Créer un screencast sous Linux / Debian (capture vidéo de l'écran) : jack + recordMyDesktop
Table des matières
Lancer le serveur audio «jack»
Date de publication: le dimanche 23 janvier 2011 à 20h04
Dernière modification: par Pascal BOYER le dimanche 23 janvier 2011 à 21h26
Il faut le lancer à la main dans un terminal:
jackd -d alsa -r 48000
- -r signifie no-real-time pour les noyaux linux qui ne sont pas compilés avec les options «temps réel»
- 48000 définit la fréquence d'échantillonnage
Si la sortie de la commande renvoie ce message:
jackdmp 1.9.6 Copyright 2001-2005 Paul Davis and others. Copyright 2004-2010 Grame. jackdmp comes with ABSOLUTELY NO WARRANTY This is free software, and you are welcome to redistribute it under certain conditions; see the file COPYING for details Cannot create thread 1 Operation not permitted Cannot create thread 1 Operation not permitted JACK server starting in realtime mode with priority 10 Cannot lock down memory area (Cannot allocate memory) audio_reservation_init Acquire audio card Audio0 creating alsa driver ... hw:0|hw:0|1024|2|48000|0|0|nomon|swmeter|-|32bit Using ALSA driver HDA-Intel running on card 0 - HDA Intel at 0xfbff4000 irq 22 the playback device "hw:0" is already in use. Please stop the application using it and run JACK again Cannot initialize driver JackServer::Open() failed with -1 Failed to start server
et vous rend la main, alors cela indique que la carte son est déjà utilisée par une tierce application (Firefox ou VLC par exemple) qu'il faut préalablement fermer.
Chez moi, lorsque le serveur se lance correctement, la commande renvoie ceci (et ne rend pas la main):
$jackd -d alsa -r 48000
jackdmp 1.9.6 Copyright 2001-2005 Paul Davis and others. Copyright 2004-2010 Grame. jackdmp comes with ABSOLUTELY NO WARRANTY This is free software, and you are welcome to redistribute it under certain conditions; see the file COPYING for details Cannot create thread 1 Operation not permitted Cannot create thread 1 Operation not permitted JACK server starting in realtime mode with priority 10 Cannot lock down memory area (Cannot allocate memory) audio_reservation_init Acquire audio card Audio0 creating alsa driver ... hw:0|hw:0|1024|2|48000|0|0|nomon|swmeter|-|32bit <=========== Le périphérique utilisé est donc: hw:0 Using ALSA driver HDA-Intel running on card 0 - HDA Intel at 0xfbff4000 irq 22 configuring for 48000Hz, period = 1024 frames (21.3 ms), buffer = 2 periods ALSA: final selected sample format for capture: 32bit integer little-endian ALSA: use 2 periods for capture ALSA: final selected sample format for playback: 32bit integer little-endian ALSA: use 2 periods for playback Cannot use real-time scheduling (RR/10)(1: Operation not permitted) AcquireSelfRealTime error
Commentaires