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• How to send an mpeg_ts stream verbatim over rtp

  30 mars 2018, par Bruce Adams

  I’m trying to write some software to capture and process data from an mpeg_ts stream.
  As part of this I need, for testing, to generate a test mpeg_ts streams for my software to capture

  One option for this is to save a real stream to disk.
  So with that in mind I have a source transport stream which is being unicast via rtp to my box via port 1234. I can view it in vlc using :

  vlc rtp://@:1234

  and I can move between channels via the "programme" menu.
  subtitles are available but no EPG
  kaffeine works as well but only shows the first channel

  I can save this stream using :

  ffmpeg -i rtp://172.16.13.81:1235 -map 0 -copy_unknown -c copy save_ffmpeg.ts

  note : that rtp ://@:1235 does not work you need your full IP address though udp ://@:1235 does work for udp streams - see https://ffmpeg.zeranoe.com/forum/viewtopic.php?t=2386

  However there is a problem. When I try to open the resulting file save_ffmpeg.ts in VLC
  instead of opening one channel at a time it opens a new window for each channel which indicates an issue.

  If on the other hand I save it using :

  cvlc rtp://@:1235 :demux=dump :demuxdump-file=save_vlc.ts

  the resulting ts file can be viewed as normal.
  What is the difference ?

  Looking at the output of mediainfo on save_ffmpeg.ts vs save_vlc.ts
  I can see that ffmpeg has stripped the streams labelled Menu #1 to Menu #5.

  >mediainfo save_ffmpeg.ts  | grep -E '^[A-Za-z]+ #'
  
  Video #1
  
  Video #2
  
  Video #3
  
  Video #4
  
  Video #5
  
  Audio #1
  
  Audio #2
  
  Audio #3
  
  Audio #4
  
  Audio #5
  
  Audio #6
  
  Audio #7
  
  >mediainfo save_vlc.ts  | grep -E '^[A-Za-z]+ #'
  
  Video #1
  
  Video #2
  
  Video #3
  
  Video #4
  
  Video #5
  
  Audio #1
  
  Audio #2
  
  Audio #3
  
  Audio #4
  
  Audio #5
  
  Audio #6
  
  Audio #7
  
  Menu #1
  
  Menu #2
  
  Menu #3
  
  Menu #4
  
  Menu #5

  I tried adding -map_metadata 0 but to no avail.

  Q1 What is wrong with the ffmpeg command ?
  How do I get it to also save the menu streams ?

  Now I can send the ts that has the menu with ffmpeg using :

  ffmpeg -re -i save_vlc.ts -c copy -f mpegts udp://127.0.0.1:9999

  to get one channel
  but again if I try to send everything :

  ffmpeg -re -i ./save_file.ts -map 0 -map_metadata 0 -copy_unknown -c copy -f rtp_mpegts rtp://127.0.0.1:9999

  then :

  vlc rtp://127.0.0.1:9999

  opens a window for each and every channel.

  Q2 How do I fix this ?

  Q3 What would the equivalent gstreamer commands be to send and recieve ts files ?

  The relevance of the final question is that one of the options being considered for implementing the MPEG_TS reader is gstreamer. Though, it probably warrants a question of its own.

• Anomalie #3540 (Nouveau) : menus des sous-rubrique

  6 septembre 2015, par Franck Dalot

  Bonjour
  Tests fait en 3.0.20 mais aussi en 3.1 sur grml.eu SPIP 3.1.0-beta SVN [22404]

  Actuellement, pour que les menus apparaissent dans la partie public, il faut la création de deux rubriques, sans quoi ne sont visible que les articles.
  Par contre le problème, est que si une personne fait la création d’une rubrique avec deux sous-rubrique, n’apparaitra dans la partie public que les articles et pas les menus.
  Il n’est donc pas évident de se rendre compte qu’il a un classement.
  Pour faire simple, cela donne :

  - Rubrique A
  — Sous-rubrique1
  --- Article 1 de la sous-rubrique1
  — Sous-rubrique2
  --- Article 1 de la sous-rubrique2

  Il n’y a pas de menu dans l’espace public.
  Alors que logiquement, il devrait y avoir au minimum le menu "Rubrique A" avec les sous-menus qui la compose quand on clique dessus.
  Ou alors.
  Le menu "Rubrique A" avec les sous-menus au survol
  Sinon
  Pas le menu "Rubrique A" mais au moins les menus "Sous-rubrique1" et "sous-rubrique2"

• ffmpeg with 720p video and y4m file [migrated]

  30 mai 2013, par Robert Cantarutti

  I was simulating a lot of videos in cif format, also all videos came with yuv format file.
  I used the expression below and it works well :

  ffmpeg -s cif -r 30 -i video.yuv -vcodec mpeg4 -g 12 -bf 2 -sameq video.m4v

  But now I'm looking for simulations with HD videos and they come with y4m extensions. Do you know witch expression I should use ?

  I tried to replace "-s hd720", instead of "-s cif" and still not working :

  ffmpeg -s hd720 -i ducks_take_off_420_720p50.y4m -vcodec mpeg4 -g 12 -bf 2 -sameq video.m4v

  error : "Option video_size not found."