Why doesn't Web Audio API sound on iOS?

Why doesn't my script of Web Audio API sound on iOS?

Here are major missing points.

Did you mute your iPhone?

Yeah, really it's possible.

Did you listen to an user action?

Web Audio can't start by script itself on iOS. You need to create a listener, e.g. onclick.

Did you set an argument properly?

bufferSource.start() or oscillator.start()

bufferSource.stop() or oscillator.stop()

work on the desktop browsers but doesn't on iOS.

bufferSource.start(0) or oscillator.start(0)

bufferSource.stop(0) or oscillator.stop(0)
should work on any modern browsers.

How to rotate a video file?

You may have done this

$ ffmpeg -vfilter "rotate=90" -i input.mp4 output.mp4

but you would have

unrecognized option 'vfilters'.

Error splitting the argument list: Option not found

So you should run:

$ ffmpeg -i input.mp4 -vf "transpose=1" output.mp4

then input.mp4 will be rotated at 90 degrees to output.mp4.

TweetDeck > HootSuite

If you manage multiple accounts, the web app is better than the desktop one owing to its process burden.

I thought HootSuite was the best service for Twitter which can manage multiple accounts (on the web).

Here are HootSuite and TweetDeck as web apps for Twitter.

• HootSuite for free subscription is limited to 4 accounts managed.
• TweetDeck is however free to use totally.

Why not use TweetDeck?

It seems to have to have more improvement but if it improves continuously then it's the best for your personal use.

Mac Shortcuts to input Alphabets with Accents or Symbols

Mac OS Cheat Sheet: How to Input Accents and Symobols

Here is how to input accents and symbols with keys on Mac.
You can try to type on the form on the right of each row.

Mac Key Legend

symbol	name
⌘	Command key
⌃	Control Key
⌥	Option Key
⇧	Shift Key
⇪	Caps Key
fn	Function Key

Accents (Diacritic)

name	example	keyboard	keys	here to practice
cédille	ç	any	⌥ + c
capital cédille	Ç	any	⌥ + ⇧ + c
acute (accent aigu)	é á	any	⌥ + e, an alphabet
grave (accent grave)	è à	Japanese, etc.	⌥ + _, an alphabet
		English	⌥ + `, an alphabet
circumflex	ê î	any	⌥ + i, an alphabet
Umlaut	ä ü	any	⌥ + u, an alphabet
tilde	ñ	any	⌥ + n, an alphabet

Symbols

name	symbol	keyboard	keys	here to practice
Yen	¥	Japanese	¥
Yen	¥	English	⌥ + y
back slash	\	Japanese	⌥ + ¥
leader	…	any	⌥ + ;
guillemet start	«	Japanese	⌥ + ]
		English	⌥ + \
guillemet close	»	Japanese	⌥ + ⇧ + ]
		English	⌥ + \
bullet	•	any	⌥ + 8
degree	°	any	⌥ + ⇧ + 8
Eszett	ß	any	⌥ + s
euro	€	any	⌥ + ⇧ + 2
apple		any	⌥ + ⇧ + k
delta	∆	any	⌥ + j
function	ƒ	any	⌥ + f
phi	ø	any	⌥ + o
capital phi	Ø	any	⌥ + o

Cheat Sheet as Presentor on MacOS

Mac OS Cheat Sheet as Presenter

This is for presentation.

Mac Key Legend

symbol	name
⌘	Command key
⌃	Control Key
⌥	Option Key
⇧	Shift Key
⇪	Caps Key
fn	Function Key

Mac OS

Display

keys	action
fn ⌘ F1	Mirror (Duplicate) the current desktop to the projector.
⌘ ⌥ D	Hide/show the Dock.

Chrome

Display

keys	action
⌃ ⌘ F	Switches to the full screen.
⇧ ⌘ F	Switches to the presentation mode.

Navigate

Tabs

keys	action
⌘ ⌥ →	Switches to the next tab.
⌘ ⌥ ←	Switches to the previous tab.

Bookmark

keys	action
⌥ ⌘ B	Open Bookmark Manager.

Theremin on Processing

Theremin on Processing in progress?

If you want Japanese, here is Japanese version.

Introduction

While thinking of what I can do with Processing, I stuck on, "Can I play Theremin with the camera built in the Mac?"

I'm afraid if someone has done already and there is :0

I found however it's too small to control and doesn't work well for music (can't make pitch staircase) so I decided to create my own one.

I thought up several implementations for that, but I had meager time and wanted to make with as much vanilla Processing as possible.

Thus my app will be kind of a mashup.

Development Details

From sound libraries

• minim (sound library for Processing)
• sound (in vanilla Processing)

I have chosen "sound" due to no need of more functionality.

From video libraries

• video (in vallina Processing)
• OpenCV
• BoofCV (CV library on Java)

I have chosen "BoofCV" because video has no tracking feature and OpenCV couldn't be smoothly installed into my Mac...


Well, this is the screen:

Artifacts

Here is the repository.
GitHub - Theremin on Processing

You can download the application from here:
GitHub - Theremin on Processing - release page

The resolution of the camera is now fit to FaceTime HD (1280x720) in my Mac. Sorry for now if your camera doesn't match...

The usage is written on the project page above.

I did check if I can play a melody :)

Conclusion

During the creation what I felt is this has problems in its accuracy for real performance. Infrared camera devices (e.g. Kinect, Leap Motion) are better for control but here I did without special devices.

This article and artifacts are work in progress after Boulez.

Playing Videos

To prove this Theremin on Processing can play music, I asked my friend, Neko Piano to play with it :)

Here are playing videos.

Checking its control and trying to sing a scale:

Singing "When You Wish Upon a Star":

Neko Piano played a Theremin-like instrument for the first time... so with some wrong pitches.
It's proven however this is a musical instrument! :)
For that matter I couldn't find any videos to play music with Theremin-like digital instrument, you're blindly concerning in technologies, are't you? :)

How to Crop Tabs in Chrome

Did you want to crop tabs in your window in Chrome?
For example you did open lots of tabs but they are not related to other tabs then you may want to separate them.

One solution is to use the extension Tab Scissors:

This enables you cut tabs in one window off into two windows.


But my super recommendation is just to drag tabs in the window.

1. Select several tabs to crop.
1. Click the one tab.
2. Click the other tab in the other side with shift key.
2. Drag those selected tabs
3. You get another window with selected tabs.

Like

Enjoy it :)