Matrox Marvel G400-TV, The Swiss Army Knife

The Matrox Marvel G400-TV is much more than an all-purpose videocard. Looking over Marvel’s features and specifications, hardly a thing comes to mind this videocard doesn’t have or could be missing. Beyond the well known performance of the Matrox G400 graphics engine, the Marvel G400-TV responds to the needs of both PC enthusiasts and video editors. It’s equipped with an arsenal of new and groundbreaking features, such as: hardware MJPEG digital video capture and editing, DualHead output, DVD playback, 2D/3D acceleration, TV tuning and a whole package of ready-to-use software that makes creating and editing your own movies as simple as a click of a mouse.

Although somewhat more expensive, a hardware MJPEG codec offers numerous advantages, including video capture at full frame rate and full resolution without any dropped frames or color bleeding, jagged edges, blockiness or other motion artifacts that result from using software codecs. The Marvel G400-TV preserves the same high-quality image during video capture as during video playback, because its hardware MJPEG codec is dedicated solely to video compression and decompression. To further enhance the image quality of the Marvel, its hardware capabilities are complemented by software optimizations that make sure image degradation does not occur when transferring video data to the PC. This offers a far better solution than all of the software-based codecs used by other products.

But before we get too technical about some of the benefits of the Marvel’s hardware codec, let’s first take a closer look at some of the features the G400-TV has to offer.

 

Features

256bit DualBus

Building on the success of the G200’s 128 bit DualBus architecture, the G400 effectively doubles the graphics engine bandwidth by moving to a 256 bit DualBus architecture. That may sound like marketing hype, but if we take a closer look there’s more to it than that.

The DualBus architecture actually enables the graphics engine, the actual processing unit within the graphics accelerator, to simultaneously process input and output data. It does so by using two 128 bit buses (hence the DualBus), one for input and the other for output. To maximize data transfer, data is being read from and sent to the graphics engine on every clock cycle. This is to have a maximum data throughput at all times and to keep the buses from being idle.

Furthermore, by using a 128bit memory bus and subsequently clocking the memory to a higher clockspeed than the graphics engine, the 256bit DualBus is able to read and write data to the memory without it being idle, as the DualBus architecture allows it to do both in one clock cycle—thus further upping the performance.

AGP 4X

Although the G400 is a full-featured AGP 2X graphics accelerator, it is also designed to take full advantage of the AGP 4X specification.

AGP graphic cards actually access the main memory by using DMA, Direct Memory Access, transfers very much like many other devices in your system. Large data buffers inside the G400 allow it to optimize the fetching of commands and data from different locations in memory.This basically means that these data buffers prevent long waiting times in the data fetching process across the AGP bus, thus optimizing the data throughput across the bus as fewer clock cycles are needed to get the data back and forth between the main memory and graphics engine.

To take advantage of the high AGP bus bandwidth, the G400 uses a Symmetric Rendering Architecture, SRA. Within the SRA, the G400 treats AGP memory exactly as if it were local video memory, meaning that it can read and write to it at AGP 4X rates but still treat it if it were local video memory rather than memory accessed across the AGP bus.

To alleviate some of the strain on AGP and local memory, the SRA uses a hierarchical texturing system which actually stores certain image data, such as textures and bitmaps, across either the on-chip cache, local video memory or AGP memory.

With the hierarchical texturing system, small and frequently used textures are usually stored and read from local video memory while large and infrequently used textures are stored and read by using AGP texturing from AGP memory. This hierarchical texturing system allows the G400 to make use of the available memory with the utmost efficiency.

Environment Mapped Bump Mapping

It sounds like yet another hollow phrase, but actually Environment Mapped Bump Mapping is a DirectX 6 quality feature which can be used to substantially increase the virtual realism of 3D scenes. In fact, graphics accelerators that support this feature will be able to render 3D scenes with more realism than ever before.

Environment Mapped Bump Mapping is essentially a technique that allows a much higher level of detail to be added to a scene than could be possible with texture mapped polygons alone. Fine details such as the pock-marked surfaces of bricks in a dungeon and scratches on the surface of a wall can be added with ease. Special effects such as realistic water surfaces, heat shimmering off hot asphalt on a summer day, or even air turbulence in flight simulators can also be uniquely generated by Environment Mapped Bump Mapping.

The advantages of Environment Mapped Bump Mapping are so profound that anything short of ten pages wouldn’t even cover the basics, so to at least give some sort of a guideline the following summary gives an impression of its workings.

In its simplest form, bump mapping adds realism to textures and objects by creating the illusion of bumps, or variations in surface depth, on an otherwise flat surface. This means that a flat plane can be transformed into the dimpled surface of a golf ball, the gnarled bark of a tree or the rough surface of a rock. For bump mapping to be convincing, we must perceive variations in surface depth even though the surface is actually flat.

A flat surface reflects more light than a bumpy surface does, hence the term bump mapping; if we reduce the amount of light coming off of a flat surface we get the impression that it is bumped. Thus bump mapping uses lighting and shading effects of the texture to create the appearance of surface depth.

To create this result, all areas of the surface must be specified as either elevated or sunken. To do this, a second texture or ‘bump map’ is required to define depth or height for every pixel in the conventional texture map.

To complete the effect, an ‘environment map’ is required. The environment map represents what should be reflected off the surface. It can be as simple as a bright circle representing a single light source or a complex environment map consisting of multiple light sources and effects due to other environmental factors such as clouds and shadows.

Vibrant Color Quality Rendering

One of Matrox’ strong points hasn’t been neglected with the Marvel G400-TV, and that’s image quality in 2D as well as 3D rendering. The G400’s rendering engine was specifically designed to ensure that multi-textured applications are rendered with the utmost precision, that the image will not suffer from color banding, tearing or ugly dither patterns. Vibrant Color Quality Rendering does this by using 32 bit precision and rendering for just about everything.

Stencil Buffering

A stencil buffer determines whether a particular pixel should be rendered or not. However, unlike the z-buffer, which represents depth values, a stencil buffer represents a stencil or mask on the frame being selected. For example the cockpit of a spacecraft is a very simple example of how a stencil could be used. The inside of the cockpit acts as a stencil and masks complex scenes so that external scenery is only visible in the areas specified by the stencil mask. So instead of rendering all of the scenery and then doing an overlay of the cockpit, the 3D engine needs only update the scenery that’s visible.

DualHead display

The DualHead display feature allows your Marvel G400-TV to support two separate displays with as many as eight different configuration options. DualHead display can use either a monitor or an analog Flat Panel as primary display and a TV as a secondary. Unlike traditional multi-monitor solutions that simply extend applications across two displays, DualHead display offers a variety of combinations, such as: Dualhead DVD Max, DualHead Zoom and DualHead Clone, not yet seen on any other graphics card. As their names suggest, you can output DVD or other video streams full-screen to TV with DualHead DVD Max, zoom part of the desktop full screen to the second display with DualHead Zoom, or clone the desktop on a second display with DualHead Clone.

Hardware MJPEG Codec

The Marvel G400-TV offers amateur and seasoned video editors high quality video editing capabilities in one card. With its hardware MJPEG (Motion Joined Photographic Experts Group) codec, the Marvel G400-TV ensures picture quality that is as close to the original as possible.

During MJPEG compression, each individual frame in the video clip is compressed and saved to disk; with NTSC that comes down to 30 images per second at a 704×480 resolution. Because MJPEG preserves the integrity and image quality of each individual frame, MJPEG has become the industry standard for frame accurate nonlinear video editing.

The hardware MJPEG codec (compression/decompression) as used on the Marvel G400-TV offloads processing from the computer’s CPU because it performs all video compression and decompression functions itself. Conversely, a software codec requires that the computer’s CPU perform all of the mathematically-intense compression and decompression calculations, so a software codec is CPU-dependent and so can’t render at full frame rate and full resolution, even on a very powerful system.

Due to the hardware MJPEG codec, the Marvel can be paired with a significantly less powerful system than can a videocard with a software codec. For example, with a software codec, we’d need at least a 450 MHz system to compress a 30-second clip at half NTSC resolution. On the same system, the Marvel’s hardware codec would achieve full NTSC resolution with significantly higher image quality and full-frame playback.

Software MPEG2 Transcoder

The Marvel G400-TV is equipped with an easy-to-use software transcoder for converting MJPEG and AVI video files into MPEG2 format—once a videoclip has been captured and/or edited in MJPEG format it can be easily converted into MPEG2.

TV Input

The external Marvel connector box, which holds the video and audio in/output connectors, also includes a TV-tuner that permits watching TV on a PC. This feature is not something one cannot find on other all-in-one solutions, but the thing that really sets this one apart is that it has stereo audio output.

Software Bundle

The Marvel G400-TV software bundle features Avid Cinema, an intuitive video editing software package designed to lead amateur users through the movie-making process. With Avid Cinema, full-motion video, audio and graphics can be easily captured from a VCR, video camera or TV and edited using Avid’s nonlinear editing capabilities. Movies can then be distributed in a variety of formats, including Quicktime or AVI.

The Marvel G400-TV also bundles the Matrox Software DVD Player, the LSX-MPEG2 Transcoder, Ulead Photo Express and the Matrox PC-VCR Remote, which is compatible with Microsoft’s DirectShow and Video for Windows. In addition the Marvel G400-TV supports Microsoft NetMeeting, WebTV and VideoText decoding.

Capturing Video

Full Motion Video

Capturing video essentially involves transferring a video stream from a video source—such as a video camera, VCR or TV—to your computer. This video stream needs to be compressed by means of a codec prior to being saved on harddisk.

As mentioned, the Marvel G400-TV uses a hardware codec, which offers superior image quality over the more commonly used software codecs.

To be able to test the hardware MJPEG image quality, ease-of-use, CPU usage and the benefits of DualHead Display for video capture, we decided to use the built-in TV-tuner to capture a five-minute selection.

PC-VCR Remote

Capturing video can be done easily using the Matrox PC-VCR Remote, which has all the features and buttons arranged as on a VCR Remote, hence the name.

The PC-VCR Remote is a intuitive piece of software that supports all of the features normally used with your TV and VCR, and more. It records TV programs or other video sources directly onto the harddisk, changes TV channels, preset audio and video capture parameters, and programs parental lock and timer control. Remote functions supported include :

All modes
– closed captioning window control
– video capture
– picture capture
– instant record
– quick timer record
– video adjustment and volume control
– mute button

TV mode
– channel switching
– last channel recall
– enable favorites

File mode
– load single file or playlist (multiple files)
– play, stop, pause, next and previous files in playlist
– click and seek on progress bar

Channel Switching on the Fly

Easily scan through all available channels or favorites by using the up and down channel arrows. Using the [Jump] button allows you to jump back and forth between the previous and current channel.

TV Channel Preview

The PC-VCR Remote also offers a TV Channel Preview mode. In the preview mode, preview up to 30 channels at a time. If the PC-VCR Remote favorites feature is enabled, only the channels defined as favorites will be displayed in the preview window. To view a particular channel in the video window, double-clicking on the desired channel automatically switches to it.

Keyword Detection

If a channel is able to transmit Closed Caption text, you can set the PC-VCR Remote to detect a particular keyword, and trigger a recording, pop-up the video window or save the text.

 

How To Capture Video

Full Motion Video

But let’s take a closer look at the procedure involved with capturing video.

– Start PC-VCR by clicking Start -> Programs -> Matrox Video Tools -> Matrox PC-VCR Remote

To capture from the TV tuner, click the TV button in the Input menu. The playback window will automatically display the TV image on the desktop. When using DualHead, the same image will also appear simultaneously on TV.

For capturing video from a VCR or video camera using the input connectors on the Marvel’s connector box, click Line. Right-click the remote’s display and select either S-Video or Composite. The Marvel connector box has two composite video connectors (one input and one output) and two S-Video connectors (one input and one output). Most types of video equipment use composite video, but some devices such as S-VHS VCRs and HI-8 video cameras use S-Video, which offers a higher quality video signal. Again, when using DualHead, the same image will also appear simultaneously on TV.

– Select the Properties icon -> Recording tab. Click the [Browse] button to indicate where the file should saved -> [Save] -> [OK].

– Click the [Record to video file] button. And after you’ve captured the desired fragment press [Stop].

Immediately after pressing [Stop], the Video File Information window will pop up with details about file size, length and format, which can be closed by pressing [OK].

To view the file just captured, press [Open] and double-click the file.

Video Snapshot

The PC-VCR Remote also allows video snapshots. Click the [Video Snapshot] button on the PC-VCR Remote; the images are saved as still images of the PC-VCR Remote video window.

 

Other Options

The before-mentioned video capture options all default to the highest quality settings. Therefore, you might want to adjust them to take advantage of their versatility.

Select the Properties icon -> Recording tab. Under Recording settings, use the low disk use or high video quality slider bar to adjust the resolution settings. Because the Marvel G400-TV uses a hardware codec, and thus offloads the CPU, we’d recommend using the highest quality setting (default) for the initial recording and using that as the basis for all further editing.

Select the Properties icon -> Recording tab -> Capture options to adjust the compression settings. If you are low on diskspace, select to a higher video stream compression ratio—at the cost of some image quality.

To adjust the audio quality, select the Properties icon -> Recording tab -> Audio quality settings and adjust as required.

 

Quality Considerations

Image Quality

High contrast shots can best demonstrate whether or not a codec introduces artifacts in the captured video stream.

Some high contrast shots cause problems for software codecs. In software, maintaining color fidelity of such shots can cause the CPU to choke and drop frames. Unlike a software codec, the Marvel’s hardware codec captures high contrast shots at full frame rate, at full resolution, with exceptionally precise, full-color fidelity.

High contrast shots are also subject to compression artifacts. For example. When video is compressed by a software codec these artifacts appear as garbled and noisy patches along contours in the image, making video appear fuzzy and disjointed.

Video with rich colors, such as cartoons, will help determine the color reproduction capabilities of the codec. If captured video looks washed out and dull, then the capture device or software is not of very good quality.

Color bleeding is another way to determine if the color reproduction capabilities of the codec are high quality. Bleeding occurs when the color in one area blends into another area rather than leaving a solid, defined boundary. Color bleeding is characteristic of video captured with a software codec.

Similar to high contrast shots, processing fast-moving images can be taxing on a software codec and may cause poor quality output or dropped frames, resulting in choppy playback and distorted image quality.

Audio Quality

Audio/Video synchronization commonly deteriorates during video capture. Since audio and video are recorded onto separate tracks, the codec may have problems keeping the audio and video in sync. During playback this would result in words being spoken before or after the mouth moves.

Audio/Video synchronization is an important factor to consider when evaluating playback because some software codecs are unable to maintain a lock between the audio and video tracks.

 

Other Software

Avid Cinema

Avid Cinema is an intuitive video editing package designed to lead amateur users through the video making process. With Avid Cinema, full-motion video, audio and graphics can be easily captured from a VCR, video camera or TV and edited using Avid’s nonlinear editing capabilities. Movies can then be distributed in a variety of formats, including Quicktime or AVI.

LSX-MPEG2 Transcoder

The LSX-MPEG2 Transcoder is an easy-to-use utility for converting MJPEG and AVI video files into MPEG2 format. Once a videoclip has been captured and/or edited in MJPEG format, the transcoder can easily convert that file into MPEG2.

Although MJPEG offers the highest picture quality, MPEG2 is used for portability, for distribution on the Internet as well as to save harddisk space if needed.

Matrox Software DVD Player

Based on the latest technology from Ravisent Inc., this DVD player supports standard and advanced navigational features that include aspect ratio scaling, full-screen output to TV, slow motion playback and support for Dolby Digital Audio. Besides providing smooth full-frame, full-resolution playback in single monitor mode, the Matrox Software DVD player has been optimized for Matrox’s DualHead display. DualHead DVDMax mode displays DVD titles full screen on TV while leaving a fully accessible Windows desktop on the monitor.

Ulead Photo Express

Ulead’s consumer photo editing and enhancement software, Photo Express 2.0, is friendly, easy-to-learn and provides a wide range of attractive, template-based photo projects. Even those new to image editing can get quickly started with animated icons, pick-and-apply editing and other advanced features as the step-by-step instructions guides them through the whole process.

Matrox Quick Connect

The Matrox Quick Connect program automatically starts after installing the card and drivers for the first time. The program ensures proper connections to external video devices and also acts as a troubleshooting tool, prompting you to check for specific things that may be wrong, such as VCR setting, region (NTSC or PAL) or cable type.

WebTV Support

The Marvel G400-TV supports Microsoft WebTV support for Windows. With Windows 98 Second Edition allows use of WebTV for Windows to take advantage of the interactive television content available through WebTV, finding favorite TV programs easily with the online Electronic Programming Guide and receipt of information from the Internet without tying up a phone line.

Videoconferencing support

With your Internet connection properly configured you can use Microsoft NetMeeting to connect to family, friends and business contacts from your home or office.

 

Conclusion

With all of the features the Matrox Marvel G400-TV has to offer and the high quality image of its hardware codec the Marvel G400-TV is simply the best all-in-one card available. There is no product on the market with a similar price tag that offers the flexibility and broad range of features the Marvel G400-TV has to offer. Although the cost of a hardware video capture and editing solution may be slightly higher than a software one, the Matrox Marvel G400-TV delivers as promised on all counts.

For seasoned video editors and enthusiasts on a budget, this card justifies buying a more professional software package such as Adobe Premiere to be able to make full use of the Marvel’s potential and providing a solid basis for all of their work.

 

 

Ludo Morgan
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