Monday, April 25, 2016

too many files bug and php error reporting

Our audio search page had a bug where if too many files were selected, the results would not be displayed. With the help of S & B, constructed a workaround. The form was submitting all fields of the large table, instead of only submitting the hidden variables which had the fileids. So, made the main form submit to a dummy destination, and made another form with the hidden variable, submitting to the actual destination. That solved the issue, which was that there were too many fields being submitted. We did not have to change max_input_vars.

While troubleshooting, we wished to see detailed error reports. The way to do that was
ini_set('display_errors',1);
error_reporting(E_ALL);

for each php page.

Wednesday, April 06, 2016

cyberoam fail-over issue

PB had a problem where the 2nd gateway was not being automatically used as failover when the main gateway failed. Apparently it was due to the way in which Cyberoam had been configured. Tech support explained it, and PB fixed it. 

Tuesday, March 29, 2016

Xmms alternative

P reports that Xmms is no longer available on Ubuntu 14.04, and some of the ubuntu forum posts have broken links. His solution was to recompile and use Audacious instead. 

dns limitations on our mail server

We were doing some explorations of the feasibility of remote hosting our mail server which sends out daily emails to around 50,000+ subscribers. Seeing some posts about rate limits to Google public DNS servers etc, and our own experiences with DNS failures, we should perhaps run our own DNS server as well as mail server if we plan to shift the email server. 

Sunday, March 27, 2016

Firefox problems with HTML5, Vimeo and Youtube

One issue seen with Firefox - Vimeo embedded player not appearing on screen - seems to have been sorted out at some time - the current version 45.0.1 does not seem to have this issue. Or is it that it still has issues with embeds like iframe src="//player.vimeo.com/video/xxxx instead of src="https://player.vimeo.com/video etc ? There are lots of people with issues with Firefox and Vimeo.
http://techawakening.org/vimeo-videos-not-working-in-firefox-solution/2490/

Then there is the persistent stutter - for audio as well as video using html5 playback from Firefox on Windows. The only solution for that seems to be to force Flash player playback. This can be done for youtube as in my earlier post.



problem reading memo field

After a PHP upgrade from 5.3 to 5.5, one of our php applications reading data from an Access .mdb file had an issue - other fields were displaying fine, but the data from the memo field was showing blank.

After poking around for a couple of days, PB finally found the solution to be the one suggested in the comments at
https://bugs.php.net/bug.php?id=52658

That is, he had to add the optional cursor_type parameter SQL_CUR_USE_ODBC like
$cnx = odbc_connect('$databaseName', 'user', 'pass', SQL_CUR_USE_ODBC);

 Then it works. 

Tuesday, March 22, 2016

Airdroid vs ES File Explorer

One more post about my Xiaomi Mi3 phone. Though this is probably applicable to all Android phones.

I'd earlier used ES File Explorer to transfer files to and from Windows shares to the phone over Wifi. But when transferring to shares with a large number of files, or while transferring large files, ES File Explorer would keep popping up a 'Failed' dialog box, and would need repeated 'Retry' attempts to transfer multi-MB files. Finally looked for alternatives, and found Airdroid's features include file transfer. I use it in 'local network' mode, by typing in the ip address, so extra charges, no need of external network etc. ES is still useful for local file browsing etc.

Xiaomi Mi3 with Android 4.4.4 - soft home and back buttons

After my last post about my phone, there were some more developments. Now the headphone socket does not work at all. But thankfully the earpiece works fine. Then, after frequent falls onto hard cement floors, the left corner of the screen cracked slightly, and the home, back and recent apps buttons on the bottom bezel of the phone stopped working.

Since I had heard of apps with 'soft home button', I installed several of them. None of them seemed to work with Xiaomi's MIUI. Then I installed MyHomeButton which creates a notification in the notification pull-down screen. This worked, but with the drawbacks that:
  1. It would not start on rebooting the phone - I have to remember to open the app settings, turn off and turn on the check-boxes for Home and Recent Apps, then the notifications would appear. 
  2. No back button.
  3. Use requires a swipe from the top to bring down the notification bar, a swipe sideways to view the notifications, and then a tap to activate the home button. A bit cumbersome.
I lived with the above drawbacks till today, when I installed Back Button Gesture Launcher. Or rather, the trial for the paid app. Since it is a paid app, it had a somewhat helpful 'Help' section, which mentioned that for the onscreen button to be visible, what settings need to be enabled on Xiaomi -
  1. Settings -> Installed Apps -> Downloaded -> Back button -> Permission Manager -> Display pop-up window, Enable. 
  2. Settings -> Additional Settings -> Accessibility -> Back button -> Accessibility, Enable. 
Now, this app is a paid app, and one of the comments directs users to install the Back Button app instead, which is a free app. So I did that, after uninstalling Back Button Gesture Launcher. Granted the permissions again, and ready to go. A small issue with this app is that the icons don't seem to be movable from their location on the right side of the screen. But that is probably not a big issue.


Tuesday, March 08, 2016

funny characters seen in Putty session

After a server upgrade (I think), I started seeing funny characters when using Putty to ssh into our local server, like

P suggested this might be the solution,

That is, change character translation in Putty to UTF-8. The setting is in Window -> Translation. Worked.




Sunday, February 14, 2016

smooth plot in Matlab

This post has some useful techniques for using in Matlab, for smoothing data using
http://stackoverflow.com/questions/12987905/how-to-make-a-curve-smoothing-in-matlab

If curve-fitting toolbox is present, smooth can be used. Or we can roll our own, as mentioned in the link.

Saturday, February 13, 2016

video stabilization plugin for virtualdub

Video stabilization used to be available only in high-end video editing software. Realized now that Virtualdub has a plugin, too! And its development dates back to  2003. Used the Deshaker plugin from
http://www.guthspot.se/video/deshaker.htm
for a video of an oscilloscope trace, pretty good!

Friday, February 12, 2016

multiple issues with sending bulk email

SSSIHL tied up with Benchmark for sending some 4000 emails, they wanted to make it into a newsletter every couple of months. There were multiple issues with the email sending.

  1. The first time around, the sssihl.edu.in SPF record had not been updated to include benchmark servers, which resulted in spam filtering blocks for most of the mails. Along with SPF update, Benchmark also recommended whitelisting the Benchmark mail server IPs for sssihl.edu.in mail servers. 
  2. Found that Google Apps allows whitelisting. Updated the SPF record.
  3. Then found that the SPF record was returning an error, too many lookups, via the test at  http://www.kitterman.com/spf/validate.html - googling showed that having Godaddy's  include:smtp.secureserver.net in the SPF record causes a very large number of lookups. Moved the sending of emails from the Godaddy server to google apps, removed that include, then the SPF validated. 
Finally most of the emails went through after the valid SPF. 

cleaning up C drive

All these years, I had relied on various tips and tricks for cleaning up C drive on Windows, and had never used the Properties -> General tab -> Disk Cleanup utility's "Compress old files" feature, because it used to take a long time to run. But yesterday I did, and it made 9 GB available on a drive which had only 600 MB free!

Add 2 GB to Google drive storage

K sent me an email telling me about "an annual ritual by Google. I did it last year too and got 2GB."

Do the security checkup and get 2GB added:
http://www.theverge.com/2016/2/9/10940046/google-drive-free-2gb-space-security-checkup

http://googledrive.blogspot.com/2016/02/safer-internet-day-2016.html

Have now added a google calendar reminder for this :)

Tuesday, February 09, 2016

Apache 403 Forbidden errors

P had a problem after he migrated data from an old hard disk to a new hard disk on our internal server. A couple of folders in the hard disk were supposed to be available via the local webserver - but after the migration, those were returning 403.

Finally, the issue turned out to be permissions for the parent directory. Gave the permissions, also had to add Indexes to the Options line in apache2.conf for one of the folders, all done.

https://wiki.apache.org/httpd/13PermissionDenied

Sunday, February 07, 2016

retuning tv set-top box

Doordarshan DTH, now called FreeDish, migrated from INSAT-4B to GSAT-15. P sir and R called me for re-tuning their set-top box. Since the satellites are nearby, there was no need to re-align the antenna.

R had managed to enter the correct values of frequency, polarization and symbol rate in TP edit mode. It only needed a scan of the correctly entered transponder values. The relevant menu item was in the Installation menu, Scan current ANT.

Saturday, January 30, 2016

SGH database update for MBV files

Guest post from PB.

After the local server hdd crash in Nov 2015
​,​
 we had lost the sghtelugu file_id records. On re-importing the files into the database, I missed out the info that the mbv files had a different download filename
.

Due to this sghtelugu database and sgh database had different download filenames causing end
​-user download issues.

Did the following.
​...​


1. Tried to create a soft link in dl.radiosai.org expecting that http download link would automatically get redirected to the  softlink. But this did not work. It downloaded the file without the modification.

2. The only way is to update the records 
​both sghtelugu and the schedule page database (radiosai)

a. Created a SQL query that would give me the update SQL statements :

psql -d internal_db -A -F ',' -t  -c "SELECT 'UPDATE our_primary_key SET download_filename = \'' || download_filename || '\' WHERE filename = \'' || filename ||'\';' FROM our_primary_key WHERE filename <> download_filename AND filename ILIKE '%mbv%' " -o /home/sgh/update.sql

​This sql statement searches for all the MBV files where the filename is not matching the download filename in our internal database and forms a update sql list. 


UPDATE file_id SET download_filename = 'MBV_2003_08_MODIFIED.mp3' WHERE filename = 'MBV_2003_08_UNMODIFIED.mp3';
UPDATE file_id SET download_filename = .... etc 

about 1358 records

b. Executed this set of update queries on sghtelugu database. This step cleans up the local sghtelugu database

c.​
​ Then modified the update.sql file by using find-replace the database table name and column names like

UPDATE web_db_table_name SET dfileName = 'MBV_04_MODIFIED.mp3' WHERE fileName = 'MBV_04_UNMODIFIED.mp3';
etc

d. Logged into our website Plesk and then to phpMyAdmin database and executed the modified update queries.

Friday, January 15, 2016

Shoutstats update

After our internal server upgrade, Shoutstats stopped working. P did some digging and found that not only were rrdtool and php5-rrd not installed, but with the later versions of PHP, the short tags

Monday, January 11, 2016

quick review of Netflix India

A very quick review of Netflix's India offering, comparing it with the choices for Netflix streaming in the USA.

  1. The selections are very different, of course. For example, the Indian selection does not have "Who framed Roger Rabbit", many of the genres in http://ogres-crypt.com/public/NetFlix-Streaming-Genres.html are just missing in the Indian version. (link removed when Blogger unpublished this post)
  2. There are around fifty Indian movies (only) - youtube's selection is much wider for Hindi movies.
  3. Ditto for documentaries, eg. BBC documentaries. 
  4. If you want to switch countries using a VPN like PureVPN, you can't use Firefox's Private Mode - Netflix doesn't work well with Private Mode. (link to quora page removed when Blogger unpublished this post - https://www.quora.com/Why-doesnt-Netflix-allow-you-to-watch-movies-with-Chromes-incognito-mode ) You have to clear the website preferences using History -> Clear Recent History -> Time Range to Clear -> Everything -> Details -> Cookies, Cache and Site preferences (for Firefox). 
Edit: 15 Jan.
As of now, if you connect to a US VPN, you can access all the US titles even if your Netflix account is from India. 

This page (link removed when Blogger unpublished this post - http://www.finder.com/in/netflix-india-vs-netflix-us-titles-list ) has a comparison of titles available in India vs US - two and a half pages of titles available in India, eighteen pages of titles available in USA with maybe a page or so available in India but not available in the USA. 

Edit: 7th Nov 2022 - Blogger unpublished this post saying it violates community guidelines. Removing links and asking for a review. In what way does this violate community guidelines, I wonder.  

Wednesday, January 06, 2016

Chrome not loading https pages

Related to my earlier post, I found that Chrome on XP was not loading the https pages. Apparently this is related to XP reaching end of life and not supporting the latest ECC in https, as mentioned in the last post at the page
https://code.google.com/p/chromium/issues/detail?id=451311

So, for loading the https pages with this issue on Windows XP, the workaround is to use the latest Firefox.