DLNA's full name is Digital Living Network Alliance, whose purpose is enjoy your music, photos and videos, anywhere anytime, DLNA (Digital living Ne Twork Alliance), launched by Sony, Intel, Microsoft and other wireless and wired networks designed to address personal PCs, consumer appliances and mobile devices, has made possible the unlimited sharing and growth of digital media and content services, with more than 280 member companies currently in existence.
DLNA its entire application to 5 functional components. From bottom to top in order: Network interconnection, network protocol, media transmission, device discovery control and management, media format.
1. Network interconnection. It prescribes the type and protocol of the network being accessed. At present, mainly include:
Wired network: 802.3.i/u
Wireless network: 802.11/a/b/g
2. Network protocol. It prescribes the network protocols used. At present, its provisions must support IPV4. However, given the shortcomings of IPv4 such as address space, IPV6 will be supported in the near future. Of course, consider the many applications and equipment of existing IPv4. The double stack of protocols that support IPV4 and IPV6 and ensure IPv4 and IPv6 interconnection will be favored for a long time to come.
3. Media transmission. It stipulates that all DLNA devices must support the use of HTTP protocol for media transmission. This will make it a topic for a long time in the future to improve the high-speed and secure transmission of large data on the HTTP protocol. Simply being safe, TLS may be a good choice. In addition, IPSec has become a required option in the IPV6 protocol. This also solves the security problem to some extent. However, it seems that the work of using software as a decryption is never the right choice. Because, in real applications, few customers do not dictate your speed. Of course, you can also use RTP for other proprietary media streaming protocols. However, the premise is that you have supported the transmission under the HTTP protocol.
4. Equipment discovery, control and media management. This functional component is one of the most important levels. Maybe it's because Intel is the initiator of UPnP, so when it comes to Dlan, all of UPnP's stuff, of course, won't be wasted. is not because UPnP for a long time stay in the protocol phase, very few applications, IDG is an exception, the Intel is to launch the DLNA, I am not clear: Currently, it employs UPnP Device Architecture 1.0 and UPnP AV 1.0 and UPnP Printer:1. This is just the tip of the iceberg in a bunch of standards on the UPnP forum. The UPnP thing, as if still quite a lot, here is not in detail. In short, it is through a series of steps and protocols to achieve the discovery and management of equipment, but also through the manufacturer's definition of AV and printer standards to achieve media management. A lot of concepts and nouns, the next time to introduce:
5. Media format. This is the last component. It provides a media format for the sharing and use of digital media and content. It must be supported by: JPEG, LPCM, MPEG2. Other optional media formats are:
Image JPEG PNG, GIF, TIFF
Audio LPCM AAC, AC-3, Atrac 3plus, MP3, WMA9
AV MPEG2 MPEG-1, mpeg-4*, AVC, WMV9