The most important aspect of EDIUS NLE Systems is Canopus codec technology. Canopus has developed several innovative codec technologies, and these have always been the driving force behind most Canopus products.
EDIUS NLE software now comes with the powerful Canopus HQ (High Quality) codec. This means if you use EDIUS NLE software for nonlinear editing, you will have access to this high quality codec regardless of whether or not you have Canopus hardware installed. When using EDIUS NLE software for editing HDV, select the HQ codec to be used throughout the project. The HQ codec uses the same resolution found in HDV cameras (1440 x 1080i for example).
During capture, the HQ codec transcodes the native HDV MPEG-2 Transport Stream into a Canopus HQ format AVI using “intra-frame” compression (all the data required to decode the frame is located within the same frame, as contrasted to the “inter-frame” compression used in MPEG where most frames are reliant on information from other frames to be decoded.) This increases realtime performance by reducing the overhead required to decode the file for playback and editing, while still maintaining true HDV quality.
Another major advantage of the Canopus HQ codec is that it uses a dynamic variable bit rate in order to create a file that still maintains all of the original quality of the MPEG-2 Transport Stream. This bit rate will automatically adjust itself to a higher or lower data rate based on the information that is being processed. For example, video that had less color and motion (a shot of the blue sky ) would have a lower bit rate than video that had lots of color and motion (like an amusement park). Even if both of these scenes are in the same video clip, the bit rate will adjust over time, keeping quality high without using an excessive data rate for ‘simple’ video. This is why we say that the HQ codec has a dynamic and variable bit rate. In general this bit rate will float no lower than 100 Mbps and no higher than 170 Mbps, but for most ‘normal’ video will sit between 130-140 Mbps in default quality setting. As you can see, even at 130 Mbps these HQ AVI files can be 5 times larger than the native HDV MPEG-2 Transport Streams. The trade off generates a file that maintains all the original quality of the HDV footage, in a compression format (Canopus HQ) that is easy for editing software to process.
EDIUS NLE software can process both native HDV MPEG-2 Transport Streams and Canopus HQ AVI files. Canopus HQ AVI files, however, allow for much more realtime performance than the MPEG-2 Transport Streams. Because the HQ codec uses intra-frame compression, every frame of these HQ AVI files contains the full information needed to process any effect, title, or transition within EDIUS (unlike MPEG-2 files, which require extra decoding for each frame of video because of inter-frame compression). This means that on a system where you could get only one stream of MPEG-2 to play back in realtime, you could get up to four layers of HQ AVI files to play back in realtime with simple PiPs applied.
Canopus codec technology also allows EDIUS NLE software to process multiple formats and frame rates within the same timeline. When starting an EDIUS project, the user can select a codec, as well as the resolution and frame rate (HDV 1080/60i, HDV 720/30p, DV NTSC 4:3, etc). These project settings will determine how all clips added to the timeline are processed. As an example, a project for HDV might be set up as HDV 1080/60i using the Canopus HQ codec. If the user drops 1080i Canopus HQ AVI files into the timeline these clips playback effortlessly as the project settings match the format of the AVI files. The user is still free to add other clips to the timeline that are not the same as the project setting currently used. If a user decides to bring in SD MPEG-2 clips, SD 16 x 9 clips, or even NTSC or PAL DV clips, the EDIUS timeline will accept them and they will remain in their native format on the timeline. During playback EDIUS Pro 3 will pre-process these clips to match the project settings being used in realtime, without making any changes to the original clip. So while the SD MPEG-2 clip will remain an SD MPEG-2 clip on the disk, during playback in an HDV project there is processing power being used to convert that clip on-the-fly to the HDV project setting. This is what we refer to as “pre-processing.”
Pre-processing also comes into play if there is an effect, title, or transition that needs to be applied. As an example, let’s consider that SD MPEG-2 clip placed on the 1080/60i project timeline. The SD MPEG-2 clip is converted to 1080/60i on-the-fly during playback, without changing the original file. If a color correction is applied to that clip, there will be additional processing we refer to as “effect processing.” Upon playback of the SD MPEG-2 clip, EDIUS Pro 3 will now be doing pre-processing (to make the clip play back at the project setting) and then effect processing for the color correction. This means that the color correction is being processed at 1080i instead of the SD resolution of the original MPEG clip, because the pre-processing has already occurred before the effect processing. This is a lot of information to be processed, yet EDIUS Pro 3 software can do this and more in realtime, because of the high performance and high quality Canopus codecs build into the application to maximize processing performance.
All of the processing described thus far happens solely within the EDIUS NLE software. That means that even if you use EDIUS software with an OHCI card, a supported Canopus realtime DV card (like DVStorm), or one of the Canopus HDV hardware cards, the processing will still be handled in the same manner — within the software.
Canopus hardware becomes important for capturing footage and for output to an external monitor when realtime output is needed.
Canopus pioneered Scalable Technology as the best way to prolong the life of its products, thereby benefitting its customers with significantly higher ROI than competing products. This concept remains true for EDIUS Pro NLE software and EDIUS NLE Systems, as well. With EDIUS software, CPU power is the primary fuel for realtime performance. More CPU power available on the system means that more layers, titles, and effects can be processed in realtime.
Even with the introduction of the HQ codec, dual processors are currently necessary to edit this HDV in realtime. HQ AVI files can be five times larger than standard DV clips, so editing two streams of HQ AVI is comparable to editing 10 DV streams! Editing the native MPEG-2 Transport Stream requires even more processing power. That is why EDIUS Pro 3 software is specifically designed to take advantage of available processing power and yield increased performance with more CPU power. Currently, a dual Pentium 4 Xeon 2.8GHz system can edit two to three layers of Canopus HQ (1080i) clips in realtime. If using native MPEG-2 Transport Stream clips, typically only one layer can be edited in realtime. In addition to CPU speed, realtime performance is also dependant on hard disk and memory transfer speed.
Next Section > EDIUS NX with HD Expansion Kit and EDIUS SP with HD Expansion Kit
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