Sun10202019

Last updateFri, 11 Oct 2019 10am

 

Introducing – Tools for Cinema Quality Assurance

cat_pr1_sm_jpg

Cinema Test Tools for the Non-Technical Manager 

Cinema Test Tools is a free resource for the cinema industry, tuned most particularly for the non-technical manager. The tools include several DCPs, all with interesting means of testing the sound and picture quality for the interested by lightly trained staff. The lessons on sound and light are written to provide a foundation to communicate with the technician who must respond quickly and well to the information that they discover.

The key is a free Online Managers Online Walk Through Checklist that correlates with the many DCPs. It helps bring an understanding of the many nuances of the auditorium's situation in a straightforward way. 

Lens Tangents | DCinema Acquisition

Capture – with lens or microphone, perhaps moving electrons around with a stylus, or perhaps conversion from an analogue form. Regardless, the beginning is acquisition.

You believe that Snellen eyechart or your lying eyes?

Chris Chinnock of Insight Media has tied together a group of interesting data to counter the meme that the visual acuity of the Human Visual System is incapable of discerning differences in 4K or 8K unless one is close enough to get nose oil on the screen.

Finally those who see movement flaws and dithering in 4K materials from distances supposedly impossible can stop doubting themselves, armed with science. Effects such as Film layers put over video that are composed of various forms of dithering dirt that show up on LED screens can be explained. ...– even though that addition is perhaps worthy for the 2K or 4K projection to remove the video look.

See: 8K TVs Top TV Line-ups for a Reason

For those not familiar with Chris and Insight Media, he has been assembling various focused multi-day seminars which go beyond what is typically delved into during HPA (they go into topics of the future but are not as focused on any one topic) or the NAB/IBC/ISE/CES circuits (which dance around immediately interesting topics generated from the new developments that manufacturers are showing). Nothing wrong with those, but the Insight Media sessions hit their topics from experts in with newly developed information from several tangents.      

For example, the October 2018 Display Summit held at the Harman International facility in Northridge gathered 30 experts on light field and LED technology. (It took 5 of them before I understood that there will never be a Star Wars hologram kit in my cereal box, ever. And although I have been in Barco facilities that had walls full of LED displays under test – headed to concerts, stores and exhibition displays, I was still surprised to hear a Barco/Cinionics speaker discussing LED walls for cinema.)

And here is a link for a little music to listen to while reading Chris' piece: El Panquelero - Silvia Perez Cruz & Javier Colina Trio

Moviola Teaches Glossary

Wow...in addition to being a great glossary of production tools, Moviola has created a glossary that shows how all great glossary should be created in the future. Words for the word-readers, and nicely produced vids for the impact. And what a set of font face choices.

Moviola's Visual Glossary

Update – Ludé on Light Field Displays

Pete Ludé posits from the view of having worked with worked with CableLabs, starting from the basic question – If we could buy a large light field display, how could we use it for different types of content (e.g., Sports, DIY Instructional Video, Concert, or Scripted Drama), and what parameters would be most relevant and needed (Field of View, Resolution, Viewing Distance) to come to how much data is required to capture in those cases. 

And from there explains and works into Light Field Display from the basics to the complex that we will have to deal with in the near-ish future:

Pete Lude speaking at SMPTE 2018 on Light Field Array technology

Read more ...

What Means, New SMPTE Pink Noise...and How?

SMPTE ST-2095-1 is a new standard for Pink Noise. It took a great deal of work by a great number of clever people, a lot of listening and testing and tweaking. The cool thing is that it isn't made with a lot of transiticators, but rather, with digits. This is THE Digital Pink Noise Standard.

Pink Noise has been one of those things that has always been around, and people don't think much about it. Flick a switch, and there it is. But it took a sophisticated circuit to do right, and it wasn't always implemented the same...or even well. That is much less likely now because with the standard is a python script that is very easy to implement.

The equipment that you rely upon may already use it. For example, the great audio tools set named Audio Tools from Studio Six Digital, has already implemented it.

But what if you just want to make some of your own? That is the point of this post – to give a few tips on how to create a usable Pink Noise .wav file using the python script that is delivered with the SMPTE Calibration Pink Noise Standard ST-2095-1...and with luck and permission, attached as a download here.

Since the programming language ‘python’ is installed as a standard part of the Mac computer, that is what you'll see with the drawings and instructions following. There are also some pictures of the basic use of the Audacity, the free and Open Source audio tool. Audacity is available for Windows, but the pictures are from a Mac.

Just to be clear:

1) Python and Audacity are both freely available for Windows and Linux and Mac
2) Allowing for normal directory adjustments, the commands are the same whether used on a Mac or Windows or a Linux based computer. In Windows, of course, one uses the ‘cmd’ window instead of a 'Terminal', and one can’t use cut and paste on the Windows system as one can with Terminal on the Mac and Ubuntu (pointing out only one of several usable versions of Linux OS.)
Windows Python Installer: <https://python.org/downloads>
Audacity downloads are at: <http://web.audacityteam.org/download/>

1) Download the SMPTE Python File

One source is the SMPTE Documents website.

2) Prepare the Computer

On your Mac computer, in Finder, click “Command-Shift U” to go to 'Utilities' folder.
Drag the .py file to Utilities folder; authenticate with your password when asked.
While still in Finder, click “Command-Shift O” (O as in Opal) to go to 'Documents' folder.
Create a new Folder (Cmd-N) and immediately type "pink_noise", then Return to name it.
Open the 'pink-noise' folder with Cmd-O or double click.

3) Using Terminal to Create Some Noise

Do “Command Spacebar”, then type “Terminal”. When ‘Terminal’ appears, click “Return”
In Terminal, type “python " including a trailing space.
From the Utilities folder, drag the 'ST-2095-1-generator.py' icon to the Terminal window.
Add a space
From the top of the previously opened ‘/Documents/pink_noise’ folder, drag the folder icon to the Terminal window.
Add a slash bar and a file name for the pink noise file to be generated: e.g., "/48_10_1.wav"
The line should look something like:

python /Applications/Utilities/ST-2095-1-generator.py Documents/pink_noise/48_10_1.wav

Hit “Return", then wait until the script tells you how long the process took and the RMS value.

Go to ‘Documents/pink_noise folder’ to see the new .wav file. Click once, hit Space bar to listen.

If you are unfamiliar with the techniques detailed above, all that dragging and dropping is used to avoid figuring out –and mistyping – the paths to the documents. Terminal is kind enough to let you drag a file and it fill in the data.

4) To Modify file duration, channel numbers and bit rate

In Terminal, click up arrow which brings up the previous command.
Hit left arrow to the Capital "D" in Documents. Type "-d 20 ", or the desired length in seconds.
Note the space. Make certain there is only one space in between the '20' and the 'D'.
Hit the right arrow to 2nd underscore in the .wav file name. Hit "delete" 2 times. Type "20".
Hit "Return" to create the 20 second file.
The following command will create a .wav file that has 6, 30 second channels of 96k pink noise.

python /Applications/Utilities/ST-2095-1-generator.py -d 30 -c 6 -9 Documents/pink_noise/96_30_6.wav

The six channels in that example will play simultaneously. To create a file that will play the channels consecutively, or to change the levels or add a Fade In or Fade Out, or trim the lengths (a 10 second request will create a file longer than10 seconds), it is necessary to use an audio editing program. While many are available, the examples used below are for the well regarded, free and Open Source program, “Audacity” .

5) To install Audacity

Open a browser page to: http://sourceforge.net/projects/audacity/
Click the "Download" button
Double-click on the .dmg file, which will open an Audacity Install window
Drag the Audacity folder to the Applications folder.

6) To Open .wav File In Audacity

In the 'pink_noise' folder, Right-Click or Control-Click on the .wav file
Roll down to "Open with". Select "Open with Audacity”
audacity_opn_with
Click "OK" to "Make a copy of the files before editing (safer)
audacity_copy_yes
You should see a single channel of pink noise that is a little shorter than 22 seconds.
audacity_one_channel
To Cut or Fade Out from 20 seconds, with the "I-bar" selected, click, hold and drag to the right.
audacity_choose_panel
To Cut:
Leaving the last 1.8 seconds selected, hit 'Delete'.
To Fade:
Leaving the last 1.8 seconds selected, pull down from 'Effects menu' (at top) to 'Fade Out'
Click Command-A to select the entire track

To quickly add channels of the same modified sound:
Click “Command-D” three times to create 8 channels
Click "X" in upper left corner of any track to eliminate one track.
audacity_kill_channel
Good practice, but not mandatory:
Name the channel by pulling down the box to the right of the 'x'.
Note: The fourth channel will always be the LFE channel
channel4_lfe_always_rename

7) To Sequence one track after the other

Click Cmd-A to select all the tracks.
Pull down the menu "Tracks" to "Align Tracks" to "Align End to End"
'Click Cmd-F' and 'Shift-Cmd-F' to get the entire set of tracks in the window.
Slip/Adjust tracks as desired.

8) To Export to broadcast WAV file use as .wav or for use as DCP

Pull down 'File' to 'Export Audio'. (Cmd-Shift-E)
Name file as desired, but definitely change the name or directory.
In 'Format' pull down to 'Other uncompressed files'.
Click 'Options';Select 'Header: WAV (Microsoft)'; Encoding: 'Signed 24 bit PCM'; Click 'Save'

9) To make channels Rotate…and LFE play last (See N.B. following Technique)

In Advanced Mixing Options: Click the 2nd box down on left. It will get a red outline
Click 'Channel: 3' on right side. A connection will appear.
Click 'Channel: 2' on right side. Connect it to 3rd box down on left side.
Click on connection bar between 3rd box on both sides to remove it.
Do the same to swap RtSurr and LftSurr for Channels 5 and 6 - have real fun with 8 channels.
audacity_mixing_options
Click ‘Save’. The Next panel is metadata which is not supported in .wav files; Click ‘OK'
NB: This technique only works if all channels have identical signals! If, for example, the LFE channel were increased by 10 dB before the Export, following the above Export example will create a Right Surround that is 10 dB too hot.

10) Verifying the .wave file

Go to /pink_noise folder and open new file in Audacity using the “Open As…” technique described previously. If you merely double-click on the .wav file, iTunes will likely import it and play it for you.
audacity_verify
This is what it should look like when complete. It will play out L, C, R, RtSurr, LftSurr, LFE
Now that the .wav file is open, filters can be applied or levels can be adjusted.

11) To add level to a channel

Select – carefully select – the audio portion of the track, then pull down ‘Effects’ to ‘Amplify’, then put in the number of dB to add (or -dB to subtract).
Do your best not to amplify the silence. But it is possible that you will not be able to avoid ‘grabbing’ a small portion of it.

You must export again to create a .wav file. When you “Save” in Audacity, you are creating an Audacity specific file set, not a playable .wav file.

But if you already have saved the .wav file so it plays channels in the proper order, then you don’t need to swap them on export again.

There is more potential in using the Audacity program, but this should serve the basic needs.

Please send document corrections or suggestions via the Contact Form. Thanks.

Subcategories

The technology of acquisition explained; from cameras and lenses, to memory and local storage, from storyboarding and CGI...place or read it here.

Storage. It wasn't that long ago that trying to get a 9 Gig RAID working on a sophisticated LAN was monumental, if not impossible. 9 years perhaps?

Now, terabyte drives are here. Enough to go with holographic storage soon?

There is a thrust for acquisition to take on some of the aspects of post. We are way to conservative for something fancy like that. But, we'll let you modern people talk about it.

Camera, but virtual. 

Film has higher resolution, no matter what that means. It is important.

We are hoping that we won't be talking much about how many electrons in the full well capacity, but we might...never know. There is just so much new coming out, that cameras and their accessories need a whole category by themselves...and here it is.