Wireless transmission of a high-quality multimedia signal from a head unit to a device (TV, projector, streaming player, etc.) is exactly what the term Miracast hides. This technology is a natural market reaction to the "closed" smart products of Apple and Intel, that is, it inherits the principles of AirPlay and WiDi, but is subject to 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. An intermediary router does not participate in the translation process - the sender and recipient communicate directly.
Miracast. What is this miracle?
The exclusive right to the trademark (full name of the brand is 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: “Ensure the outputmedia 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 a "smart" device (provided that the OS supports the Miracast standard) can synchronize their device with a TV / projector and work with a large-scale image without installing additional software.
Basic Features
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 connected device (if there is no internal location of the hardware), replaces part of the home network and builds a conditional bridge with broadcaster. Moreover, the signal of the ITU-T H.264 format is considered here not as a method of exchanging files, but as a mechanism for capsular transportation of a media packet (graphics are sent and received as they are).
At the time of the presentation of Miracast (that this happened exactly in September 2012 is not an accident: in less than 2 months 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 audio standards include two-channel LPCM, "stereo 5.1" AC3 and ACC.
More about the connection process
Step by stepactivating the Miracast option (which is probably already clear) involves several steps. You need to act in this order:
- Turn on PC/Smartphone/PDA.
- Turn on data receiver (TV or presentation screen).
- Link both devices with the corresponding pre-installed program.
Select and run a specific file in the media display copy mode on the recipient's monitor.
The intermediary router does not take part in such “negotiations”: two devices form a direct secure channel, through which the broadcast subsequently takes place. In simple terms, Miracast (there is no doubt today that this technological direction as a type of work with photo and video information will be more popular than a traditional HDMI gateway) is an architectural add-on over Wi-Fi Direct of later versions (3.50 and older). The applied H.264 compression format allows you to recreate an exact copy of data elements on any atypical visualizer, including a projection screen.
Benefits for everyone
Even an inexperienced user will offhand name several reasons for the demand for Miracast. Firstly, we are talking about operational comfort: devices detect each other “over the air”, and identification takes place in a matter of seconds, and interaction takes place without intermediaries (there is no need to purchase a connecting cable). Secondly, the removable Miracast adapter is so automated that optional adjustments fora specific device model is not needed - the dongle itself recognizes the sender / recipient of graphic information. In addition, there is 3D support against the backdrop of full security of the broadcast content.
Other benefits include:
- 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 fully apply to budget gadget models);
- possibility to transfer "heavy" video (FullHD);
- minimization of additional processes (excessive load on the smartphone/tablet battery is excluded).
Miracast and its weaknesses
Unfortunately, in the world of highly intelligent technologies, the wording "without flaws" is almost never found. The fact that the current version of Miracast (Android, it must be said, is only one of many operating systems that have linked their fate with this standard, but in the segment of mobile shells its dominance is beyond doubt) is imperfect, evidenced by:
- still poor compatibility (sometimes the status "Pending connection…" is displayed on device screens, but the recognition operation does not find a logical continuation);
- Max resolution support at 1920x1200 as demand for 4K grows;
- using proprietary H.264 codec;
- exorbitant degree of disguise of products with software on boardand "iron" 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 a Miracast gadget, the normal Wi-Fi connection is blocked. And, as you know, not all smartphones and tablets are equipped with a 2-channel adapter (there is a shortage even in the premium segment). And, finally, the dynamics: 30 FPS and 720x480 are very modest figures today, but with weak processors, even they sometimes do not find understanding on the part of the visualizer (on the big screen, the video goes with noticeable jerks).
Analogues and their fundamental differences
Miracast friendly operating systems are Android (since version 4.2 Jelly Bean), Windows 8.1 (desktop and portable) 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 cannot guarantee a normal dialogue between the sender and recipient of media content. Representatives of the Apple lineup do not perceive Miracast at all, as they are "sharpened" for the original AirPlay platform 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 change radically.
There are only two wired analogues - MHL and HDMI. Of the obvious differences, it is worth notingthe 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 manufacturers
Although the technology is open source, its wireless image transmission algorithms are primarily focused on the potential of Windows OS and Android OS. Therefore, it is not surprising that the list of manufacturers keeping up with the times includes several hundred positions. True, there are also unpleasant system exceptions associated with updating the control shell. So, in particular, Miracast did not find support for Windows 7 (moreover, the problem could not be solved either with the help of author's assemblies or by installing auxiliary software).
The most recognizable brands seen "in love" with Wi-Fi Direct and H.264:
- Qualcomm.
- MediaTek.
- AMD.
- Microsoft.
- Intel.
Near future from Miracast's position
The idea of wireless HDMI is certainly interesting. However, displaying information from a smartphone or tablet on a huge screen is not so difficult. Much more troublesome is to find a worthy alternative to the SMARTs protocols. And in this regard, Miracast is just not going smoothly.
Besides, 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 same details in the transmitted stream). Secondan 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 / movement sensor of the source device (full conjugation is promised in new firmware; then the "asleep" smartphone will learn to turn off the projection screen without additional user commands).
Now regarding the parallels with DLNA technology. Miracast is a "straight-line" way: broadcasting a "live" picture from the gadget's screen to another monitor occurs according to the shortest algorithm and without auxiliary communication nodes. Under the abbreviation DLNA, there is a whole combination of various 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 on a mirror principle (“what I show is what 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 about 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 updated from the "seven" - is among the minimum requirements. In addition, the applicability of the broadcast standard to RT 8.1 and later OS builds has been announced.
Preparing your computer/gadget for wirelessbroadcasting media content to a third-party monitor
For a device with a G8 on board, the list of actions that ensure the broadcasting process comes down to two points:
- Synchronization of devices (transmitter and receiver) in the signal coverage area.
- Activation of the "Projector" option.
Moreover, there are several scenarios for displaying content. Picture/video can be:
- broadcast in duplicate mode (simultaneous display on 2 displays);
- render only on the monitor of the receiving device;
- transfer by dragging the desired 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. The engineers of 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 left the factory assembly line before 2012 got support from Miracast. The technical solution was special HDMI-keys (signal adapters). At the moment, dozens of different companies are engaged in their manufacture. As a result, products entering the market vary greatly in price and quality. Moreover, there is also a functional imbalance: one adapter canto build "bridges" only within the Miracast standard, it costs nothing for others to find a "common language" with Apple devices or establish a "dialogue" over DLNA. That is why it is so important to study thematic forums and visit the official websites of manufacturers before buying.
Summary of the most popular dongles
Prices for Miracast Dongle range from 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. This is a direct connection that allows you to play "massive" video in 1920x1200 format.
Mocreo Dongle (30-35 c.u.) – support for three protocols is guaranteed: Miracast, AirPlay and DLNA.
Pythons brand "Keys" ($70-$80) generally recognize the same standards as Mocreo.
GeekBuying adapter (50-60 USD) – provides mirroring via Miracast and DNLA algorithms.
In addition, original Wi-Fi Certified Miracast dongles are on sale, sharpened for one type of signal.
