Category:Video
Quick Tips
Cinemagoer Extract
imdbpy search movie "12 Monkeys" python ../../util/test.py 0114746 > 12_Monkeys.json
Image Stabilization
FFMPEG
ffmpeg -i input.mp4 -vf vidstabdetect=shakiness=10:accuracy=15 -f null - ffmpeg -i input.mp4 -vf vidstabtransform=smoothing=30:zoom=0 output.mp4
First command generates the convolution file, second command applies it.
Remove Subitles
ffmpeg -i series_launch_english.mp4 -c copy -sn series_launch_english_nosubs.mp4
See Also: https://start.duckduckgo.com/?q=Advanced+SubStation+Alpha&ia=web
DVD Handling
TL;DR (updated 2025-07-15):
Rip from DVD
makemkvcon mkv --minlength=3600 disc:0 all mkv_out_01/
Set Crop
export FILE=mkv_out_01/foo.mkv
(ffmpeg -i "$FILE" -vf cropdetect -f null - 2>&1 & echo $! > /tmp/cropdetect.id) | grep crop | head -30000 | awk '{print $14}' | sort | uniq -c | sort -n && pkill -P $(cat /tmp/cropdetect.id)
export CROP=crop=720:200:90:60
Compress
Cartoons with Interlacing:
export VPATH=Family_Guy-S05D01 ; ls $VPATH | perl -e '$a=0;while(<>){$a++;$b="0".$a;if($a>9){$b="".$a;}chomp;print"export FILE=".$_." && ffmpeg -i \"\$VPATH/\$FILE\" -map 0 -vf \"yadif=1:-1:0,\$CROP\" -c:v libx264 -crf 23 -preset fast -b:a 192k -c:s copy Family_Guy-S05E$b.mkv\n";}' | sh
Latest (2025-07-29, used for live action, but should work for animation also)
$ export VPATH=s01d01/ ; export LAST_NUM=0; export SEASON="01"; export SHOW="Le_Bureau" ; ls $VPATH | perl -e '$a='$LAST_NUM';while(<>){$a++;$b="0".$a;if($a>9){$b="".$a;}chomp;print"export FILE=\"".$_."\" && ffmpeg -i \"\$VPATH/\$FILE\" -map 0 -vf \"yadif=1:-1:0,\$CROP\" -c:v libx264 -crf 23 -preset fast -b:a 192k -c:s copy '$SHOW'-S'$SEASON'E$b.mkv\n";}'
Make ISO Image
$ time dd if=/dev/sr0 of=/media/bob/backup/media/tmp/How_to_Train_Your_Dragon.iso bs=4M status=progress
Copy to Disk
makemkvcon mkv --minlength=3600 disc:0 all mkv_out_01/ makemkvcon mkv --minlength=3600 iso:How_to_Train_Your_Dragon.iso all dragon_out/
Downscale MKV With Subtitles and Audio
export FILE=mkv_out_01/foo.mkv
(ffmpeg -i "$FILE" -vf cropdetect -f null - 2>&1 & echo $! > /tmp/cropdetect.id) | grep crop | head -30000 | awk '{print $14}' | sort | uniq -c | sort -n && pkill -P $(cat /tmp/cropdetect.id)
export CROP=crop=720:200:90:60
ffmpeg -i "$FILE" -map 0 -vf "$CROP" -c:v libx264 -crf 23 -preset fast -b:a 196k -c:s copy Magnificent_Seven-The.mkv
ffmpeg -i "$FILE" -map 0 -vf "yadif=1:-1:0,$CROP" -c:v libx264 -crf 23 -preset fast -b:a 196k -c:s copy Magnificent_Seven-The.mkv
To use AAC if Vorbis is barfing:
ffmpeg -i "$FILE" -map 0 -vf "$CROP" -c:v libx264 -c:a aac -crf 23 -preset fast -b:a 196k -c:s copy Magnificent_Seven-The.mkv
ffmpeg -i "$FILE" -map 0 -vf "scale=-1:720" -c:v libx264 -crf 23 -preset fast -b:a 196k -c:s copy "../$FILE"
(ffmpeg -i "$FILE" -vf cropdetect -f null - 2>&1 & echo $! > /tmp/cropdetect.id) | grep crop | head -10000 | tail -5000 | shuf | head -10 && pkill -P $(cat /tmp/cropdetect.id) ffmpeg -i "$FILE" -vf cropdetect -f null - 2>&1 | grep crop | head -10000 | tail -5000 | shuf | head -10
crf 23 is mid-field
crf 28 is aggressive compression
ffmpeg -i "$FILE" -map 0 -vf "scale=-1:720" -c:v libx264 -crf 23 -preset fast -b:a 128k -c:s copy Firefly-s01e01-Serenity.mkv
ffmpeg -i mkv_out_01/Zombieland_t00.mkv -map 0 -vf scale=-1:720 -c:v libx264 -crf 23 -preset fast -b:a 128k -c:s copy Zombieland.mkv
720:368:0:54
ffmpeg -i input.mp4 -vf "crop=720:368:0:54" -c:v libx264 -crf 23 -preset fast output.mp4
ffmpeg -i mkv_out_01/Zombieland-J1_t00.mkv -map 0 -vf "crop=720:352:0:66" -c:v libx264 -crf 23 -preset fast -b:a 128k -c:s copy Zombieland.mkv
Fix aspect ratio without changing pixels:
ffmpeg -i input.mp4 -c copy -aspect 16:9 output.mp4
All Episodes
export CROP=crop=720:480:0:0
export VPATH=monk-s06d01 ; ls $VPATH | perl -e '$a=0;while(<>){$a++;$b="0".$a;if($a>9){$b="".$a;}chomp;print"export VPATH=\"'$VPATH'\" && export FILE=".$_." && ffmpeg -i \"\$VPATH/\$FILE\" -map 0 -vf \"yadif=1:-1:0,\$CROP\" -c:v libx264 -crf 23 -preset fast -b:a 192k -c:s copy Monk-S06E$b.mkv\n";}' > cmd.sh
export VPATH=mkv_out_02 ; ls $VPATH | perl -e '$a=8;while(<>){$a++;$b="0".$a;if($a>9){$b="".$a;}chomp;print"export FILE=".$_." && ffmpeg -i \"\$VPATH/\$FILE\" -map 0 -vf \"\$CROP\" -c:v libx264 -crf 23 -preset fast -b:a 192k -c:s copy Scrubs-S01E$b.mkv\n";}'
ls mkv_out_01/ | perl -e '$a=0;while(<>){$a++;$b="0".$a;if($a>9){$b="".$a;}chomp;print"export FILE=".$_." && ffmpeg -i \"mkv_out_01/\$FILE\" -map 0 -vf \"\$CROP\" -c:v libx264 -crf 23 -preset fast -b:a 192k -c:s copy Scrubs-S01E$b.mkv\n";}'
Interlacing in Cartoons
Detect Interlacing:
ffmpeg -i input.mp4 -vf idet -frames:v 100 -an -f rawvideo -y /dev/null
remove interlacing artifacts with:
export VPATH=Family_Guy-S05D01 ; ls $VPATH | perl -e '$a=0;while(<>){$a++;$b="0".$a;if($a>9){$b="".$a;}chomp;print"export FILE=".$_." && ffmpeg -i \"\$VPATH/\$FILE\" -map 0 -vf \"yadif=1:-1:0,\$CROP\" -c:v libx264 -crf 23 -preset fast -b:a 192k -c:s copy Family_Guy-S05E$b.mkv\n";}' | sh
-vf "yadif=0:-1:0" -c:v libx264 -flags +ilme+ildct -crf 23 -vf "yadif=0:-1:0" -flags -ilme -flags -ildct -c:v libx264 -crf 23 -vf yadif yadif=0:-1:0 (default) yadif=1:-1:0 (double frame)
list tv show seasons
video/tv/incoming$ find . -type f -name '*.mkv' | perl -e 'while(<>){chomp;if ($_=~/\/.*\/.*\//){}else{$a=$_;$a=~s/(-[SV][0-9][0-9]).*/$1/;print $a."\n";}}' | sort | uniq | cut -d '/' -f 3
Resetting a USB DVD Drive in Linux
If your USB DVD drive becomes unresponsive in Linux, you can attempt to reset it without rebooting your system by following these steps:
Identify the USB Device
Use the lsusb command to list all USB devices and find your DVD drive:
lsusb
Bus 002 Device 005: ID 152d:0562 JMicron Technology Corp. / JMicron USA Technology Corp. JMS567 SATA 6Gb/s bridge
Check the Device Status
Use dmesg or look at /var/log/syslog or /var/log/messages for any specific issues.
USB Device Reset
Reset the USB device by echoing a special value to the /sys directory:
echo 0 | sudo tee /sys/bus/usb/devices/usb[Bus]/[Bus]-[Device]/authorized echo 1 | sudo tee /sys/bus/usb/devices/usb[Bus]/[Bus]-[Device]/authorized
Replace [Bus] and [Device] with the appropriate numbers from the lsusb output.
Unloading and Reloading the Kernel Module
If you know the kernel module for your USB drive, unload it:
sudo rmmod uhci_hcd
And reload it:
sudo modprobe uhci_hcd
Restarting the udev Service
Restart the udev service, which manages device nodes:
sudo service udev restart
Using usbreset
Compile and use the usbreset program for a more convenient reset.
Note: Replace uhci_hcd with the module specific to your system. Always ensure no process is using the device before attempting a reset.
Caution: Resetting kernel modules and USB devices can lead to an unstable system state. Use these commands carefully and ensure you're not affecting other essential USB devices.
If these methods do not resolve the issue, the problem may lie with the hardware of the drive, USB port, or cable. Consider trying a different port or cable.
FFMpeg
Resize
Scale, Match Vertical to Suit 720
ffmpeg -i input.avi -filter:v scale=720:-1 -c:a copy output.mkv
Players
MPV
Prefer French audio:
$ mpv ./Futurama-S0[123]*mkv --alang=fr,fre,en --loop-playlist
Use two sets of subtitles:
$ mpv kaamelott_book_1_volume_2.webm --sid=1 --secondary-sid=2
Specify a subtitle file and run two sets of subtitles:
$ mpv kaamelott_book_1_volume_1.webm --sub-file=kaamelott_book_1_volume_1.en-GB.vtt --sid=1 --secondary-sid=2
Subtitle Processing
Dual Subtitles
Option 1: Use secondary-sid
mpv has a secondary-sid option, which lets you specify a second subtitle track to render alongside the primary one.
For example:
Where:
--sid=1→ the main subtitle track (e.g., English)--secondary-sid=2→ the secondary subtitle track (e.g., French)
You can check the track IDs by running:
or just mpv video.mkv and press j to cycle through tracks and note their IDs.
Option 2: External subtitle files
If you have separate .srt or .vtt files for English and French:
You can also use .vtt files this way.
Option 3: Config file
If you often want this behavior, add to your ~/.config/mpv/mpv.conf:
You may need to adjust the numbers (sid) to match your preferred language tracks.
More Options
You are correct: in mpv 0.35.1, there is support for --secondary-sid (to select a second subtitle track already present in the media), but there is no option called --secondary-sub-file.
This is because mpv’s “secondary subtitle” system only applies to subtitle streams already loaded, either from the container or from a single external subtitle file loaded as primary.
What works:
If your video already contains both English and French subtitle tracks:
You can enable them both like this:
This renders both subtitle tracks simultaneously. They will stack in the same position unless you adjust one of them with options like sub-pos or sub-margin-y.
If you have two separate external subtitle files (.srt or .vtt):
By default, mpv will only load one external subtitle file, even if you specify multiple --sub-file arguments — it ignores the rest.
Workarounds:
- Mux both subtitle files into the video container (e.g.,
.mkv) Usemkvmerge:
- This displays both lines in one cue.
- Use an mpv Lua script to load two external subtitle files. There are community Lua scripts that let you load and display two external subtitles, one at the top and one at the bottom. See the mpv Lua script resources page: https://mpv.io/resources/
Summary:
--secondary-sub-fileis not implemented.--secondary-sidworks, but only with embedded tracks.- For external files: either mux them into the video file, combine them manually, or use a Lua script.
If you’d like, I can help you:
- Write a shell script to mux
.srtfiles into.mkvautomatically. - Write a minimal Lua script to load and render two
.srtfiles in mpv.
- Then you can use
--sidand--secondary-sidas above. - Manually combine them into one subtitle file. Example:
Voice Acting
- 10 Voice Tones: https://old.reddit.com/r/TikTokCringe/comments/1at3n7a/voiceover_actor_explains10_tones_used_during_reads/
- "im an audio for video engineer, im the person directly communicating with the voice actor to make sure the producer is happy during recording, and it really is wild the amount of times they give what is a really over the top read from their point of view, and we have to prop then up to get them to go even bigger and more exaggerated. It feels unnatural, and bizarre, but it plays well in a VO"
- "It's like that for stage plays and performances. a persons delivery really flattens out the farther it travels so you gotta make it over-the-top"
- "im an audio for video engineer, im the person directly communicating with the voice actor to make sure the producer is happy during recording, and it really is wild the amount of times they give what is a really over the top read from their point of view, and we have to prop then up to get them to go even bigger and more exaggerated. It feels unnatural, and bizarre, but it plays well in a VO"