Livestreaming with BM TV Studio

We have an ATEM TV Studio Switcher ( in the shop, which allows us to connect up to 9 cameras at the same time with a neat IP based control interface. It sounds like perfect solution for live streaming and event (HDMIs->ATEM TV Studio->Youtube), but challenges surfaced quickly.

The ATEM TV Studio has a USB connector which sends the mixed feed as an H.264 stream, in order to stream a video feed to youtube, we can choose from Wirsecast/FlashMediaLiveEncode (FMLE). Unfortunately, none of them works with the BM ATEM TV Studio Switcher.

Luckily, provide a free livestreaming software called Procaster (, which supports the BM interface out of the box!

We ended up stream the feed through and use OBS (, an opensource broadcasting program as the ultimate solution.

Because the unverified channel can only serve up to 50 people, we use the screen/window capturing function of OBS to capture and re-broadcast the stream to youtube to work around this. Soundflower is being used for redirecting sound from the programme to OBS.

Connection map

Primary stream
Cameras —HDMI/SDI—>BM ATEM TV Studio—USB—>iMac—->Livestream Procaster—> channel

Mirrored stream (through another computer)
Chrome (Opening as a popup)–>OBS–>Youtube

Sound mixing
Another challenge we had was to mix the sound from the sound panel with the SDI video feed supplied by the video company. As the sound panel only provides XLR output and we didn’t have any USB sound capturing device, we used the Sony HDV camera as a XLR->HDMI convertor to the BM ATEM interface. Which worked pretty well.

The cost to go backward…

In this article (The Four Horsemen of the Cyber Apocalypse) , it talks about the possible scenarios that will paralyse digital system. They are certainly valid but I can’t stop thinking of a this question, what is the tipping point for people start to move back to paper-based system?

Given the current database and networking technology, there’s almost no real “safe” system that can be created and left alone without being upgraded. Let alone the attach to cloud based service, for institutes that efficiency is not the top priority, paper based system could be a better solution in terms of security.

In the Silo series written by Hugh Howey, it described a post-apocalypse scenario that the whole human kind lives underground. The “history” of the earth is being modified and changed in the database so no one really know what happened, except for the managements of the silos. This top administrator of the silo has access to physical books, which document the “real history” of the past.

Let alone whether there’s a “real history/reality“, just by thinking about this digital history rewriting scenario is scary enough. There are legal requirements for some institute to keep paper-based record, but is there any company/institute that want to move back to paper-based record/database from a digital system? What is the cost of it? Is there any formula for that?

To boil it down to one question, how much does it cost to convert a database (e.g. MySQL/Postgresql) to a paper-based system?

Self learning and textbook

Just watched Good Will hunting over the weekend in memory of Robin Williams. How a teacher inspire students in an elite school in Dead Poet Society was certainly up-lifting for me as an educator. The friendship/brotherhood in Good Will Hunting was also touching. A scene in the movie made me think about what learning is/could be.

Not everyone has the incredible memory that Will has in the movie, but we have access to the books he read. The interesting thing is what he chose to read, not just any book but textbooks! It really is the quickest way of diving in any field if you know nothing about it. I may start with the recommendations on this page and keep an eye on the College Open Textbooks ( project.

How we see the world differently with mobile phone- VVS

This is probable an old video, but it is really funny. Shooting video in portrait with mobile phone, also known as “Vertical Video Syndrome”/VVS.

What we can see here is the merging of 2 different technologies (video tech and mobile phone). The vertical format of most mobile phones is definitely a sensible design, but it wouldn’t work when the orientation of the camera (landscape/portrait) correspond to the orientation of phone. What is the solution?

A simple approach maybe having a phone that shoots in landscape mode while being hold “up-right”.

Mm… why isn’t there a phone like this?

Using Google Drive to share documents

One of the problems of using GDrive in a school/company is the file ownership. If someone who owned/created the file left and the account was deleted, it will be gone forever. I order to further migrate the data to the cloud service, transfer the ownership to a “school owned” account is essential.

However, explaining all these by an email would be extremely boring… Finally I’ve created my first PowToon..

Prejudice and door lock

Which one is more powerful? A door lock or prejudice?

I encountered 2 broken door lock incidents in the past few days, luckily nothing went wrong. 

One of the door usually requires a smartcard to open, as the system was faulty that day, someone disabled the lock to make sure people have access to it. However I still swipe my card every time when I push an unlocked door…

Here’s an image of a classic InfoSec theory (Which is about “CIA”)


It talks about integrity, availability and confidentially. If you are living in an apartment building in Hong Kong, most of the time if you forgot to lock the door, nothing will happen. The challenge for anyone who’s trying to break in an apartment/system is that there’s a cost for testing each door. Most people will assume a door is “locked”.

How about when we try to share a new idea? Do we assume people will not take it and just drop it? To me, prejudice is much more powerful than a door lock, cause after all, we all assume a door lock can lock the door… but it isn’t always the case.


CSV to XML tool

When working on a small website project, the client sent an excel file for the database. However this time I intended to use pure XML instead of database, so a CSV->XML tool is needed.

This website is exactly the tool I wanted. You can simply upload the CSV and it will convert it to XML for you. You can specify the root and record name for the XML file, makes it an even better tool!