mysql database table crash and recovery

There was a power outage yesterday at the studio, and the UPS also tripped. PB reports:
The phplist mailist list server gave the error message

> Message:
> Database error 144 while doing query Table './path/to/tablename' is marked as crashed and last (automatic?) repair failed
>
>
> Currently running the repair on the table tablename​ as suggested here:
>
> http://stackoverflow.com/questions/8843776/mysql-table-is-marked-as-crashed-and-last-automatic-repair-failed
>
> cd /var/lib/mysql/path/to/relevant/db
> myisamchk -r tablename.MYI
>
> ​looks like its going to take a long time.....​


and later,

Recovery successful.

​This was done by stopping mysql database:

service mysql stop​

myisamchk -r tablename.MYI

- recovering (with sort) MyISAM-table 'tablename.MYI'
Data records: 0
- Fixing index 1
- Fixing index 2
- Fixing index 3
- Fixing index 4
Data records: 119477877

service mysql start

testing schedule page and audio search page accessibility with screen reader software

We got a report that the audio search results were not accessible with JAWS 14.137 screen reader software. The google chrome accessibility page lists JAWS and NVDA. Downloaded and tested both. Found JAWS 14.0 working perfectly fine with our audio search page, with Firefox and Chrome. Also with IE8 (on my machine which has Win XP, highest version of Internet Explorer is IE8). Also fine on NVDA, which is free, as against JAWS which is $1000. Probably reasons, some of which I also faced:

1. Opening the page in a new tab instead of a new window causes problems. Open all pages in new windows instead.

2. Using old version of browser may cause issues on radiosai.org - upgrade to latest version of browser.
 

Google Apps Education edition

I had a query asked of me, whether the Google apps for a domain was the "Free edition" or the "Education Edition". Also about the number of users allowed for Edu edition. Here was my reply.

Google apps Education edition allows unlimited users for educational institutions, and 3000 users for other non-profit institutions.
https://productforums.google.com/forum/#!topic/apps/fptTBRXfGPM

You can check which edition you have - Education edition or not - by seeing how much space each user gets. According to this page,
https://support.google.com/a/answer/175121?hl=en
Education edition users get 30 GB, Free edition users get 15 GB.

This is seen at the bottom of your inbox, "Using 4.13 GB of your 15 GB" or "Using 4.13 GB of your 30 GB" or something like that.

source timeout on icecast

On May 21, we had changed the source timeout property on icecast from 10 to 40 seconds hoping to reduce the number of times the server dropped connection. This strategy suggested by PB seems to have worked, since then the connection has not dropped even once when I was operating the live broadcast. Edited  icecast_all.xml  and  icecast_tel_live.xml  and made the source timeout 40 sec. The original suggestion was as below.

changing default browser font for other languages

Using this post as a guide, changed the default font for Malayalam on Firefox to Rachana, which is more readable.

Tools -> Options -> Content tab -> Advanced button in default fonts -> Fonts for: chose Malayalam in the drop-down list, and changed the options other than Proportional to Rachana.

recordings with M-Audio MobilePre

As noted in an earlier post, the M-Audio MobilePre is an el-cheapo USB preamp interface. But I had to rely on that for some trial recordings.

Using a Maxim mic, laptop sound card noise floor is around -50 dB

M-Audio MobilePre with Maxim mic noise floor is around -60 dB

Using dynamic mic - Ahuja ASM-780XLR - results were similar.

Nose floor rises to -40 dB when capture slider increased to 80%.

The XLR input on the MobilePre seems to be defective - S/N almost unity! -18 dB of noise

"NEW" label on schedule page

As requested, PB has added the "NEW" label on our schedule page for "Concert" category also. He had to modify the csv generation local code as well as the schedule page code for this.

brief outage

There was a brief outage of radiosai services. The issue was with Cloudflare dns returning SERVFAIL for our domains. Conversation with Cloudflare:

avfs - Avisynth filesystem

The simpleslug pages mentioned AVFS. Tried it out. A 10 minute 2K planetarium show - Solar Quest - is seen as a 250 GB file after mounting. After Effects 4.1 complains error retrieving frame - not enough storage is available. But GL_warp2Avi works, even though it has the 2 GB file size limit for actual files, it seems to handle larger virtual avi files. Tested with 18 GB credits virtual avi file. 

replacing an acrilconvex mirror with a vialux mirror

From 2011, our fulldome projection has used an Acril Convex first surface spherical mirror. Last year, I'd purchased a used Vialux mirror. Today, we tried out the Vialux mirror, and decided to leave it installed for one show as a trial.

The Vialux mirror mini-review from Paul Bourke is here. As he notes, the extraneous reflections are more for the vialux mirror. The overall effect in the theatre is to reduce contrast and increase the brightness of the black levels. So we'll use the vialux only as a backup. Also did some back-of-the-envelope calculations of their radii of curvature.

After putting back the Acrilconvex mirror, I wonder if the perception of higher black levels was just an illusion. Maybe I'll try a light meter test next time, with a suitable frame on both mirrors. 

radius of curvature of spherical mirror

Did some back of the envelope calculations for the radius of curvature of our spherical mirrors, and with the help of the alternate segment theorem at this page, measuring x and y with a ruler got me r, the radius of curvature.

For the Acrilconvex mirror, 2x = 56 cm, y = 14.5 cm, so r = ( (28)^2 / 14.5 + 14.5 ) / 2 = 34.3 cm

For the Vialux mirror, 2x = 56 cm again, but y = 12 cm, so r = ( (28)^2 / 12 + 12 ) / 2 = 38.7 cm

simpleslug upscale

Checked out simpleslug upscale. Not directly useful for me, since the output is set to presets like 1080p 720p etc. Internally, it uses Blackman Resize, which is similar to, but better than Lanczos with higher number of taps. From this discussion linked on that page, it looks like sinc resize with avisynth might yield the best results for upscaling. But in our case, the loss of clarity seems to be more due to the codec used for the lo-res videos.

Update (2 June): As mentioned by the SimpleSlug author in the comments, was able to use simpleslug upscale with SimpleSlugUpscale(prog=true,outwidth=2048, outheight=2048)

As compared to doing Lanczos resize + Sharpen in Virtualdub below.

Software Bisque Seeker - docked windows, IMAGE

Found that starting Seeker with only one monitor leads to a docked visuals window. Starting Seeker with two monitors makes it un-docked.

Also, found that <IMAGE> does not render at all in fisheye mode. Directly changing <IMAGE> to <DOMEIMAGE> did not put the images in suitable positions.

Rendering of flat movie Explorers of Mars,

Rendering of dome movie of Explorers of Mars, with <IMAGE> changed to <DOMEIMAGE>

Image Sequence Scanner

One of the many tools to check a sequence of images for corrupt or missing files - ISS or Image Sequence Scanner. But it does not detect errors in files like this bad frame,

why I removed ads

When I first started this blog, I had clicked through and added Adsense as Google recommended. But then, months of zero earnings later, I removed it, but did not post about it. According to this page, it's advisable not to put ads on your site if your traffic is below 10,000 page-views a month. Mine is only 1,400, so it really did not make sense to put ads on this blog. 

resources from newtonscannon

Checking out the www.newtonscannon.com blog, found these useful resources:

cgskies.com  has free samples.

compiz lighttwist plugin for blended large desktop. Could possibly be useful for blended two-projector dome setup?

some links for miscellaneous jobs

Hypercube Time Stretcher for stretching wav files to sync to video.

Stackoverflow discussion about how to map an ffmpeg frame to an opengl texture.

Webpagetest.org for analyzing web page load speeds - and an old link to a test run in 2011.

Online tool for Hex color-code generation.

Frame-rate up-conversion virtualdub filter. Increase frame-rate by integer values - 2x, 3x and so on, interpolating frames.

The frame interpolation above could be used along with slow-motion for virtualdub ideas in this thread. 

more experiments with Software Bisque Seeker Theater Edition

More trials with Software Bisque Seeker Theater Edition:

1. The About Seeker menu item and Solar System Map feature work when not in "Fulldome" mode, and when the flat screen version of "None" is selected in Settings -> Dome Projection.
2. When writing scripts, leaving a space after the command tag and the first argument is a must. Wasted a lot of time wondering why <WAIT>20 was not working - it should be <WAIT>  20
3.  <DOMEIMAGE> doesn't work with jpg files. Targa files as given in the example are fine.
4.  <DOMEIMAGE> works best for small images - distorts panoramas etc.
5. <QUIET> 0 makes not only sound effects, but also a counter of time elapsed while running scripts in flat screen mode - not in fulldome mode. 
6. The spaceship movement seems to be auto-linked to the nearest object. 

As an example for the last point, after doing <WARP> "Earth" , using spaceship thrusters to move towards the moon and creating a waypoint there, when time is advanced, the camera and ship movement sync to make the moon centred. This is sometimes a problem, like when we want to make the moon move across the ecliptic. The moon as seen from earth is displayed too small to be visible in fulldome mode. But if we move close enough to the moon as to make it visible, camera and ship are no longer locked to earth, but are locked to the moon!

Also, access to the Software Bisque support forums are linked to the subscription. After one year subscription elapses, "Access Denied" to the support forums. In my case, "Access Denied" even 12 days before expiry of subscription. Can't even reply to my own bug-report post!

Winebottler and Winamp on Mac

The Telugu team wanted to continue making playlists by dragging and dropping to Winamp, but move to Mac from Windows. I sent them the following options.

There is a "Winamp for Mac", but that has an interface similar to iTunes and not like Winamp. So, for a Winamp-like solution on Mac, there are various options:

1. Run virtualbox, run Windows inside virtualbox, run winamp in that window. Free software, but will take time to install windows, and will be slow.

2. Run Wine and Winamp on Wine. Free software, but takes hours to install, complicated installation.

3. Run CrossoverMac and Winamp using crossover. Software costs $16, we can download a 14 day trial, see if it works, and then pay if needed.

4. Installing WineBottler - http://wine-review.blogspot.in/2010/01/winebottler-for-os-x.html and installing winamp inside it.

Apparently Winebottler 1.4 was already installed. Installing Winamp 5.5 inside it worked, but unfortunately drag and drop files into playlist was not working. Then they uninstalled Winebottler by simply dragging the app to trash, installed the latest version which was 1.7, installed Winamp 5.5 inside it, then it worked fine. 

cleanly removing applications from OS X

Looking for Winebottler drag and drop support (dragging and dropping from Finder to Winamp does not work), found this macrumors forum post about cleanly removing applications.

The steps include searching for the software by name in the default (Macintosh HD) volume, and expanding the search to include system files and hidden files. And then deleting them.