Thursday, July 19, 2018

loudness with reaper - dB and RMS and LUFS

Found an interesting discussion on Reaper forums regarding RMS normalization to particular presets - https://forum.cockos.com/showthread.php?t=165331

In particular, the advice given by Michal is, "use actions from SWS.

SWS: Set RMS analysis/normalize options
Here you can set your RMS level target, it is one time operation..

SWS: Normalize items to overall peak RMS
You can select all items on the track and run this action for RMS normalization to predefined level.."

Of course, right now I'm not likely to try any of these...

Monday, July 09, 2018

troubleshooting streaming delay on Google Home device

While testing our Google Assistant action for our audio streams, SC reported that
 I'm still seeing ~100 second delays even on this stream on the Home device. On my phone/browser, it plays instantly.

I tried changing the burst-size but initially did not find any difference - 

64 kB  = 65535   = 100 sec delay - this is the default burst-size for icecast
128 kB = 131072  = 100 sec delay
256 kB = 262144  = 100 sec delay
512 kB = 524288  = 100 sec delay
1 MB   = 1048576 = 100 sec delay

Then it turned out that I was using a relay for testing, and on-demand was set to 1. After setting the relay's on-demand parameter to 0 (so that the relay is always ready and doesn't have to start after a new connection is made),  

128000 = started within 4 seconds!
64000  = 100 sec delay

Repeated this three times, waiting 100 sec + each time after restarting the server. Seems to work well with 128000. So, set this as the burst-size for all our streams. 

Sunday, July 08, 2018

Google Home Mini - a mini review

As long as you don't have inflated expectations, this device does a pretty good job. But my initial problem was that I had higher expectations from Google :)

Expectation - I thought "Google Home" should be able to do a google search, like
OK google, do a google search for callisthenics
Sorry, I don't understand.

Reality - the device needs the prompt "tell me about", or "what is" - like
OK google, tell me about callisthenics.
According to wikipedia, callisthenics is.... (the first sentence only.)

OK google, what is a meteorite?
etc.

OK google, tell me more about callisthenics.
Sorry, I don't know how to help with that yet.

So, it can't read more than the first sentence.

It can tell jokes and do trivia etc, as described in various posts elsewhere.

OK google, tell me a joke.
(it tells a different one-liner every time.)

It needs an exact match for playing radio stations. For example,
OK google, play all india radio on tunein
Sorry, artists aren't available on tunein.

OK google, play All India Radio Classical on tunein
Sure, here's All India Radio Classical on tunein - (plays immediately).

Unfortunately, the music player in the API seems to buffer for quite a while, so currently, if we do
OK google, ask Radiosai to play bhajans
Playing radiosai bhajanstream - (plays after 100 seconds!)
We will try to fix this. It appears this is fixed now, by increasing the burst-size to 128000 on our server.

The radiosai action is a work in progress, but currently, things like this work -
OK google, talk to Radiosai
Sairam, welcome to radiosai etc...
Search for Climate Change
It appears your current device does not have a screen, so here's the first result... etc
(plays immediately).

OK google, increase volume to 50%
works when radiosai or some other agent is not having context.

The touch interface on the device has recently been enabled. So, long touch on either side makes it pause or resume, a tap on the left side makes it reduce volume, and a tap on the right side makes it increase volume. This was not immediately obvious.

It can do more complicated things, but within a limited repertoire. For example,
OK google, tell me how to make idlis
(reads out ingredients and steps one by one, saying let me know when you want to continue, etc.)
OK google, continue
Nothing is playing at the moment
OK google, next ingredient
(reads out the next ingredient.)
OK google, next.
(reads out the next ingredient.)
OK google, next.
(Reads instructions one step at a time, we have to say next for the next step.)
OK google, previous step
(Reads the previous instruction)
(Asks if we want an alarm to be set for required time, etc.)

Apparently there's a 640 character limit for each interaction from the device. So, reading out a large page would need user interaction like the above series of steps for the recipe. Wikihow works in a similar way.

OK google, wikihow
Hi, how's it going?
Bake a cake.
Hi, how's it going?
Wiki how to bake a cake.
I didn't get that, can you tell me what you were looking to do one more time?
(never got it to work.)

It can play news, weather forecast etc. - OK google, how is my day?

And for those with home automation systems, it can be set up to put on lights, play something on the TV with Chromecast, and so on.

So, some people will like it, especially if they memorize the phrases needed for the device to do the required action. But others will be frustrated by it. Examples can be seen in the comments in the article below,


Edit - and here is a "comprehensive list which is periodically updated" from CNET, of all Google Home commands - https://www.cnet.com/how-to/google-home-complete-list-of-commands/

Tuesday, July 03, 2018

packet sniffing wifi

Packet sniffing on a wifi network is a bit more complicated than using a wired network and a hub. Promiscuous mode alone is not enough -

https://osqa-ask.wireshark.org/questions/61656/promiscuous-mode-not-working

https://wiki.wireshark.org/CaptureSetup/WLAN#Monitor_mode

Then the packets have to be decrypted.

https://wiki.wireshark.org/HowToDecrypt802.11

For that, if using WEP, the WEP password has to be converted to the Hexadecimal key -
http://corecoding.com/utilities/wep2hex.php

change Google Home mini wifi settings without Google Assistant app

Trying out a Google Home Mini device. For setup, it needs the Google Home App on an Android or iOS device. For changing certain settings, it needs Google Assistant to be enabled on your phone. Since my current phone runs an earlier Android version than 5.0 which is the least required for Google Assistant, I am unable to change language of the device, unable to change the voice, and so on. Even changing the wifi network needs a different procedure than the one listed on google support.

So, my procedure, found by trial and error, was:

1. Open the Google Home app
2. Tap on the devices icon on top right corner.
3. If there is a card which says "your speaker name" speaker needs setup, and a setup link, you can use that.
4. Else, click on your device name, if it is listed, and the three dots on top right.
5. Choose reboot.
6. From the list of linked devices, unlink the device for which wifi needs to be set up.
7. Tap the back button to go to the home screen of the Home app.
7. Then the app would say that it has found one device which is ready for setup.
8. Click through to set up, including linking to an account and wifi settings.
9. When using a wifi network which was previously configured, it does not ask for the wifi password again.


Friday, June 29, 2018

ITR2 - paying income tax

1. Using the java based ITR2 utility needs openjfx in addition to installing java etc - on Mint/Ubuntu, sudo apt-get install openjfx

2. PAN / TAN of deductor = PAN/TAN of employer

3. importing - pre-filling the form - takes longer than a minute on the Acer laptop, takes 10 seconds on the i7 machine.

4. The re-calculate button of the java utility is not the same as validation. On clicking Save, validation errors pop up. So, use 'Save' to validate, and 'Save draft' to save partially completed form.

5. For the first time, I needed to pay tax. Payment is via https://onlineservices.tin.egov-nsdl.com/etaxnew/tdsnontds.jsp , Challan 280 at the bottom of the page. Netbanking and Debit cards are accepted. The type of payment is Self Assessment Tax.

6. The Challan serial number and other details like date are available in the pdf made available to download from the SBI post-payment screen. These have to be entered in the ITR2 form under self assessment tax payment made, and then submitted.

5. The Aadhaar based verification of return did not work for me - said that service is not registered with UIDAI. The bank account based verification worked.

Friday, June 22, 2018

blender z axis flip

Just a quick recipe for flipping an object in Blender -

  • Select object
  • Ctrl A (for Apply)
  • Choose Scale
  • Enter Z scale as -1
  • Ensure that scale checkbox is ticked under apply.


Wednesday, May 30, 2018

unhelpful error message - google groups

While adding users to a google group, came across this error - An error (#847) occurred while communicating with the server.

Apparently this has nothing to do with internet connectivity issues. These forum posts point to a bad email id in the submitted batch. Sure enough, there was a "blogger.com" email id in the batch which was causing problems for me. Removed it, all well. 

Tuesday, May 29, 2018

Google Apps legacy documentation

Looks like legacy Google apps users can't purchase extra drive storage - Can't purchase Google Drive Storage in legacy Google Apps Free edition - https://productforums.google.com/forum/#!topic/apps/z0tUAkQl_rM

Friday, May 11, 2018

Linux Mint Live CD / DVD

Some notes for Linux Mint Live CD / DVD


  1. username is mint, and no password.
  2. sudo does not ask for password.
  3. to take a backup, can do sudo cp -R /source/folder /destination/folder
  4. to switch between screens, Ctrl+Alt+F2 or Ctrl+Alt+F7 etc - need to press Fn also on Mac keyboard.

web hosting on github

A useful option for small static websites -

https://help.github.com/articles/using-a-custom-domain-with-github-pages/

https://pages.github.com/

The limits are quite generous - https://help.github.com/articles/what-is-github-pages/

"GitHub Pages sites are subject to the following usage limits:

  • GitHub Pages source repositories have a recommended limit of 1GB .
  • Published GitHub Pages sites may be no larger than 1 GB.
  • GitHub Pages sites have a soft bandwidth limit of 100GB per month.
  • GitHub Pages sites have a soft limit of 10 builds per hour."

Sunday, May 06, 2018

C++ programming - using fstream in a cross-platform manner

Some notes about making use of fstream in cross-platform code - 

Some interesting methods are discussed at
https://stackoverflow.com/questions/9739948/write-a-file-in-a-specific-path-in-c/40980510#40980510

In Visual Studio,
disable deprecation, use _CRT_SECURE_NO_WARNINGS - 

Configuration Properties >> C/C++ >> Preporocessor >> Preprocessor Definitions >>  _CRT_SECURE_NO_WARNINGS

A working code snippet - 

    char path[80];
    char foldername[80];
    sprintf(path,"homeuser/file.txt");
    sprintf(foldername, "homeuser");
    CreateDirectoryA(foldername, NULL);
    std::ofstream file(path); //open in constructor
    std::string data("data to write to file");
    file << data;

Friday, May 04, 2018

making an alexa skill

The Amazon Echo Dot, Google Home Mini, etc are inexpensive ways to listen to streaming radio without the need for interacting with a screen. The Echo can be used with Skills to make it easy to accomplish a particular task. Though in theory, radiosai is available on tunein and it should be possible to listen via tunein, of late, it doesn't seem to work. Alexa says, "I can't listen by genre on Tunein". So, tried to make an official Radiosai skill.

There was already a Radio Sai skill, but that one was missing AfriStream and AsiaStream. So, decided to try to implement this skill, with some improvements, as an official radiosai skill.

Changes in the user interface - the screenshots given here are no longer similar to Amazon's AWS console or the Skills console. Instead of uploading the sample utterances as a text file, I manually created the utterances in the Skill console using the wizard. Also added some confirmation before playing each stream, like


var message = 'Playing Bhajan Stream.';
this.response.speak(message);
this.attributes['stream'] = 'BhajanStream';
controller.play.call(this);

and also added a stop call to the AudioPlayer -

'AMAZON.CancelIntent' : function () { 
// adding the line below to stop the audio player 
controller.stop.call(this); 
////////////// 
var message = 'Good bye.'; 
this.response.speak(message); 
this.emit(':responseReady'); 
}

It looks like only the playModeIntentHandlers are active - the others don't seem to be called. Have submitted for being made available to the public.

Edit: Update May 11 -
1. Bug fixes by the owner of this repository, looks like the SDK had some changes so the zip file needed to be changed.

2. How to build an Alexa audio streaming skill from a template - YouTube video - lots of similar resources available

3. Audio player skill sample from Amazon, for multiple streams. 

Wednesday, April 25, 2018

Tuesday, April 17, 2018

Notes on compiling software lockin amplifier

Abbreviated notes from the software lock-in amplifier at https://github.com/hn-88/SoftwareLockin/

French lockin works on USB stick. Lubuntu 12.04

edited the pro files to add
QT += widgets

vumeter.h:40:25: fatal error: QtGui/QWidget: No such file or directory
on Mint 18.1

edit h files to make QtGui/QWidget QWidget

make clean
qmake multi.pro
make


error: ‘const class QString’ has no member named ‘toAscii’ - solved using

(was solved by install of package qttools5-dev-tools
more info here...) not used

QByteArray QString::toAscii() const
Returns an 8-bit representation of the string as a QByteArray.

This function does the same as toLatin1().

So, replaced in lockin.cpp and dockoutput.cpp

output has NaN

Edit: 20 Apr
ui_lockingui.h:13:29: fatal error: QtWidgets/QAction: No such file or directory
compilation terminated.
Makefile:406: recipe for target 'lockingui.o' failed
make: *** [lockingui.o] Error 1

probably have to find replace again?

Also QWidgets/QApplication

changed to QApplication etc - find replace QWidgets/ with nothing.

sudo apt-get --reinstall install libqt4-opengl-dev

Maybe if I upload the makefile?



Friday, April 13, 2018

USB to TTL link dump

A collection of links about communicating with serial control lines over USB - Arduino etc - 

Tuesday, April 10, 2018

bouncing emails in google groups

Maintaining google group by deleting bounced emails. And if needed, re-adding them. 

https://support.google.com/a/answer/7552660?hl=en

Edit: Users can reset their bounce status by going to https://groups.google.com/bounced?pli=1 or https://groups.google.com/a/example.com/groups/bounced?pli=1
next to Bounce Status, email status -> Reset bounce status. (which appears only if it is bouncing.)

Monday, April 09, 2018

Arduino IDE on Linux Mint

From https://playground.arduino.cc/Linux/Mint/
we should probably not use
sudo apt install arduino
because it is outdated or non-standard, and we should instead use the 64 bit binary from 
https://www.arduino.cc/en/Main/Software