Glad you enjoyed it JP!
I've been swamped today so I haven't have a chance to up the vid but I think I'll take a break to do that.
As a far a conversions, remember, the beauty of ffmpeg is that you generally are telling it what you want to output because ffmpeg can automagically determine the input. So the 720p60 coding I do for PLUG videos would work for anyone if that is the output they wanted. Obviously a recording at 30 or 24fps would not benefit from this so you actually could omit the "-r 60" parameter and ffmpeg will retain the frame rate from the source.
I don't have the screencast command line in the slides but here it is:
ffmpeg -f alsa -ac $achans -ar 44100 -i hw:$mic -f x11grab -r 15 -s $size -i :0.0+$offset -f avi -c:a pcm_s16le -c:v mjpeg -q:v 1 $1.avi
$achans = 2 (my webcam, a Logitech C910, is stereo)
$size = 1980x1080 (the size of the screen I'm recording)
$offset = 0,0 (using the origin since the entire screen is being recorded instead of just a window)
$1 = the output file name that gets .avi appended
This avi will contain mjpeg video and pcm audio which Cinelerra likes. Which for me was necessary in case I needed to do any editing. You could encode directly to mp4 but YMMV for either case. It really depends on your hardware.
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
Keith C. Perry, MS E.E.
From: "JP Vossen" <email@example.com>
To: "Philadelphia Linux User's Group Discussion List" <firstname.lastname@example.org>
Sent: Tuesday, December 22, 2015 5:08:14 PM
Subject: [PLUG] ffmpeg slides and cheat sheet
Thanks to Keith for a very interesting `ffmpeg` talk last night at PLUG
Also, per the "ffmpeg vs. avconv" discussion my notes are: Ubuntu 14.04,
ffmpeg = avconv, but as discussed that may vary and may chance.
No pressure, but I'd be interested in both the slides and a cheat sheet
of `ffmpeg` commands to use for different things.
Things I've tried to do over the years:
* Rip audio from a video file
* Capture video of a Linux desktop (your screen-cast stuff)
* Convert .flv to <something better>
* Convert m4a to mp3
* Convert FLAC into mp3
* Convert ogg into mp3
Stuff from your
which is already in the slides anyway.
Whatever else comes to mind. :-)
JP Vossen, CISSP | http://www.jpsdomain.org/ | http://bashcookbook.com/
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