HD web video
Jul/094
High definition video or HD video as it is known, is digital video with higher resolution than the previous standards (i.e. SD video and DVD). This high resolution is achieved through new video file formats, which allow new codecs, certain performance optimizations (like deblocking) and a lot higher bandwidth(bitrate).
HD resolutions are noted with the number of lines and if it is progressive or interlaced stream. Thus 540p for instance means – resolution 960 x 540 pixels (assuming 16:9 aspect ratio) and progressive stream. Note that interlaced streams are primarily available for compliance with older standards like DVD.
Progressive download – streaming?
Jul/090
Http streaming or as it is better known – progressive download, which has been developed as a marketing term by Macromedia as the “poor man’s streaming solution” for their Flash platform. Progressive download is available from Flash 7 onwards and in essence means a “play-as-you-download” method, that works with standard http web servers. The concept is not invented by Macromedia though, as it has existed for some time with the development of streamable file formats.
Progressive download streaming is achieved by downloading a file “progressively” i.e. from the start onwards up to the end and playing it. FlashVideo(FLV) is a streamable file format as the packets of video data are defined in a “row”(or queue) and can be interpreted one by one, without a need to read all the packets to the end first. As a result progressive streaming provides a similar experience to true media server streaming, but without the need of a media server.
True Streaming with a media server
Jul/090
Streaming means the ability to read parts of the content without loading it in whole. In the sense of web, video streaming means the ability to play video without having to download a file first.
Protocol based streaming or as it is called true streaming, uses a specifically designed network protocol to send packets with video data over a network connection. This approach requires a network server which implements this protocol and provides stream data to a client(player). This type of servers are called “Media Servers” since they generally serve media in the form of video and audio streams (and it was good marketing started by Macromedia).
Live video broadcasting
Jul/090
A video stream that is being broadcasted in near realtime on the net is called live video broadcast or live video feed. Live video can be broadcasted on the internet through a real time protocol by a streaming media server. Live video broadcasting allows an experience similar to TV or satellite broadcast. Another term for live video broadcasting is online TV. The main emphasis of this technology is time synchronization. As with satellite TV there is always a slight delay with live internet video due to network delays and stream processing(replication).
Video on-demand
Jul/090
When video is stored and the played by request it said to be on-demand. The majority of the video on the web today is prerecorded on-demand material. When video is stored it can be regarded as content rather then a broadcast and thus can be categorized an linked in a more complex manner.
Flash Video
Jul/091
FlashVideo(FLV) is the video format that Macromedia created for their FlashPlayer rich media browser plugin. Due to the fact that FlashPlayer plugin (now owned by Adobe) has a web presence in excess of 97%. It is safe to say that about every computer that connects to the internet can play video in FlashVideo format.
The file format of .FLV files is by design based on the h.263 standard. The newer FlashPlayer(9.0.0.29 or above) supports h.264/mp4 files which may have extension .flv(.f4v).
Web Video File Formats
Jul/091
File formats containing video are called video formats. These file formats now in the time of web video are usually container formats. A container format is essentially a sequence of packets containing data like video frames and audio samples. This sequence of packets can be regarded as a stream, thus many of the modern container file formats can be used for streaming video. Besides the streamable packet structure these container formats provide another great benefit – codec abstraction. A codec (‘coder-decoder’) is a algorithm that allows video information to be stored digitally in a more efficient manner. With this codec abstraction container formats are capable of “outliving” the initial codec they were intended to work with and achieve better results(in video quality/storage) while maintaining a good level of compatibility over time. Some formats have been created around a single codec instead of supporting multiple ones, however that approach is considered outdated in the web video era.
Content Delivery Network (CDN)
Jul/093
A content delivery network or CDN is a computer network specialized for delivery of specific type of content. This type of networks specialize in content replication on targeted or global basis.
A content delivery network consists of points of access which allow certain content to be served to end users. The main benefit from such a network is the ability to serve a large number of users simultaneously and possibly on a global scale. A CDN can provide the means to deliver content to a huge number of users while maintaining reasonable cost of scaling. A CDN s total bandwidth capacity can go way beyond a single backbone connection that a DC would have.
If you need to deliver a large “amount” of content to a large number of users a using a CDN is the only way to do it. Microsoft for instance uses about a dozen of CDN’s for hire to deliver content to end users.
Video Self-hosting
Jul/090
Web video can be hosted on a regular web server by using progressive download. This is the do-it-yourself version of web video publishing and is called by some free video hosting. This basic type of video publishing is easy to learn for web designers and is often used by designers that do not have access to better technology or technical knowledge to use it.
Video Hosting
Jul/094
A web video hosting service allows content owners to upload their video to a specialized network and then use this content into their own website. Another term for video hosting is streaming hosting(or stream hosting) and it is also referred to as business video hosting as opposed to free video hosting.
Streaming Video
Jul/091
Streaming is the ability to use content without (down)loading it in whole first. This is very important for web video since a user would usually want to watch the video online instead of downloading it first. When it comes to web video on a technical level streaming is achieved in two main ways:
- Streaming network protocols – this is the low level concept it involves sending(or broadcasting) packets over an IP network. A media server is required for this process and a player compliant with that server’s protocol. This method is also referred as “true streaming” or “live streaming” when it is used with a real time feed. Examples of this concept are Macromedia(now under Adobe) Flash Media server and it’s RTMP protocol and Helix Server(Real Media) with the RTSP.
- File container formats – Some video container formats are designed to be like a stream of packets and can be used in a streaming context. This is also called “Progressive Download” a regular HTTP web server is used for the process. Examples of file formats used for streaming include: .flv(Flash Video), .wmv(Windows Media Video) and many others popular formats.
There is also a hack to progressive download called PHP Streaming. This hack concept solves(sort of) some of the limitations of progressive download namely: random access capability.
Web video
Jul/090
Web video is any video accessible through the web. Web video is a distinct type of medium. This type of medium is usually related to video that is directly viewed online, on a web page, through an internet browser. It can be live broadcast or on-demand. In the sense of technology a slightly better term for web video is – streaming video.
Web video has become a significant medium in the last years largely due to the huge popularity of video sharing services, specifically youtube.com.
Common cases of web video usage are:
- Video sharing sites
- Web TV
- Video blogs (vlogs)
- Corporate News
- Video Advertising
- Product reviews
Web video example:
get Adobe Flash Player
This web site makes use of the Adobe Flash Player.
VIDEO PLAYER and video hosting service.