HowTo

[rwoodleyhowto]

Theta/Ubuntu

Installing ptpcam on Unix:

https://emsi.wordpress.com/2015/06/10/raspberry-pi-and-dslr-remote-capture-control/

[rwoodleyhowto]

OpenCV/Python on Mac

OpenCV is installed in /usr/local/python/cv2

Virtual environments are in ~/.virtualenvs

You choose your virtual env with the command ‘workon’. (The workon command is from virtualenvwrapper.) e.g.: workon cv

You need a symbolic link to the OpenCV installation for each virtual environment you create.

Notes here: https://www.pyimagesearch.com/2018/08/17/install-opencv-4-on-macos/

[rwoodleyhowto]

Connect to Windows 10 Home share from OSX as guest

1. Set up a folder on windows, click on Sharing and make it fully accessible to Everyone. This is the folder you will connect to from OSX.

2. Make  that Windows recognizes your current Wifi network as a private network. (You don’t want to do this for a public network obviously).

3. In Control Panel/Windows Defender Firewall, Enable file and print sharing for private network.

4. Allow connections without a password: Go to Control Panel, Network and Sharing Center, Advanced sharing settings and then expanding All Networks. Here you will see an option called Password protected sharing, which you can turn off. 

5. You can’t use the Group Policy Editor on Windows 10 Home. It also doesn’t allow you to set up a Guest account. So you have to follow the instructions here: https://answers.microsoft.com/en-us/windows/forum/all/windows-10-home-no-guest-account/7e5748c4-5216-4897-bc75-51d16826679b

[rwoodleyhowto]

ffmpeg - stitch stills into a video.

ffmpeg -r 1/2 -i img%03d.png -c:v libx264 -vf fps=25 -pix_fmt yuv420p ~/out2.mp4

The 1/2 means each still last 2 seconds.

[rwoodleyhowto]

Ricoh Lights

Flashing Blue - Booting Up

Green - Charging. Flashing when low it says, tho always seems to flash.

Red - Problems, unplug.

White light, green Wi-Fi - Plug-in mode.

[rwoodleyhowto]

Screen Capture with OBS

Under Settings/Output/Recording:

  Quality: ‘Indistinguisable’

  Encoder: Hardware

Under Settings/Video:

  Both resolutions: 1920x1080

  FPS: 60

Under Settings/Advanced/Video

  Color Format: NV12

  YUV Color Space: 601, YUV Color Range: Partial

that last one (partial) is important to avoid wash out.

When you upload to vimeo the quality will degrade. :(

[rwoodleyhowto]

stl to printing

1- The project to run is 3dPrintTest. Once you’ve got a mesh you like, click on link on lower-right to export an STL file.

2 - Open MeshLab. Do these 4 steps:

2a - Under Filters/Cleaning And Repairing, Remove Duplicate Faces and Remove Duplicate Vertices. Then Remove Faces from Non-Manifold Edges.

2b - Export.

3 - Upload corrected STL file to Shapeways.

[rwoodleyhowto]

gulp, browser-sync

install node, then:

npm install gulp-cli -g sudo npm install gulp-cli -g sudo npm install gulp -D

sudo npm install browser-sync --save-dev

then you need a gulpfile.js:

var gulp        = require('gulp'); var browserSync = require('browser-sync').create(); var reload      = browserSync.reload; // Static server gulp.task('browser-sync', function() {    browserSync.init({        server: {            baseDir: "./"        }    });  gulp.watch('public/**/*.html').on('change', reload);  gulp.watch('public/**/*.js').on('change', reload);  gulp.watch('public/**/*.css').on('change', reload); });

gulp browser-sync

[rwoodleyhowto]

Add audio to video

Add audio to video:

ffmpeg -i RootBot1.mov -i BotJam.m4a -shortest RoootBotMusic2.mov

Add fade out at 3 minutes for 4 seconds long:

ffmpeg -i RootBotMusic2.mov -af "afade=t=out:st=180:d=4" RootBotMusic3.mov

[rwoodleyhowto]

Loop animated gif

Install ImageMagick. Instructions here: https://www.imagemagick.org/script/download.php

convert -loop 0 old.gif new.gif

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Add 360 meta data to edited equirectangular pics

exiftool -ProjectionType="equirectangular" blah.jpg

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side-by-side video, with time offset.

# extract the desire portion. Be very careful to get an exact time so the loops line up. ffmpeg -i ../dance148.mp4  -ss 00:00:46 -t 00:00:03.75  extract.mp4 # now make the loop. ffmpeg -re -f lavfi -i "movie=filename=extract.mp4:loop=10, setpts=N/(FRAME_RATE*TB)" newLoop.mp4 # shrink it. ffmpeg -i newLoop.mp4 -c:v libx264  -vf scale=960:480 -an small.mp4 # get each offset portion. placement of -ss and -t flags is important apparently. ffmpeg -i small.mp4  -ss 00:00:00 -t 00:00:03.75 small1.mp4 ffmpeg -i small.mp4  -ss 00:00:01 -t 00:00:03.75 small2.mp4 ffmpeg -i small.mp4  -ss 00:00:02 -t 00:00:03.75 small3.mp4 ffmpeg -i small.mp4  -ss 00:00:03 -t 00:00:03.75 small4.mp4 # combine them, side-by-side ffmpeg -i small1.mp4 -i small2.mp4 -i small3.mp4 -i small4.mp4 -filter_complex hstack=4 output2.mp4 # now make a loop. ffmpeg -re -f lavfi -i "movie=filename=output2.mp4:loop=10, setpts=N/(FRAME_RATE*TB)" sideBySideLoop2.mp4

See many examples here: https://trac.ffmpeg.org/wiki/FancyFilteringExamples

[rwoodleyhowto]

python

Get dictionary keys in sorted value order:

sorted(x, key=x.get)

[rwoodleyhowto]

Video formats

WEBM to MP4:

See http://superuser.com/a/744133

ffmpeg -i input.webm -c:v libx264 -c:a aac -strict experimental -b:a 192k output.mp4

If you get the dreaded “width not divisible by 2 “ you can manually specify the aspect ratio with this switch: “ -vf scale=720:480 “

To slow down a video use the -filter:v "setpts=3.0*PTS"  switch, e.g.:

ffmpeg -i output.mp4  -filter:v "setpts=3.0*PTS" -an  limitSet.mp4

Quality:

Default command gives quick and dirty results:

ffmpeg -i hyperbolicTesselation.webm outputSimple.mp4

The command above is only slightly better.

For best results use this. Lower CRF is better. ‘preset’ values are: ultrafast, slow, veryslow. veryslow is very best:

ffmpeg -i hyperbolicTesselation.webm -c:v libx264  -crf 10 -preset veryslow -c:a copy crf10presetVerySlow.mp4

That command gives 25% compression. Setting crf to 20 is almost as good but gets 75% compression. **You can also add -r 30 to get 30 fps **which may be better on twitter.

See: https://trac.ffmpeg.org/wiki/Encode/H.264

Audio:

-c:a copy       copies audio as-is.

-an                 no audio. more here: http://superuser.com/questions/268985/remove-audio-from-video-file-with-ffmpeg

Extract:

ffmpeg -ss [start] -i in.mp4 -t [duration] -c copy out.mp4`

Color:

This makes the Ricoh’s a little more colorful:

ffmpeg  -i dollyZoom.mp4  -vf "eq=contrast=1.0:brightness=0.00:saturation=1.75" dollyZoomColors.mp4

Looping:

ffmpeg -re -f lavfi -i "movie=filename=input.mp4:loop=10, setpts=N/(FRAME_RATE*TB)" output.mp4

loop = 10 means loop 10 times.

green screen - Don't use these. Kept for reference.

ffmpeg -f lavfi -i color=c=black:s=2424x3240 -i vout.mp4 -filter_complex "[1:v]chromakey=0x70de77:0.1:0.2[ckout];[0:v][ckout]overlay[out]" -map "[out]" -ss 00:00 -t 00:18 voutg.mp4

BUT mp4 cannot handle alpha channel so, this means the green will become black, but not transparent.

ffmpeg -i a.mov -vf "chromakey=0x70de77:0.1:0.2" -c copy -c:v png output.mov

then convert it to webm which chrome will render correctly.

ffmpeg -i output.mov output.webm

this works, but the file is gigantic because png format is lossless. See discussion here: https://video.stackexchange.com/questions/21397/green-screen-to-transparent-with-ffmpeg

green screen - Use this.

ffmpeg -i voutSmall.mp4 -vf "chromakey=0x70de77:0.1:0.2" -c copy -c:v libvpx -b:v 1M -auto-alt-ref 0 output.webm

Twitter won’t take webm. But if you convert your webm to mp4 and upload, it looks ok.

Facebook won’t play videos in HD by default. You can edit your settings to enable this: Enter your facebook settings and click on video, from there your upload video quality should be set to default, simply choose "HD if available". Of course you can’t force people to enable that setting! So by default it will suck.

[rwoodleyhowto]

Ricoh Theta S Video

The Ricoh purports to record video in 1920x1080. And indeed in dual hemisphere mode that is the size. But once you put the video through the Ricoh App it comes out as 1920x960.

So you have video in 1920x960. If you try to extract a still from it in iMovie you have 2 options: 

1 - click on the movie in the browser pane. It will export a 1920x1080 frame but the sides will be cut off.

2 - click on the movie in the timeline pane. It will export a 1920x1080 frame but there will be a black band on the top and bottom.

The only way to get a frame that is 1920x960 that I know of is to use ffmpeg:

ffmpeg -i 1920x960/movie.MP4  -ss 00:00:07.000 -vframes 1 -y frame.png

[rwoodleyhowto]

Edit out green screen in Premiere Pro

This video is good:

https://helpx.adobe.com/premiere-pro/atv/cs5-cs55-video-tutorials/creating-a-green-screen-key-using-ultra-key.html

- in effects, find ultra key. drag it on top of your video in the timeline.

- open the ‘Effects Control Panel’. you can find this with the help function.

- Use the eye-dropper to click on the darkest green you can find.

- Select Alpha Channel to see how good it worked. Use the sliders to adjust, per the video. Select ‘Composite’ to view.

[rwoodleyhowto]

oauth for new chrome apps

- upload your app to the chrome developer dashboard. that will give you an app id.

- Go to the Google API Console

- From the drop down in the upper right, select 'Chrome Apps'. <---

- Select Credentials. Click on 'Create Credentials'. Use the APP ID you got when you uploaded your app to the app store. (Chrome Developer Dashboard). Add the OAUTH client_id to your manifest.

- In the Chrome Developer Dashboard click on 'More info' and copy the public key to your manifest.