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• MPEG DASH SRD : How to properly re-assemble multiple tiles into a single tile [closed]

  21 juin 2024, par ATrashInTheWorld

  I am trying to build a web player that is able to stream MPEG DASH, but with SRD information in the manifest. I have a problem at the "gluing" of the tiles part.

  


  How the data is set :

  


  I have a video of a resolution of XxY, which I've divided in tiles of NxM, meaning that I now have the NxM videos of the same duration as the original one, but which is reduced to a smaller resolution, a portion from the original (seeing only the upper left corner for example).

  


  I have fragmented those tiles for the MPEG DASH streaming format, meaning an init.mp4 and the m4s fragments for each tile. To note that I have the tiles in multiple bitrate, in order to imitate some adaptive streaming.

  


  The "gluing" part :

  


  The gluing part consists of gluing the tile togheter into 1 big tile, aka the original video. The SRD information allows me to know where each tile should be position to reconstruct the original video shape. Once I have the spatial information from the manifest, I use this command to glue the tiles togheter :

  


  ffmpeg.exe -i v1 -i v2 -i v3 -i .v4 -i v5 -i v6 -i v7 -i v8 -i v9 -filter_complex "[0:v][1:v][2:v][3:v][4:v][5:v][6:v][7:v][8:v]xstack=inputs=9:layout=0_0|w0_0|w0+w1_0|0_h0|w3_h0|w3+w4_h0|0_h0+h3|w6_h0+h3|w6+w7_h0+h3" out.mp4


  


  The command above allows me to "glue" together tiles from a grid of 3x3 tiles, into 1 big tile.

  


  The web streaming method :

  


  To stream, I use JavaScript MediaSource, and I am appending the fragments to the buffer continuously, like this reference

  


  The issue :

  


  The issue is that the FFMPEG gluing command only works on proper mp4 videos, not with fragments (m4s). I cannot glue the wanted m4s tiles back into a bigger one. However, the JavaScript player only takes fragments, meaning that I cannot just send continuous mp4 video.

  


  I have tried many things with fragments and full videos, but the only solution I found for this chicken-egg problem is to :

  


  

  1. Create video clips with smaller duration for each tile, at each bitrate.

  


  2. Glue the desired video clips tiles together with the FFMpeg command.

  


  3. Convert that glued video in one big fragment, and send it.

  


  


  However, I feel that it is not a clean method and I fear that I am missing something.
Is there a better solution that I am not aware of ?
Any idea suggestions are welcome.

  


  Thank you for your time.

  


• MPG to MP4 Video Conversion after Azure Media Services Retirement [closed]

  30 juillet 2024, par Yousef

  I'm hosting a C# Blazor Application in Azure App Service and was leveraging Azure Media Services to transcode mpg videos to mp4 in Jobs. However, Azure Media Services was retired last month and the services are going to stop next week so I have to find an alternative.
I have looked at multiple alternatives but couldn't find a simple conversion tool.
In Azure Media Services I was using the following configuration


  


  I can't seem to find the same configuration in the tools I have looked at. I tried Bitmovin but the encoding takes 5 - 10 Minutes (unlike Azure Media Services which takes 2 minutes) and the result of the encoding is a folder with 4 mp4 segments that are not part of the original mpg video.

  


  I tried ffmpeg locally but I can't get it to work in an Azure App Service.

  


  Does anyone have any suggestion of an alternative to Azure Media Service when it comes to Transcoding mpg videos to mp4 in a background task ?

  


• Evolution #3892 : Différence de tri entre {id_patate IN ...} et {id_patate ?}

  27 janvier 2017, par b b

  Hop, vu que cela semble impossible et que marcimat propose une solution alternative, on peut fermer le ticket ? Sinon, on le repousse à "99 plus tard" :p