The core technology of HD player is chip decodingprogrammeA good high-definition player can decode multiple formats of multimedia, and its output stream is small. It can be operated on the TV through a remote control to complete video on demand.All high-definition players (machines) can only perform specific video on demand, playback, etc.The definition of playable film and television is4K（3840x2160）、1080P（1920x1080）、720P、1080i、480P(Standard definition）Etc.[1]
HD player is developing towards function integration, which includes local HD playback, network HD playback and other functions.For example, some high-definition players have online high-definition movie and TV on demand, video RSS subscriptionInternet TV, variety entertainment, web browsing, Thunderbolt download, online MTV on-demand, weather forecastVisual broadcasting, local 4K1080PHD play, picture play, etc.
High definition player (machine) mostly refers to hardware equipment, that is, through connecting TV, output high-definition pictures, connectHome cinema systemOutput DTSDolby surround sound effect。Its core technology is embedded general processor+hardware DSPdecoderThe popular solutions are Huawei Hisilicon 3798, Realtek 1185, 1186 (3D)Sigma Design 8643、8671、Amlgic 8726M。
Operating systemLinux、AndroidAndroid and Linux+Android dual systems.
After years of development, Linux has relatively mature technology and supports many file formats, which perfectly solves the problems of Blu ray original disk navigation, next-generation audio source code output, external subtitles and many user-friendly operations.The disadvantage is that the firmware is relatively closed, the interface is non-standard, and the portability is difficult. If users want to add new functions, they must have professional programming knowledge. Sigma Design's firmware is fully encrypted, and the manufacturer has to add functions.
Android system is a popular Android 2.3, 4.0, 5.1 or even Android 7 operating system ported to platform computers and mobile phones. Users can download and install a large number of Android applications by themselves. The interface is standard, and the development of applications is simple with strong portability. The machine will not fail to update because the manufacturer's subsequent development stops.The disadvantage is that the local hard disk play function is relatively weak in the Android environment,Blu ray navigationThe next generation source code output and subtitle attachment functions are not mature. Although the CPU is fast, the software is not stable, and its usability and stability are not as good as those of pure Linux players.With the rapid development of Android system application technology in recent years, some manufacturers have recently completed and released hard disk players that support Blu ray navigation, have powerful local playback functions and complete specifications, such as Egrid's 4K Blu ray navigation hard disk player A5/A10 series products.
Linux+AndroidDual system, local high-definition broadcast and RSS network media use mature Linux system, and the extended function installation application uses Android Android system.This solves the problem of imperfect Android local playback,LinuxThere is a problem with the extension installation application.
The resolution output of high-definition players is not an indicator of the quality of high-definition players. All high-definition players can reach 4K1080PFor true output, the main factors affecting the image quality are the image decoding algorithm and the method of image denoising in the later stage.Relatively speaking, Huawei HiSilicon Hisilicon's image quality is gorgeous and relatively pleasing to users. Sigma Design can provide more delicate image output with higher contrast. Simga Desing's color is lighter, while Realtek's color is brighter. Different chip platforms bring different styles of products to users.All film to digital will be generatedHot PixelEach family also has its own unique secret technology to deal with noise reduction.
In the early days, the network function of high-definition players was just a simple additional function, which could only be used to play movies in the LAN. Since Realtek vigorously improved the network on-demand function, the network on-demand function has overshadowed the most important hard disk playing function of high-definition players.The VOD function is convenient and practical. The most difficult thing for users is to choose a movie they likeDVD playerThe way to buy DVDs is to go to an audio and video store. The legal version is usually more than 15 yuan, which is high in cost. If there are more DVDs to keep and sort, it is also a troublesome thing.The network on-demand function of the high-definition player uses an intuitive way to classify movies, TV dramas, variety shows, animation, etc. After entering, it can also be classified into love, war, history and other types. Users can easily find their favorite movies according to their needs, and also support the intelligent acronym search function.The remote control is used for all operations, and the UI interface is friendly. You can collect movies and continue to watch breakpoints. If you have not watched the last movie, you can continue to watch the last breakpoint by directly pressing Continue.TV series episodes are broadcast continuously. You don't need to select an episode. You can watch it at one go.The on-demand platform on the high-definition player is mainly set up by high-definition enthusiasts themselves. Through a special film collection program, the source address of the film that is publicly played for free on major video websites on the Internet is translated into the address that can be played by the player, and the player can play on-demand.The advantage is that free videos can be seen on the computer and can be seen on the high-definition player. The definition is quite high, reaching1080P。The disadvantage is that it is unofficial maintenance. Once the video website changes the link mode, the high-definition player cannot be seen. The maintenance level of various platforms is different. Some can play, some can not play, and some are stuck in the process of playing, just like buying a "flower disc". The user experience is not good.
In recent years, as the Android platform has become the mainstream operating system platform for high-definition players, it has greatly enriched the network playback function of high-definition players. Now, as long as the high-definition players of the Android operating system are used, users can install various popular APP applications, obtain and watch various online video programs. Of course,These APP applications need to comply with relevant national policies and regulations.
On line on-demand function, National Radio and Television 181 redefined a new name for high-definition player with this function:Internet TVThe set-top box, dominated by the broadcast control platform of the seven major radio and television departments, gathers all major content publishers to replace the original disorderly pirated chain on-demand platform. With the latest authentic film source and the most powerful CDN, it monitors the broadcast 24 hours a day, which not only ensures the continuous updating of content, but also ensures the smooth playing experience of users.With the license dealer as the payment platform, pay certain viewing fees to the license dealer through recharge cards, online banking and various online payment methods.The charging experience is good and the free experience is poor, which has become the consensus of users.
Display effect
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HD movie source, HD playerHD TVAlso, how can I see the clearest picture?
Player output mode corresponds to display device support mode
with4K TVFor example, the clearest state is to let the player output 4K 3840 x 2160 signals to the TV.
Take the 1080P TV as an example, the clearest state is to let the player output 1080P signal to the TV (for the 1366 * 768 HD READY TV, we also recommend to directly input 1080P signal in principle, although the player usually cannot provide 1366 * 768 display format).
Try to avoid artificially reducing the display quality
For example, a 4K movie is played in 1080P output mode, which reduces the image quality artificially.
On the premise that the output mode corresponds to the display mode, the last step is to find a suitable playback source.If it is a 1080P TV, it is naturally the best to play 1080P Blu ray discs, PS3 high-definition games, etc., and then the definition from high to low is720P(such as online movies)1080I(Hong Kong, CCTV HD), 480P (DVD)576I（Standard definitionCable TV).Obviously, even if1080PThe effect of watching cable TV programs on FULLHD TV is also the worst.If you want to really enjoy high-definition TV, you'd better upgrade to high-definition TV as soon as possible.
Product Introduction
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Local on the marketHD on-demandThere are many machines with comprehensive functions and reasonable prices.Basically supported1080PFormat source output,
These high-definition players range from 399 yuan to more than 2000 yuan, which is of course a big difference.At the entry level below 800 yuan, basically popular videos can be decoded and played smoothly.However, I am not satisfied with the color and audio restoration.At the level of 2000 or so.Basically very satisfied!In particular, the images of high-end equipment and fever equipment (such as medium and high-end projection) on the 100 inch screen are quite different.
If you are at the entry level, watch it on a 40-50 inch TV at home.I suggest a machine of about 1000 yuan (excluding hard disk).This level is very cost-effective.I don't recommend 399 or 499.It's really beginner~~Although it can meet the requirements of watching movies.Once you have compared them, you will find that there are shortcomings.It's like having a digital camera for 1000 yuan and a digital camera for 10000 yuan, but the results are different.After years of survival of the fittest, the current mainstream HD players in the market are:Egreat , HiMediaKeborEtc.
Network HD playback can not only play local high-definition video, but also directly demand network video through networking.It is an upgraded product of HD player.At present, it has developed the latest generation of intelligent high-definition broadcaster, joined the Android intelligent system, can connect to the wired network and WIFI, can install various Android software, browse the web, watch TV, watch movies, watch videos online, and chat online, which is equivalent to a tablet computer
HD Player Source
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HD source is very important for HD player. All HD players are around source. Without source, HD player will be useless.
Source size
The capacity of a complete HD movie is more than 1G, and 1G-5GHD filmIn terms of the field, they are all small capacity movies. Generally, the capacity of a complete HD movie is between 10G and 40G, and some even reach more than 100G.generally speakingBlu ray discThe capacity is about 40G, and the source below 40G is edited or compressed.The editing method is to extract the main video, remove the shooting tidbits, and only add some audio tracks, such as 20G or so, only add DTS, AC3 audio tracks, and remove the hugeNext generation track。hold1080PThe resolution of is recompressed to720PThe resolution of only AC3 audio track can effectively reduce the weight of high-definition movies.
Source carrier
Due to the large volume of the film source, the main carrier of the film source isSATA hard diskThe carrying capacity is generally 1T, 1.5T and 2T.
Source acquisition
For the final consumers, there are two main sources of film source: one is to directly go to the seller to spend money to copy, and the other is to find seed downloads on professional websites on the Internet.The dealer of high-definition player will provide the source, as long as you bring it with youmobile hard disk driveJust choose in the past.Online movie sources are generally found in HD professional forums, such as HD video news, where there are many movie sources to choose from.
key word
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Intelligent
Implant in HD playerAndroid system, you can let the high-definition player do something similarMultimedia computerThe same work, such as playing games, downloading software, and even writing a personal blog in front of the TV screen with a remote control through an application program. These are the manifestations of the continuous development and intelligence of high-definition players. Of course, such high-definition players are no longer just digital video devices,HD box or smart box can make it easier for people to understand the development direction of HD player intelligence.
Network function
The key word "network" has attracted considerable attention in the HD industryConcept of Internet of ThingsDriven by, many home appliances have begun to move closer to the network. For example, many flat screen TVs have network functions, which also urges the high-definition player industry to include network functions.Nowadays, many HD manufacturers have been able to support users to watch videos online through the joint video website, and can watch blockbusters without downloading.According to the network, it has produced practical functions such as web browsing, picture browsing, online playing of SWF animation, etc.
Blue ray source compatible
Blu ray disc players have the advantage of supporting major global distributors in terms of film sources.The HD player has the advantages of localization, convenience of hard disk application, and relatively popular price.In the face of consumer demand for Blu ray decoding functions and pressure from Blu ray players, many high-definition player manufacturers have incorporated the compatibility of Blu ray sources into their product development strategies.
Functional integration
Under the background of 3C integration, many household appliances have broken through the limitation of single product function and started to evolve towards interconnection and even functional integration.In the high-definition broadcasting industry, in addition to the functional integration between products with similar functions, the marginal integration of different categories has gradually emerged.For example, many flat-panel TVs have integrated network broadcast and HD decoding functions, while HD players have also integrated network broadcast, TV signal reception and other functionsHTPCIts rich operation performance is close to.
wireless network
With the popularization of the network,wireless networkThe function has become the standard configuration of almost all high-end products, and all kinds of high-definition players have also scrambled to integrate this function, which has also promoted the gradual increase of wireless network transmission speed, and can meet the data transmission needs of high-definition movie playback.
Shanzhai brand
As the early HD product market is in its infancy, there is a large profit margin, and the threshold for the production of HD players is relatively low, so many brands quickly flooded the market, and even there are bad businesses that sell non HD products to consumers by taking advantage of consumers' uncertainty about the concept of "HD", that is, "shanzhai brands".
The "fake HD player" does not support true HD, and its quality is poor and maintenance is difficult. Product complaints frequently occur.HD players are highly technical. If they are "copycat", it will be a disaster for the market and consumers.
When consumers buy, it is best to identify several large domestic high-definition player brands.
usage method
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HD hard disk playerThere are two kinds of built-in hard disk and no built-in hard disk.
First, connect the player to the TV. Both video and audio should be connected. You can useHDMI cable、Ypbpr 、AV cable。The TV is set to video mode.
Built in hard disk
The player can be connected to the computer USB portmobile hard disk driveMode, copy the movie.Then unplug the USB cable and it will become the player mode, which can be played on the TV.
Without built-in hard disk
Turn on the TV and player, connect to the network settings, such asrealplay All players can be connected to the network, and can automatically match the network. Then click the corresponding website or TV station to playHD filmVideo.
Digital TV set-top box is composed ofTuner、QAMDemodulatorTS streaming solutionMultiplexerMPEG-2decoder、PAUNTSCVideo encoderEmbedded CPU system and peripheral interface, CA module and uplink dataModulatorform.The working principle is shown in the attached figure.
The working process of digital TV set-top box is roughly as follows: the tuner receivesHigh frequency signalThe QAM demodulator is used to complete the channel decoding and separate the transmission stream containing audio, video and other data information from the carrier.The transport stream generally includes multiple audio and video streams and some data information.Demultiplexer is used to distinguish different programs, extract corresponding audio, video and data streams, send them to MPEG-2 decoder and corresponding parsing software, and complete the restoration of digital information.For pay TV, conditionsReceiving moduleThe audio and video streams are descrambled, and smart cards with the functions of identifying users and accounting are used to ensure normal viewing by legitimate users.MPEG-2decoderComplete the decompression of audio and video signalsVideo encoderAnd audio D/A conversion to restore analog audio and video signals, display high-quality images on conventional color televisions, and provide multi-channel stereo programs.
Digital TV set-top boxIt is the fusion product of computer and TV in terms of function, but its structure is different from both. From the perspective of signal processing and application operation,Set top boxIt includes the following levels:
(2) Transport layer: including demultiplexing, which divides the transport stream into video, audio and data packets.
(3) Program layer: including MPEG-2 video decoding.MPEG/AC-3 audio decoding.
（4）User layer: including service information, electronic program list,graphical user interface(GUI), browser, remote control, conditional access, data decoding.
(5) Output interface: including sub analog videoaudio interface, digital video and audio interface, data interface, keyboard, mouse, etc.
Digital STBIt reflects the development level of multimedia, computer, data compression coding, scrambling and descrambling algorithm, encryption and decryption algorithm, communication technology and network technology, so the technology content is very high. The key technologies involved are:
(1) Multiplexing and decompression technology: after the analog signal is digitized.The amount of information increases dramatically, and data compression is essential.MPEG-2 video compression standard is widely used in digital TV, which is suitable for multiple definitionimage quality：
MPEG-4 adopts object-based compression coding method, which combines image andVideo segmentationProcessing separately into different objects not only improves theData compression ratioIt can also realize many content-based interactive functions, providing a broader platform for multimedia data compression coding.
along withlarge-scale integrated circuitTechnology and embedded system technology,Digital STBThe hardware implementation mostly adopts special chips or digital signal processing (DSP) chipsCPU coreAndMPEG-2、MPEG4Transport stream solutionMultiplexer、DVBcurrencydescramblerMPEG audio and videodecoderIt is integrated with NTSC/PAL encoder to form the core chip of STB.To realize real-time demultiplexing and real-time data information processing.
(2) DownlinkData demodulationChannel decoding technology: compressed data cannot be directly transmitted on the channel, and it needs to bechannel coding And modulation.The digital TV and value-added services usually transmitted in the cable TV network mostly adoptQAM(QuadratureAmplitude Modulation) modulation mode and RS (ReeDSOlomon)Error correcting coding。
(3) Modulation and coding of uplink data: In interactive applications, three modes are generally used, namely, the use of telephone lines to transmit uplink data.Ethernet is used to transmit uplink data and wired network is used to transmit uplink data.Because the uplink data is much less than the downlink data, the OP-SK (QuadraturePhaseShiftKeying) or 160AM mode is often used for modulation.
(4) Network browsing technology: In order to realize the true network browsing, in addition to considering the uplink and downlink data, the cable television network and Internet connection must also consider running IP (Internet Protocol) on it.
（5）real-time operating system ：Digital STBThe operating system in uses the real-time operating system (RTOS. Real Time OperatingSvstem). RTOS can work in a real-time environment and occupy a small memory space. It is responsible for managing local resources and network resources, providing basic operating functions and device access control.
（6）Middleware technology: Middleware technology, namely open business platform, has becomeInteractive TVThe core technology of.Middleware usually consists ofJava Virtual Machine, web browser, image and multimedia module, etcApplication Program InterfaceTo make applications independent of operating system and hardware platform.It makes the development of application program more simple, and the openness and portability of products are stronger to ensureSet top boxAnd the effective recovery of investment.
Related differences
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Difference between local player and network player
Different network access
In short“Android set-top box”It can be regarded as a way to obtain video programs through the Internet“Set top box”。That is to say, the common set-top box is connected toCoaxial cable, it is cable television network;The Android set-top box is connected to the Internet.
Different main functions
The programs watched by traditional TV are fixed, and they cannot access the Internet, nor can they dominate TV programs according to consumers' own preferences. They do not have content and applications that can be loaded.And connectedAndroid set-top box, access the Internet through Internet cable or wireless WIFI, and realize web browsing, video movie playing, online chat, game entertainment, online movie and TV on TV. You can control TV programs according to your preferences, or install applications at will.
Different program contents
In terms of program content, ordinarySet top boxIt receives various TV channels, andAndroid set-top boxIt realizes the same functions as computers through the Internet, such as online watching movies and TV, game entertainment, web browsing, microblog, blog, email, online chat, etc.
