Monday, July 19, 2010

extracting text from pdf

A good way to extract text from pdfs which are predominantly text, is in my case using the free Mobipocket Creator, since I have it installed anyway. It creates an intermediate html file and images extracted into a folder, useful for converting to other formats etc.

Thursday, July 15, 2010

using the Optoma EP1080 for mirrordome

Trying out the Optoma projector with the mirror sourced from Bangalore, had some issues with colour calibration. The NVidia control panel on the Acer laptop as well as the OS X display control panel on JG's Macbook both mention turning the brightness and contrast all the way up - and they are meant for flat panels and CRTs, not projectors. Mentioning sites like this for calibration to Paul Bourke, he said just leaving everything at the defaults except the gamma setting can get 90% good results.

Windows Media Encoder batch jobs

As noted in a previous post, Windows Media Encoder batch jobs can be made to work by making batch files with lines like
cscript.exe wmcmd.vbs -wme
cscript.exe wmcmd.vbs -wme
cscript.exe wmcmd.vbs -wme

But WMVAppend needs all the files to be encoded this way, otherwise it cannot append files, even if they were created with the same wme file, using the GUI!

Friday, July 09, 2010

more updates on the Transcend MP 330

After my last post on the Transcend MP 330, some more info. The 60 ms lead was probably due to the Darla card. Recording live using the Tascam US-1641 and the MP 330, found the MP 330 to have a lag of 10 ms in 30 minutes. Which is very good.

Using the built-in mic, excessive sensitivity is a problem. Keeping it at a distance of 2 feet and talking in a normal conversational tone keeps it from saturating, but anything louder than that makes it clip. A bit of hum at 5.5kHz and 11 kHz or so. Noise-reduction removes that, of course.

using the Optoma EP1080

Finally got my hands on the Optoma TX 1080 aka EP 1080 projector which Paul Bourke recommends. It had some issues which had to be sorted out before use in the Planetarium.

The Optoma logo - Startup logo had to be made a black screen. Logo capture needed VGA input - it did not capture from S-Video. Supplying a 1920 x 1080 signal, it captured with no issues. Takes a minute or so to capture.

Turn off confirmation - When turning off the projector with the remote, it displays "To turn off, press Power button". Since this should not be displayed during the show, had to work out the turn off using RS232 or network option.

Network control - An RJ45 jack allows the projector to be controlled via an ethernet network. It has a built-in web server, and ip address can be set from the menu. Unfortunately, the manual did not mention that the web server is password protected. Found the password by trial and error, admin for the Administrator login. Once logged in, password can be disabled, so that just pressing login leaving the password field blank logs you in. The interface is not fully compatible with firefox, IE gives best results. Unfortunately, our control machine upstairs does not have a network card, so RS-232 seemed to be the way to go.

RS-232 - Tried many times with Hyperterminal, but did not succeed till, by trial and error, found the following:
(a) The projector needs to be turned on after the computer connects to the RS-232 port via hyperterminal or whatever.
(b) The string to be sent to the projector has a space in it. It should be ~0000 1 and not ~00001
(c) Autoit version 3.3.0 onwards are not compatible with Win98 etc.
(d) The control machine upstairs had no CD-drive, and since it runs Win98FE, needed this driver to recognize the 1 GB Sandisk flash drive.

Once I worked out all these, could get an autoit script to send the On and Off commands using a hyperterminal window which was opened at startup.

Time taken to autodetect - Autodetecting the S-video signal was taking more than a minute. Sending the S-video signal using RS-232 ~0012 9 after 30 seconds does the job - brings up the video in 34 seconds.

Mirror deformation - For using the projector in the mirrordome configuration, the mirror needs some support, without which it deforms under its own weight. Jury-rigged with thermocol, will try again using reduced mirror area.

Tuesday, July 06, 2010

notifications on radio silence

Following a conversation with B, I thought about ways to detect silence when SGH goes off the air on AsiaStar, and using the parallel port for detecting silence and so on. P came up with the Restless Winamp plugin to be installed at the playout server. We did that, and modified the C:\Documents and Settings\User\Application Data\Winamp\winamp.ini file by adding
[Restless Winamp Plugin]

P then suggested using the sound card instead for silence detection, and immediately found the Piraside Silence Detector - software which does this very job! Hooking up a modem to the machine can then make it dial P or me when the silence is detected. But it does not work as easily as given on it's home page - a bat file with commands sent to COM1 etc don't work under WinNT or above. XP etc do not allow direct access to hardware from the Command Prompt, unlike DOS. After tests with hyperterminal etc, the solution of choice is currently autoit - using a user dll and control script to send AT commands to the modem. Just simple ATDT to dial the number, using a ProcessWait to wait for a while, ATH to hang up and so on.

Monday, July 05, 2010

adventures with Sony Readers

The Sony Reader PRS-500 had come back to me from A in December 2009, "not working". The screen was showing ghosting, taking a long time to change pages and so on. Sent it to the US for repair and or firmware upgrade. There, nothing was done since the Sony store guys just sent N to the website. Finally it came back, and found it working reasonably well. Probably the battery had some issues due to being left idle for many months, and a few charge / discharge cycles brought it back in the pink.

Because of the delays, purchased a Sony PRS-300 because R was also interested. Tried out the Calibre software, which has matured a lot since its inception in 2006-2007. Found that only the 0.6 versions and earlier support the PRS-500 with old firmware. Conversions to LRF or EPUB take 20-30 seconds per book, and there is a nice bulk conversion system.

Found a small glitch - when "merging" different versions, it is supposed to change all meta data to match the destination version. But the metadata for author in the EPUB files were not being changed. The calibre window shows the correct author name, but on uploading to the device, the device shows the original un-corrected Author name.

Transcend MP 330

Trying out the Transcend MP330. Surprisingly good recording options. 32 kHz ADPCM wav files in Best mode. 128 kbps stereo. With the built-in mic, saturates at two feet with my singing - it is a bit too sensitive. But quality is good. With line-in, AGC - automatic gain control, I think. Only 0.05 second - 50 milliseconds - lag after 45 minutes of recording. I tested it by playing back a wav file from Sathya using the Darla card, assuming that the Darla itself is close to frame-accurate. In terms of frames, for 25 fps, that would be just over one frame. Far better than the M-Audio Mobile Pre!