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Porteus Video Tutorials

Posted: 18 Sep 2015, 01:28
by brokenman
Do you think people are more inclined to watch instructional videos or read instructions?
Do you think there would be a niche for video tutorials on how to do stuff in Porteus?
If so, are you capable of making said videos?

If anyone wants to take this on, the community could provide video tutorials and we could find a suitable medium to deliver them. I have a bunch of video tutorials ready to go.

Re: Porteus Video Tutorials

Posted: 18 Sep 2015, 04:25
by donald
First of all, we (me too) need a Tutorial how to make video Tutorials.

Re: Porteus Video Tutorials

Posted: 18 Sep 2015, 12:31
by Bogomips
Personally run shy of them. Find them off-putting, headache from watching kde5 video. Prefer a frame by frame presentation along the lines of http://www.vpnbook.com/howto/setup-openvpn-on-ubuntu. No problem in going back to a previous frame. 8)

P.S. Great if frame is enlargeable for screens lacking in resolution.

Re: Porteus Video Tutorials

Posted: 18 Sep 2015, 18:08
by brokenman
First of all, we (me too) need a Tutorial how to make video Tutorials.
That part is easy. I have a script that uses ffmpeg to record the screen in high quality.
If done tastefully (short and without a distracting music track) instead of like a lot of YouTube content... then I think you have a winner.
Those types of youtube videos are great instruction on how NOT to make instructional videos.
Prefer a frame by frame presentation
That looks really nice although I imagine it would be more work. Sometimes I find the added commentary of a video enlightening.

Re: Porteus Video Tutorials

Posted: 19 Sep 2015, 06:24
by donald
I have a script that uses ffmpeg to record the screen in high quality.
Would you (please) share it.

This could be a nice porteus app if embedded in a simple GUI, providing some options like
start /stop, change video resolution and output format.
I'm just thinking loud, this is not a module request.. :wink:

Re: Porteus Video Tutorials

Posted: 21 Sep 2015, 00:50
by brokenman
Can only say that this will work in Porteus v3.1 XFCE. Provides good quality recordings with or without sound. Be aware that it is using display :0 and sound card 1 (hw:1)

#!/bin/bash

case $1 in
low )
low=true
shift
;;
hi )
hi=true
shift
;;
* )
echo "Usage: $0 hi sound"
echo " $0 low nosound"
exit
;;
esac

if [ $hi ]; then
[ "$1" = "sound" ] && ffmpeg -f alsa -i hw:1 -f x11grab -r 25 -s 1920x1080 -i :0.0 -vcodec libx264 /tmp/record-screen.avi
[ "$1" = "nosound" ] && ffmpeg -f x11grab -r 25 -s 1920x1080 -i :0.0 -vcodec libx264 /tmp/record-screen.avi
else
[ "$1" = "sound" ] && ffmpeg -f alsa -i hw:1 -f x11grab -s 1920x1080 -r 25 -i :0.0 -vcodec libx264 -preset medium -crf 22 -y /tmp/record-screen.mp4
[ "$1" = "nosound" ] && ffmpeg -f x11grab -r 25 -s 1920x1080 -i :0.0 -vcodec libx264 /tmp/record-screen.mp4
fi

Re: Porteus Video Tutorials

Posted: 21 Sep 2015, 08:51
by donald
Thanks for sharing.

ffmpeg is an interesting tool
I use it to get the sound (without re-encoding) out of (youtube) video files.

If anyone is interested:
ffmpeg -i "input-video.*" -vn -acodec copy "output-audio.*"

"-vn" means no video.
"-acodec copy" says use the same audio stream that's already in there.

"ffmpeg -i input-video.*" will give you the audio/video format info for your file.
Read the output to see what codec it is, to set the right filename extension.

Re: Porteus Video Tutorials

Posted: 21 Sep 2015, 16:31
by brokenman
I use it to get the sound (without re-encoding) out of (youtube) video files.
Interesting use. Thanks.

Re: Porteus Video Tutorials

Posted: 23 Sep 2015, 01:32
by Rava
donald wrote:ffmpeg -i "input-video.*" -vn -acodec copy "output-audio.*"
Do you know how to compare the resulting quality from such (often mp2 file) compared to what e.g. http://www.listentoyoutube.com/ aka "YouTube to MP3 Converter" would give us, when both used on the same initial youtube clip? Best using a classical music piece, with lots of piano, or only piano...

Re: Porteus Video Tutorials

Posted: 23 Sep 2015, 06:33
by donald
It depends on what kind of audio track is in the video file.
I don't use flash, youtube works fine with html5 and you can rightclick the
video and save it as a webm file.This webm file contains (afaics) an ogg audio track.

Every (except lossless codecs) compression codec cuts off parts (frequencies) of
the music which you can't get back. And every codec use different Algorithms to do that.
When you re-compress a file into another (codec) version even more is lost.
((Codec A has cut off some parts, and now codec B cut off some different parts.(additionally))
Quality goes down.

Conclusion
If they only extract the audio, you will have the same quality.
If they extract the audio, decompress -> re-compress it into another File format
more (quality) is lost.
Even if they choose a higher Bit-rate, you can't get back what was lost by the
first compression of the original sound file.

But you can always use Audacity to make the file "sound" better
(e,g. normalisation, reduce clipping etc.)

How to compare the Quality?....I think by ears only.

Re: Porteus Video Tutorials

Posted: 23 Sep 2015, 12:22
by Rava
^

You are right on all that, nice to see some audiophile pal on here. <B

I use flash, and only html5 when the site wants / needs that.

Due to the way I customize the colours of all webpages, I have some issues seeing the controls of the html5 player.

(I define my own colours for all web pages and disallow webpages to use their own colours.

That gives at times a buggy result, like with some BB forum software, like on here with phpBB, I don't see the icons for "Reply with Quote" or "Edit post" at top of a post, next to the title. That is all black on black and only by hovering with the mouse I see via the popup text what button below the mouse is, and sadly, the same goes for some of the the html5 players controls...

Maybe there is a way to debug it, but so far I found none.