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• Adding album cover art to FLAC audio files using `ffmpeg`

  27 décembre 2022, par user5395338

  I have ripped files from an audio CD I just bought. I ripped using the Music app on my Macbook Pro, Catalina 10.15.6 - output format was .wav as there was no option for FLAC. My plan was to change format using ffmpeg :

  


  % ffmpeg -v
ffmpeg version 4.4 Copyright (c) 2000-2021 the FFmpeg developers


  


  Except for the "album cover artwork" addition, the .wav-to-.flac conversion implemented in the short bash script below seems to have worked as expected :

  


  #!/bin/bash
for file in *.wav
do
echo $file 
ffmpeg -loglevel quiet -i "$file" -ar 48000 -c:a flac -disposition:v AnotherLand.png -vsync 0 -c:v png "${file/%.wav/.flac}"
done


  


  A script very similar to this one worked some time ago on a series of FLAC-to-FLAC conversions I had to do to reduce the bit depth. However, in that case, the original FLAC files already had the artwork embedded. Since this script produced usable audio files, I decided that I would try adding the artwork with a second ffmpeg command.

  


  I did some research, which informed me that there have been issues with ffmpeg (1, 2, 3, 4) on adding album artwork to FLAC files.

  


  I have tried several commands given in the references above, but still have not found a way to add album artwork to my FLAC files. The following command was a highly upvoted answer, which I felt would work, but didn't :

  


  % ffmpeg -i "01 Grave Walker.flac" -i ./AnotherLand.png -map 0:0 -map 1:0 -codec copy -id3v2_version 3 -metadata:s:v title="Album cover" -metadata:s:v comment="Cover (front)" output.flac

...


Input #0, flac, from '01 Grave Walker.flac':
  Metadata:
    encoder         : Lavf58.76.100
  Duration: 00:06:59.93, start: 0.000000, bitrate: 746 kb/s
  Stream #0:0: Audio: flac, 48000 Hz, stereo, s16
Input #1, png_pipe, from './AnotherLand.png':
  Duration: N/A, bitrate: N/A
  Stream #1:0: Video: png, rgba(pc), 522x522, 25 fps, 25 tbr, 25 tbn, 25 tbc
File 'output.flac' already exists. Overwrite? [y/N] y
[flac @ 0x7fb4d701e800] Video stream #1 is not an attached picture. Ignoring
Output #0, flac, to 'output.flac':
  Metadata:
    encoder         : Lavf58.76.100
  Stream #0:0: Audio: flac, 48000 Hz, stereo, s16
  Stream #0:1: Video: png, rgba(pc), 522x522, q=2-31, 25 fps, 25 tbr, 25 tbn, 25 tbc
    Metadata:
      title           : Album cover
      comment         : Cover (front)
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
  Stream #1:0 -> #0:1 (copy)

...



  


  I don't understand the error message : Video stream #1 is not an attached picture. It seems to imply that that the artwork is "attached" (embedded ???) in the input file, but as I've specified the artwork is a separate file, this makes no sense to me.

  


• Transition between FFMpeg streams

  25 juillet 2021, par spectacularbob

  I have been running a Youtube livestream for a while and I am developing a solution so that I can run the stream remotely through a browser. My plan is to have an ASP.net core web api project running a background service that when I send the streaming information to it, it launches FFMpeg to stream a USB webcam. I also need to be able to press a button to "mute" the stream so it shows a blank video with some text overlay (i.e. "Technical Difficulties").

  


  My solution so far is to use two instances of FFMpeg. When I switch modes, I kill one process and start the other one. I have gotten it working somewhat, but when I switch back and forth between "mute mode" and "streaming mode", Youtube seems to choke on the stream being changed. I suspect it's because when I go from mute mode back to stream mode, youtube doesn't recognize that the mute mode has ended. Also, mute mode displays the text like I want, but it causes the Youtube player to stop being "live" so that if I do get the regular stream going again, the user has to click the "Live" button to be up to date.

  


  Here's the command line for both modes :

  


  Stream Mode :

  


  ffmpeg.exe -f dshow -i video="<webcam>" -f dshow -i audio="<microphone>" -vcodec libx264 -pix_fmt yuv420p -preset veryfast -r 30 -g 60 -b:v 3500k -f flv rtmp://a.rtmp.youtube.com/live2/<stream key="key">&#xA;</stream></microphone></webcam>

  


  Mute Mode (blank.mp4 is a 3 second long blank video) :

  


  ffmpeg.exe -stream_loop -1 -i ./FFMpeg/blankvid.mp4 -vf "drawtext=fontfile=C\\\\:/Windows/Fonts/Arial.ttf:text=&#x27;Technical Difficulties&#x27;:fontcolor=white:fontsize=60:box=1:boxcolor=black@0.5:boxborderw=5:x=(w-text_w)/2:y=(h-text_h)/2" -vcodec libx264 -pix_fmt yuv420p -preset veryfast -r 30 -g 60 -b:v 3500k -f flv -flvflags no_duration_filesize rtmp://a.rtmp.youtube.com/live2/<stream key="key">&#xA;</stream>

  


  Last note : I know that there may be a way using a color filter to create the black video, rather than having a blankvid.mp4. If you also know how to get the parameters for that, it would be very helpful.

  


• Evolution #4559 : Découpage et rangement des CSS de l’espace privé

  29 avril 2021

  Bon, les divers ajustements des css du privé ont fait mettre le pied dans l’engrenage.

  J’en profite pour faire un tour d’horizon et noter ce qu’il resterait à faire.
  J’ajoute au cahier des charges le reformatage de css, si le but du rangement est de faciliter les interventions, la lisibilité du code en fait partie.

  Pour éviter les malentendus : la proposition est de rester en gros sur les bases du rangement actuel, en complétant et en ajustant un peu.
  Et plus loin dans le futur, en cas de tabula rasa je pousserais à adopter un rangement à la Integraal, pour ma part.

  Composant	Rangement	Formatage	Commentaire
  alertes	ok	ok
  bando	ok*	ok	Contient aussi les menus de navigation, à déplacer dans un composant dédié
  boutons	ok	ok
  box_skins	ok*	ok	À renommer en « box » tout court (le vieux box.css a été supprimé)
  clear	-	-	Contient quelques resets et des styles utilitaires (pour masquer, etc.). Doublon avec utils.css, fusionner les 2 ? Pour le reset, il y a déjà celui de meyer, par ailleurs.
  content	-	-	Contient beaucoup de choses. Les styles correspondant aux sections pourraient être rangées ailleurs (#pied, #chemin). Le #wysiwyg également sans doute.
  exceptions	-	-	S’il s’agit vraiment de règles spécifiques à des pages précises, renommer en « pages » ? Contient la liste des plugins → à déplacer ?
  forms	ok	ok
  grids	-	-	Encore utilisé ?
  icons	ok*	ok	Contient aussi les onglets, à déplacer dans un composant onglet.css
  layout	ok	-
  lists	ok*	-	Contient des composants qui pourraient être déplacés ailleurs : pagination, plan du site, menu-item + divers (.en-edition, ...)
  minipres	ok	-
  picker	ok	-
  reset	ok	-
  table	ok	-
  theme	-	-	Tout le contenu devrait être dispatché dans les composants adéquats. Ne laisser que des choses spéciales ne pouvant être rangées ailleurs.
  typo	ok*	-	Quelques styles pour les documents qui devraient être dans medias plutôt
  utils	ok	ok	Cf. commentaire sur clear.css
  vieilles_def	-	-	Vide (???)