Miracast - what is it? Wireless multimedia transmission

Wireless transmission of high-quality multimedia signal from the head device to a certain device (TV, projector, streaming player, etc.) 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 (the full name of the brand - Wi-Fi Certified Miracast) is the unification of the 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 goal was formulated as follows: "To 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 (provided that the OS supports the Miracast standard) can synchronize its device with the TV / projector and work with a large-scale image without installing additional software.

Basic Characteristics

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

At the time of Miracast's presentation (it was in September 2012, it was not an accident: less than 2 months later, the technology was adopted by the updated Android operating system and, accordingly, was used not only in Google products), there were more than fifty supported resolutions: 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.

Step-by-step activation of the Miracast option (which is probably already understandable) provides for 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's monitor.

The mediator-router does not accept participation in such "negotiations": 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 there is no doubt) 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 on the phone calls several 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 community of manufacturers (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-tech technologies, the formulation "without flaws" practically does not occur. The fact that the current version of Miracast (Android, it should be said, 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 proprietary codec H.264;
• The unlimited degree of disguise of products on board which has software and hardware to implement the technology (no logos on the packaging and / or the case of the device).

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

Concerning Intel WiDi, it can be said that this connection standard has long been 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 very convenient with frequent synchronizations, and the stability of the signal during dynamic data exchange (Miracast significantly "sags" when action scenes unfold on the screen).

Miracast in the eyes of producers

Although the technology is open source, its algorithms for wireless image transmission are primarily focused on the potential of Windows and the 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 systemic exceptions associated with updating 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 is certainly interesting. However, it's 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 just does not go smoothly.

In addition, direct competitors - AirPlay and Chromecast - behave much smarter at certain points. 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 / motion sensor of the source device (full coupling is promised in new firmware, then the "asleep" smartphone will learn to turn off the projection screen without additional commands User).

Now about the parallels with DLNA technology. Miracast is a straight-line way: live images from the gadget screen to another monitor are transmitted by the shortest algorithm and without auxiliary communication nodes. Under the acronym 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 the 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, the applicability of the broadcasting standard to RT 8.1 version and later OS assemblies is announced.

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) in the signal range.
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 the maximum out 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 its fullest.

The demand for a comfortable transfer of content led to the fact that Miracast support even got those TV models that left the factory 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 is why before buying it is so important to study the thematic forums and visit official websites of manufacturers.

Overview of the most popular dongles

Prices for Miracast Dongle vary within the range of 30-100 conventional units. After purchasing and installing 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 that 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" brand Pythons (70-80 cu. E.), Usually 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.