MPEG2 playback considerations and common issues

MPEG2 Playback Considerations and Common Issues

MPEG2 is a video compression format used for DVD compression. It provides good image quality at the expense of large files, and it is a good solution for kyosks and presentations where some degree of control over the hardware and software installed on the target playback machine exists.

It is important to understand that MPEG2 playback is not a standard part of the Windows Media Player or any Windows systems. Every MPEG2 decoder software needs to pay royalties to the MPEG-LA patent consortium, so there are no free decoders available for redistribution. The typical cost of an MPEG2 decoder package is around U$ 15-20 PER COPY. This makes MPEG2 unsuitable for wide distribution of CD-ROMs with video content, since there is no easy way to redistribute a decoder to be installed with your content.

To make matters worse it is a known fact that some MPEG2/4 decoders on Windows do not implement all DirectShow functions required for the operation of a complex DirectShow client like Mpeg Advance Xtra. This may cause problems during playback depending on the MPEG2 decoder installed on the playback machine. Older versions of WinDVD and PowerDVD for example are known to operate incorrectly under WindowsXP, and may even corrupt the DirectShow subsystem in certain configurations when you attempt to install another MPEG2 decoder to correct the issue.

It is very difficult to estimate the percentage of MPEG2 decoders that can be used correctly with DirectShow clients, due to the large number of decoders available and specific problems with different versions of video drivers and operational systems. But it is estimated that around 50-60% of all machines with MPEG2 decoders installed will be able to play MPEG2 content using Mpeg Advance Xtra. On about 15% of machines playback is possible but minor issues may be present (mainly memory leaks.) Finally on around 30% of machines with MPEG2 decoders installed reliable playback will not be possible due to decoder issues.

Given these numbers we recommend using MPEG2 only for limited distribution, like a sales presentation or a kyosk application. In these cases it should be possible to install a clean version of the system with a decoder that operates correctly. You can use a trial version of the decoder and Mpeg Advance Xtra to make sure there are no issues with the playback before settling on one specific solution. A very good page with troubleshooting information for common MPEG2 decoder issues on Windows can be found at this link: WMP Mini-FAQ

On the Macintosh platform MPEG2 playback is handled by the optional Quicktime MPEG2 component, available for U$ 19.95 at the Apple Store. This component does not have known compatibility issues.

It is important to notice that a Windows machine with Quicktime 6 installed and the Windows version of the Quicktime MPEG2 component will be able to play MPEG2 files in Director via the Quicktime Xtra bundled with Director, without using Mpeg Advance Xtra. It is usually reported that playback quality of MPEG2 content via Quicktime on Windows is not as good as some DirectShow MPEG2 components, but keep this option in mind for situations where you must use MPEG2 content.

As a general rule a developer should only use MPEG2 only if the source format is already compressed for MPEG2, and the distribution is limited and relatively under control. MPEG1 should be used for projects with wide distribution. It is estimated that over 97% of all Windows/Macintosh machines can play CDs with Mpeg Advance Xtra MPEG1 castmembers with no additional installation and compatibility issues.