The Digital Signage Technologist

MPEG-4

MPEG-4 is an advancement over the MPEG-2. The new standard has the advantage that good quality video can be properly encoded at relatively low bit rate. MPEG-4 is the basis of the DivX codec, one of the most popular video format used on the Internet.

MPEG-4 is widely used on the Internet for its efficiency in transporting over the network. MPEG-4 video is often encoded at 1 to 2 Mbps, or 1/8 to 1/4 MB per second (128 to 256 kbps). A 1 GB memory card easily holds 1 hour of MPEG-4 video. Transmitting a 1-minute MPEG-4 content on the 512 kbps xDSL takes 30 to 60 seconds. This makes frequent content updates feasible.

To be continued…

Digital signage contents are often created in the following formats:

MPEG-1/2

MPEG-1 and MPEG-2 are two of the most common video compression formats in use. They are often used to store and deliver video content on digital signage networks. MPEG-1 is the storage format for VCDs and is rarely used today. MPEG-2 performs better than MPEG-1 at higher bit rates, and is the video format for DVDs.

MPEG-2 media clip are typically encoded at 4 to 8 Mbps, or 0.5 to 1 MB per second of video content. Higher bitrate yields better video quality. A 1 GB memory card holds about 15 to 30 minutes of MPEG-2 video.

Long clips of MPEG-2 is not suitable for delivery over the network today. It takes a typical 512 kbps xDSL connection 8-16 minutes to deliver just one minute of MPEG-2 video.

To be continued…