• Blogs
• Forums
• Tradeshows
• Partners
• White Papers
• Events

 

Edit Review — Canopus Edius NX for HDV

Aug 1, 2005 12:00 PM, By Steve Mullen

NLE/hardware bundle facilitates two methods of HDV editing.

Sidebar
Laptop Editing

With Edius NX for HDV, Canopus offers an HDV editing solution that allows editors to approach HDV material in a couple of different ways. Depending on their system's computing power and their working style, editors using Edius NX for HDV can employ either Intermediate or Native techniques. (In the July issue of Video Systems and here, see “HDV in the Real World” for an overview of four ways of editing both 720p and 1080i60 HDV. The four techniques are Draft, Proxy, Native, and Intermediate.)

Edius NX for HDV ($2,098, including the HDV Expansion Kit) is a hardware/software bundle that facilitates HD and SD editing. The bundled software component of NX for HDV is Edius Pro 3 ($699 on its own), which is a highly enhanced version of the much beloved DVStorm NLE. (When used by itself, Edius Pro 3 uses an OHCI FireWire I/O port. The OHCI port can input and output DV/DVCAM — but not DVCPRO — plus 720p30 and 1080i50/1080i60 HDV.)

Edius NX for HDV includes a PCI board that provides four functions for I/O. There's a FireWire I/O port for DV/DVCAM. A second FireWire port on the included HDV Expansion Kit supports 720p30 and 1080i50/1080i60 HDV input (720p30 cannot, however, be output). The board inputs composite and S-Video with unbalanced audio input, and it outputs composite and S-Video output with unbalanced audio. A 5.25in. front-panel bay is included with the HDV Expansion Kit. The NX analog connections on the front panel allow you to work with any kind of SD video.

The HDV Expansion Kit also provides analog component SD and HD (1080i only) output via YPbPr. The board has the advantage of hardware-based line scaling that converts the 1440×1080 resolution of 1080i (HDV and Canopus' HQ codec) to 1920×1080 (but not to 1280×720p). With other editing systems, line-scaling is handled by the CPU, which restricts realtime editing performance.

For those working with DV (perhaps downconverted from HDV), NX features a hardware DV codec that relieves the CPU from handling the task of rendering a DV output stream. NX also has a proprietary hardware and device control driver that supports frame-accurate capture and output to DV devices. Frame-accurate control means NX can output video back to an exact location on DV tape, for perfect insert recording.

Both Edius NX for HDV and Edius Pro have a Codec Option ($999). The option includes DVCPRO 50 and DVCPRO HD 4:2:2 software codecs developed in collaboration with Panasonic. The Codec Option supports compressed capture as well as compressed print-to-tape using the Panasonic AJ-HD1200A DVCPRO HD VTR. (This enables you to output your HDV production easily to a rented AJ-HD1200A.) Both 1080i50 and 1080i60 can be transferred using either an OHCI FireWire port or the FireWire port on the Edius NX Expansion Kit. Support for 720p50/720p60, Panasonic Varicam, and Pansonic P2 has been announced for Q3 — as has Sony XDCAM support.

In this review, we will be looking at the Edius NX for HDV solution. Up front it is important to note that the NX board requires a 64-bit (66MHz) PCI slot, not a PCI Express (PCIe) slot. Most new computers have switched to the PCIe bus.

Table 1 shows the codecs available to the analog and digital ports of the NX for HDV product.

When DV25 video (including 24p) is captured, it can be stored directly to disk — exactly as with any native DV solution — or encoded to MPEG-1 or MPEG-2. All streams are decompressed to 8-bit 4:2:2 uncompressed digital video when effects are encountered.

When you choose analog input, it is digitized to 8-bit digital video that can be stored as 8-bit uncompressed video, compressed by a hardware DV codec to DV25, compressed to the Canopus Lossless codec, encoded to MPEG-1 or MPEG-2, or compressed as SD to the Canopus HQ codec.

Although both 8-bit uncompressed analog video and 8-bit uncompressed rendering offer very high quality, those who demand the quality provided by 10-bit uncompressed video will be disappointed to learn this capability is not available from Canopus.

When either DVCPRO 50 or DVCPRO HD is captured via FireWire, it is stored directly to disk. It cannot be transcoded to or from any other codec during capture.

Neither NX nor SP supports JVC's 480p25/480p50/480p60 SD HDV. However, you can edit these JVC codecs with Edius Pro. No support for the JVC GY-HD100 HDV camcorder has been announced.

Native codec editing

Edius Pro 3 (with or without NX) supports native HDV editing, according to the common industry definition: that is, transport stream clips are placed directly into the timeline, where they are edited. In my tests, native editing was flawless: two streams of 720p30, but only one stream of 1080i60.

Edius also allows a timeline to contain multiple formats. An HD timeline can contain HDV, DVCPRO HD, and HQ (Canopus' intermediate HDV codec). It is also possible to include SD media. If your SD media is 16:9 anamorphic, it is simply scaled to HD resolution. If, however, your SD media is 4:3 letterbox, you have the option to letterbox, center-and-edge-crop, or zoom-and-edge-crop. For those who need to incorporate legacy material, this is a powerful feature.

As with most native NLEs, before a timeline can be recorded back to an HDV camcorder, every MPEG-2 frame must be decoded and encoded. The new video elementary stream, along with the audio elementary stream, is then packed into a new transport stream. As you might imagine, this can take hours for a long production. (There are NLE options that repackage only at cut points and, of course, during effects, which is considerably faster but still requires a time investment during export.)

All native editing require a very powerful computer. For this review, Canopus sent me the minimum recommended computer, a dual 3.4GHz Xeon system with 1GB of RAM. However, Edius Pro 3 (with or without NX) offers another HDV editing option that requires much less computing power: intermediate codec editing.

Intermediate codec editing

By splitting the editing process into two phases, the amount of computing power required is significantly reduced. The key to splitting the computational tasks is first to capture HDV and then to convert HDV to an intermediate codec. Obviously, one type of intermediate is uncompressed video.

Canopus has an intermediate codec called HQ. The company recognizes that uncompressed HD video requires massive data bandwidth and massive amounts of media storage. Canopus believes that by using an intermediate that does not degrade either HDCAM or DVCPRO HD, yet requires vastly less bandwidth than using 8-bit uncompressed, it has developed the optimal solution for editing HDCAM, DVCPRO HD, and HDV.

HDCAM and DVCPRO HD can be input only via HD-SDI. Unfortunately, neither SDI nor HD-SDI is an option for NX. Either you must buy the Codec Option and use the Panasonic HD1200A VTR for FireWire output of DVCPRO HD material — or buy a Canopus HD workstation to input HDCAM. Therefore, NX only accepts HD in the form of HDV via FireWire.

Canopus developed the HQ codec to keep the image quality of Sony HDCAM and Panasonic DVCPRO HD video data, while allowing compression for realtime editing. The HQ codec supports variable bit rate (VBR) to sustain high quality while keeping total data bandwidth low by adjusting compression rates between simple images and complex images within a video stream. In addition, the HQ codec's calculation method allows optimal speed performance during decompression and compression.

Table 2 shows the sampling characteristics used by DVCPRO HD and Sony's HDCAM — as compared with the Canopus HQ codec.

Compared with the DVCPRO HD and HDCAM codecs, the Canopus HQ codec uses 4:2:2 subsampling and downsamples the luma resolution to 1440. Therefore, the luma resolution is equivalent to that of HDCAM and higher than that of DVCPRO HD — while chroma resolution is higher than that of both DVCPRO HD and HDCAM.

Canopus has performed a series of tests in which codecs are fed a signal that sweeps from 1MHz to 30MHz. The tests compare the HDCAM signal output with the HQ signal output.

The tests clearly show that the luma response and chroma response for the Canopus HQ codec have the more extended frequency response. The Canopus codec was operating at a data rate of only 105Mbps, which is considerably lower than that of HDCAM (140Mbps) and approximately equal to that of DVCPRO HD (100Mbps).

The data rate — 15MBps — for the 8-bit HQ codec is a fraction of that of 8-bit uncompressed video, which has a data rate of 124MBps. Moreover, HD HQ video requires very little computing power (compared to HDV) to edit in realtime. And, significantly, a RAID is not required.

Canopus provides several ways you can make use of the HQ codec. If you have at least a dual 3.4GHz Xeon, you can capture 720p30, 1080i50, and 1080i60 HDV via FireWire and convert it in realtime to HQ during the capture.

A 3.4GHz dual Xeon system supports five streams of 720p30 and three streams of 1080i HQ video. Obviously, if you have the computing power, this is the optimal way to edit HDV.

One last important point: the NX hardware drivers are available for Premiere Pro. So if you would prefer to use the Adobe NLE rather than Edius Pro 3, you can.

Once you make the decision to purchase a powerful computer, Edius NX for HDV is a reliable and sophisticated solution for editing both SD and HD. I recommend it highly.

---

Laptop Editing

Recently, I tried editing both 720p30 and 1080i60 HDV on my 3.2GHz Prescott P4 laptop, which has 1GB of RAM and an 800MHz FSB. (See my “Home-Building for HDV” here for further details.) I used the Edius Pro 3.3 MPEGCapture Tool to acquire 720p30 HDV via i.LINK from a JVC GR-HD1 camcorder. (Enable “Continue capturing when a discontinuous stream during the capture is detected.”) Each shot was automatically dropped into a Bin. The following five-second transitions could be performed in realtime with native 720p30 HDV: 3D Fly-away, 3D Flying Sphere, 3D Cube Spin, 3D Peel Away, 3D Page Peel, Box or Circle with soft colored edge, Slide, Stretch, Clock Wipe, and Dissolve. Since transitions are typically shorter, I found this performance acceptable.

Static titles (with fade-in/out) can be played in realtime, as can clips with Monotone, White Balance (three color wheels), and YUV Curve (gamma curve) filters.

However, when clips are color-corrected, a Dissolve in realtime is now limited to only four seconds. If you want to use other transitions on corrected clips, or work with keys, you'll need to render the effect. A one-minute chroma key took almost 2.5 minutes to render. An export to HDV took 3X the timeline duration.

After capturing 1080i60 HDV, I found the native clips could not be played in either the source or timeline monitor. This was not an unexpected finding because editing 1080i requires more than two times greater computing power than editing 720p30 — for no significant increase in spatial resolution.

Next, I tried editing HD-resolution material encoded to HQ on my Dell 9100 laptop. To accomplish this, you first use the MPEGCapture Tool to acquire HDV via FireWire into a Bin. Second, you either select all clips and drop them into the timeline, or preview each clip and drop only desirable clips into the timeline. Third, you export the timeline as an HQ movie. I found 720p30 HDV could be converted to 1280×720 HQ at a 1:1 time ratio, while 1080i60 HDV could be converted to 1440×1080 HQ at a 2.5:1 ratio. Obviously, Canopus needs to make the HDV-to-HQ conversion a double-buffered operation so capture/conversion can be done automatically on any computer. Doing so would not save time, but it would save effort.

Next, I imported both HQ movies into Edius Pro and trimmed each into clips I then placed into the timeline. Transitions with 720p30 HQ could now be 20 to 30 seconds long. Transitions on color-corrected clips could be at least 10 seconds long. Moreover, keys were now realtime. At least three streams can be superimposed. This is very acceptable performance.

An export to HDV took 3X the timeline duration. Clearly, if you can accept the time required to convert your HDV source material to HQ, you'll be able to edit almost any production in realtime on a P4 system.

Next, we'll look at the most interesting question. Will HQ enable us to edit 1060i60 on a laptop in realtime? I found that transitions (3D Fly-away, 3D Flying Sphere, 3D Cube Spin, 3D Peel Away, 3D Page Peel, Box or Circle with soft colored edge, Slide, Stretch, Clock Wipe, and Dissolve) could be up to three seconds long. Static titles (with fade-in/out) can be played in realtime, as can clips with Monotone, White Balance (three color wheels), and YUV Curve (gamma curve) filters.

When, however, clips are color-corrected, a Dissolve is now limited to only two seconds. If you want to use other transitions on corrected clips, or work with keys, you'll need to render the effect. A one-minute chroma key took almost 3.5 minutes to render.

An export to HDV took almost 5.6X the timeline duration. Once again, if you can accept the time required to convert your HDV source material to HQ, you can edit 1080i60 video on a P4 system. As you can see, Canopus has found a way to provide two types of Edius Pro 3 editing. If you do not have a dual Xeon, the native HDV path eliminates HDV-to-HQ conversion time. Conversely, the HQ codec increases realtime performance at the expense of HDV-to-HQ conversion time. Neither path supports 1080i60 editing.

If you have a dual Xeon system, which can convert HDV to HQ in realtime during the FireWire capture, the HQ codec avoids the significant costs incurred working with uncompressed video while providing optimal 720p30 and 1080i60 video quality. A dual Xeon also maximizes native 720p30 editing performance — although it provides minimal native 1080i60 performance.

---

BOTTOM LINE

Company: Canopus San Jose, Calif.; (408) 954-4500

Website: www.canopus.com

Product: Edius NX for HDV

Assets: Included HDV Expansion Kit supports 720p30 and 1080i50/1080i60 HDV input; HQ codec allows for more powerful realtime editing (and less required bandwidth) with HDV material.

Caveats: DVCPRO 50 or DVCPRO HD cannot be transcoded upon input via FireWire.

Demographic: Optimal for HDV editors with dual Xeon systems.

© 2008 Penton Media, Inc.