Capture cards and codecs

Cable-Modem - Contention Ratios

A B C D E F G H I J K L M N O P Q R S T U W

Cable-Modem:
Fast consumer internet connection transfered over a cable network of optical fibre rather than through ADSL which is based upon copper telephone lines.

Cache:

A temporary memory store where frequently used content is stored enabling it to be retrieved with greater speed than if it was held in normal memory.

Capture card:
A device used for creating media from an audio/video feed and outputting it in a digital format.

Codec:
A compression/decompression algorithm used for encoding video into a file and then allowing it to be played back by a media player.

Concurrent Conncetions:
The number of active connections retrieving a stream at a given time.

Content Delivery Network (CDN):
A network of servers optimised for supplying data to each individual client. Servers are normally set up to supply content to geographical areas, or bypass bottlenecks by using alternative routes from point to point.

Contention Ratios:
The number of users sharing a particular connection. Home user ADSL lines normally have a contention ratio of 50 to 1 which means that for any given 512kbps connection there could be up to 50 different households sharing the line. Whilst this sounds a lot, it is normally rare for lots of people to be tranfering lots of data at the same time, so the sharing is "transparent". Unfortunately this is not good for streaming, and so if two people out of those 50 connections are watching a broadband stream at the same time, there will not be enough bandwidth available. On occasions like this, buffering may occur.

Capture Cards

There are several ways to get your video from tape into your PC.

On many new camcorders there is a firewire output which will plug directly into a firewire card inserted into a PCI slot on your computer (some even have them onboard).

For legacy tapes and machines, and also higher quality output there are a large range of products of which we recommend the Osprey range from Viewcast.