How the DVD format works. video art

BOOKS AND ARTICLES
Free library / Directory / video art

How the DVD Format Works

video art

My task was to evaluate the quality of the reproduction of sound recordings. First, the parameters of the device were measured when operating in the mode of a classic audio CD player. The models differed from each other only in minor details. The frequency response ranged from 20 to 20.000 Hz with a deviation of 0,3 dB. The linearity of the transducers was excellent, and the signal-to-noise ratio was at least 92 dB. When evaluating the linearity of the transducers using a Denon disk reference signal, it turned out that at the lowest levels, the signal path was completely damped. Therefore, at these levels, the signal drops out, and the signal attenuation is accompanied by noise pulsation.

Since the measurement and test discs are in DVD format? recommended by ARA (Acoustics Renaissance for Audio) are not yet available, it remains to conduct a subjective test. With a high recording density, it needs to be processed by another memory block. This necessity is caused by the fact that after loading a CD, the device determines within a few seconds what recording format is available on the disc. In this case, part of the recorded material is copied to the player's memory. Then you can turn on playback mode. Since signal processing in memory takes a relatively long time, you should put up with a slightly slower turn on of all modes. For the purpose of monitoring, the input of a digital-to-analog converter was connected to the digital output. This made it possible to verify once again that:

1) The signal accompanying the image has a sampling rate of 44,1 or 48 kHz, while on a CD it is 96 kHz. according to ARA requirements:

2) the signal coming from the CD is on the digital output in SPDIF format, i.e. it can be further processed using conventional digital-to-analogue converters;

3) When playing audio recorded using the Dolby Digital system, the optical output transmits the signal in PCM AC-3 format, designed for Dolby Digital decoders.

Structurally, both models are very modern. This confirms their weight, which is comparable to that of conventional CD players: most of the drive parts are made of plastic, the electronics are located on three printed circuit boards, and the classic transformer has been replaced by a much lighter switching power supply, which has already become standard for VCRs.

Of the DVD-formatted CDs, the disc recorded in 1996 at the Prague concert hall "Rudolfinum" with works by Antoni Dvořák and Bedřich Smetana seemed the most interesting to me. The interest can be explained by the fact that the recording was made in the most advanced format, which requires ARA as the maximum, i.e. with a sampling rate of 96 kHz and 24-bit conversion. These ARA recommendations regarding the specified sample rate are met when mixing the highest quality recordings, provided that it is done without cables.

Similar requirements apply to the storage and processing of records on matrices. With a sampling rate of 96 kHz, a 16-bit or 24-bit converter can be used (depending on the number of channels and the length of the recording: 1.6 bits = 8 channels = 93 minutes; 24 bits = 2 channels = 182 minutes). The playback of the recorded material was unbeatable. Unfortunately, there was nothing to compare with, the disc was the only one, moreover, there is no similar recording in CD format. However, it can be assumed that DVD recordings will only be made by high-class professionals in studios equipped with the best equipment.

Here, an unambiguous separation of analog and digital signals should occur, and the analog signal will be intended for processing the effects signal. When listening to a DVD disc of recorded movies that has been dubbed at a sampling frequency of 48 kHz. through conventional stereo devices, the listener does not hear the sound, in particular, the average dialogue channel. This sound is largely disproportionate. It is necessary to turn off the TV, the sound part of which works from the same sound signal supplied through the SCART connector, and stubbornly automatically turned on every time a DVD disc is loaded. On the other hand, at a very low level of the reproduced signal, you may notice the penetration of the signal from the TV tuner.

The playback quality, compared to all available video sources, is much more perfect and dynamic, with less distortion. Despite the fact that the players belong to the middle price category, they can not be blamed for anything. The most interesting part of the test, i.e. we unfortunately had to postpone the comparison of playback quality in multi-channel home theater mode until we have a sufficient number of movies recorded using appropriate systems at our disposal.

After that, we will return to the DVD CD players again. Classic CDs in these players are apparently played through the same converter, which is otherwise controlled by software. This is expressed both in its limited linearity (see above) and in its playback quality, which, compared to the best CD players, is still not without some drawbacks. First of all, they should include a softer, not so hard sound of low frequencies, then a noticeable coloration of the upper part of the frequency range, as well as a rather sensitive decrease in dynamics with less precise localization and limitation of the depth of space.

These shortcomings, however, are comparable to those of similar mid-range players ($350 to $520). The first examples of DVD CD players fully confirmed the technical viability of this format. Its commercial distribution will depend mainly on the availability of related software. Otherwise, there is a danger that this format will remain only the fruit of a technical experiment, as happened, for example, with the HDCD format, where there are only 180 storage media and the prospect of expanding this number to 400 titles in the near future.

On the other hand, DVD recordings made in accordance with the ARA recommendations are almost free of flaws, but what studios can provide such conditions?

Author: Miroslav Lobov

We recommend interesting articles Section video art:

▪ Details about all video camera formats

▪ AVerMedia DVD EZ Maker USB Plus

▪ Video editing. Gluing language

See other articles Section video art.

Read and write useful comments on this article.

<< Back

Latest news of science and technology, new electronics:

The existence of an entropy rule for quantum entanglement has been proven 09.05.2024

Quantum mechanics continues to amaze us with its mysterious phenomena and unexpected discoveries. Recently, Bartosz Regula from the RIKEN Center for Quantum Computing and Ludovico Lamy from the University of Amsterdam presented a new discovery that concerns quantum entanglement and its relation to entropy. Quantum entanglement plays an important role in modern quantum information science and technology. However, the complexity of its structure makes understanding and managing it challenging. Regulus and Lamy's discovery shows that quantum entanglement follows an entropy rule similar to that for classical systems. This discovery opens new perspectives in the field of quantum information science and technology, deepening our understanding of quantum entanglement and its connection to thermodynamics. The results of the study indicate the possibility of reversibility of entanglement transformations, which could greatly simplify their use in various quantum technologies. Opening a new rule ... >>

Mini air conditioner Sony Reon Pocket 5 09.05.2024

Summer is a time for relaxation and travel, but often the heat can turn this time into an unbearable torment. Meet a new product from Sony - the Reon Pocket 5 mini-air conditioner, which promises to make summer more comfortable for its users. Sony has introduced a unique device - the Reon Pocket 5 mini-conditioner, which provides body cooling on hot days. With it, users can enjoy coolness anytime, anywhere by simply wearing it around their neck. This mini air conditioner is equipped with automatic adjustment of operating modes, as well as temperature and humidity sensors. Thanks to innovative technologies, Reon Pocket 5 adjusts its operation depending on the user's activity and environmental conditions. Users can easily adjust the temperature using a dedicated mobile app connected via Bluetooth. Additionally, specially designed T-shirts and shorts are available for convenience, to which a mini air conditioner can be attached. The device can oh ... >>

Energy from space for Starship 08.05.2024

Producing solar energy in space is becoming more feasible with the advent of new technologies and the development of space programs. The head of the startup Virtus Solis shared his vision of using SpaceX's Starship to create orbital power plants capable of powering the Earth. Startup Virtus Solis has unveiled an ambitious project to create orbital power plants using SpaceX's Starship. This idea could significantly change the field of solar energy production, making it more accessible and cheaper. The core of the startup's plan is to reduce the cost of launching satellites into space using Starship. This technological breakthrough is expected to make solar energy production in space more competitive with traditional energy sources. Virtual Solis plans to build large photovoltaic panels in orbit, using Starship to deliver the necessary equipment. However, one of the key challenges ... >>

Random news from the Archive

Tidal floods are associated with a special type of slow ocean wave. 11.07.2018

An international team of researchers has found a link between seasonal sea level fluctuations and the long, long ocean-crossing Rossby waves.

This connection could help coastal cities like Miami better anticipate and mitigate the effects of tidal flooding.

"We've known for a long time that sea levels are rising and that there are significant fluctuations across time scales, including seasonal fluctuations that cause tidal flooding in cities like Miami, where they typically occur in late summer or early fall," the engineer said. University of Central Florida Thomas Wahl - We can predict tides and we know what causes sea levels to change seasonally, but we have found that in some years there is much more seasonal variation along the Gulf Coast and in the US than elsewhere, which leads to major flooding and increases the risk of flooding during the hurricane season. These unusually strong seasonal variations have been poorly understood, and the Rossby waves have proven to be the missing element."

Rossby waves, sometimes called planetary waves, are generally associated with the Earth's rotation and move very slowly. Such waves take months or even years to cross the oceans. Tracking them and understanding how they can increase the risk of flooding makes it possible to predict periods of dangerously high tides months in advance, Wahl explained.

"Using this information could help us develop an operational tool that will give home and business owners and city leaders the time they need to prepare and mitigate negative impacts," he added.

According to the National Oceanic and Atmospheric Administration, tidal flooding occurs due to high tides, rising sea levels, land subsidence and loss of natural barriers. The federal agency has determined that such floods cause various public nuisances, such as road closures. The frequency of this type of flood has increased by 100 percent in the US compared to 30 years ago.

Other interesting news:

▪ plastic gold

▪ Self-guided goggles

▪ Positive thinking strengthens the immune system

▪ Photoshop for smartphones

▪ Stove+oven+refrigerator

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ site section Color and music installations. Selection of articles

▪ article Last will be first. Popular expression

▪ article When did the first jewelry start to be worn? Detailed answer

▪ article Measurement of small dimensions without a micrometer. home workshop

▪ article Against telephone pirates. Encyclopedia of radio electronics and electrical engineering

▪ article Car subwoofer. Part 1. Encyclopedia of radio electronics and electrical engineering

Leave your comment on this article:

All languages of this page

Home page | Library | Articles | Website map | Site Reviews