk&#xA;}&#xA;</image>

  



  I know there's a project called Splicer (http://splicer.codeplex.com/) but I can't find suitable documentation or clear examples that I can follow (these are the examples that I found).

  



  The closest I want to do, which I find here on CodePlex is this :
How can I create a video from a directory of images in C# ?

  



  I have also read a few threads about ffmpeg (for example this : C# and FFmpeg preferably without shell commands ? and this : convert image sequence using ffmpeg) but I find no one to help me with my problem and I don't think ffmpeg-command-line-style is the best solution for me (because of the amount of images).

  



  I believe that I can use the Splicer-project in some way (?).

  



  In my case, it is about about > 30 000 images where each image should be displayed for about 200 ms (in the videostream that I want to create).

  



  (What the video is about ? Plants growing ...)

  



  Can anyone help me complete my function ?