Suramya's Blog : Welcome to my crazy life…

October 14, 2020

Walking around in a Cell using Virtual Reality

Filed under: Computer Hardware,Emerging Tech,Tech Related — Suramya @ 11:59 PM

It’s hard to view 3D data on a 2D screen efficiently which is why Virtual Reality (VR) & Augmented Reality (AR) have so many fans as they allow us to interact with data in 3D, making it more intuitive and easier to process (for some use cases). Now there is another application for VR that actually makes sense and is not just hype. Researchers at University of Cambridge & Lume VR Ltd have managed to convert super-high resolution microscopy data into a format that can be visualized in VR.

Till 2014 it was assumed that we could never obtain a better resolution than half the wavelength of light. The Nobel Laureates in Chemistry 2014 managed to work around this limitation creating a new field called Super-resolution microscopy that allows us to obtain images at nanoscale. This enables us to see the individual molecules inside cells to track proteins involved in various diseases or watch fertilized eggs as they divide into embryos. Combining this with the technology from Lume VR allows us to visualize and interact with the biological data in real time.

Walking through the cells gives you a different perspective and since the data is near real time it allows us to literally watch the cell’s reaction to a particular stimuli. This will have massive implications for the Biomed/BioTech fields. Maybe we can use it to figure out why organ rejections happen or what causes Alzheimer’s.

“Data generated from super-resolution microscopy is extremely complex,” said Kitching. “For scientists, running analysis on this data can be very time-consuming. With vLUME, we have managed to vastly reduce that wait time allowing for more rapid testing and analysis.”

The team is mostly using vLUME with biological datasets, such as neurons, immune cells or cancer cells. For example, Lee’s group has been studying how antigen cells trigger an immune response in the body. “Through segmenting and viewing the data in vLUME, we’ve quickly been able to rule out certain hypotheses and propose new ones,” said Lee. This software allows researchers to explore, analyse, segment and share their data in new ways. All you need is a VR headset.”

Interestingly vLUME is available for download as an Open Source program from their Git repository. The program is free free-for-academic-use. Check it out if you are interested in how it works.

Source: New virtual reality software allows scientists to ‘walk’ inside cells

– Suramya

October 13, 2020

It is now possible to generate clean hydrogen by Microwaving plastic waste

Filed under: Emerging Tech,Interesting Sites,My Thoughts — Suramya @ 2:33 PM

Plastic is a modern hazard and Plastic Pollution has a massive environmental impact. As of 2018, 380 million tonnes of plastic is being produced worldwide each year (source: Wikipedia). Since we all knew that plastic was bad a lot of effort was put in to get people to recycle plastics and single use plastics have been banned in a lot of places (In India they are banned as of 2019). However as per the recent report by NPR, recycling doesn’t keep plastic out of landfills as it is not economically viable at a large scale. It is simply cheaper to just bury the plastic than to clean it and recycle. Apparently this has been known for years now but the Big Oil companies kept it quite to protect their cash cow. So the hunt of what to do with the plastic continues and thanks to recent breakthroughs there just might be light at the end of this tunnel.

Apparently plastic has a high density of Hydrogen in it (something that I wasn’t aware of) and it is possible to extract this hydrogen to use as fuel for a greener future. The existing methods involve heating the plastic to ~750°C to decompose it into syngas (mixture of hydrogen and carbon monoxide) which are then separated in a second step. Unfortunately this process is energy intensive and difficult to make commercially viable.

Peter Edwards and his team at the University of Oxford decided to tackle this problem and found that if you broke the plastic into small pieces with a kitchen blender and mixed it with a catalyst of iron oxide and aluminium oxide, then microwaved it at 1000 watts then almost 97 percent of the gas in the plastic was released within seconds. To cherry on top is that the material left over after the process completed was almost exclusively carbon nanotubes which can be used in other projects and have vast applications.

The ubiquitous challenge of plastic waste has led to the modern descriptor plastisphere to represent the human-made plastic environment and ecosystem. Here we report a straightforward rapid method for the catalytic deconstruction of various plastic feedstocks into hydrogen and high-value carbons. We use microwaves together with abundant and inexpensive iron-based catalysts as microwave susceptors to initiate the catalytic deconstruction process. The one-step process typically takes 30–90 s to transform a sample of mechanically pulverized commercial plastic into hydrogen and (predominantly) multiwalled carbon nanotubes. A high hydrogen yield of 55.6 mmol g−1plastic is achieved, with over 97% of the theoretical mass of hydrogen being extracted from the deconstructed plastic. The approach is demonstrated on widely used, real-world plastic waste. This proof-of-concept advance highlights the potential of plastic waste itself as a valuable energy feedstock for the production of hydrogen and high-value carbon materials.

Their research was published in Nature Catalysis, DOI: 10.1038/s41929-020-00518-5 yesterday and is still in the early stages. But if this holds up at larger scale testing then it will allow us to significantly reduce the plastic waste that ends up in landfills and at the bottom of the ocean.

Source: New Scientist: Microwaving plastic waste can generate clean hydrogen

– Suramya

October 12, 2020

No Batteries or Electronics Required to power the Internet of Plastic Things

Filed under: Emerging Tech,Tech Related — Suramya @ 11:48 PM

One of the problems we face when trying to create devices that connect to each other or have built in intelligence is how do we power such devices? The trade-off has always been between portability and connectivity. Now, thanks to the efforts of Researchers at the University of Washington, we have a technique for three-dimensionally (3D) printing plastic objects that can communicate with Wifi devices without batteries or electronics. Building on top of previous work in which another research team managed to transmit their data by either reflecting (1) or not reflecting (0) a Wi-Fi router’s signals. However the problem was that they needed multiple electronic components to work, which is something that’s not always feasible. The team published their paper back in 2017 and have been hard at work enhancing their technology since then. Now after years of effort they have managed to map the Wi-Fi backscatter technology to 3D geometry and create 3D CAD Models that can be printed using standard 3D Printers. This drastically reduces the cost of implementing this technology and opens the field for 3D printed devices for any and all projects.

Printed Wi-Fi. We present the First 3D printed design that can transmit data to commercial RF receivers including Wi-Fi. Since 3D printing conventional radios would require analog oscillators running at gigahertz frequencies, our design instead leverages Wi-Fi backscatter, which is a recent advance in low-power wireless communication where a device communicates information by modulating its reflection of an incident Wi-Fi signal. The device can toggle an electronic switch to either absorb or reflect an ambient signal to convey a sequence of 0 and 1 bits. The challenge however is that existing Wi-Fi backscatter systems [Kellogg et al. 2016] require multiple electronic components including RF switches that can toggle between reflective and non-reflective states, digital logic that controls the switch to encode the appropriate data as well as a power source/harvester that powers all these electronic components. Our key contribution is to apply Wi-Fi backscatter to 3D geometry and create easy to print wireless devices using commodity 3D printers.

To achieve this, we create non-electronic and printable analogues for each of these electronic components using plastic filaments and integrate them into a single computational design. Specifically,To print the backscatter hardware, we leverage composite plastic Filament materials with conductive properties, such as plastic with copper and graphene fillings. We characterize the RF properties of these filaments and use them to design fully 3D printable antennas and RF backscatter switches (see §3).

* In lieu of digital logic electronics, we encode bits with 3D printed plastic gears. Specifically, ‘0’ and ‘1’ bits are encoded by the presence and absence of tooth on the gear respectively. To backscatter a se-
quence of bits, the gear teeth are configured to toggle the backscatter switch between reflective and non-reflective states.

* We leverage the mechanical nature of many sensors and widgets to power our backscatter design. We present computational designs that use push buttons to harvest energy from user interaction as well as a combination of circular plastic springs to store energy. Finally, we design 3D printable sensors that directly power the backscatter system, through their sensing operation.

The team basically has managed to leverage mechanical motion to power their devices. e.g. pushing a mechanical button will use the mechanical motion to provide power for it to transfer data. Another really interesting side effect of their research will be to drastically reduce the electronic waste generated because these devices will no longer require batteries to operate.

Currently they have managed to power a detergent bottle that signals when it’s empty and automatically order’s refills among other things. I can envision it being used in smart clothing in the near future to power the data transmission or powering mechanical dials & switches for digital systems that don’t need to be wired into the system. In fact there there are multiple such usecases which will benefit from this technology. Sky is the limit for this tech. In fact it might even be feasiable to use this in space missions where every gram of weight needs to be managed and removing the need for heavy batteries will have an immediate impact on cost.

I will definitely be keeping an eye out for future breakthroughs in this area.

Source: IEEE Spectrum: Here Comes the Internet of Plastic Things, No Batteries or Electronics Required

– Suramya

October 9, 2020

Cosmic Radiation levels on the Moon measured to be 200 times higher than at the surface of Earth

Filed under: Astronomy / Space — Suramya @ 10:09 PM

One of the problems with having Humans in space and living there is how to deal with cosmic radiation. When we start talking about having habitats in Space, for example on the Moon or on Mars, dangers of cosmic radiation is one of the risks that we have to address. We don’t have to worry about it in our daily life because on Earth we are protected by its magnetic shield from the cosmic radiation, however once we get outside the atmosphere & magnetic shield it becomes an issue. Unprotected humans living on the Space Station are at significant risk for radiation sickness, increased risk of cancer and degenerative diseases. Dangers of Cosmic radiation are long known however there has never been any accurate measurement of how much stronger the Cosmic radiation is on the Moon since it doesn’t have an atmosphere or magnetic field to block the dangerous radiation and knowing the strength of the radiation would be crucial in designing habitats on the Moon to protect the astronauts living there.

Now thanks to an International collaborative effort we finally have an answer to the question “How much higher is the Radiation on the moon, as compared to Earth & the ISS”. Using the Lunar Lander Neutron and Dosimetry (LND) which was part of the payload on China’s Chang’e-4 lunar probe (which landed on the far side of the moon early last year) the researchers were able to measure the radiation it was exposed to. Basically the LND measured the total amount of radiation it was exposed to over the 2 week period of its operation and sent that data back to earth where the researchers divided the total radiation dose by the amount of time tool operated to calculate the daily total.

This gives us the first concrete measurement of the Cosmic radiation on the surface of the moon. Unfortunately the numbers are not pretty, the base Radiation level on the surface of the Moon is approximately 200 times more than the base Radiation level on the surface of the Earth. Even when we compare it to the level on the ISS, it turns out that the moon has over 2.6 times higher radiation levels than the ISS making it very risky for unshielded humans to stay there for a long duration.

The only way to protect the astronauts is to shield their habitats and spacesuits. For the spacesuits there is ongoing research to identify the best material for shielding (lead works great but is heavy) and for the habitats the cheapest and most effective option would be to just build the whole thing underground. The lunar soil would act as a shield to protect the interior and best of all it doesn’t require us to lift heavy shielding material into orbit reducing the cost of the missions. As per the team’s calculations burying the habitat under ~30 inches of lunar soil would give it protection equivalent to ground level on Earth.

For the assessment of the radiation exposure, the relevant quantities have to be measured by the detector systems: The absorbed dose, D, is the ratio of the energy (E; usually measured in keV) deposited in a detector and the mass, m, of the detector and is expressed in units of Gray (Gy = J/kg). Division by the accumulation time results in the measured dose rate (expressed in Gy/hour). Using a combination of two detectors in coincidence, one measures the distribution of energies deposited in a detector to obtain the linear energy transfer (LET) spectrum [usually in units of keV per micrometer (keV/μm)]. This spectrum is integrated with so-called quality factors, Q, used as biological weights to obtain the dose equivalent, H, which is expressed in units of Sievert (Sv = J/kg). The exact procedures are defined by the International Commission on Radiation Protection (17). Because the human body is not made of silicon, and to make dose, dose rate, and LET measurements more easily comparable to others, one normally converts the values measured in Si to the corresponding quantities in water using a constant dose conversion factor of 1.30 (18).

The Lunar Lander Neutrons and Dosimetry (LND) experiment is described in more detail in the literature (19), but we summarize the pertinent information here for convenience. The LND is mounted in the payload compartment of the Chang’E 4 lander. The red arrow in Fig. 1 points at the reclosable door that protects LND from the cold lunar nights but is open during lunar daytime. The LND consists of a stack of 10 dual-segment silicon solid-state detectors (SSDs), A to J, as shown in the main part of Fig. 2. Total absorbed dose and dose rate are measured in detector B, and the absorbed dose (rate) from neutral particles is measured in the inner segment of the C detector, C1, with the closely spaced detectors B and D as well as the outer segment of C, C2, serving as anticoincidence to discriminate against charged particles. The LET is then determined as discussed above from the dE/dx measured using three different combinations of detector pairs with different counting rates and average path lengths. Penetrating particles are measured by requiring signals in all 10 detectors.

More details of the research are available on the paper published in the journal Science Advances late last month. Check it out if you are interested in learning more technical details about the project.

Source: Businessinsider.in: After measuring radiation on the moon for the first time, scientists say a lunar base should be built underground to protect astronauts

– Suramya

October 7, 2020

Battle Ground (Dresden Files 17) by Jim Butcher

Filed under: Reviews-Urban Fantasy — Suramya @ 11:23 PM

Battle Ground (Dresden Files 17)

by Jim Butcher

Description:

THINGS ARE ABOUT TO GET SERIOUS FOR HARRY DRESDEN, CHICAGO’S ONLY PROFESSIONAL WIZARD, in the next entry in the No. 1 New York Times and No. 1 Sunday Times bestselling Dresden Files.

Harry has faced terrible odds before. He has a long history of fighting enemies above his weight class. The Red Court of vampires. The fallen angels of the Order of the Blackened Denarius. The Outsiders.

But this time it’s different. A being more powerful and dangerous on an order of magnitude beyond what the world has seen in a millennium is coming. And she’s bringing an army. The Last Titan has declared war on the city of Chicago, and has come to subjugate humanity, obliterating any who stand in her way.

Harry’s mission is simple but impossible: Save the city by killing a Titan. And the attempt will change Harry’s life, Chicago, and the mortal world forever.

Buy From:

Rating: (5/5)

Review:

The latest entry in the Dresden Files picks up right from where it left off in the previous book. Dresden is hurting, his allies are scrambling and a Titan has declared war on the human race starting with Chicago. This is a fight that is magnitudes larger than anything Dresden has been in the past and in his own words, he is fighting way outside his weight class. But true to his character he can’t give up knowing that he could have helped save people and the book is a fast moving script with beautifully written fight scenes and even though Harry is fighting beings much more powerful than himself it never gets to a point where it feels ridiculous (looking at you Supernatural).

There are some major events in the book that will have lasting impact on the Dresden universe, specifically there is a scene about half way through that shocked me as it came out of the blue and I had to re-read the para to process it. It is a major spoiler so I can’t give more details but it rocked Harry down to the core.

Interestingly the book also sets up the stage for the next few entries in the series by making vague references to another threat. I am happy to see more books in the series are planned and thanks to the skill of the author I don’t see the series becoming a cliche anytime soon.

Final Verdict: Awesome Book, do read it (as long as you have read the previous books in the series otherwise it won’t make much sense).

Trip to Evolve Back, Coorg

Filed under: Travel/Trips — Suramya @ 7:43 PM

As you know, thanks to Covid-19 traveling has been a distant memory this year and for me that has been the most difficult part that I needed to adjust to this year. We did 11 trips last year including my trip to Antarctica & China, in contrast we had only done 3 trips so far in 2020 and the last trip I took was to Yercaud in March 1st week. So it was getting to the point where I really needed to take a break and travel somewhere but we were both concerned about Covid and didn’t want to take unnecessary risks. After a lot of discussion we finally decided to take the plunge and do a short trip to Evolve Back, Coorg. It is a highly rated property and after reviewing their policies, feedback from folks who traveled there after the lockdown was removed & the reviews we felt comfortable enough to book with them.

We started early morning at 6am from Bangalore on Friday, 2nd Oct. Normally when we travel we stop a few times on the way for food, snacks (coconuts) etc, but this time we decided that we will not stop anywhere and prepared accordingly. We carried all the ingredients for making sandwich’s in the car and as always we also had the water camper with us along with my portable refrigerator to keep my drinks cold. This has been one of the best investments that we made as it makes traveling a lot simpler and I don’t need to keep buying cold drinks/water throughout the trip.


Driving through nature is fantastic. Especially after so many months of staying home

The drive was quite nice with good road connectivity for the most part. There was a stretch of about 30-40 kms which was a problem as there was ongoing road-work happening in the stretch. But other than that the drive was fantastic. We did see a lot of bikers on the way as everyone seems to have taken this opportunity of the long weekend to travel. But I also noticed that folks were mostly avoiding the restaurants/shops on the way and instead eating on the side of the road with their own group only. I saw multiple cars stopped on the road where the folks were drinking from flasks & eating snacks that they carried. Another interesting data point I noticed was that the mask usage went down drastically after we left Bangalore city limits. In Bangalore most of the folks wear masks and only a few are not, however outside Bangalore most of the people were not wearing masks and this reinforced our decision of not stopping anywhere even though we were tempted by really fresh looking coconuts.

Due to the good road conditions and limited traffic we made the trip in 5 hours 30 mins and arrived at EvolveBack. As soon as we arrived and were entering the property we were asked to sanitize our feet (by walking through an antiseptic footmat) and our hands using hand sanitizer. To reduce the interaction we had already submitted all our identity documents online and just needed to sign one form. This was also done in a very safe way; they asked us to take the pen from one stand, sign and then immediately put it in another stand where it would be taken for Sanitization before being made available for the next guest to use. I was slightly concerned when 5 more groups of people arrived just after we did but the hotel already had seating in the reception that followed Social distancing between the groups so my concern was quickly addressed.


View of the Pool & the Lilly Ponds from the Living room


View of the Pool & Lilly Ponds from the outside

After we finished checking in , one of the staffers escorted us to our cabin which was a few mins walk from the reception area. Almost immediately I was floored by the property with its well kept paths, giant trees and the beautiful tweeting of birds. While walking she explained about the various activities available, the timings of the restaurants and facilities. Since it was near lunch time we dumped our luggage in the room and explored the cottage & pool for a bit before walking over to the Granary multi cuisine restaurant which was about 10-15 minutes’ walk from our room for lunch. We were one of the first people to arrive for lunch and after our temperature was taken we were seated at a windowside table overlooking the pool. The pool was closed due to Covid but the view was amazing and we even had a lot of birds (Sparrows) flying around inside the restaurant. I wanted to feed them some bread but Jani refused to let me as she felt that it would create a nuisance for the staff and other guests who might not like it.


The Lovely Pool view at the Granary Multi-cuisine restaurant

As part of their Covid-19 precautions, all restaurants on the property have gotten rid of the physical menu’s and we were asked to view the menu online via the link provided to us on check-in. The food was scrumptious and for me the highlight of the meal was the ‘Coffee Rasagulla’ which was basically a regular Rasagulla soaked in diluted Coffee. At first I was a little apprehensive of ordering something with Coffee in it as I am not the world’s biggest fan of Coffee but this was phenomenal. The Rasagulla was sweet enough that it countered the taste of Coffee and together it was a unique taste. After lunch we walked around the property a little bit before heading back to the cottage for some rest as we had gotten up early and drove a lot. We were warned to keep the glass doors closed for safety because we were in the middle of a jungle and we followed that rule. Even then I woke up to find a nice big spider in the bathroom and Jani found a frog on the deck sunning itself on the deck chairs.


Spider I found in the Bathroom

In the cottage we were planning on soaking in the pool but fell asleep in the really comfortable bed. By the time we woke up it was late evening and the pool was too cold for us to enjoy a dip in. So we just lazed around near the pool and just relaxed. The pool was well maintained and the back of the property was open to nature so it was very peaceful and relaxing. Soon enough it was time for Dinner and we walked over to the Granary Restaurant for another great meal followed by a short walk around the estate at night. Due to the large area of the estate (300 acres) we hardly met any of the other guests. Mostly we would pass some of them while walking around on the estate.


Shot of where the Cultural program is held


Gigantic Palm tree we found while exploring


Pics taken around the property


Pics taken around the property

Since this was supposed to be a relaxing trip we didn’t register for any of the activities (another reason was that most of them were starting early in the morning between 5am – 6am and neither of us were interested in waking up that early to go bird-watching (as we could see most of them from our cottage) or nature therapy (which we were anyway doing by walking around the estate). On the second day we got up for a lazy breakfast followed by a walk around the property. We were lucky enough to see two Giant Malabar squirrel’s during our walk. One was high up in the trees but the other one was fearless enough that I walked up to within a foot of it to take photos without it being scared of me and running away. We also spotted many many species of birds but they were harder to identify because they keep moving so fast.


Giant Malabar squirrel we spotted on the way

After building up our appetite for lunch we walked over to PepperCorn Restaurant which is a specialty restaurant that we had booked for lunch. The place is built on the lake-shore and we had a lovely view of the lake during our lunch which was again phenomenal. They had a special homemade ice-cream available called ‘kadi patta’ (Curry Leaf) which sounded interesting so I ordered it and it was surprisingly tasty.


Lunch at Pepper Corn Specialty Restaurant

Post lunch we again walked around the property to digest the meal and explored their Nature Shop which had a great collection of natural stuff like jams, local wine, locally made flower vases etc. We bought a few things and then retired back to the cottage to enjoy the pool. It was a bit chilly at first but once we got in and were moving around it felt great. We tried the Jacuzzi built in to the pool as well but I prefer the regular pool as it was less noisy. Since it was a small pool there wasn’t much to do but just laze around and enjoy the nature. After a long relaxing session in the pool we took a shower and just hung out in the room before falling asleep.


Lily’s in our Backyard

The next day we had a slightly more busy schedule starting with Breakfast followed by an hour long session on Coffeeology and history of the estate. This was the first time we met & interacted with a few of the other guests. During the session we learnt about various types of coffee and how it’s prepared followed by a tasting session. We tried 6 different preparations of coffee during the tasting: Espresso (black coffee), French Press (Black Coffee), Cappuccino (milk + coffee), Vietnam coffee (milk + coffee), South Indian filter coffee (milk + coffee) and Moroccan coffee (milkmaid + coffee). Since I am not a big coffee drinker I just took really small sips of my share before passing them to Jani who loved all the options. I really liked the Moroccan Coffee because it was cold + very sweet but Jani didn’t like it for the same reason.


This is how many coffee’s Jani tasted (i helped with a few)

After the session, walked over to the Souvenir shop to buy some souvenir’s & lots of coffee and then hung out at the pool for a bit before heading over to the Vaidhyashala for our massage treatments. I did the Abhyanga (Full body massage with herbal medicated oil which removes toxins in the body) and Kati basti (massage targeted for lower back, to reduce the lower back pain) and both were great. I felt so relaxed and rejuvenated after the massage ended that I even asked them if they have a branch in Bangalore. Unfortunately that isn’t the case though they do have centers in all the EvolveBack locations including Coorg, Hampi and Kabini. I really like the massage but not so much that I would drive over for a stay just to get a massage.

After the massage we weren’t supposed to wash off the oil till next day, so we ordered room service as we didn’t feel like walking around smelling like medicinal oil and feeling sticky. The sandwiches we ordered were ok, nothing too great but not bad either. After dinner we read for a while and I tried to get a good photo of the night sky but since I didn’t have my telescope I was only moderately successful.

On the last day of our stay we woke up early to pack and then had a quick breakfast as we wanted to leave early. After breakfast we settled our bill and started back. The drive back was uneventful for the most part. We did stop once on the way at a Spice store so that we could stock up on Spices but other than that we drove non-stop and reached home by 6pm. The overall trip was a huge success and we both feel really rejuvinated after the break. I will highly recommend Evolve Back to everyone even though they are on the expensive side they are definitely worth it.

Jani has also started blogging about our trips so you can read her writeup at her blog as well if you are interested.

– Suramya

October 1, 2020

Windows XP and Server 2003 successfully compiled from leaked source code

Filed under: Computer Security,Computer Software,Tech Related — Suramya @ 9:39 AM

Last week in a major leak the source code for Windows XP & Windows Server 2003 was leaked on the Internet via the 4chan website. Post which it propagated like wildfire across the internet via torrents & mirrors. There were some doubts cast about the authenticity of the leak but knowledgeable folks who reviewed the code claimed that the leak looked authentic.

Now a developer who goes by the name NTDEV successfully compiled Windows XP from the leaked source code. Unfortunately it looks like the XP source code is missing some important files due to which they were unable to compile critical files such as Winlogon.exe. Which makes it impossible to install the compiled Windows XP to try it out. Fortunately they had better luck with the Windows Server 2003 source code and were able to install the compiled copy on a VM successfully.

NTDEV posted a 22 min video showcasing their journey and you can check it out here if you are interested. Their Twitter feed has more information and screenshots of their process & proof.

You can probably expect a lot more information & details on the source to be published over the next few weeks as people go over the code and then start publishing their findings.

– Suramya

September 30, 2020

How to fix vlc’s Core dumping issue while playing some videos

Filed under: Computer Software,Computer Tips,Knowledgebase,Linux/Unix Related,Tech Related — Suramya @ 11:37 PM

Over the past 2 days I found that the VLC install on my computer was suddenly having issues playing some of the video files on my computer. Initially I thought that it was a problem with the video file, then I realized that this was also happening with videos that had be playing fine earlier. When I ran vlc from the command line to play the problem video it gave the following output on screen when it crashed:

[00005587b42751b0] dummy interface: using the dummy interface module…
[00007f00c4004980] egl_x11 gl error: cannot select OpenGL API
[00007f00c4004980] gl gl: Initialized libplacebo v2.72.0 (API v72)
[00007f00c402a310] postproc filter error: Unsupported input chroma (VAOP)
[00007f00bd986e50] chain filter error: Too high level of recursion (3)
[00007f00c4028d40] main filter error: Failed to create video converter
[00007f00bd986e50] chain filter error: Too high level of recursion (3)
[00007f00c4028d40] main filter error: Failed to create video converter
[00007f00bd986e50] chain filter error: Too high level of recursion (3)
[00007f00c4028d40] main filter error: Failed to create video converter
[00007f00bd986e50] chain filter error: Too high level of recursion (3)
…
…
[00007f00c44265c0] chain filter error: Too high level of recursion (3)
[00007f00c4414240] main filter error: Failed to create video converter
[00007f00bd9020d0] main filter error: Failed to create video converter
[00007f00cc047d70] main video output error: Failed to create video converter
[00007f00cc047d70] main video output error: Failed to compensate for the format changes, removing all filters
[00007f00c4004980] gl gl: Initialized libplacebo v2.72.0 (API v72)

A google search told me that a possible solution was to disable hardware acceleration in the Video settings but that didn’t fix my problem. So I took a look at the kernel.log file in /var/log and I got the following error when the program crashed:

Sep 30 21:11:44 StarKnight kernel: [173399.132554] vlc[91472]: segfault at 28000000204 ip 00007f2d8916c1d8 sp 00007f2d8aa69db0 error 4 in libpostproc.so.55.7.100[7f2d8915c000+1d000]
Sep 30 21:11:44 StarKnight kernel: [173399.132568] Code: 98 48 8d 44 07 20 0f 18 08 8b 44 24 08 4d 8d 0c 1a 4d 8d 04 2b 85 c0 0f 85 cb fd ff ff 4c 8b 6c 24 28 4b 8d 04 29 4b 8d 14 20 <41> 0f 6f 01 43 0f 6f 0c 29 41 0f 7f 00 43 0f 7f 0c 20 43 0f 6f 04

Spent about an hour searching for the solution using the details from the kernel.log but got nowhere. Finally I found a forum post where one of the solutions offered was to remove the vlc configuration files, since I didn’t have any other bright idea’s I renamed the vlc config folder by issuing the following command:

mv ~/.config/vlc ~/.config/vlc_09302020

Then I started vlc and just like that everything started working again. 🙂 Not sure what caused the settings to get borked in the first place but the issue is fixed now so all is well.

– Suramya

The Dark Prophecy (Trials of Apollo 02) by Rick Riordan

Filed under: Reviews-Young Adult Fantasy — Suramya @ 2:39 PM

The Dark Prophecy (Trials of Apollo 02)
by Rick Riordan

Description:

Zeus has punished his son Apollo–god of the sun, music, archery, poetry, and more–by casting him down to earth in the form of a gawky, acne-covered sixteen-year-old mortal named Lester. The only way Apollo can reclaim his rightful place on Mount Olympus is by restoring several Oracles that have gone dark. What is affecting the Oracles, and how can Apollo/Lester do anything about them without his powers? After experiencing a series of dangerous–and frankly, humiliating–trials at Camp Half-Blood, Lester must now leave the relative safety of the demigod training ground and embark on a hair-raising journey across North America. Fortunately, what he lacks in godly graces he’s gaining in new friendships–with heroes who will be very familiar to fans of the Percy Jackson and the Olympians and Heroes of Olympus series. Come along for what promises to be a harrowing, hilarious, and haiku-filled ride. . . .

Buy From:

Rating:

Review:

In the second entry to the trials of Apollo series we rejoin the Apollo/Lester, Leo & Calypso who are on the way to Indiana to find the second Oracle. During the quest they need to depend on each other more often and we learn more about Apollo’s past history with some of the major characters in the books and how that is causing the current mess they all are in. Apollo grows up a bit through the course of the novel and even though he is still self-centered and narcissistic to the core its good to see him start showing empathy towards the other characters. Plus his commentary on House-hold chores is hilarious along with the usual pop-culture references.

The book also briefly references other Pantheon’s so it will be interesting to see if that is expanded in the future books and if we have a crossover or not. Since this is a YA Fantasy the fight scenes are detailed enough to be fun but not so that it’s too gory. However there are a few scenes that younger readers might find a bit frightening. So parents would need to keep that in mind.

The book nicely sets up the next entry into the series and I am really looking forward to reading it.

Overall, I would highly recommend this book for any Fantasy book lovers.

September 29, 2020

Mounting a Network drive over ssh in Windows using WinFsp & SSHFS-Win

Filed under: Computer Software,Computer Tips,Knowledgebase,Linux/Unix Related,Tech Related — Suramya @ 1:16 PM

I have computers running both Windows & Linux and at times I need to share files between them and I have been looking for a convenient way to access the files from my Linux machine from my Windows machine without having to run SAMBA on the Linux. This is because historically SAMBA has been a security nightmare and I don’t want to run extra services on the computer if I can avoid it. Earlier this week I finally found a way to mount my Linux directories on Windows as a network mount over SSH using WinFsp & SSHFS-Win and I have been running it for a couple of days so far without any issues. (So far)

Follow these steps to enable SSHFS-Win on your windows machine:

Install WinFsp (Windows File System Proxy)

WinFsp is a set of software components for Windows computers that allows the creation of user mode file systems similar to FUSE (Filesystem in Userspace) in the Unix/Linux world. You can download it from the project’s GIT repository. The Installation file is available by clicking on the download link under ‘Releases’ near the top right corner of the page. The latest version is WinFsp 2020.1 at the time of this writing.

You install the software by running the MSI file you downloaded and the default options worked for me without modification.

Install SSHFS For Windows

SSHFS-Win is a minimal port of SSHFS to Windows. It is available for download from the project’s Git repository. You can compile from source or download the installation file by clicking on the download link under ‘Releases’ near the top right corner of the page. The latest version is SSHFS-Win 2020 at the time of this writing.

Please note that you will need to have WinFsp installed already before you can install SSHFS-Win successfully.

Usage:

Once you have installed both the software you can start using them and map a network drive to a directory using Windows Explorer or the net use command. Instructions for use are as below (Taken from the project Documentation):

In Windows Explorer select This PC > Map Network Drive and enter the desired drive letter and SSHFS path using the following UNC syntax:

\\sshfs\REMUSER@HOST[\PATH]

The first time you map a particular SSHFS path you will be prompted for the SSH username and password which can be saved using the Windows Credential Manager so that you don’t get prompted for it again. In order to unmap the drive, right-click on the drive icon in Windows Explorer and select Disconnect.


Visual demo of how to Map a Network drive using SSHFS-Win

You can map a network drive from the command line as well using the net use command:

net use X: \\sshfs\suramya@StarKnight

You will then be prompted for the password and once you authenticate you can use the new drive as usual. You can unmap the drive as follows:

net use X: /delete

I find this quite useful and hope you do as well.

Thanks to MakerLab, Department of Computer Science, HKU for pointing me in the correct direction

– Suramya

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