December 4, 2018

Recording a Multi-day Event

I was asked to suggest equipment for recording a 5-day seminar.  It is estimated that about 30 hours of recording will be done in total.  This will be a pretty standard corporate knowledge sharing event - few speakers talking to a small audience while using their laptops to share slides.  I suspect there will be live coding examples, so the resolution of this part will have to be reasonably high.  Working on a whiteboard will be an option, so the camera will have to be manned.


I rely on Sennheiser G3 for recording the speaker.  Batteries (2xAA) can be swapped during the breaks for continuous recording.
For ambient audio and as a fall-back I use Sony PCM-M10 recorder. Batteries (2xAA) can be swapped during the breaks for continuous recording.  The recorder has space for more than 10 hours of recording, so the daily backup is desired.  I record in PCM16/48kHz.  The built-in 4GB flash is sufficient for 5h 45min of recording so daily backup is required.

Desktop/Slides Recording

My tried and true solution is a hardware recorder with HDMI pass-through.  External power brick is used, so no batteries to worry about.

AverMedia C285 is probably obsolete by now but it certainly does the job - it supports resolution up to 1920x1080 at 30fps.

The recorded stream is stored on the internal 2.5" SATA drive - I have a set of three such 128GB SSDs.  Each can store more than 13 hours of 1080p 30fps video/audio stream in MP4 container.

Speaker/Audience Recording

Use GH5 with 12-35 2.8 zoom lens to record speaker and audience.  4K recording recommended so that a no loss zoom-in on the speaker face can be done in post.  A single battery will comfortably power the camera for about 2 hours.  I have 4 batteries, so daily recharge of those will be required.  Camera has 2 SD card slots. Usually I record 4K 30fps in MOV container at 100 Mbps rate. Two 128GB cards should suffice for 6 hours or live video recording.  Daily backup will be required though.

Post Processing

During post processing the following tasks are performed:
  • clips are synchronized;
  • dynamic compression for audio is performed;
  • video exposure/color adjusted ;
  • content is edited to maintain tempo into clips of reasonable length - less than 45min;
  • content is rendered to desired resolution (720p?  1080p?) and bitrate - YouTube guidelines recommended;
  • Opening/closing credits are added.  Adding corporate branding is an option as well.

Storage Requirements Summary

For a week-long events the following storage is required:

Recorder   Built-in StorageStorage for a week-long (30hours) event
Audio4GB, 5 hours20GB
Screen120GB, 13 hours300GB
Video2x128GB flash, 6 hours   256GB*5 - about 1.4TB

Seems to be totally manageable.  If full time video can be avoided, those become totally trivial.

March 24, 2017

Blogger on iOS?

The app crashes and apparently was discontinued.  Mobile web GUI is barely legible.  What's going on?  What are the alternatives?  Frustrating to see a basic functionality being taken away.

What's up?

It was a while!
My free time was spent on RoboPanner.  An umbrella term for my camera motion control efforts.  Check out the web site and links from there to github.
Learned a lot (markdown rulz!) including about myself- apparently I love writing code!  And have strong opinions about doing it right. While waiting for appointment today I searched github for a code to handle button debounce/click//double click.  Plenty of code exists.  Some very primitive, some hairy with ability to add callbacks as in C.  None is expressing my thinking with reliance on C++ inheritance for callbacks.  I suspect my way of thinking about GUI can be traced back to MFC.  Not sure it is that good, but I certainly see the benefits.  Look forward to writing that code and sharing it here!

July 18, 2016

Multi-Camera Live Switching

Cheesycam has a good overview of a live streaming setup based around BlackMagic Design 4K ATEM.  Nice step up from the minimalist setup I described earlier.
Check it out!

March 16, 2016

TheaterGames Production of НЕИЗВЕСТНЫЙ С ХВОСТОМ

TheaterGames retained me to shoot this season productions with НЕИЗВЕСТНЫЙ С ХВОСТОМ being the first one.  The enthusiasm of young actors is infectious.  Professionalism of adults involved is humbling for me. Masha and Marianna can keep tabs on this chaos and manage to get fantastic results.   Ilya Dimov's original music and performance are totally awesome.  As my kids would say.  My son is singing his pieces months after hearing those for the first time.

Here are some technicalities. What worked:
  • Planning the shoot and setting exposure in advance.  I was shooting at ISO400, f4.5-f5.  As usual 24fps, 1/48sec.
  • TheaterYou location is intimate and three cameras give a good coverage.  Canter one above the bleachers 12mm. I operated camera on the right.  Used 14-140mm zoom for the first time, mostly at around 35mm.  The camera on the left was fixed at its whidest zoom which is 28mm I think.
  • I used two audio recorders but ended up using only one audio track, from Zoom H1 positioned just three feet from the center of the stage.
  • In post: Audio: three (3!) layered compressors - first at 1:2 at -18dB, second at 10:1 at -9dB, third hard limiter at -6dB.
Still problematic.
  • Not happy with my operation of focus on a new 14-140mm zoom.
  • As always in the theater, setting white balance is a pain.
Thank you to TheaterGames!  Both myself and my son enjoyed it!

October 1, 2015

Modded iRig Pre + RØDE NTG1 vs Takstar SGC-598

Today I received and modified iRig Pre ($28) and decided to test it together with RØDE NTG1 ($200) against Takstar SGC-598 ($30).  Now, this is not entirely fair comparison if only because the latter should be always camera-mounted while the former can be mounted on a boom.

Nevertheless, give it a listen...

Both mics were sitting about 2 feet from my mouth.  Recording was done into Panasonic Lumix G7 with audio sensitivity at its lowest: -12dB.  In post I normalized audio and reduced audio channel level by 6dB.  No compression or equalization was added.  During normalization a gain of 9.2dB was applied to a clip with iRig Pre and a gain of 11.8dB was applied to a clip with Takstar.  But the result is a wash in my opinion.  Charming!  And yes, this is not a fair comparison.  But still....

September 28, 2015

ACM event at eBay

It all went smoothly.  I used G3 lav for speaker audio and Sony PCM-M10 to record ambient sound and questions.  HF G20 used to shoot slides, G7 with 12-35 f2.8 lens to film audience, GH4 with 35-100 f2.8 lens to film the speaker.
Here is my post workflow:
  • Copy all the footage into editing workstation.
  • Import the footage into Sony Vegas Pro.  Work around Sony bug of importing Panasonic footage.
  • Sync all the tracks.  I do it by waveform.  HF G20 requires adding extra frame of silence between MTS files.  Sony PCM M10 is typically skewed tward faster clock so requries added silence (fraction of a sec) as well.
  • Do multi-track editing.
  • For all video tracks: add these filters: white balance, brightness and contrast, levels.  Set those using reference card footage I captured during production and color correction GUI.  Sometimes this does not work - e.g. G20 footage can look so different I use color match filter instead for just G20 track.
  • For all audio tracks: add compression.
  • Add credits, lower thirds, etc
  • Render for YouTube
Now the footage is ready to be passed to customer!