Miracast - what is it? Wireless multimedia transmission

Wireless transmission of high-qualitymultimedia signal from the head device to a certain device (TV, projector, streaming player, etc.) - this is exactly what is hidden behind the term Miracast. This technology is a natural reaction of the market to the "closed" intellectual products of Apple and Intel, that is, it inherits the principles of AirPlay and WiDi, but at the same time obeys somewhat different functional algorithms. The standard is based on the capabilities of Wi-Fi Direct. Therefore, the path of information from the carrier to the visualizer is limited to two points. The router-mediator does not participate in the translation process - the sender and the recipient communicate directly.

Miracast. What is this miracle?

The exclusive right to a trademark (fullthe brand name - Wi-Fi Certified Miracast) has a Wi-Fi Alliance. However, there are no special logos or abbreviations for marking products supporting the technology. The inscription "WiFi Miracast" is usually applied to devices that have passed the certification procedure in accordance with the requirements of the Display test plan.

The primary problem was formulated as follows: "Ensure the withdrawal of media content from a PC monitor or mobile gadget display, to a large screen without resorting to the use of wires and third-party networks." At the same time, special emphasis was placed on the quality of the received signal.

Today, every user of the "smart" device (withprovided that the OS supports the Miracast standard) can synchronize its device with a TV / projector and work with a large-scale image without installing additional software.

Basic Characteristics

The fundamental basis of technology isfunctional algorithms Wi-Fi Direct: Miracast-adapter, which is inserted into the HDMI port of the conjugate device (if not provided for the internal location of the "iron"), replaces a part of the home network and builds a conditional bridge with the broadcaster. And the signal format ITU-T H.264 here is not considered as a way to exchange files, but as a mechanism for capsule transport of a media packet (the graph is sent and received as it is).

At the time of the Miracast presentation (what is itit happened in September 2012 - not by accident: less than 2 months later, the technology was adopted by the updated Android operating system and, accordingly, was applied not only in Google products) there were more than fifty supported permissions: 17 - CEA, 29 - VESA, 12 - the so-called telephone. Among the recognized sound standards are two-channel LPCM, "stereo 5.1" AC3 and ACC.

Learn more about the connection process.

The step-by-step activation of the Miracast option (which is probably already understandable) involves several stages. You need to act in this order:

1. Enable PC / smartphone / PDA.
2. Enable the data receiver (TV or presentation screen).
3. Associate both devices with the appropriate preinstalled program.

Select and run a specific file in the display mode of a copy of the media display on the receiver monitor.

The mediator-router in such "negotiations"Participation does not take: two devices form a direct protected channel, which subsequently transmits. In simple terms, Miracast (which is a technological area like the kind of work with photo and video information will be more popular than the traditional HDMI-gateway, today no longer doubts) is an architectural add-on over Wi-Fi Direct of later versions (3.50 and older). The same H.264 compression format allows you to recreate an exact copy of the date elements on any atypical visualizer, including on the projection screen.

Advantages that everyone will feel

Even an inexperienced user will say by nameseveral reasons for the demand for Miracast. First, we are talking about operational comfort: the devices detect each other "by air", and identification takes place in a matter of seconds, and interaction - without intermediaries (there is no need to purchase a connecting cable). Secondly, the removable Miracast adapter is so automated that optional adjustments to a particular device model are not needed - the dongle itself recognizes the sender / receiver of the graphic information. In addition, there is a support for 3D on the background of full protection of the broadcast content.

Among other advantages:

• the popularity of the described communication standard in the producer community (more than 500 companies are focused on the implementation of "mirror broadcasting");
• no visible delays in signal processing (this rule does not apply to budget gadget models);
• the possibility of transmitting a "heavy" video (FullHD);
• minimization of additional processes (the excessive load on the battery of the smartphone / tablet is excluded).

Miracast and its weaknesses

Unfortunately, in the world of high-intellectualtechnologies, the formulation "without flaws" practically does not occur. The fact that the current version of Miracast (Android, I must say, is only one of many operating systems that linked their destiny with this standard, but in the segment of mobile shells its dominance does not cause doubts) is imperfect, testifies:

• still weak compatibility (sometimes the status "Pending connection ..." is displayed on the device screens, but the recognition operation does not find a logical continuation);
• support for maximum resolution at 1920x1200, while the demand for 4K is growing;
• the use of the proprietary H.264 codec;
• the unlimited degree of disguise of products on board which is present software and hardware for the implementation of technology (no logos on the packaging and / or body of the device).

Also, many users see the inconvenience,that when using the Miracast-gadget, the work of a normal Wi-Fi connection stops. As you know, not all smartphones and tablets are equipped with a 2-channel adapter (deficit is observed even in the segment of premium-class offers). And finally, the dynamics: 30 FPS and 720x480 - very modest indicators for today, but with weak processors, even they sometimes do not find understanding from the visualizer (on the big screen the video goes with noticeable jerks).

Analogues and their fundamental differences

Operating systems that are friendly toMiracast, - Android (since version 4.2 Jelly Bean), Windows 8.1 (for desktop and portable devices) and Amazons Fire. As for a Linux-based PC, it will not be possible to achieve adequate recognition when synchronizing with certified products without hacking. However, huck is fraught with failures and can not guarantee a normal dialogue between the sender and the recipient of media content. Representatives of the same line Apple does not perceive Miracast at all, as they are "sharpened" for the original platform technology AirPlay.

With respect to Intel WiDi, it can be said that thisthe connection standard for a long time was positioned as the property of the corporation of the same name and was not available for gadgets with third-party processors. But with the release of version 3.5, the situation should radically change.

Wired analogs only two - MHL and HDMI. Of the obvious differences, it is worth noting the cable base of the contact, which is not quite convenient with frequent synchronizations, and the stability of the signal during dynamic data exchange (Miracast essentially "sags" when action scenes unfold on the screen).

Miracast in the eyes of producers

Although the technology has an open sourcecode, its algorithms for wireless image transmission are primarily focused on the potential of Windows OS and Android OS. Therefore it is not surprising that the list of manufacturers, keeping pace with the times, has several hundred positions. However, there are also unpleasant system exceptions related to the update of the control shell. So, in particular, did not find support for Miracast Windows 7 (and the problem could not be solved either with the help of author assemblies or the installation of an auxiliary software).

The most recognizable brands, seen "in love" with Wi-Fi Direct and H.264:

• Qualcomm.
• MediaTek.
• AMD.
• Microsoft.
• Intel.

Near future with Miracast position

The idea of ​​creating a wireless HDMI, of course,interesting. However, it is not so difficult to display information on a huge screen from a smartphone or tablet. Where it is troublesome - to find a worthy alternative to the SMARTs protocols. And in this regard, Miracast is just not all smooth.

In addition, direct competitors - AirPlay andChromecast - in some moments behave much "smarter". For example, they allow sending video content to a large monitor and simultaneously navigating through the menu (without showing these very details in the transmitted stream). The second unpleasant nuance concerns the playback mode - Miracast often plays the video to the end, not responding to either the sensor or the commands of the position / movement sensor of the source device (full coupling is promised in new firmware, then the "asleep" smartphone learns to turn off the projection screen without additional commands user).

Now about parallels with DLNA technology. Miracast is a "straight-line way: the live image" from the gadget's screen to another monitor is transmitted by the shortest algorithm and without auxiliary communication nodes. Under the abbreviation DLNA hides a whole combination of different standards. That is, to establish mutual understanding, devices need the presence of an "interpreter" (router). And still: members of Digital Living Network Alliance are able to operate only files, and two "interlocutors" Miracast work on a mirror principle ("what I show, then I transmit"), and when solving some technical difficulties, they can exchange content in optimal synchronization mode.

Miracast Software Compatibility: Windows-based versions

The official Microsoft page contains information on the mandatory operating conditions under which it is possible to get acquainted with the functional package of Miracast technology.

Windows 8.1 - pre-installed or upgraded from the "seven" - is one of the minimum requirements. In addition, it announced the applicability of the broadcasting standard to RT 8.1 and later OS assemblies.

Preparing the computer / gadget for wireless media content transfer to a third-party monitor

For the device with the "eight" on board, the list of actions that ensure the broadcasting process is reduced to two points:

1. Synchronization of the device (transmitter and receiver) located in the range of the signal.
2. Activate the "Projector" option.

And there are several scenarios for displaying content. Picture / video can be:

• broadcast in duplicate mode (simultaneous display on 2 displays);
• visualize only on the monitor of the receiving device;
• transfer by dragging the desired items from the screen to the screen.

Miracast and Android operating system

Many electronics manufacturers are trying to squeeze outmaximum of Miracast technology. LG, for example, integrates it into smartphones and TVs for several years now. Do not fall behind and engineers Sony, Samsung, Panasonic - wherever there is an Android OS older than 4.2, this standard is realized, as they say, to the fullest.

The demand for comfortable content transferled to the fact that support from Miracast got even those TV models that left the factory assembly line before 2012. The technical solution is the special HDMI-keys (signal adapters). At the moment, dozens of different companies are engaged in their manufacture. As a result, products entering the market are seriously different for both price and quality. Moreover, there is also a functional imbalance: one adapter can build bridges only within the standard Miracast, others do not need to find a "common language" with Apple devices or establish a "dialogue" for DLNA. That's why before buying so it is important to study the thematic forums and visit the official websites of manufacturers.

Overview of the most popular dongles

Prices for Miracast Dongle vary within30-100 conventional units. After the purchase and installation of the adapter, almost any TV equipped with an HDMI port can be connected to the gadget via a wireless channel. This is a direct connection, which allows you to play "massive" video in 1920x1200 format.

Dongle Mocreo (30-35 USD) - support for three protocols is guaranteed: Miracast, AirPlay and DLNA.

"Keys" of the Pythons brand (70-80 cu.), As a rule, recognize the same standards as Mocreo.

GeekBuying Adapter (50-60 USD) - provides mirror translation by Miracast and DNLA algorithms.

In addition, the original Wi-Fi Certified Miracast dongles are also on sale for one type of signal.