Product Reviews

MPEG Charger is an entry-level, software-only MPEG encoding tool from Terran Interactive. It comes packaged as an add-on option for Cleaner 5.

MPEG video encoding is often used to distribute video in non-Internet settings, such as DVD, satellite or cable TV transmissions. There are two versions - MPEG-1 and -2. MPEG-1 is popular as an audio format and is used in the widespread MP3 file format, it is also used in the VideoCD format. MPEG-2 offers better quality and full frame rate and full-size TV images, though the data rate is too high for most people to use on the Internet, even over a broadband connection.

Until recently it was difficult and expensive to perform MPEG-2 encoding on a desktop PC or Mac. Cleaner and QuickTime have offered MPEG-1 encoding for a few years, but MPEG-2 encoding has usually been the preserve of high-end products costing many thousands of pounds. New processors, such as the G4, have allowed desktop users to gain access to software based encoding for the first time.

MPEG Charger requires an installed version of Cleaner 5. It will update this to 5.02 and add a further set of MPEG encoding options to the Settings windows. However, the install will not take place cleanly if you have disabled the Radius DV codec, supplied with Cleaner 5. This codec is often disabled because it clashes with QuickTime, but you'll need to re-enable it to allow MPEG Charger to install. It would have been helpful if this had been documented in the ReadMe file.

There is a good, if short, manual with a clear explanation of MPEG aspect ratio and how best to approach encoding for different delivery platforms. Also highlighted in the ReadMe are possible problems in encoding DV into MPEG, due to differing field dominance between the formats; this is helpful but should really be in the main manual. All of the MPEG encoding options are discussed in the manual or references to the main Cleaner manual are

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given.

Make a scene

MPEG Charger simply integrates itself into the Cleaner 5 interface, presets are supplied for MPEG-2, DVD, MPEG-1, VideoCD and Web. It's possible to control many aspects of the MPEG encoding process such as data rate, peak rate, GOP size, encoding structure in terms of i, b and p frames, as well as the chroma format. It's also possible to specify 4:2:2 ratio instead of the usual 4:2:0 for DVD. This will be useful for those working for broadcast, as they could deliver a completely finished file in-house.

One last choice is the ability to use variable bit-rate (VBR) over constant bit-rate (CBR). Selecting VBR will usually give better results, as the video is first pre-processed to find the complex and simple sections, then some of the available bit-rate is taken from the simple scenes to use in the complex scenes. An example would be a static landscape versus an explosion, the static landscape will take a lower bit-rate to encode than the fast moving explosion. CBR gives the same bit-rate to everything, sometimes resulting in blocky detail in fast moving scenes.

Once you choose a setting, Charger operates just like normal Cleaner 5 video encoding, with one important catch: if you haven't got the Radius codec selected, MPEG-2 encoding will stop with no error message, just 'error', this issue should really be handled more elegantly.

Terran's hardware-based MPEG SuperCharger includes a PCI board to accelerate the MPEG encoding, and if speed is important to you then this is a better option than the software-only Charger. The Media Press range of encoders is substantially more expensive, but it offers real-time encoding and component video inputs. Apple's DVD Studio Pro also offers MPEG-2 encoding, primarily for use with DVD authoring. The purchase cost of DVD Studio Pro roughly equals the cost of the Cleaner 5 package, though they offer different additional functionality.

MPEG Charger offers access to MPEG-2 encoding at an affordable price. The functionality allows complete control over the MPEG encoding process and the results are of quite a high quality. The clash with QuickTime is time consuming, but this is more of a general Cleaner 5 problem.

Hardware-based products will deliver a higher-quality result in less time, but are more expensive, if your needs for MPEG-2 are infrequent or only for 30-second clips then this will be perfect for you. However, if you need MPEG-2 for DVD or have longer clips to encode then you should really look elsewhere.