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• what codec to specify to accessing my HDMI-to-USB adaptor, under Linux ? [closed]

  14 mai 2022, par David

  A week or so ago,I bought a HDMI-to-USB adapter, to use to capture video
TV content from my TV's set-top box. (Xfinity, if it matters. Box generically is :
"XiD X1"...I have both the Pace and the Cisco models available here in this house.)

  


  Specifically, here's the adapter I bought,from Amazon :
https://www.amazon.com/gp/product/B09FLN63B3

  


  So, I'm fluent in both Windows (Win-11) and Linux (Debian 'Bullseye', on my chromebook).

  


  The adapter does not come with any recommendations for what software/drivers to (try to) use, but I was prepared for that.
After some google searches, I decided to first try using the cmd-line
'ffmpeg' program, because I'm
quite familiar with that (excellent !) piece of open-source software !

  


  So, after a day or two of (mostly) success recordings under Win-11, using
ffmpeg's Microsoft-based 'dshow' (aka 'DirectShow'), I decided to attempt to get
up to the same level of accomplishment on my Chromebook, under Linux, also
using 'ffmpeg'.

  


  [Ok...a very brief explanation of 'mostly' successful. I'll
post another separate question here, about the specifics of my glitches,
using 'dshow' on Windows. But, essentially, when I try to record to a MP4
file, I get 2 scenarios of glitch : #1 : Suddenly, dropped packets surges up,
and I get "1000 dropped' yellow msg #2 : On other trials, I get '...contains
no image...'.) So, I figured I should first give a Linux a chance,
before spending more effort trying to resolve the glitches on Windows.]

  


  My first snag, was learning that 'dshow' seems to be specific to 'Windows',
and thus ffmpeg is getting 'unknown' for my reference to 'dshow'. After more hours of 'guessing', I've finally learned/concluded that there are other things
(something call "DeckLink" is one such alternative ?) for Linux, but I'm unclear
what extra Linux packages might exist for ffmpeg support, or whether I will need to built a more complete 'ffmpeg' (e.g. from source code), to get things going under Linux ?

  


  Is my device able to be accessed from some tools other than 'ffmpeg' ?
(e.g. VLC or Handbrake or whatever ?) more easily, on the Linux platform ?

  


  [If I had to, I'd probably invest another $20-$50 in some other hardware
device that goes from HDMI-to-USB (USB-A/B), if it were ]

  


  All ideas are welcome...(TIA)

  


  — Dave

  


• Video Concat using ffmpeg [closed]

  17 juin 2022, par Milan K Jain

  ffmpeg -i url1 -i url2 -i url3 -i url4 -filter_complex "[0:v:0]scale=1920:1080[c1] ; [1:v:0]scale=1920:1080[c2] ; [2:v:0]scale=1920:1080[c3] ; [3:v:0]scale=1920:1080[c4], [c1] [0:a:0] [c2] [1:a:0] [c3] [2:a:0] [c4] [3:a:0] concat=n=4:v=1:a=1 [v] [a]" -map "[v]" -map "[a]" /Users/myname/Downloads/f1-2017-07-12.mp4 -y

  


  In Place of url I want to give link U get from after storing my video in amazon s3 bucket
Someone pls help

  


• Anomalie #4245 (Fermé) : Petit bug de sous_repertoire()

  11 décembre 2018

  Découvert hier, un enchaînement tueur :

  <span class="CodeRay"><span class="local-variable">$demo</span> = sous_repertoire(_DIR_TMP, <span class="string"><span class="delimiter">'</span><span class="content">demo_</span><span class="delimiter">'</span></span>);
  <span class="comment">// $demo = 'tmp/demo_'</span>
  <span class="local-variable">$bug</span> = sous_repertoire(<span class="local-variable">$demo</span>, <span class="string"><span class="delimiter">'</span><span class="content">potiron</span><span class="delimiter">'</span></span>);
  </span>
  Télécharger

  Le système a rencontré une erreur lors de l’écriture du fichier tmp/demo/potiron/.plat.

  En fait, lors de l’appel de sous_repertoire($base, $subdir), la fonction vire les / et _ finaux de $base (mais pas le _ final éventuel de $subdir).
  Il se retrouve ici à vouloir créer le répertoire tmp/demo/potiron au lieu de tmp/demo_/potiron et n’y arrive pas, vu que le répertoire parent (demo) n’existe pas.

  Histoire¶

  Après quelques fouilles archéologiques, il se trouve que le problème survient probablement avec r8196 qui refactore différemment le code de r6395 :
  - 6395 fil@rezo.n     if (!preg_match(',[/_]$,', $base)) $base .= '/';
  - 8196 esj@rezo.n     if (preg_match(',[/_]$,', $base)) $base = substr($base,0,-1);
  - 16035 fil@rezo.n     $base = rtrim($base, '/_');

  Le tout devait être, je suppose, pour prendre en compte les excentriques répertoires "plats" (dépendants maintenant de la présence de la constante _CREER_DIR_PLAT).

  Corrections¶

  Plusieurs corrections possibles :
  - A) virer la constante _CREER_DIR_PLAT et ses actions, et le rtrim de ce souligné (on est en 2018…).
  - B) simplement appliquer le rtrim du souligné si _CREER_DIR_PLAT est présent (ça corrige pas le bug que $subdir n’aurait alors pas ce rtrim non plus !)
  - C) B + corriger le rtrim pour $subdir de la même manière.

  Je suis partisan de A) sur le trunk, et B) ou C) sur 3.2 et 3.1.

  Des avis ?