How to watch P2P stream using SopCast in Ubuntu: an Idiot Guide

Another step in eliminating Windows completely from my laptop. The last thing being getting a complete astronomy software package (camera control, autoguiding, image processing).

OK, here it is:

1) If you’re using Ubuntu 9.10, the instruction given in this page may save a bit of your working time.

2) If you’re not that lucky (I have 8.04 for instance, and am for some reasons too reluctant to change), get sp-auth from this page. Download it to your home directory, e.g. /home/you

3) Extract the tarball. Open a terminal, and type (don’t forget to press ENTER afterwards ): tar xvfz sp-auth.tgz

4) Change the working directory: cd sp-auth

5) Now try opening a channel. E.g. from the command line: ./sp-sc-auth sop://broker.sopcast.com:3912/69850 3908 8908 > /dev/null  & (Get the sop url from the channel you want to view. The number 8908 is the port number you’ll use later, the 3908 is rather arbitrary; I don’t know what it is exactly)

6) If there’s an error message saying something about “libstdc++…” you probably need libstdc++5. Type: sudo apt-get install libstdc++5-3.3-dev from the command line. Retry step 5), you should see no more error messages.

7) Open vlc. From the menu: Applications –> Sound & Video –> VLC media player, or type vlc from the command line.

‘8) In vlc, open a network stream. From the menu: File –> Open Network Stream, or press Ctrl+N.

9) Select the “HTTP/HTTPS/FTP/MMS” radio button, and type: localhost:8908/tv.asf in the text box. Press OK. You should be able to watch the channel now.

10) If there’s no sound coming out, check vlc settings, make sure that ALSA audio output module is selected. In vlc, edit the settings from the menu: Settings –> Preferences, or press Ctrl+S. Select the “Advanced Options” check box, and look at the options Audio –> Output modules. Select “ALSA audio output” from the drop-down menu. Restart vlc.

This page provides another instruction, if you follow it you won’t need vlc anymore to play the stream. Setup time will be more or less the same however, I think.

./sp-sc-auth sop://broker.sopcast.com:3912/69850 3908 8908 > /dev/null  &

A Runner’s Tale

See here how a failed attempt to run 10km turns into a cross-country run:

http://connect.garmin.com/activity/18270426

Half of the run was spent thinking, how the hell do I get out of this forest!

But it was a fine run after all. Not bad, even if the timing is anything but close to being “good”.

Why Astrophotography?

It’s the question I sometimes ask myself. A bit of reflection gives the answer: it’s its multi-disciplinary nature that attracts me to it. It’s not sheer photography, neither it’s sheer astronomy. There’s just a bit of everything. Just to mention some:

- Astronomy: from understanding the movement of the heavenly bodies, celestial sphere coordinate system, to astrophysics, the formation, evolution, and death of stars and galaxies.

- Photography: mastering the camera. How to do focusing. How to select the appropriate exposure. How to post-process. How to make a nice composition. What is light frame, dark frame, offset frame, bias frame. What to do with noise and hot pixels.

- Optics: one needs to be able to a certain degree assess the quality of the telescopes and the issues around it. Should it be a reflector or a refractor or a catadioptric. What is the good focal-to-aperture ratio. How important is magnification. What is chromatic aberration, spherical aberration, astigmatism.

- Mechanics: should it be alt-azimuth or equatorial mounting. What is the principle of tracking. How to balance an equatorial mount. How to polar align. How to guide.

- Computer and software: from automating the image acquisition, autoguiding, and image processing.

This for sure will keep me busy for years to come.

My first deep-sky astrophoto!

The Orion nebula:

With the stuck mount problem removed, the long nights of deep-sky imaging begin…

UPDATE: A new picture of the same object here.

Access Linux Partitions from Windows

Simply googling led me to so many alternatives; but only one worked for accessing my Kubuntu 8.10 partition from my Windows XP: http://www.ext2fsd.com/

So long procrastination*!

*) You know, wandering your mind while rebooting from Windows to Linux and back is some sort of procrastination…

Do you know that Apu has a PhD degree?

See here: http://simpsons.wikia.com/wiki/Apu_Nahasapeemapetilon

This is the second funniest satire next to PhD comic that I’ve ever heard about the fate of PhDs

Notes from near the Equator

One of the “missions” of the recent visit to Indonesia was to get acquainted with the sky of the southern hemisphere, when possible also to capture some photographs. Now, carrying a 6-inch Schmidt-Cassegrain, along with the tripod and the equatorial mount, is cumbersome, if not impossible. So the idea was to bring along some simpler equipments: a binocular for observing, and a small tripod for photographing, so that I could create a star trail or something like that. But darn it! As I was sitting in the aircraft before departure I realized that neither of them was in my luggage. And so observation must then be limited to naked-eye visual only. It was not so bad, it turns out, as it was pretty exciting to see Orion up high near zenith, with different orientation from the one one would be seeing in Europe. It also looks interestingly smaller. My immediate speculation was this might be another form of the Moon illusion; well, it’s just a guess, I would like to further investigate this later. The Crux was another impressive discovery. It was actually my visual cue, sort of, to really understand after-midnight sky. Once I identified the Crux, other stars were much easier to find, comparing the sky map picture to the real night sky.

The idea of creating a decent star photograph was simply forgotten. Until the 31st of December. I had no idea that Venus and the Moon would be very close together that day. I simply went outside, and behold! Two heavenly bodies were on the show, right in front of our house. So here’s the scenic, something that was unthinkable to make a few weeks earlier.

Leaving Indonesia for Indonesian: Airport To Do list

I’ve been doing this for like three times, yet still made a mistake, lacking one or two documents. There’s just too much bureaucracy in this country. So I thought a ToDo list would be useful.

1. Before you enter the check-in area, you need to show your flight ticket to the officer standing at the entrance door, and pass through the security check.

2. Once you pass the first security check, go to the fiscal counter to pay the fiscal fee. It is now Rp 2,500,000.00, unless you have an NPWP (Indonesian tax ID, sort of) or you can show a proof that you live abroad. In those cases you don’t need to pay the fiscal fee, and may go directly to step 3 below.

3. Check in, get the boarding pass. Pay an airport tax of Rp 100,000.00. This tax is not included in your flight ticket, even though there it is stated that the ticket cost includes service fee, tax, etc. And they don’t accept credit card. So remember to bring this minimum amount of cash when you check in.

4. Ask for immigration card at the check-in counter. This card consists of two parts: departure and arrival part. Fill out both, except for the flight number field in the arrival part.

5. Before entering the gate area you will pass through two counters, one checks your fiscal fee payment, the other checks your passport and visa. Show your fiscal payment receipt or the proof that you don’t need to pay the fiscal fee at the first counter (your NPWP, or in case you live abroad, a signed statement saying that you’ve presented yourself to the Indonesian embassy in the country where you live usually will do). At the second counter you will have to show your immigration card and give the departure part to the officer there. Keep the arrival part with you, you’ll need it later when you return to your ‘beloved’ country. I usually slip it inside my passport cover and leave it there all the time.

6. Well, that’s all. If you’ve done all these long before the boarding time, say an hour or so, don’t enter the gate immediately. Just wait somewhere near the souvenir shops, there’s a lot of seats there. If you try to enter the gate, the officer will say something like “Are you an idiot or what? your boarding time is still one hour from now. Just wait outside!”

There you are… Hope it’s helpful. Have a nice flight!

Riddles

Some riddles from one of the (largely unseen and unpopular) German TV shows… Just drop me a comment if you think you know the answer. Correct answers will be awarded with……… congratulations from me

1. Some months in a year have 31 days, some have 30. How many months have 28 days?

2. A man has 6 daughters, each of them has one brother. How many children does the man have?

Behold…

Found this in a book; just can’t stand not to share it

“Reader,

You may feel tempted to write your own (simpler) proof of Fermat’s last theorem.

I have strong views about such a project. It should be written in the Constitution of States and Nations, in the Chapter of Human Rights:

It is an inalienable right of each individual to produce his or her own proof of Fermat’s last theorem.

However, such a solemn statement about Fermat’s last theorem (henceforth referred to as THE theorem) should be tempered by the following articles:

Art. 1. No attempted proof of THE theorem should ever duplicate a previous one.

Art. 2. It is a criminal offense to submit falso proofs of THE theorem to professors who arduously earn their living by teaching how not to conceive false proofs of THE theorem.

Infringement of the latter, leads directly to Hell. Return to Paradise only after the said criminal has understood and is able to reproduce Wiles’ proof. (Harsh punishment.)”