Linux video: Difference between revisions

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* Display webcam video stream with '''mplayer''' [https://help.ubuntu.com/community/Webcam]:
* Display webcam video stream with '''mplayer''' [https://help.ubuntu.com/community/Webcam]:
mplayer tv:// -tv driver=v4l2:width=640:height=480:device=/dev/video0
mplayer tv:// -tv driver=v4l2:width=640:height=480:device=/dev/video0

== How-To ==
=== Find duplicates ===
Source: https://ubuntuforums.org/showthread.php?t=1110498
<source lang=perl>
#!/usr/bin/perl
use File::Path;

# Source: https://ubuntuforums.org/showthread.php?t=1110498
# Modified by Xeyownt

my $ofh = select STDOUT; #Make stdout hot
$| = 1;
select STDOUT;

$getimages = 1000; #render out 1000 images
$deletefirst = 300; #delete the first 300
$totalimages = $getimages - $deletefirst;
$minmatch = 2; #might use this later (not used now)

exit unless defined($ARGV[0]);
$searchdir = "$ARGV[0]"; #directory to scan
$searchdir = $searchdir . "/" unless $searchdir =~ m/\/$/;
$basedir = "/tmp/hashchecker/"; #working directory, this directory will get clobbered, make it something uniq in /tmp/
$basedir =~ s|/\z||;
print "Searching '$searchdir'...\n";

print "Cleaning up hsh directory '$basedir'...\n";
rmtree($basedir); #see, I told you.

print "Rendering $getimages frame(s), skipping the first $deletefirst. ($totalimages end result)\n";

@videofiles=`find "$searchdir" -type f -printf "%p\n" | grep -Ei "\.(mp4|flv|wmv|mov|avi|mpeg|mpg|m4v|mkv|divx|asf)"`;
foreach $i (@videofiles)
{
chomp $i;
print "Processing '$i'...";
@filename = split(/\//,$i);
$imgdir = $basedir . "/$filename[-1]";
mkpath($imgdir);
$data=`cd "$imgdir"; mplayer -really-quiet -vo png -frames $getimages -ao null "$i" 2>&1`;
@data=`find "$imgdir" -type f -name "*.png" | sort`;
for ($deletecount=0; $deletecount < $deletefirst; $deletecount++)
{
chomp $data[$deletecount];
unlink $data[$deletecount];
}
print "mogrify -resize 10x10! -threshold 50% -format bmp \"$imgdir/*\"\n";
$data=`mogrify -resize 10x10! -threshold 50% -format bmp "$imgdir/*"`;
$data=`find "$imgdir" -type f -name "*.png" -delete`;
print "\n";
}
print "Calculating hash table...\n";
@md5table=`find "$basedir" -type f -name "*.bmp" -exec md5sum "{}" \\; | sort | uniq -D -w32`;
foreach $x (@md5table)
{
chomp $x;
$x =~ m/^([0-9a-f]{32})/i;
$md5=$1;
$x =~ m/^[0-9a-f]{32}[ \t]*(.*)/i;
$fullpath=$1;
@filename = split(/\//,$x);
open (MYFILE, ">>$basedir/$md5.md5") or die "couldnt open file\n";
print MYFILE "$fullpath\n";
close (MYFILE);
}

@hashfiles=`find "$basedir" -type f -name "*.md5"`;
foreach $i (@hashfiles)
{
chomp $i;
@uniqfiles=`sort "$i" | uniq`;
$uniqsize=@uniqfiles;
if ($uniqsize > 1)
{
$firstpass = 1;
foreach $x (@uniqfiles)
{
chomp $x;
@filename=split(/\//,$x);
if ($firstpass == 1)
{
$outfile=$filename[-2];
$firstpass=0;
}
else
{
if ($outfile ne $filename[-2])
{
open (COUNTFILE, ">>$basedir/$outfile.count") or die "$outfile -> couldnt open file\n";
print COUNTFILE "$filename[-2]\n";
close (COUNTFILE);
}
}
}

}
}
print "Here come the delicious dupes:\n";
@hashfiles=`find "$basedir" -type f -name "*.count"`;
foreach $i (@hashfiles)
{
chomp $i;
print "$i\n";
@uniqfiles=`sort "$i" | uniq -c`;
foreach $x (@uniqfiles)
{
chomp $x;
$x =~ m/^[ \t]*([0-9]{1,50})/i;
$percent = $1/$totalimages*100;
$x =~ m/^[ \t]*[0-9]{1,50}(.*)/i;
$filename=$1;
printf "\t%.2f% match with %s\n",$percent,$filename;
}
print "\n";

}
exit;
</source>

=== Create video thumbnails ===
==== ffmpegthumbnailer ====
Requires {{deb|ffmpegthumbnailer}}:
<source lang="bash">
THUMBDIR=thumbnails
THUMBSUMMARY=summary.png

make_thumbnails()
{
if [ -d $THUMBDIR ]; then
mv $THUMBDIR $THUMBDIR-$(date +"%Y%m%d%H%M%S")
fi
# sudo apt install ffmpegthumbnailer
SIZE=512
mkdir -p "$THUMBDIR"

i=0
for f in *; do
[ "$f" = "$THUMBDIR" ] && continue
echo -- "$f"
ffmpegthumbnailer -s $SIZE -i "$f" -o "$THUMBDIR/$f-10.png" -c png -t 10
ffmpegthumbnailer -s $SIZE -i "$f" -o "$THUMBDIR/$f-20.png" -c png -t 20
((i++))
# [ $i -lt 5 ] || break
done
echo "Doing montage..."
montage -label %f -frame 5 -geometry "$SIZEx$SIZE+2+2>" $THUMBDIR/*.png $THUMBSUMMARY
mv $THUMBSUMMARY $THUMBDIR/
}
</source>

Note that the thumbnail summary can be quite big. Use viewer like {{deb|feh}} to view it. The same application can be used to view thumbnails easily:

<source lang="bash">
THUMBDIR=thumbnails
THUMBSUMMARY=summary.png

view_thumbnails()
{
# sudo apt intall feh
feh -dF --zoom fill $THUMBDIR
}

view_thumbnails_summary()
{
# sudo apt intall feh
feh $THUMBDIR/$THUMBSUMMARY
}


</source>

==== ffmpeg ====
<source lang="bash">
ffmpeg -itsoffset -5 -i "$srcimg" -vcodec mjpeg -vframes 1 -an -f rawvideo -s 200x200 -loglevel quiet "$dest"
</source>

Revision as of 08:47, 16 July 2017

Related Pages

Play videos

Mplayer

External links


Playing video files

MPlayer plays video files. Many video formats are supported. To play a file: 

mplayer <SOMEFILE>

Here a short summary of keyboard shortcuts that can be used during playback:

Key Function
Left Right Forward / backward 10 seconds
Down Up Forward / backward 1 minutes
PgDn PgUp Forward / backward 10 minutes

Some frequently-used options: 

mplayer -xy 2 <SOMEFILE>       # Plays a file with a scale factor of 2


Playing DVD's

Here some handy examples. Mplayer can also be used to play dvd files directly from the harddisk. Check man mplayer for more examples. 

mplayer dvd://1                                  # Quick start playing dvd from dvd-reader
mplayer dvd://5-7                                # Only plays titles 5 to 7
mplayer dvd://1 -dvd-device /path/to/directory/  # Play DVD title 1 from a directory with VOB files
mplayer dvd://1 -alang fr -slang en              # Play in Japanese with French subtitles

bug: There is apparently a bug that prevents subtitles to be displayed even though the option -slang is given on the command-line. As a workaround press the key J while playback to cycle through the subtitles.

Record video

SimpleScreenRecorder

SimpleScreenRecorder is a very simple and powerful tool to record desktop on Linux.

  • Fullscreen - 128kb mp3, H.264 superfast setting
Roughly 2Mbps for desktop recording. On i5-4300U CPU @ 1.90GHz, it takes 40% of one core.

VLC

We can use VLC to record the desktop, for instance to make Youtube tutorial videos.

  • Go to Media → Convert/ Save
  • Select the Capture Device tab
  • Set Capture Mode to Desktop.

VLC foresee several profiles:

  • H.264 + MP3 (.MP4 container).
Roughly 1Mbps for desktop recording. On i5-4300U CPU @ 1.90GHz, it takes 95% of one core.
  • Youtube SD.
640x480 - Roughly 1Mbps for desktop recording. On i5-4300U CPU @ 1.90GHz, it takes 40% of one core.
  • Youtube HD.
Issues
  • VLC does not record audio

Encode video

HandBrake

HandBrake is a powerful, yet easy to use video encoder for Linux.

Tips - Encode a DVD title
  • Click Source.
  • Select DVD to encode, and select folder VIDEO_TS (don't open it), and click OK.

Movie subtitles

Gnome Subtitles

Gnome Subtitles is an excellent application to generate, or resync subtitles file (format .srt...). 

sudo add-apt-repository ppa:pedrocastro/ppa
sudo apt-get update
sudo apt-get install gnome-subtitles

Creating a ScreenCast

From [1]:

  1. Created an Intrepid instance in VirtualBox.
  2. Used gtk-recordmydesktop to record only the VirtualBox window.
  3. Create the intro and outro slides in OOo and recorded them using gtk-recordmydesktop.
  4. Import all three clips into Pitivi and exported them as a single ogv.
  5. Recorded the speech in Audacity while watching the screencast and exported it as a wav file.
  6. Converted the ogv to an avi using mencoder.
  7. Imported the avi and wav into avidemux, mashed them together and saved an avi.
  8. Used ffmpeg2theora to convert it back to an ogv.

Another solution: http://wiki.ubuntu.com/ScreencastTeam

Webcam

  • Display webcam video stream with mplayer [2]:
mplayer tv:// -tv driver=v4l2:width=640:height=480:device=/dev/video0

How-To

Find duplicates

Source: https://ubuntuforums.org/showthread.php?t=1110498 

#!/usr/bin/perl
use File::Path;

# Source: https://ubuntuforums.org/showthread.php?t=1110498
# Modified by Xeyownt

my $ofh = select STDOUT; #Make stdout hot
$| = 1;
select STDOUT;

$getimages = 1000; #render out 1000 images
$deletefirst = 300; #delete the first 300
$totalimages = $getimages - $deletefirst; 
$minmatch = 2; #might use this later (not used now)

exit unless defined($ARGV[0]);
$searchdir = "$ARGV[0]"; #directory to scan
$searchdir = $searchdir . "/" unless $searchdir =~ m/\/$/;
$basedir = "/tmp/hashchecker/"; #working directory, this directory will get clobbered, make it something uniq in /tmp/
$basedir =~ s|/\z||;
print "Searching '$searchdir'...\n";

print "Cleaning up hsh directory '$basedir'...\n";
rmtree($basedir); #see, I told you.

print "Rendering $getimages frame(s), skipping the first $deletefirst. ($totalimages end result)\n";

@videofiles=`find "$searchdir" -type f -printf "%p\n" | grep -Ei "\.(mp4|flv|wmv|mov|avi|mpeg|mpg|m4v|mkv|divx|asf)"`;
foreach $i (@videofiles)
{
 chomp $i;
 print "Processing '$i'...";
 @filename = split(/\//,$i);
 $imgdir = $basedir . "/$filename[-1]";
 mkpath($imgdir);
 $data=`cd "$imgdir"; mplayer -really-quiet -vo png -frames $getimages -ao null "$i" 2>&1`;
 @data=`find "$imgdir" -type f -name "*.png" | sort`;
 for ($deletecount=0; $deletecount < $deletefirst; $deletecount++)
 {
   chomp $data[$deletecount];
   unlink $data[$deletecount];
 }
 print "mogrify -resize 10x10! -threshold 50% -format bmp \"$imgdir/*\"\n";
 $data=`mogrify -resize 10x10! -threshold 50% -format bmp "$imgdir/*"`;
 $data=`find "$imgdir" -type f -name "*.png" -delete`;
 print "\n";
}
print "Calculating hash table...\n";
@md5table=`find "$basedir" -type f -name "*.bmp" -exec md5sum "{}" \\; | sort | uniq -D -w32`;
foreach $x (@md5table)
{
 chomp $x;
 $x =~ m/^([0-9a-f]{32})/i;
 $md5=$1;
 $x =~ m/^[0-9a-f]{32}[ \t]*(.*)/i;
 $fullpath=$1;
 @filename = split(/\//,$x);
 open (MYFILE, ">>$basedir/$md5.md5") or die "couldnt open file\n";
 print MYFILE "$fullpath\n";
 close (MYFILE);
}

@hashfiles=`find "$basedir" -type f -name "*.md5"`;
foreach $i (@hashfiles)
{
 chomp $i;
 @uniqfiles=`sort "$i" | uniq`;
 $uniqsize=@uniqfiles;
 if ($uniqsize > 1)
 {
   $firstpass = 1;
   foreach $x (@uniqfiles)
   {
     chomp $x;
     @filename=split(/\//,$x);
     if ($firstpass == 1)
     {
       $outfile=$filename[-2];
       $firstpass=0;
     }
     else
     {
       if ($outfile ne $filename[-2])
       {
         open (COUNTFILE, ">>$basedir/$outfile.count") or die "$outfile -> couldnt open file\n";
         print COUNTFILE "$filename[-2]\n";
         close (COUNTFILE);
       }
     }
   }

 }
}
print "Here come the delicious dupes:\n";
@hashfiles=`find "$basedir" -type f -name "*.count"`;
foreach $i (@hashfiles)
{
 chomp $i;
 print "$i\n";
 @uniqfiles=`sort "$i" | uniq -c`;
 foreach $x (@uniqfiles)
 {
    chomp $x;
    $x =~ m/^[ \t]*([0-9]{1,50})/i;
    $percent = $1/$totalimages*100;
    $x =~ m/^[ \t]*[0-9]{1,50}(.*)/i;
    $filename=$1;
    printf "\t%.2f% match with %s\n",$percent,$filename;
 }
 print "\n";

}
exit;

Create video thumbnails

ffmpegthumbnailer

Requires ffmpegthumbnailer: 

THUMBDIR=thumbnails
THUMBSUMMARY=summary.png

make_thumbnails()
{
	if [ -d $THUMBDIR ]; then
		mv $THUMBDIR $THUMBDIR-$(date +"%Y%m%d%H%M%S")
	fi
	# sudo apt install ffmpegthumbnailer
	SIZE=512
	mkdir -p "$THUMBDIR"

	i=0
    for f in *; do 
    	[ "$f" = "$THUMBDIR" ] && continue
    	echo -- "$f"
    	ffmpegthumbnailer -s $SIZE -i "$f" -o "$THUMBDIR/$f-10.png" -c png -t 10
    	ffmpegthumbnailer -s $SIZE -i "$f" -o "$THUMBDIR/$f-20.png" -c png -t 20
    	((i++))
    	# [ $i -lt 5 ] || break
    done
    echo "Doing montage..."
    montage -label %f -frame 5 -geometry "$SIZEx$SIZE+2+2>" $THUMBDIR/*.png $THUMBSUMMARY
    mv $THUMBSUMMARY $THUMBDIR/
}

Note that the thumbnail summary can be quite big. Use viewer like feh to view it. The same application can be used to view thumbnails easily: 

THUMBDIR=thumbnails
THUMBSUMMARY=summary.png

view_thumbnails()
{
	# sudo apt intall feh
	feh -dF --zoom fill $THUMBDIR
}

view_thumbnails_summary()
{
	# sudo apt intall feh
	feh $THUMBDIR/$THUMBSUMMARY
}

ffmpeg

ffmpeg -itsoffset -5 -i "$srcimg" -vcodec mjpeg -vframes 1 -an -f rawvideo -s 200x200 -loglevel quiet "$dest"
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