MP4 : Relationship between GPS and PMP

GPS
The Global Positioning System (GPS) was developed in the United States from the 70s of this century. It lasted for 20 years and cost US$20 billion. It was completed in 1994 and has full-time real-time navigation and positioning in the sea, land, and air. A new generation of satellite navigation and positioning systems capable. The use of surveying and mapping departments in China in the past 10 years shows that GPS has won the reputation of surveying and mapping workers with all-weather, high-precision, automation, and high-efficiency. It has been successfully applied to geodetic surveys, engineering surveys, and aerial photogrammetry. Vehicle navigation and control, crustal movement monitoring, engineering deformation monitoring, resource exploration, and geodynamics have brought a profound technological revolution to the surveying and mapping industry.

The Global Positioning System (GPS) is the second generation satellite navigation system in the United States. It was developed on the basis of the Meridian Satellite Navigation System, which adopted the successful experience of the Meridian System. Like the Meridian system, the global positioning system consists of three parts: the space part, the ground monitoring part and the user receiver.

The space portion of the Global Positioning System uses 24 constellations of satellites with a height of about 20,200 kilometers. The 21+3 satellites are near-circular orbits with an operating period of approximately 11 hours and 58 minutes. They are distributed on six orbital surfaces (four on each orbital surface) with an orbital inclination of 55 degrees. The distribution of the satellites enables the observation of more than four satellites at any time anywhere in the world and can maintain a well-positioned geometry (DOP). This provides continuous global navigation capabilities over time.

Global positioning system has the characteristics of good performance, high precision and wide application. It is the best navigation positioning system so far. With the continuous improvement of the Global Positioning System, the continuous improvement of hardware and software, and the continuous application of the field of application, it has now spread throughout various sectors of the national economy and has gradually begun to penetrate people’s daily lives.



Exploring the Mystery of the Application of PMP Since the launch of the first true PMP in 2002 by the French ARCHOS, the PMP market has undergone a three-year evolution. PMP has evolved from a single multimedia player to a multi-functional personal digital media center. This article would like to take a look at the functional evolution of PMP to share with readers the prospects of PMP applications, in order to have a reference for the follow-up PMP designers and vendors.
First, the choice of the program Many companies in the launch of PMP, the choice of the program is cautious and cautious, which directly determines the future market positioning and functional applications of the product, where I still review the market mainstream PMP solutions.
1. High-end PMP solutions advocated by TI, AMD, and INTEL Most of these solutions use soft decoding, and they advocate using a large number of software codecs to support the new image file formats on the market. CPU frequency is high, and the entire hardware interface is rich in functions. Can support a lot of high-end applications, similar to GPS, HDTV, DV, PDA features easily, the program's shortcomings are obvious, high cost, high design threshold, requires software capabilities, a variety of licenses, enough for you to stop. Because of the rich features of such programs, our system design has become more and more complicated, and the software architecture has become complicated. The cycle of making prototypes and debugging samples is also quite long. With the exception of the rare powerful design companies and vendors that have introduced productized PMPs, they have been forced to abandon R&D. In the use of LCD, the main use of 3.5 to 7-inch screen is mostly, some products use windows CE operating system, use the touch screen to do more design.
2. The CODEC in the mid-end PMP solution SIGMDESIGNS represented by SIGMADESIGNS and FREESCALE is hardware. The typical EM8511S supports the most popular MPEG4 encoding formats such as DIVX and XVID. RM and WMV9 are not supported. If you want to support these image formats, Can only hope to update the model of the chip. Fortunately, such solutions support hard disk, high-definition TV output, freescale IMAX21 processor support RM and other movie formats, the program cost is moderate enough to meet the design needs of ordinary portable multimedia players. At present, there are many companies that can offer such schemes, so the threshold is not too high. Basically pre-interlaced 1K LICENSE, you can import into production. Unconsciously, it has become the most mainstream PMP solution on the market. The most popular of these types of programs is the 3.5- and 4-inch design. There are also companies that use 2.5-inch card readers. They are the best in the industry and they have taken another look.
3. Low-end PMP solution represented by SUNPLUS, ZORAN.
Some readers may think that such a scheme is not a PMP scheme and is more willing to use it as a high-end MP3 scheme because it hardly supports any mainstream MPEG-4 format. Most of the image files must be converted by the built-in conversion software before the CPU can decode them. The quality of the image is also very general, perhaps because it is used to do DV, and it is easier and cheaper to support camera functions than other solutions. Many companies and manufacturers who were not optimistic about such products at the time had suffered a lot of losses. They all used the built-in FLASH+SD card to build their own platform. The cost was even lower than the domestic famous brand MP3, so they took up a lot. Large customer base. For cost considerations, most of the early adopting 2.5-inch analog screen design, the cost is very low, the price engulfed most consumers.
Here I give a table, we can make a horizontal comparison intuitively:
Solution TI AMD INTEL Sigmadesigns FREESCALE SUNPLUS ZORAN
Operating System Linux Wince Wince Linux Linux Other Other
Supports video formats DIVX/XVID/MPEG1/2/4H. 264/WMV9 DIVX/XVID/MPEG1/2/4H. 263/WMV9 DIVX/XVID/MPEG1/2/4WMV9 DIVX/XVID/MPEG1/2/4 MPEG4/H. 263/RMFlash game/movie ASF ASF
Support video NONE Yes Yes NONE Yes Yes Yes
Support reading card All All All All SD SD SD
Support Hard Disk Yes Yes Yes Yes No No No
Mainstream LCD 3.5 to 7 touch screen 3.5 to 7 touch screen 3.5 to 7 touch screen 3.5 to 4 2.5 to 4 2.5 2.5
The cost is high, about $220 high, about $210 high, about $230, about $190, about $120 low, about $60 low, about $70

Second, the application of the exploration of PMP In addition to the most basic appreciation of movies, music playback, image browsing, text reading, listening to FM and other functions, in recent years, many PMP increased the number of digital partners, video recorders, GPS, DVB-T, PDA, network, etc. Features. Now let us introduce these features one by one.
1. Digital companions are basically realized by the OTG function. With the large-capacity HDD, digital photos and videos can be easily backed up. In 2004, the digital companion market on the market was very good and sold very hot. It was originally a flash card-style digital camera companion and later evolved into the form of OTG. Ali is the best compatible chip among them. The M5637 can support mass storage class devices such as regular flash drives, removable hard drives, MP3s, and digital cameras and digital video cameras. In particular, it supports the PTP format protocol, and the mainstream digital cameras CANON and SONY all use this protocol. At present, the speed of storage backup is about 1.5MB/s, and a 256MB card can be completely backed up in less than 3 minutes. Since it is an OTG chip, it can be used as a USB 2.0 device at the same time to facilitate the exchange of files with the computer. The overall cost increases by about $3. Most manufacturers can accept it. The only regret is that you cannot select a single file for backup and cannot complete the analysis of usb devices. Most of the products can only be copied in full, I think IC vendors and PMPs This can be done when the program is integrated. In this case, many usb applications are used, such as TV tuner and so on. At this time we can choose philips, oxford and cypress OTG products.
2. The video recording function is not a pity for the large-capacity hard disk MP4. The video recording function is optimized from the home MPEG-2 disc recorder to the MPEG-2 hard disc type to the MPEG-4 hard disc type recorder, and the quality of the recording and the storage capacity are optimized. For software CODECs, such as TI, it is easy to implement such functions, but for MPEG-4 encoders to optimize a lot, consider buying other companies' well-designed encoders and then porting them to DSPs. Hardware-based codecs, such as sigmadesigns, generally require an additional MPEG-4 encoder, such as the W700's GO7007SB, but often this system adds $20 to the cost, which is not necessarily a large amount of time. Consumers pay for it.
3. PDA
Like PDAs and digital companions, this product has been difficult to find on the market and has been replaced by other products. The solutions of Intel and AMD support the WINCE platform. The old embedded microprocessors represented by PXA27X and AU1200 have rich windows platform support experience. Consumers use the WINCE-based player, you can use your own PMP like Windows, with touch screen operation, handwriting, open word, excel to handle daily files and business notes, use the powerpoint software comes with training The introductory document is output to the projector through ordinary AV signals, and it becomes a laptop computer. The business application is vividly presented. Of course, using WINCE's platform, according to different modes of authorization, need to pay unequal licensing fees.
4. Digital camera is a relatively low-end sunplus program, they can support 2 million, 3 million cmos camera, clearly capture the fun of life, arbitrary. At present, mainstream manufacturers of CMOS sensors include ominivision, micron, and pixelplus. Prices continue to drop, so adding this feature is very popular for consumers. Relative to the camera's camera function, the use rate is much higher, because most mobile phones with 300,000 and 1.3 million cameras do not support card expansion, and the memory is generally only 1M to 2M, which can not meet the shooting requirements for a long time. , so the camera's camera function has long been a device, a slogan. The MP4 built-in high-capacity FLASH, support for 1GB SD card, no doubt this feature is eager to win, while other programs to do this function cost and technical difficulty will have to increase a lot.
5. GPS
GPS Global Positioning System was added to PMP. I think many vehicle equipment makers, especially car DVD manufacturers, have been using it for a long time. As a high-end application, it is mainly done on the AMD and INTEL WINCE-based platforms. The touch screen has basically become a standard configuration, and is generally more than 4 inches, so the cost of the entire system is high, and more and more design companies are Importing GPS into PMP, many GPS receiver manufacturers are trying hard to minimize power consumption. The iTrax100 introduced by Fastrax in Finland consumes only 120mW, and its volume is only 16.2 x 18.8 x 3 (mm), which greatly saves PMP. Battery play time.