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cartTutorials a Safe Harbor blogSony DV Tapeless Workflow for RT.X2
Tapeless workflows are rapidly becoming very popular because they eliminate the lengthy process of capturing footage from video tape to the editing system hard drive. Video clips recorded to flash media in the camera can be quickly transferred to the editor’s hard drive at faster-than-realtime speeds so he/she can get right to work. In fact, the editor may be able to edit directly from the flash media when a compatible card reader is attached to the edit system, though transfer to a hard drive is recommended. The popular Sony HVR-Z7U camcorder can record DV video directly to a Compact Flash card, but the Matrox RT.X2 hardware does not work with the DV AVI Type 1 files written by the Sony unit. While Premiere Pro will accept Type 1 or Type 2 files, Matrox requires Type 2 files for realtime playback. Type 2 files follow the VfW (Video for Windows) standard, with the audio recorded as a separate file in the DV data stream, while Type 1 files have the audio multiplexed into the video stream. Type 1 files are slightly smaller than Type 2, and perhaps this is why Sony chose to write Type 1 to the flash memory. Sony also makes an optional accessory recording unit called the HVR-DR60 for users of other Sony camcorders having 1394 output. The DR60 records the same Type 1 DV files as the Z7U camera, so RT.X2 users will run into "red lines" in Premiere Pro with these files as well. The fix is to convert the Type 1 files to Type 2 so they will play realtime in a Matrox DV project. The quick and easy conversion method is to use a conversion utility from Canopus, who has for many years provided DV capture hardware for PC editors. The free Canopus DV File Converter software should allow you to quickly find and download this handy utility - you can download it here.
Conversion can be done on individual files, or you can quickly batch convert an entire folder at once. Using the Microsoft DV AVI 2 setting produces files that work in realtime with the RT.X2 hardware, enabling users to enjoy a realtime, tapeless DV workflow. Can I Edit Matrox Projects on Non-Matrox Systems?
The short answer is no, but there are workflows you can use. While there are issues opening a Matrox project on a non-Matrox machine, you can easily go from a Premiere-only project to a Matrox project for realtime effects and finishing work. If you capture DV footage with the RT.X2 and want to edit that footage on a PC that does not have Matrox hardware (Premiere only), you can install the Matrox codecs from the RT.X2 driver disc and you can then work with those Matrox DV .avi clips using a Premiere DV preset. This does not work for Matrox-captured HDV clips with the .avi extension since that codec is hardware-dependent, but there is a way around that – capture your HDV video using the Premiere HDV preset rather than the Matrox preset. The files will have an .mpeg extension, but are still compatible with Matrox projects. In this way, you can capture and rough-cut HDV projects on PCs and laptops having Premiere software only. The project can then be transferred to a Matrox machine via external hard drive. Open a NEW Matrox project using a Matrox preset to match your footage, then go to File > Import and import the Premiere project file of choice. In the clip bin, open the project folder that is created and double-click a sequence to open it and work on it. Matrox effects can now be added and you will have all Matrox features and outputs available just as if it was a Matrox project from the start. Note that Premiere DV clips should also work in a Matrox DV project (no redline), but as with any of the suggestions on this page, I really recommend doing a short test of the desired workflow to make sure it meets your needs and works as expected before committing to an actual project. Projects saved using a Matrox preset might open on a non-Matrox machine, but will open in "Desktop Mode" since Premiere will not recognize the Matrox project preset and effects. Any Matrox-specific effects you had applied will be lost, so this is not a viable option - it’s a one-way trip from Premiere to Matrox. As long as you understand these workflow limitations and pre-plan a little, you should be fine when sharing projects between Matrox and non-Matrox edit stations. Why Does Matrox RT.X2 Use a 720x486 Video Frame Size?
NTSC DV and DVD video both use a frame size of 720x480, but the D1 NTSC Broadcast Video spec is 720x486. The Matrox Axio hardware uses the D1 spec, so to maintain project cross-compatibility between the RT.X2 and Axio platforms for editors using both, the RT.X2 uses the D1 spec. If you capture using a Matrox DV preset, the video IS captured at the standard 720x480 size, so in the Premiere preview window, the DV image is centered with 3 black lines above and 3 below to fill out the 486 frame size. When exporting to DVD, the 6 extra lines are removed so the export is the proper 720x480 size.
For most editing, you can disregard the extra black lines top and bottom, but there are circumstances where some action is required. If you are doing a Matrox Page Curl or any other effect or transition where the black lines are distracting, just use the CROP function to trim them off. CROP is found in most Matrox effects if you scroll down through the effect parameters. You can also apply Matrox Move & Scale just to use the CROP function.
Note that these black lines are specific to standard-definition projects only and do not appear in HDV projects, as HDV is always 1440x1080 for 1080i/p and 1280x720 for 720p video. Consistent White Balance for Live Events
When videotaping live events such as wedding ceremonies, school plays, concerts or dance recitals, the videographer typically has no control whatsoever over the lighting. To make matters worse, the lighting may be constantly changing during the event. A church may have stained glass windows, meaning any entering sunlight may be tinted by the color of the glass. In this case, manually white-balancing the camera may produce good colors, but what happens when the outside light coming in alternates between sunny and cloudy? It can have adverse effects on the white balance. Also, cameras set up at different angles in the church may produce inconsistent colors due to the mixing of electric lighting and window lighting, resulting is mismatched clips when mixing footage from two or more cameras. Stage plays and dance recitals will usually have mood lighting applied, with different scenes having unique lighting treatments to set certain moods. There is no simple way to compensate for all the different setups. Most camcorders allow one custom WB preset, and some now offer two manual presets (A and B), but even two presets will likely not cover the range of lighting you will encounter. You also may not even have an opportunity to test the lighting to set your white balance prior to the event. Many videographers will forego manual white balance and simply set all cameras to the same preset, such as incandescent. While the colors in the recorded video may be off, the idea is that all the cameras will have a matching image and the colors can be corrected in the nonlinear editing suite. Once an appropriate color fix is created in the software, it can be applied to video from all cameras for matching results. I recently did a two-camera shoot of a school play. Some scenes were well-lit, while others were very dark to simulate evening scenes, and many scenes made heavy use of pink gels, giving the scenes an overly pink tint. I simply set both cameras to the "incandescent" WB factory preset, and only changed the exposure during the shoot, leaving the WB constant.
In post, using Adobe Premiere Pro CS3 with the Matrox RT.X2 hardware, I was able to quickly color correct each scene from the close-up camera. I then used "Copy" and "Paste Attributes" to apply the identical effects to the wide camera clips, creating a perfect match when cutting between cameras. There is no possible way I could have attempted changing white balance between scenes during the live shoot. There are certainly many situations where a custom white-balance setting may give the best results if you know the lighting will remain constant for the duration of the shoot. For ever-changing situations as described in this article, your best bet may be to choose a common preset for all cameras and color correct in post. Each situation is unique, and as a video professional you will need to make the call on each shoot yourself. For the play I’m editing, I’m very happy with the speed and ease with which I’ve reached good, matched colors throughout the production. Leaving the white balance alone during the shoot allowed me to focus on composition and exposure, which was enough work running two cameras by myself! The end results speak for themselves.
Apple ProRes 422 codec vs. Uncompressed HD
Apple introduced the ProRes 422 video codec for Final Cut Studio 2 users in 2007. The codec is said to offer uncompressed quality in a compressed codec, but many editors are nervous about using anything less than full uncompressed video to retain broadcast quality. So what is ProRes 422, and how does it measure up against uncompressed HD video? ProRes 422 is a full-raster codec, meaning the video is not scaled down. The full 1920x1080 image is used, unlike DVCPRO-HD or XDCAM, which scale HD 1080 video down to 1280x1080 and 1440x1080 respectively, effectively tossing out a large amount of picture data to save space. Next, ProRes 422 uses a full 10-bit 4:2:2 color space, which provides much better color fidelity than 8-bit color. This makes a real difference when color grading and compositing images. There is simply more color data to work with, and that can eliminate color banding issues by providing more steps in color gradients. ProRes 422 uses a variable bit-rate compression scheme in which complex scenes are less compressed than basic or static scenes, so the quality is distributed as needed to maximize the efficiency of the codec for the best possible image. For 1080i, the ProRes 422 data rate is 145Mbps, and there’s also an HQ setting with a 220Mbps rate. Compared to uncompressed HD video, ProRes files are about five times smaller, using about 20% as much hard drive space per hour. This means smaller, less expensive storage systems can be utilized, making broadcast-quality HD video production more affordable to smaller production houses and independent video producers. ProRes 422 HD video files are so efficient they can be captured and edited on a Mac Book Pro, something you wouldn’t try with uncompressed HD! There are other HD codecs with lower data rates available, but because they are more highly compressed, they take more processing power to encode and decode (play back). The ProRes 422 codec provides a good middle-ground by providing a smaller file size than uncompressed, while providing easy capture and playback on even marginal machines. But what about quality? Review after review by video professionals have consistently rated ProRes 422 quality as "visually equivalent" and "undistinguishable" from uncompressed footage, even after multiple encode/decode cycles. This can’t be said about many other compressed codecs available today. Another important benefit of ProRes 422 is that it allows more layers of Dynamic RT playback. 4 layers of 1080i can be expected, and 720p 24 editors can expect up to 14 layers of HQ footage playback in real time. For reference, a powerful 8-core machine with a video RAID might only play a single stream of uncompressed HD. Even if you don’t normally work with uncompressed video, ProRes 422 can help editors who shoot with compressed formats such as HDV, which is an 8-bit 4:2:0 format using MPEG-2 Long-GOP compression. HDV does not hold up well to editing, so by capturing to the ProRes 422 codec right away, quality will be maintained from that point on, and it’s easier for the system to work with as well. The ProRes 422 codec is supported in the AJA IoHD product, which is a portable capture and playback interface for use with Mac computers. SD and HD video with audio can be captured via a comprehensive set of professional inputs, with the incoming video being converted to ProRes 422 in the AJA hardware and sent to the Mac via Firewire. When playing back ProRes 422 clips from the Final Cut Pro 2 timeline, video is sent over the Firewire back to the IoHD to be sent out any of the unit’s many outputs to various recorders and displays at full quality. Another i/o device for the Mac is the Matrox MXO2, which has similar connectivity to the IoHD, but lacks a hardware ProRes 422 encoder – it is up to the host computer to encode to ProRes on the fly using its processor, so older Mac Books may not be up to the task to capture HD footage. As always, it’s a good idea to not only compare tech specs, but check video forums online to see how devices like these are performing for actual users to help determine which would suit your needs and budget. One last tip – while the ProRes HQ codec is great for video from high-end sources, it may be overkill for formats like HDV. It’s been reported that users are better off to use the standard ProRes 422 codec at 145Mbps with the lower-end HD formats, as there is no advantage to using the HQ codec when starting with a highly-compressed and scaled HD source format. If you’re a Final Cut Pro 2 user and have not tried working with ProRes 422, you owe it to yourself to try it today and see the benefits for yourself. Adobe Premiere Pro Transitions
Adobe Premiere Pro uses a single-track editing style for applying transitions, so to place a transition between two clips, those clips must be butted together on the same track. Older versions of Premiere used a two-track system, which meant the two clips would be on different tracks, with the ends of the clips overlapped. The transition or wipe would be placed on an effects track layered in between the two video tracks, with the transition duration determined by the amount of clip overlap. Since clips in Premiere Pro are placed end to end on a single track, there is no longer any area of clip overlap in which to place the transition. Thus, the end of the first clip and the beginning of the following clips must be trimmed before butting them together, in effect creating some overlap, or extra material, available for the transition to take place in. The transition is then dropped onto the joint between the two adjacent clips. If I want a one-second dissolve between two clips, I would trim 15 frames (one half second) of video off each clip where they meet. This creates one second of overlap, so I can then place a one-second transition where the clips meet. If I decide to lengthen the transition, one or both of the clips would need to be trimmed more to provide the necessary frames of extra video "overlap" for the transition. In the event that you have two clips on the timeline and are unable to drop a transition between them, even though you’ve trimmed the ends, zoom in to frame level ("+" key on keyboard) to examine the area where the clips meet. A small gap of one or two frames may not be visible without zooming in, but would keep you from applying a transition since the clips are not touching one another. If you are coming from Premiere 6.5 or another editing application that used a transition track, it may take a little getting used to in order to remember to trim the clip ends before applying transitions between then. Once you get a handle on the single-track workflow, I’m sure you will find it much more productive to work with as I have. RT.X2 LCD Display Calibration for CS4 Users
Matrox now offers a monitor calibration utility for RT.X2 users that allows the use of an inexpensive LCD display for accurate color grading. This does not apply to the RT.X2 LE or SD models, which lack the DVI output necessary to drive the LCD. The calibration utility is part of the new 4.0 drivers for use with Adobe CS4, and is accessed via the Matrox "TV" icon at the lower right of the Windows screen. Step-by-step illustrated calibration instructions are included in the Matrox User Guide .pdf file found on the Matrox driver disc in the "Documentation" folder, or online here: http://www.matrox.com/video/en/support/rtx2/doc/
Preloaded color bar graphics are included for NTSC, PAL, 720 and 1080 video formats. These graphics are output to your LCD, and will facilitate with the adjustment of hue, chroma, contrast and brightness. There is also a "blue only" mode for additional fine adjustment.
You don’t have to be a video engineer to achieve proper monitor calibration. Just follow the simple instructions provided to match your color bar display to the sample images, and in a matter of minutes, you will have a true-color display that you can rely on for accurate color reproduction for SD or HD editing with your RT.X2 and CS4. Interlaced vs. Progressive Video
For decades, NTSC has been the standard for US television and video, using the 29.97 frame per second interlaced video format. All standard definition TVs, video cameras and VCRs conformed to that spec, but now with HD video we hear a lot about progressive formats such as 720p and 1080p. What does this mean? Let’s use a round number of 30 to describe the number of individual "frames" that make up each second of 29.97 interlaced video. Each frame is made up of two "fields", with one field consisting of all the odd lines in the image, the other field having the even lines. Combining these two fields creates a single frame of video. Since there are 30 frames every second, each frame is 1/30 of a second long. As two fields are needed to create a frame, fields must be recorded every 1/60 of a second! The two fields combined create an entire video frame every 1/30 of a second. A typical video camera shutter speed is 1/60 of a second, so the two fields are captured 1/60 of a second apart from each other. When capturing moving subjects, some motion takes place between the capturing of the first field and the second field that make up the frame, so the images in the two fields may not match up perfectly, so fast motion may have "interlace artifacting" apparent in the picture. Hollywood movies captured on film use 24 frames per second, no fields, each frame being grabbed in its entirety in 1/24 of a second. At 24fps, the human eye can perceive that it is not viewing reality, like seeing "flip book images" displayed rapidly one after another, so subconsciously, a little imagination is used in your head to "make it real", filling in the blanks so to speak. This is what gives film its surreal quality, making it different than "video". We don’t know why, but we just like the look of film! In the video world, progressive video is the equivalent of film, capturing complete frames at once rather than mixing two interlaced fields. Many new HD cameras offer the option to shoot at 24p or 30p, which is 24 or 30 frames per second respectively, with the resulting images more closely resembling film than video. Of course, with less frames per second to work with, slow-motion may not come out as smooth, so there are certain trade-offs to get the coveted film-look. The videographer must also be careful to not pan too fast or the motion can look very jerky. It requires an entirely different way of shooting and editing and may not be for everyone. Of course, if you are videotaping a low-budget movie with the intent of having the end result transferred to film, then acquiring the video at 24 frames can make sense since no frame rate conversion will be necessary when transferring from video to film. Fast-action sports like football may also have a better "look" when shot in progressive. Another option for shooting Progressive HD is to use one of the new "60p" formats coming out, which offer 60fps shooting of non-interlaced video, in which case you can get smooth slow-motion. Some tapeless cameras even offer "overcranking", which records double the frames per second so that when played back at the normal rate you can achieve super slow motion! How Much Video Can I Fit on a DVD?
Video files must be compressed to the MPEG-2 format to meet the DVD specification. The amount of compression can vary, and is determined by the length of the program, as the compressed content must fit the available space on the DVD. At the highest quality setting, a standard 4.7GB DVD can hold 1 hour of video, but at a medium quality setting, the same DVD can hold 2 hours of video. If quality is not that important for your application, you can even fit 3 hours or more on a single DVD by compressing the material at a lower data rate. You will want to specify Dolby Digital (AC-3) audio in your DVD encoding settings, as this uses much less space than the standard "PCM" uncompressed audio, leaving more room for higher quality (less compressed) video content. While an encoding bitrate of 8.0 is about the maximum allowed for the video, I don’t recommend going above 7.0 as it can cause playability issues with some players, and any quality difference at those rates is negligible. A good rule of thumb to figure the encoding data rate is 4.5 for 120 minutes, 6.0 for 90 minutes, and 7.0 for 60 minutes or less. An easy formula to figure the proper rate is 560/minutes, assuming Dolby Digital audio encoding. MPEG-2 or H.264 for Blu-ray disc?
When encoding video for Blu-ray disc, you can use MPEG-2 or H.264 encoding. MPEG-2 is used for DVD, but a much higher data rate is used for HD content on Blu-ray, so the image can be quite good. The benefit of H.264 is that at the lower data rates used to fit long programs on a disc, H.264 is more efficient than MPEG-2 and will produce a better quality. At higher data rates though, this advantage is less apparent. Considering that H.264 takes about 5x as long to encode as MPEG-2, you must decide whether the content is worth the extra hours of encoding time. If your workflow is such that you can do the encoding overnight, then H.264 becomes a more obvious choice, but when the production demands speed, MPEG-2 is quite suitable for most jobs. Either format is supported by all Blu-ray players per the official Blu-ray specification.
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