All posts by Like Tangents In The Rain

Web Posting of the Week

Sound’s Like A Big Thing – CineTechGeek

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And now he shows up in a video of the Cine Tech Geek [CinemaCon 2014 – X-Curve Update with Barry Ferrel of QSC] making a point that may be surprising to people:

Good Speakers – so the engineer doesn’t get trapped trying to EQ badly designed speakers (or a badly designed room, one presumes)

Placed Behind Screen – the sound is transmitted (hopefully) through little holes in a membrane stretched tight as a drum from speakers (hopefully) built into a wall that is not to distant from said screen

Subtract the function of sound in air – if you’re thinking inverse-square, you are right… play with the numbers at Inverse Square Law for Sound

Something like the X-Curve appears on the RTA as a ‘result’, not a target – give or take a few dB, and with variations in the size of the room, which was requirement to allow for in Ioan Allen’s (of Dolby) original X-Curve paper and in the SMPTE 202M

James Gardiner makes the point that SMPTE is working on this topic, which is an understatement. A lot of hype has been spilt on the need for the emerging immersive sound techniques to find a common distribution package, but now that the difficult Film To File transition has largely taken place, many more engineers are spending a great deal of time reviewing the basics, going through specifications and recommended practices that evolved but now appear contradictory or merely confusing, and not to be forgotten, how are settled techniques in the analog world different in the digital world.

Examples of this fundamental research is showing up in hundreds of pages of documents generated while recently testing various rooms around the world, or testing dozens of algorithms of pink noise samples or developing techniques to find what a screen really is doing in the room, or figuring the best methods of consistently measuring luminance or audio in an auditorium. None of this is public since committee work is private until published, but it is easily obtained when one joins SMPTE and participates in the various working groups.

There are nuances in what Barry says here that could be the subject of 10 slides each, examples being how the ear can discern and ‘deal with’ reflections that microphones can’t account for, or how different frequencies in the transitions between speakers of an array will act different enough that they need to be measured properly, or how EQing to correct speakers (or the room) will make the ear ‘wince’…OK, he didn’t say wince… but using graphic EQs in the recording business came and went surprisingly quickly, before their digital transition in fact, and that lesson should have gotten to the exhibition world back then. We’re talking the late-70’s.

The desired point of this article is that there is a lot to know and do to make rooms consistently good, and keeping them that way. Putting time into SMPTE committee-work is an excellent way to pay-forward on the benefits received.

The side point is to make common certain information, such as the requirement to use FFT when setting up or monitoring components of your system. Testing for the level of a single tone is better than not testing at all, but doing real FFT work to find the THD in a component or your system is truly giving relevant and usable information.

Web Posting of the Week

Sound’s Like A Big Thing – CineTechGeek

Leave a comment

And now he shows up in a video of the Cine Tech Geek [CinemaCon 2014 – X-Curve Update with Barry Ferrel of QSC] making a point that may be surprising to people:

Good Speakers – so the engineer doesn’t get trapped trying to EQ badly designed speakers (or a badly designed room, one presumes)

Placed Behind Screen – the sound is transmitted (hopefully) through little holes in a membrane stretched tight as a drum from speakers (hopefully) built into a wall that is not to distant from said screen

Subtract the function of sound in air – if you’re thinking inverse-square, you are right… play with the numbers at Inverse Square Law for Sound

Something like the X-Curve appears on the RTA as a ‘result’, not a target – give or take a few dB, and with variations in the size of the room, which was requirement to allow for in Ioan Allen’s (of Dolby) original X-Curve paper and in the SMPTE 202M

James Gardiner makes the point that SMPTE is working on this topic, which is an understatement. A lot of hype has been spilt on the need for the emerging immersive sound techniques to find a common distribution package, but now that the difficult Film To File transition has largely taken place, many more engineers are spending a great deal of time reviewing the basics, going through specifications and recommended practices that evolved but now appear contradictory or merely confusing, and not to be forgotten, how are settled techniques in the analog world different in the digital world.

Examples of this fundamental research is showing up in hundreds of pages of documents generated while recently testing various rooms around the world, or testing dozens of algorithms of pink noise samples or developing techniques to find what a screen really is doing in the room, or figuring the best methods of consistently measuring luminance or audio in an auditorium. None of this is public since committee work is private until published, but it is easily obtained when one joins SMPTE and participates in the various working groups.

There are nuances in what Barry says here that could be the subject of 10 slides each, examples being how the ear can discern and ‘deal with’ reflections that microphones can’t account for, or how different frequencies in the transitions between speakers of an array will act different enough that they need to be measured properly, or how EQing to correct speakers (or the room) will make the ear ‘wince’…OK, he didn’t say wince… but using graphic EQs in the recording business came and went surprisingly quickly, before their digital transition in fact, and that lesson should have gotten to the exhibition world back then. We’re talking the late-70’s.

The desired point of this article is that there is a lot to know and do to make rooms consistently good, and keeping them that way. Putting time into SMPTE committee-work is an excellent way to pay-forward on the benefits received.

The side point is to make common certain information, such as the requirement to use FFT when setting up or monitoring components of your system. Testing for the level of a single tone is better than not testing at all, but doing real FFT work to find the THD in a component or your system is truly giving relevant and usable information.

Exhibitor News

MDA Immersive Audio Demo’d, and Openly (Patently?) More

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To copy directly from the Open Source Initiative website:

Open Standards Requirement for Software

The Requirement

An “open standard” must not prohibit conforming implementations in open source software.

The Criteria

To comply with the Open Standards Requirement, an “open standard” must satisfy the following criteria. If an “open standard” does not meet these criteria, it will be discriminating against open source developers.

  1. No Intentional Secrets: The standard MUST NOT withhold any detail necessary for interoperable implementation. As flaws are inevitable, the standard MUST define a process for fixing flaws identified during implementation and interoperability testing and to incorporate said changes into a revised version or superseding version of the standard to be released under terms that do not violate the OSR.
  2. Availability: The standard MUST be freely and publicly available (e.g., from a stable web site) under royalty-free terms at reasonable and non-discriminatory cost.
  3. Patents: All patents essential to implementation of the standard MUST:
    • be licensed under royalty-free terms for unrestricted use, or
    • be covered by a promise of non-assertion when practiced by open source software
  4. No Agreements: There MUST NOT be any requirement for execution of a license agreement, NDA, grant, click-through, or any other form of paperwork to deploy conforming implementations of the standard.
  5. No OSR-Incompatible Dependencies: Implementation of the standard MUST NOT require any other technology that fails to meet the criteria of this Requirement.

One can imagine that each phrase was fought over in countless hours of committee work. Let’s see how the Digital Standard Organization uses “open standard” on their site. Notice the differences and similarities. There will be a test…ongoing and on the floor of conventions and when you read PR everywhere.  Notice that the term is tied to Free in this usage, but that usage comes directly from:

Origins

The Digistan definition of a free and open standard is based on the EU’s EIF v1 definition of “open standard” with the language cleaned-up and made more explicit. Our analysis of the importance of vendor capture in determining the openness of a standard comes from this analysis.

Picking our way through their site:

Politicization of terminology

What is an open standard? The Wikipedia page shows many definitions, which specify characteristics of a specification, or of the processes that produce it and make it available.

To understand why there is no single agreed definition, and to let us build a canonical definition, we can start with two observations:

    1. The standardization process is driven by two conflicting economic motives. Established vendors see standards as a route to direct profits, while the market at large sees standards as a route to lower costs.
    2. As the economic has become digital, governments – both as users and regulators – have become engaged in the conflict between these two interest groups.

The definitions collected on Wikipedia can be grouped into those made by vendors, and those made by the rest of the market. The variation in definition comes from the various viewpoints expressed (e.g. W3C focuses on process while Denmark focuses on user cost).

We, the Digital Standards Organization, explicitly take the side of “the market at large”. We do not accept the definitions of “open standard” produced by vendor bodies, including W3C to some extent. We do not accept the attempts of some legacy vendors to stretch “open standard” to include RAND-licensed standards.

An open standard must be aimed at creating unrestricted competition between vendors and unrestricted choice for users. Any barrier – including RAND, FRAND, and variants – to vendor competition or user choice is incompatible with the needs of the market at large.

There is more at: Digital Standards Organization Rationale. Finally, onward to another page, which nicely correlates with the OSI group statement above:

Definition of a Free and Open Standard

The Digital Standards Organization defines free and open standard as follows:

  • A free and open standard is immune to vendor capture at all stages in its life-cycle. Immunity from vendor capture makes it possible to freely use, improve upon, trust, and extend a standard over time.
  • The standard is adopted and will be maintained by a not-for-profit organization, and its ongoing development occurs on the basis of an open decision-making procedure available to all interested parties.
  • The standard has been published and the standard specification document is available freely. It must be permissible to all to copy, distribute, and use it freely.
  • The patents possibly present on (parts of) the standard are made irrevocably available on a royalty-free basis.
  • There are no constraints on the re-use of the standard.
The economic outcome of a free and open standard, which can be measured, is that it enables perfect competition between suppliers of products based on the standard.
What have we learned? There is a community usage of Open Standard with developers. It is clear in that group what they mean by the term. There is another usage that does not fit into the logical extension of anyone’s definition, but which is held tightly by those who want to exploit the words. 

How the term is used in the theatrical exhibition side of professional audio remains to be seen.
There will be more on this topic, but this should start the conversation, and give enough background for some moments of interest at CinemaCon 2014.
Exhibitor News

MDA Immersive Audio Demo’d, and Openly (Patently?) More

Leave a comment

To copy directly from the Open Source Initiative website:

Open Standards Requirement for Software

The Requirement

An “open standard” must not prohibit conforming implementations in open source software.

The Criteria

To comply with the Open Standards Requirement, an “open standard” must satisfy the following criteria. If an “open standard” does not meet these criteria, it will be discriminating against open source developers.

  1. No Intentional Secrets: The standard MUST NOT withhold any detail necessary for interoperable implementation. As flaws are inevitable, the standard MUST define a process for fixing flaws identified during implementation and interoperability testing and to incorporate said changes into a revised version or superseding version of the standard to be released under terms that do not violate the OSR.
  2. Availability: The standard MUST be freely and publicly available (e.g., from a stable web site) under royalty-free terms at reasonable and non-discriminatory cost.
  3. Patents: All patents essential to implementation of the standard MUST:
    • be licensed under royalty-free terms for unrestricted use, or
    • be covered by a promise of non-assertion when practiced by open source software
  4. No Agreements: There MUST NOT be any requirement for execution of a license agreement, NDA, grant, click-through, or any other form of paperwork to deploy conforming implementations of the standard.
  5. No OSR-Incompatible Dependencies: Implementation of the standard MUST NOT require any other technology that fails to meet the criteria of this Requirement.

One can imagine that each phrase was fought over in countless hours of committee work. Let’s see how the Digital Standard Organization uses “open standard” on their site. Notice the differences and similarities. There will be a test…ongoing and on the floor of conventions and when you read PR everywhere.  Notice that the term is tied to Free in this usage, but that usage comes directly from:

Origins

The Digistan definition of a free and open standard is based on the EU’s EIF v1 definition of “open standard” with the language cleaned-up and made more explicit. Our analysis of the importance of vendor capture in determining the openness of a standard comes from this analysis.

Picking our way through their site:

Politicization of terminology

What is an open standard? The Wikipedia page shows many definitions, which specify characteristics of a specification, or of the processes that produce it and make it available.

To understand why there is no single agreed definition, and to let us build a canonical definition, we can start with two observations:

    1. The standardization process is driven by two conflicting economic motives. Established vendors see standards as a route to direct profits, while the market at large sees standards as a route to lower costs.
    2. As the economic has become digital, governments – both as users and regulators – have become engaged in the conflict between these two interest groups.

The definitions collected on Wikipedia can be grouped into those made by vendors, and those made by the rest of the market. The variation in definition comes from the various viewpoints expressed (e.g. W3C focuses on process while Denmark focuses on user cost).

We, the Digital Standards Organization, explicitly take the side of “the market at large”. We do not accept the definitions of “open standard” produced by vendor bodies, including W3C to some extent. We do not accept the attempts of some legacy vendors to stretch “open standard” to include RAND-licensed standards.

An open standard must be aimed at creating unrestricted competition between vendors and unrestricted choice for users. Any barrier – including RAND, FRAND, and variants – to vendor competition or user choice is incompatible with the needs of the market at large.

There is more at: Digital Standards Organization Rationale. Finally, onward to another page, which nicely correlates with the OSI group statement above:

Definition of a Free and Open Standard

The Digital Standards Organization defines free and open standard as follows:

  • A free and open standard is immune to vendor capture at all stages in its life-cycle. Immunity from vendor capture makes it possible to freely use, improve upon, trust, and extend a standard over time.
  • The standard is adopted and will be maintained by a not-for-profit organization, and its ongoing development occurs on the basis of an open decision-making procedure available to all interested parties.
  • The standard has been published and the standard specification document is available freely. It must be permissible to all to copy, distribute, and use it freely.
  • The patents possibly present on (parts of) the standard are made irrevocably available on a royalty-free basis.
  • There are no constraints on the re-use of the standard.
The economic outcome of a free and open standard, which can be measured, is that it enables perfect competition between suppliers of products based on the standard.
What have we learned? There is a community usage of Open Standard with developers. It is clear in that group what they mean by the term. There is another usage that does not fit into the logical extension of anyone’s definition, but which is held tightly by those who want to exploit the words. 

How the term is used in the theatrical exhibition side of professional audio remains to be seen.
There will be more on this topic, but this should start the conversation, and give enough background for some moments of interest at CinemaCon 2014.
Societies

SMPTE’s Metamers

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but takes different meanings depending on the many different possible viewpoints. One group will use the word to mean that two articles of clothing can look identical under the lighting of the store, but will look wildly different in the light of the bedroom. It is also metamerism that allows what looks one way on the screen in RGB to look similar when printed with CMYK inks. It is also used in the controlled tests of the lab when a person is asked to mix 3 colors in order to match a target color – in fact, it was similar tests that the then young International Commission on Illumination (the CIE) used to proof the tri-stimulus system and to come up with the various color models that we are familiar with (think horseshoe).

SMPTE Screen for Committee Work

Metamers are in the news because of laser light replacing xenon, and, like the always present but exacerbated ‘speckle’ is something that heretofore sloppy but lucky implementations were able to hide – not that the engineers were sloppy, but the technology was so ‘force over subtlety’ that the age didn’t allow any better. Unlike speckle, no one knows for certain whether metamers will be an actual audience problem. It may be something that we run into everyday and ignore. There are things like this that we just don’t notice on the movie screen as well – for example, what is seen as a circle if you are in a center seat takes the shape of an ellipse if you are over to the side. But the human visual system compensates for this with ease – you see it but you ignore it…except for stereoscopic movies, where the brain ‘sees’ an ellipse, and just adds that to the pile of straw waiting to get too heavy…bringing headaches and dissatisfied customers…force over subtlety yet again.

New Audio Systems – The attempt for same sound with different structures

Now, with increased computational power and the desire to immerse the audience with ‘natural’ sound, the audio world has entered the realm of (attempting) the creation of an equivalent set of combined sounds taking different presentation positions (the Object of object-based audio essence–OBAE) while attempting to create the same sound regardless of different variables – an audio metamer for want of a better term. The new Object-based audio systems presume that they can dial in a particular set of numbers to get a different arrangement of speakers to act just like another…across different systems with different crossovers and spectral response.

Good luck with that. The term of art is: to be subjectively consistent, making best use of the available resources.

Lest this progress be decried as just another manufacturer’s method of raking over the audience to get more money…or the exhibitor’s money since better audio doesn’t really have a ‘return from end-user’ built into the business model…directors are also pushing for this change, since it is the logical extension of what we all imagined audio could be back in our teen-age, garage-band, more-speakers-in-the-car days.

But that isn’t what we are here to write about. Our topic has to do with the many and several ways to achieve KAVI-based bliss when using the SMPTE Committee site. That is the true -mer, sharing knowledge (or in the case of your author here, only sharing time since he all too often finds himself as the dullest crayon in the room during these engineering meetings.) But getting into the process of using the SMPTE website needs some explaining for the novice. This may be the first of many tutorials.

Soon (hopefully, and relatively) there will be pictures and arrows here, with tips from good/better/best people making comments on this article. Because everyone has met this problem, not only learning how to guide themselves through the login and the disappearing Record My Attendance and the Please Vote emails with cryptic messages.

{mp4 width=”660″ height=”400″}smpte_1{/mp4}

Societies

SMPTE’s Metamers

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but takes different meanings depending on the many different possible viewpoints. One group will use the word to mean that two articles of clothing can look identical under the lighting of the store, but will look wildly different in the light of the bedroom. It is also metamerism that allows what looks one way on the screen in RGB to look similar when printed with CMYK inks. It is also used in the controlled tests of the lab when a person is asked to mix 3 colors in order to match a target color – in fact, it was similar tests that the then young International Commission on Illumination (the CIE) used to proof the tri-stimulus system and to come up with the various color models that we are familiar with (think horseshoe).

SMPTE Screen for Committee Work

Metamers are in the news because of laser light replacing xenon, and, like the always present but exacerbated ‘speckle’ is something that heretofore sloppy but lucky implementations were able to hide – not that the engineers were sloppy, but the technology was so ‘force over subtlety’ that the age didn’t allow any better. Unlike speckle, no one knows for certain whether metamers will be an actual audience problem. It may be something that we run into everyday and ignore. There are things like this that we just don’t notice on the movie screen as well – for example, what is seen as a circle if you are in a center seat takes the shape of an ellipse if you are over to the side. But the human visual system compensates for this with ease – you see it but you ignore it…except for stereoscopic movies, where the brain ‘sees’ an ellipse, and just adds that to the pile of straw waiting to get too heavy…bringing headaches and dissatisfied customers…force over subtlety yet again.

New Audio Systems – The attempt for same sound with different structures

Now, with increased computational power and the desire to immerse the audience with ‘natural’ sound, the audio world has entered the realm of (attempting) the creation of an equivalent set of combined sounds taking different presentation positions (the Object of object-based audio essence–OBAE) while attempting to create the same sound regardless of different variables – an audio metamer for want of a better term. The new Object-based audio systems presume that they can dial in a particular set of numbers to get a different arrangement of speakers to act just like another…across different systems with different crossovers and spectral response.

Good luck with that. The term of art is: to be subjectively consistent, making best use of the available resources.

Lest this progress be decried as just another manufacturer’s method of raking over the audience to get more money…or the exhibitor’s money since better audio doesn’t really have a ‘return from end-user’ built into the business model…directors are also pushing for this change, since it is the logical extension of what we all imagined audio could be back in our teen-age, garage-band, more-speakers-in-the-car days.

But that isn’t what we are here to write about. Our topic has to do with the many and several ways to achieve KAVI-based bliss when using the SMPTE Committee site. That is the true -mer, sharing knowledge (or in the case of your author here, only sharing time since he all too often finds himself as the dullest crayon in the room during these engineering meetings.) But getting into the process of using the SMPTE website needs some explaining for the novice. This may be the first of many tutorials.

Soon (hopefully, and relatively) there will be pictures and arrows here, with tips from good/better/best people making comments on this article. Because everyone has met this problem, not only learning how to guide themselves through the login and the disappearing Record My Attendance and the Please Vote emails with cryptic messages.

{mp4 width=”660″ height=”400″}smpte_1{/mp4}

Technique Bin

[Update] QC the Screen – Harkness Webinar

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Harkness calls it “Screen Lifecycle Management” and they feel that they have the apps to help with that.

“Anything to help Quality Control” is what we call it: Free Webinar 26th February 2014

SCREEN LIFECYCLE MANAGEMENT WITH THE HARKNESS APPS – WEB SEMINAR

The only thing better is if you and they were to join the SMPTE Study Groups that are working on Light and Audio Quality. Join Now.

Technique Bin

[Update] QC the Screen – Harkness Webinar

Leave a comment

Harkness calls it “Screen Lifecycle Management” and they feel that they have the apps to help with that.

“Anything to help Quality Control” is what we call it: Free Webinar 26th February 2014

SCREEN LIFECYCLE MANAGEMENT WITH THE HARKNESS APPS – WEB SEMINAR

The only thing better is if you and they were to join the SMPTE Study Groups that are working on Light and Audio Quality. Join Now.

Video Processing

BT.1886 Q&A – SpectraCal

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When extended band-width in video is discussed, BT.1886 gets mentioned. What is it?

SpectraCal has a nice whitepaper on the subject.

Lest there be any confusion, SMPTE specifies a gamut, so this is not going to be in the DCI projector for movies for a while. But some clever cable box or satellite group might use it to make the darks better in an alternative content feed, for example.

10 Questions, 10 Answers – BT.1886

Video Processing

BT.1886 Q&A – SpectraCal

Leave a comment

When extended band-width in video is discussed, BT.1886 gets mentioned. What is it?

SpectraCal has a nice whitepaper on the subject.

Lest there be any confusion, SMPTE specifies a gamut, so this is not going to be in the DCI projector for movies for a while. But some clever cable box or satellite group might use it to make the darks better in an alternative content feed, for example.

10 Questions, 10 Answers – BT.1886

In the News

[Update] iPhones and Flash – Urgent Updates

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25 Feb–OSX Security Update Available…do it now.  [End Update]

Did you update your Flash at the last emergency? when was that…ah~! less than 3 weeks ago.

The emergencies never cease for this decaying corpse. It is possible to live without Flash. Standards exist and are being implemented. It does not belong on your work systems, period. Adobe, Microsoft Push Fixes For 0-Day Threats — Krebs on Security

Meanwhile, on the Apple front.

DCinema is full of encrypted data, and it was in this arena that the iPhone had a flaw. It is suspected that the Mac OS has a similar flaw. Some wonder whether this has been an intentionally placed back-door, but there is no evidence of that. There is a lesson though: Code must be tested publicly. SSL flaws have been written about for the last few years, even on an amateur site like this one.

iOS Update Quashes Dangerous SSL Bug — Krebs on Security

In the News

[Update] iPhones and Flash – Urgent Updates

Leave a comment

25 Feb–OSX Security Update Available…do it now.  [End Update]

Did you update your Flash at the last emergency? when was that…ah~! less than 3 weeks ago.

The emergencies never cease for this decaying corpse. It is possible to live without Flash. Standards exist and are being implemented. It does not belong on your work systems, period. Adobe, Microsoft Push Fixes For 0-Day Threats — Krebs on Security

Meanwhile, on the Apple front.

DCinema is full of encrypted data, and it was in this arena that the iPhone had a flaw. It is suspected that the Mac OS has a similar flaw. Some wonder whether this has been an intentionally placed back-door, but there is no evidence of that. There is a lesson though: Code must be tested publicly. SSL flaws have been written about for the last few years, even on an amateur site like this one.

iOS Update Quashes Dangerous SSL Bug — Krebs on Security

White Papers HI/VI

Cinema Accessibility to Inclusion – A White Paper

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Cultures and technologies advance, not always simultaneously nor without mess excitement interesting times.

This white paper describes the film to digital transition with focus on the evolution of equipment that assists the deaf, blind, hard of hearing and partially sighted cinema patron. It includes the background cultural and legal trends in Australia, England, and the United States. It includes an Equipment Table for Closed Captions and Assisted Listening Equipment.

Please address any questions or comments to the editor of DCinemaTools, C J Flynn, who is responsible for the contents of this document.

Accessibility to Inclusion in Cinema – White Paper