Wireless transmission of a 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 slightly different functional algorithms. The standard is based on the capabilities of Wi-Fi Direct. Therefore, the path of information from the medium to the visualizer is limited to two points. The intermediary router 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 (full brand name - Wi-Fi Certified Miracast) belongs to the Wi-Fi Alliance. However, there are no special logos or abbreviations for marking products that support 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 task was formulated as follows: "To ensure the output 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." In this case, special emphasis was placed on the quality of the received signal.
Today, each user of a smart device (provided that the OS supports the Miracast standard) can synchronize his device with a 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: a Miracast adapter, which is inserted into the HDMI port of the paired device (if the internal location of the hardware is not provided), replaces a part of the home network and builds a conditional bridge with the broadcaster. Moreover, the signal of the ITU-T H.264 format is considered here not as a way to exchange files, but as a mechanism for capsular transportation of a media package (graphics are sent and received in the form as they are).
At the time of the presentation of Miracast (that this happened exactly in September 2012 - this is not an accident: less than 2 months later the technology was adopted by the updated Android operating system and, accordingly, began to be used not only in Google products), there were more than fifty supported resolutions: 17 - CEA, 29 - VESA, 12 - the so-called telephone. Recognized sound standards include dual-channel LPCM, “stereo 5.1” AC3 and ACC.
Learn more about the connection process.
Step-by-step activation of the Miracast option (what it is, probably, is already clear) involves several steps. You need to act in this order:
- Turn on the PC / smartphone / handheld.
- Turn on the receiver "data (TV or screen for presentations).
- Connect both devices with the corresponding 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 participate in such “negotiations”: two devices form a direct secure channel, through which broadcasting subsequently takes place. In simple terms, Miracast (which is more likely to be more popular than a traditional HDMI gateway as a form of working with photo and video information, is no longer in doubt today) is an architectural add-on over Wi-Fi Direct of recent versions (3.50 and older). The H.264 compression format used allows you to recreate an exact copy of the data elements on any atypical visualizer, including the projection screen.
Benefits that everyone will experience
Even an inexperienced user offhand will name several reasons for the demand for Miracast. Firstly, it is about operational comfort: the devices detect each other “through the air”, and identification takes place in a matter of seconds, and the interaction is without intermediaries (there is no need to purchase a connecting cable). Secondly, the removable Miracast adapter is so automated that optional adjustments for a specific model of the device are not needed - the dongle itself recognizes the sender / receiver of graphic information. In addition, there is 3D support against the background of the complete 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”);
- the absence of visible delays in signal processing (this rule does not fully apply to budget gadget models);
- the ability to transfer "heavy" video (FullHD);
- minimization of additional processes (eliminates excessive load on the battery of the smartphone / tablet).
Miracast and its weaknesses
Unfortunately, in the world of highly intelligent technologies, the phrase “without flaws” is practically never found. The fact that the current version of Miracast (Android, I must say, is only one of many operating systems that have linked their fate with this standard, but its dominance in the mobile shell segment is not in doubt) is imperfect, testifies:
- still weak compatibility (sometimes the status “Waiting for connection ...” is displayed on the device screens, however, the recognition operation does not find a logical continuation);
- support for maximum resolution at 1920x1200, while demand for 4K is growing;
- Application of proprietary H.264 codec;
- prohibitive degree of masking of products on board which there is software and hardware for the implementation of the technology (there are no logos on the package and / or device case).
Also, many users see the inconvenience that when using the Miracast gadget, the usual Wi-Fi connection is stopped. And, as you know, not all smartphones and tablets are equipped with a 2-channel adapter (a deficit is observed even in the premium segment). And finally, the dynamics: 30 FPS and 720x480 are very modest indicators today, but even with weak processors they sometimes do not find understanding on the part of the visualizer (on the big screen the video comes with noticeable jerks).
Analogs and their fundamental differences
Miracast's friendly operating systems are Android (starting with version 4.2 of Jelly Bean), Windows 8.1 (for desktop and portable devices) and Amazons Fire. As for Linux-based PCs, without hacking, adequate recognition will not be possible when synchronizing with certified products. However, huck is fraught with failures and cannot serve as a guarantee of a normal dialogue between the sender and recipient of media content. Representatives of the Apple model range do not perceive Miracast at all, as they are “tuned” to the original platform AirPlay technology.
Regarding Intel WiDi, we can say 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 fundamentally change.
There are only two wired analogues - 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 signal stability during dynamic data exchange (Miracast substantially “sags” when action scenes unfold on the screen).
Miracast in the eyes of manufacturers
Although the technology is open source, its wireless image transfer algorithms are primarily focused on the potential of Windows and Android. Therefore, it is not surprising that the list of manufacturers that keep up with the times has several hundred positions. True, there are unpleasant system exceptions associated with updating the control shell. So, in particular, I did not find support with Miracast Windows 7 (and the problem could not be solved either with the help of author assemblies or the installation of auxiliary software).
The most recognizable brands seen “in love” with Wi-Fi Direct and H.264:
- Qualcomm.
- MediaTek
- AMD
- Microsoft
- Intel
The near future from Miracast
The idea of creating wireless HDMI is certainly interesting. However, displaying information from a smartphone or tablet on a huge screen is not so difficult. It’s much more troublesome to find a worthy alternative to the SMARTs protocols. And in this regard, Miracast is not just going smoothly.
In addition, direct competitors - AirPlay and Chromecast - in some moments behave much smarter. For example, they allow you to send video content to a large monitor and simultaneously navigate 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 either to the sensor or to the commands of the position / motion sensor of the source device (full conjugation is promised in new firmware; then the “sleeping” smartphone will learn to turn off the projection screen without additional commands user).
Now regarding the parallels with DLNA technology. Miracast is the “straightforward path: the translation of the“ live ”picture from the gadget’s screen to another monitor occurs according to 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 a "translator" (router). And one more thing: members of the Digital Living Network Alliance are able to operate only with files, and two Miracast “interlocutors” work according to the 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 versions
The official Microsoft page contains information on the mandatory operating conditions under which it is possible to familiarize yourself with the functional package of Miracast technology.
Windows 8.1 - pre-installed or updated from the "seven" - is one of the minimum requirements. In addition, the applicability of the broadcast standard to RT 8.1 and later OS builds has been announced.
Preparing a computer / gadget for wireless broadcast of media content to a third-party monitor
For a device with an “eight” on board, the list of actions that ensure the broadcasting process is reduced to two points:
- Synchronization of devices (transmitter and receiver) located in the signal coverage area.
- Activate the "Projector" option.
Moreover, there are several scripts for displaying content. Picture / video can:
- broadcast in duplicate mode (simultaneous display on 2 displays);
- visualize only on the monitor of the receiving device;
- transfer by dragging the necessary elements from screen to screen.
Miracast and Android operating system
Many electronics manufacturers are trying to get the most out of Miracast technology. LG, for example, has been integrating it into smartphones and TVs for several years now. Engineers Sony, Samsung, Panasonic are not far behind - wherever there is an Android OS older than 4.2, this standard is implemented, as they say, to its fullest.
The demand for comfortable content transfer has led to the fact that even those TV models that came off the factory assembly line before 2012 got support from Miracast. The technical solution was special HDMI keys (signal adapters). Currently, dozens of different companies are engaged in their manufacture. As a result, the products entering the market vary greatly in price and quality. Moreover, there is also a functional imbalance: some adapters can build “bridges” only inside the Miracast standard, while others do not need to find a “common language” with Apple devices or establish a “DLNA dialogue”. That's why before buying it is so important to study the thematic forums and visit the official websites of manufacturers.
A brief overview of the most popular dongles
Prices for Miracast Dongle vary between 30-100 conventional units. After purchasing and installing the adapter, almost any TV equipped with an HDMI port can be connected to the gadget wirelessly. We are talking about a direct connection that allows you to play "massive" video in the format of 1920x1200.
Mocreo Dongle ($ 30-35) - Support for three protocols is guaranteed: Miracast, AirPlay and DLNA.
"Keys" brand Pythons (70-80 cu), as a rule, recognize the same standards as Mocreo.
GeekBuying adapter (50-60 cu) - provides mirror broadcasting according to Miracast and DNLA algorithms.
In addition, on sale there are original Wi-Fi Certified Miracast dongles, sharpened for one type of signal.