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DVI vs MIDI: What Makes a good standard?

January 17, 2021

phenixnuner

In technology the same goals can be achieved in many different ways. There is a near infinite possible ways to communication between two devices. All you need to do is look to the past to see how many different keyboard and mouse connectors existed. We currently live in a unique time when you can just walk into almost any retailer buy a computer, a random computer keyboard, a random musical keyboard and a whatever computer mouse they are most likely going to work with each other. This capability to connect two random devices is the result of good and robust standards. In this article I am going to discuss two standard MIDI and DVI. MIDI is the undisputed greatest digital communication standard ever invented. DVI is a failure of a standard that even now is unable to live up to the goals it set out to achieve in its standardization.

What do these standards do?

Here is a snippet from “The Complete MIDI 1.0 Detailed Specification Revision 96.1” which explains the purpose of midi.

“The Musical Instrument Digital Interface (MIDI) protocol provides a standardized and efficient means of conveying musical performance information as electronic data.”

The Complete MIDI 1.0 Detailed Specification Revision 96.1

Musical performance information is a very broad term, because this information can include volume level, timing between equipment and even custom messages that can contain anything the user wants.

Midi Cable

DVI is explained in a snippet from “Digital Visual Interface Revision 1.0” which was released 02 April 1999.

“The Digital Visual Interface (hereinafter DVI) specification provides a high-speed digital connection for visual data types that is display technology independent. The interface is primarily focused at providing a connection between a computer and its display device.”

Digital Visual Interface Revision 1.0

DVI supports analog video in some form factors so its own description is not quite right.

What did they set out to do?

To determine if a standard is successful we need to know what each standard was trying to achieve. To start we will look at what DVI was trying to achieve.

Another snippet explaining the goals from “Digital Visual Interface Revision 1.0”

The DVI interface enables:

  • Content to remain in the lossless digital domain from creation to consumption
  • Display technology independence
  • Plug and play through hot plug detection, EDID and DDC2B
  • Digital and Analog support in a single connector

Now for understanding the goals of MIDI we need to look at the document that inspired MIDI a paper presented at the 70th AES convention. The proposal written by Dave Smith and Chet Wood of Sequential Circuits for what was then dubbed “The ‘USI’ , Or Universal Synthesizer Interface” along with comments from others in the industry would evolve into MIDI.

“The Universal Synthesizer Interface is a specification designed to enable inter-connecting synthesizers, sequencers and home computers with an industry-wide standard interface.”

“Expandability – The interface is designed to be expandable. …. A status byte extension capability is provided.”

The ‘USI’ , Or Universal Synthesizer Interface

This means that you can make a new special code for a expanded functionality on MIDI. Also, a very important thing about MIDI is the device only responds to status bytes (messages types) it understands and ignores the rest. Which mean you can implement a new version of MIDI without worrying about causing glitches in older devices.

What makes a standard successful?

The success of a standard will be judged by the following criteria.

  1. Does the standard achieve the goals of its development?
  2. Does the standard have longevity?
    1. How long was in common usage?
    2. Are products still sold today using the standard ?
    3. Does it still exist in compatible revisions (eg. USB-C is not physically compatible with USB A but, is electrically compatible so that with a simple passive adapter you to connect a USB A to USB-C). This revision cannot be developed by an standards body that was independent of the original standards body.
  3. Does the standard provide easily accessible and affordable documentation?

When is a standard super seceded?

So lets quickly discuss why a standard gets super seceded even after achieving adoption and could be considered successful. The standard could lose market share, because it is implemented poorly, it is expensive to implement, it does meet design goals and finally it does not evolve with the application.

So lets start with MIDI does it meet design goals

  1. Enable inter-connecting synthesizers, sequencers and home computers with an industry-wide standard interface
  2. Expandability

We can see from the 8-bit guy’s video on the Roland MT-32 MIDI sound module that it was used to create music in early computer games and that computers where capable of sequencing of MIDI. Atari consider MIDI so important it was installed by default on their computers. These facts alone show that it achieved its first goal.

Yamaha DX7

Now its second goal expandability the example I give of this is the first commercially successful digital synthesizer the Yamaha DX7. A video YouTuber—AudioPilz—in his Bad Gear series covered this synthesizer. It had a difficult programming interface, but could be controlled by using third-party editor programs. Literally the only feature that cannot be controlled by MIDI on the Yamaha DX7 is the power switch. I found this out by skimming the manual for the Yamaha DX7 on a Website called DX7 SYSEX. SYSEX is how the DX7 manages it audio presets and how MIDI expansion is implemented. SYSEX is stand for System Exclusive message which described in “The Complete MIDI 1.0 Detailed Specification Revision 96.1” as


“System Exclusive Messages System Exclusive messages may be used to send data such as patch parameters or sample data between MIDI devices. Manufacturers of MIDI equipment may define their own formats for System Exclusive data. Manufacturers are granted unique identification (ID) numbers by the MMA or the JMSC, and the manufacturer ID number is included as part of the System Exclusive message. The manufacturers ID is followed by any number of data bytes, and the data transmission is terminated with the EOX message. Manufacturers are required to publish the details of their System Exclusive data formats, and other manufacturers may freely utilize these formats, provided that they do not alter or utilize the format in a way which conflicts with the original manufacturers specifications.

Certain System Exclusive ID numbers are reserved for special protocols. Among these are the MIDI Sample Dump Standard, which is a System Exclusive data format defined in the MIDI specification for the transmission of sample data between MIDI devices, as well as MIDI Show Control and MIDI Machine Control.”

The Complete MIDI 1.0 Detailed Specification Revision 96.1

To Long; Didn’t Read (TL;DR)

  1. Manufacturers are allowed to send custom MIDI messages when using System Exclusive messages
  2. Manufacturers must use their Manufacturer ID number for their custom messages
  3. Manufacturers must publish their System Exclusive Messages it cannot be secret
  4. Manufacturers must allow other manufacturers to utilize these formats freely (without royalty) ,but they cannot alter their original manufacturers message format.

The beauty of SYSEX expansion method is that MIDI can be expanded without having to issue new revisions or modifying the baseline messaging format. Which means you can run multiple custom SYSEX message formats into a synthesizer that is unaware of these new format’s existence and experience no random misfiring or adverse affects. MIDI clearly met its design goals and has many features that are not discussed.

Does MIDI have longevity? MIDI is still in common usage considering it is nearly impossible to purchase a computer, tablet or cellphone that does not support MIDI suggest that it is in common usage (Supported by Windows, MacOS, Linux, Android and iOS). Considering that a whole industry of MIDI controller and keyboard exist it definitely still sold today meeting the second condition of a longevity. Also the standard has released its first ever revision of version 2.0 which was released January of 2020 expanding the capabilities while maintaining backwards compatibility. MIDI documentation is freely available to anyone who creates a registered account with the MIDI association. Clearly MIDI is a successful standard that is willing and able to evolve with user use cases and is easy enough to implement that people have been implementing it for decades.

MIDI 2.0 Standard Diagram

Now Lets discuss DVI first does DVI achieve the goals of its development. First lets see its goals

The DVI interface enables:

  1. Content to remain in the lossless digital domain from creation to consumption
  2. Display technology independence
  3. Plug and play through hot plug detection, EDID and DDC2B
  4. Digital and Analog support in a single connector

DVI manages to achieve goals one through three flawlessly but, fails at the fourth goals which means it fails it objective. The reason it fails is because not every cable is able to achieve this performance. The DVI working group decided to spread these capabilities across five cables (there is only one midi cable).

DVI-A – it is a fully analog VGA compatible DVI cable. So it is a funny shaped VGA cable.

DVI-D Single Link – Fully digital but, half the bandwidth of a dual link DVI

DVI-D Dual Link – Fully digital and can achieve the maximum bandwidth of the DVI specification.

DVI-I Single Link – Analog and digital but, only supports half of the maximum bandwidth of the digital DVI section

DVI-I Dual Link – Analog and full digital bandwidth

There should of only ever been Dual link DVI-I cables this meets the design goals and is less confusing for consumers. This cable would have been more expensive but, cost is controlled by difficulty of manufacturing and number of units made. Less units are made when you have five different types of cables. We can see this in terms of cost on Monoprice for a 6ft VGA cable, a Dual link DVI-I and an HDMI 2.0 cable. The VGA cable was the cheapest at $4.09 USD . The HDMI 2.0 cable cost $6.99 USD and the dual link DVI-I was the most expensive at $9.15 USD. The HMDI 2.0 supports higher resolution and refresh rates than DVI but, cost less showing the benefits of economies of scale.

The longevity of a standard is how long it was in common usage. We can answer this question with an Intel press release which said AMD would remove DVI-I in 2015 and hinted at that Displayport would allow the features of the future. So lets say 1999-2015. Are products still being sold using the standard lets check the top 10 best selling products on Amazon & Bestbuy.

Acer SB220Q Monitor the most popular monitor on Amazon
AbbreviationResolution
FHD1920×1080
QHD2560×1440
UHD3840×2160
Table explaining the monitor abbreviation

Example FHD@75HZ -1920×1080 at 75Hz


Amazon Best Seller
1Acer SB220Q FHD@75Hz (HDMI & VGA)
2HP 24mh FHD@60Hz (Displayport,HDMI & VGA)
3Sceptre E205W-16003R -FHD@60Hz (HDMI & VGA)
4Sceptre C275W-1920RN FHD@75Hz (HDMI & VGA)
5HP VH240a FHD@60Hz (VGA & HDMI)
6Asus VG248QG FHD@165Hz (HDMI,DVI-D & Displayport)
7LG 27GL83A-B 1 QHD@144Hz (Displayport & HDMI)
8Dell SE2719H FHD@60Hz (HDMI & VGA)
9AOC C24G1 FHD@144Hz (HDMI, Displayport, DVI & VGA)
10Ben Q GW2480 FHD@60Hz (VGA,HDMI & Displayport)
Best Selling Monitor on Amazon access on January 2 at 4pm
Bestbuy Best Seller
1HP 6XJ00AA#ABA FHD@60Hz (HDMI & VGA)
2LG 24ML44B-B FHD@75Hz (HDMI & VGA)
3Lenovo Q24i-10 FHD@75Hz (HDMI & VGA)
4Dell S2319NX FHD@60Hz (HDMI & VGA)
5HP X24ih FHD@144Hz (HDMI & Displayport)
6HP V21 FHD@60Hz (HDMI & VGA)
7Acer K242HQL FHD@60Hz (DVI,HDMI & VGA)
8HP OMEN QHD@165Hz (Displayport & HDMI)
9Samsung UR55 UHD@60Hz (HDMI & Displayport)
10LG 27GN850-B QHD@144Hz (HDMI & Displayport)
Best Selling Monitors on Bestbuy Access on January 2 at 4pm

Seven of the twenty monitors would not have been able to hit their refresh rate targets using DVI. However, their is no resolution that DVI could not achieve in best selling monitor. The rest of the monitors normally would have a combination of HDMI and VGA which could of easily been driven from a single Dual link DVI-I port on the back of the monitor. For 65% of the best selling monitors on each website a single Dual link DVI-I port would work with no loss in capability. DVI also appeared on some of these monitors which seems pointless considering HDMI can handle a DVI-D signal. No revisions of DVI exist because, the standard body no longer exist and the website is not even up. In an HP white paper from March 2011 title “An Overview of Current Display Interfaces” the body was defunct and had not met since 2006. This meant that they could never adopt apple’s Mini DVI like Mini display port was made a standard. Also HDMI is not a continuation of DVI because, it was not released by the same standards body. According to the same HP white paper as quoted below.

“ After the DDWG failed to agree on a specification for a consumer version of the DVI specification, Silicon Image formed a new consortium to develop a digital interface specifically for the consumer TV market, this time with six leading CE companies. The result was the High Definition Multimedia Interface, or HDMI.”

“An Overview of Current Display Interfaces” by HP

As, the website is not up I am not able to tell the standards cost or distribution or any known funding model. DVI is a failure because, it did not accomplish its goal in most cases and did not adapt to the needs of the application.

Who is the standards body?

An important part of a successful standard is not just well thought out technical details, but ways to maintain and update standards. Standards like DVI where superseded because, they where never maintained or updated. To understand what makes a good standards body we must look at the difference between MIDI Manufacturers Association (MMA)/ MIDI Association and Digital Display Working Group (DDWG) .

We will start with the MIDI Association which has a clear financing model. Corporate members pay to support the organization and get to input into the future MIDI standards and branding. The MMA does not have different tiers of corporate membership everyone pays a fee based on yearly sales and is an equal member. The MIDI Associate also has an individual membership which is free and allows user to get standards for free but, does allow them to supply any input.

DDWG Logo

As far as I can tell the DDWG does not have a way for anyone to apply to join the organization. You were allowed to join the DDWG Implementer forum (DDWG-IF). The DDWG-IF has two membership tiers Promoters which are made up of the founding members and Adopter which is anyone who joins the DDWG-IF. Their is no way to become a promoter according to “DIGITAL VISUAL INTERFACE SPECIFICATION REVISION 1.0 ADOPTER’S AGREEMENT”. The agreement also needs the sign off from a promoter. Joining the DDWG-IF does not give you any right to influence or change the standard. The only people who could change the standard appear to be the Promoters. This is very different from the MIDI Associate which is probably the reason that only the initial version of the standard was released. Since adopters where not allowed to provide any input and where “Not Partners” as stated in the adopter agreements. The other problem with this approach is DDWG does not have any administrative authority.

“While the Promoters may select an entity to handle certain administrative tasks for them, no party is authorized to make any commitment on behalf of all or any of them.”


Except from DIGITAL VISUAL INTERFACE SPECIFICATION REVISION 1.0 ADOPTER’S AGREEMENT

So then is authorized to implement a revise DVI standard in the first place? Also, DDWG did not even process memberships they had Promoters (founding members) process memberships. As an adopter you do pay a membership fee, but what these funds do is very unclear.

Why you should care!

You should care, because bad standards do not die! You can still buy computer monitors with DVI connections even when a standards body doesn’t exist. As much as I trashed DVI when HDMI was in developed DVI was the basis. DVI was a standard with no user feedback and many of the problems with HDMI inevitably come from this problem. Standards get rolled into each other and become new standards.

DVI is by far not the worst standard in existence some successful standards are written to advantage and/or require you to use a specific companies products. DVD-Video is a prime example of biased standards. This fact can be demonstrated by the archive of “DVD FAQ” of videodiscovery.

A disc can have up to 8 audio tracks (streams). Each track can be in one of three formats:

  • Dolby Digital (AC-3): 1 to 5.1 channels
  • MPEG-2 audio: 1 to 5.1 or 7.1 channels
  • PCM: 1 to 8 channels.

Two additional optional formats are supported: DTS and SDDS. Both require external decoders.

The “.1” refers to a low-frequency effects (LFE) channel that connects to a subwoofer.

Discs containing 525/60 (NTSC) video must use PCM or Dolby Digital on at least one track. Discs containing 625/50 (PAL) video must use PCM or MPEG-2 audio on at least one track. Additional tracks may be in any format. Many MPEG-2 discs include Dolby Digital.

For the case of the North American NTSC Disc one of the required tracks was Dolby Digital meaning to be compliant with the standard you had to include a Dolby Decoder while you did not have to include a decoder for the competing standards DTS or SDDS. It is also mentioned that many MPEG-2 Disc had Dolby Digital tracks as well. This gives Dolby a massive advantage over its competitors since it mandatory or effectively mandatory in most cases. Dolby’s competitors are now expensive questionable additions on a player.

If you are a product designer or a customer who want to have choice in what they buy then you care about standards. If you want new cutting edge features then you care about standards. Some features can not be added without violating standards. The future direction of technology depends on good standards that allow for growth and creative approaches to problem solving.

See Also

Sources

  1. The Complete MIDI 1.0 Detailed Specification version 96.1 third revision
  2. Digital Visual Interface DVI revision 1 released 02 april 1999
  3. “The ‘USI’ or Universal Synthesizer Interface” by Dave Smith and Chet Wood
  4. The Best Sound for MS-DOS Games – Roland MT-32
  5. Bad Gear – Yamaha DX7 – Synth Of Fear???
  6. Manual for DX7 with midi format documentation access from dxsysex
  7. MIDI Support by OS
    1. Android
    2. MacOS
    3. Linux
    4. Windows
  8. Details about MIDI 2.0™, MIDI-CI, Profiles and Property Exchange
  9. Monoprice access Jan2 2021 at 3:36Pm EST products numbers: 614, 85 & 3992
  10. Leading PC Companies Move to All Digital Display Technology, Phasing out Analog (an Intel press release)
  11. “An Overview of Current Display Interfaces” (an HP white paper) released March 2011
  12. About page on midi.org access jan 3 2021
  13. http://www.ddwg.org/jointheif.asp wayback archive from july 2012
  14. http://www.ddwg.org/lib/DDWG_Adopters_Agreement.pdf wayback archive from march 17 2012
  15. http://www.videodiscovery.com/vdyweb/dvd/dvdfaq.html wayback archive from march 29 1997

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