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• What's the single ffmpeg command for converting a video file to mpeg-dash format with adaptive bitrate ?

  28 février 2021, par Tariq Hasan

  Resultant resolutions should be of 240p, 480p, 720p and 1080p. The resultant .mpd file must be a single file.

  


• How to concatenate multiple init segments and chunks from the DASH video stream ?

  17 novembre 2022, par Umakant

  I'have written a dash player in python that receives chunks from the DASH server using adaptive bitrate algorithm. Once entire video streaming is over, I need to concatenate all following received segments into one single mp4 file.

  


  root@cap31:~/don# ls
chunk0-00001.m4s  chunk2-00015.m4s  chunk2-00035.m4s  chunk2-00055.m4s  chunk2-00075.m4s  chunk3-00010.m4s  chunk3-00030.m4s  chunk3-00050.m4s  chunk3-00070.m4s
chunk0-index.m4s  chunk2-00017.m4s  chunk2-00037.m4s  chunk2-00057.m4s  chunk2-00077.m4s  chunk3-00012.m4s  chunk3-00032.m4s  chunk3-00052.m4s  chunk3-00072.m4s
chunk1-00002.m4s  chunk2-00019.m4s  chunk2-00039.m4s  chunk2-00059.m4s  chunk2-00079.m4s  chunk3-00014.m4s  chunk3-00034.m4s  chunk3-00054.m4s  chunk3-00074.m4s
chunk1-index.m4s  chunk2-00021.m4s  chunk2-00041.m4s  chunk2-00061.m4s  chunk2-00081.m4s  chunk3-00016.m4s  chunk3-00036.m4s  chunk3-00056.m4s  chunk3-00076.m4s
chunk2-00003.m4s  chunk2-00023.m4s  chunk2-00043.m4s  chunk2-00063.m4s  chunk2-00083.m4s  chunk3-00018.m4s  chunk3-00038.m4s  chunk3-00058.m4s  chunk3-00078.m4s
chunk2-00005.m4s  chunk2-00025.m4s  chunk2-00045.m4s  chunk2-00065.m4s  chunk2-00085.m4s  chunk3-00020.m4s  chunk3-00040.m4s  chunk3-00060.m4s  chunk3-00080.m4s
chunk2-00007.m4s  chunk2-00027.m4s  chunk2-00047.m4s  chunk2-00067.m4s  chunk2-index.m4s  chunk3-00022.m4s  chunk3-00042.m4s  chunk3-00062.m4s  chunk3-00082.m4s
chunk2-00009.m4s  chunk2-00029.m4s  chunk2-00049.m4s  chunk2-00069.m4s  chunk3-00004.m4s  chunk3-00024.m4s  chunk3-00044.m4s  chunk3-00064.m4s  chunk3-00084.m4s
chunk2-00011.m4s  chunk2-00031.m4s  chunk2-00051.m4s  chunk2-00071.m4s  chunk3-00006.m4s  chunk3-00026.m4s  chunk3-00046.m4s  chunk3-00066.m4s  chunk3-index.m4s
chunk2-00013.m4s  chunk2-00033.m4s  chunk2-00053.m4s  chunk2-00073.m4s  chunk3-00008.m4s  chunk3-00028.m4s  chunk3-00048.m4s  chunk3-00068.m4s


  


  I tried all the solutions mentioned on following links :
https://trac.ffmpeg.org/wiki/Concatenate
ffmpeg converting m4s to mp4

  


  Most common solution was to append the cat files in mp4 :

  


  for x in *index* *-*[0-9]*.m4s; do cat $x >> output.mp4; done


  


  But this video does not play after the second init segment starts rendering resulting into video getting stuck. I believe maybe because in my case, I have multiple init segments pointing to different chunks.

  


  Hence, I'm looking for some way to get the one single mp4 video file by concatanating all these init segments and chunks correctly.

  


• 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.