I realize the upgrade cost is considerably higher than buying the QT codecs, but depending on how often you run into this situation, it might be worth it. Doesn't Quicktime have to be able to play it first in order for AMA to work? I thought you had played it on your system through Quicktime, but rereading this you may have just opened it to use the movie inspector to see what the codec was.
If QT wouldn't play it on your system, then upgrading won't help the situation, and I apologize for leading you down a dead end.
That's exactly what I did, Carl. Right now, it won't play in QT Pro. I just get audio, no video. This is a good article to read You are going Mac to PC right? Marianna: You are going Mac to PC right? Marianna: Calibrated works Is Calibrated or Raylight preferable? Or will the Avid Codecs PE work for free?
Call me a dummy, but I don't know where to find this? Thanks, Adman. I found it and ran the install program, but I still get the white screen no codec when I import the file. I would have thought, with FCP becoming so popular, this would be something that comes up all the time, but a search of the forum and web-at-large yields no concensus solution.
In rare occasions, audio is embedded inside dedicated DIF frame structures. Files recorded this way are written inside QuickTime. MXF container is also used since the launch of P2 cards. Treasured detects the profile used in unplayable DVCPro HD files , as well as the presence of additional audio tracks , after a P2 card data recovery.
Our team of technicians will prepare the specific Repair Kit that can fix your damaged files and guarantee a perfect result to keep going your postproduction work.
Was this article The video is sampled at the same rate as D-1, D-5, or Digital Betacam video -- pixels per scanline -- although the color information is sampled at half the D-1 rate: in line NTSC , and in line PAL formats. See below for a discussion of color sampling. DV uses intraframe compression: Each compressed frame depends entirely on itself, and not on any data from preceding or following frames. However, it also uses adaptive interfield compression; if the compressor detects little difference between the two interlaced fields of a frame, it will compress them together, freeing up some of the "bit budget" to allow for higher overall quality.
In theory, this means that static areas of images will be more accurately represented than areas with a lot of motion; in practice, this can sometimes be observed as a slight degree of "blockiness" in the immediate vicinity of moving objects, as discussed below.
Roger Jennings' papers run through the detailed numbers. The consumer-oriented DV uses 10 micron tracks in SP recording mode. Sony's DVCAM professional format increases the track pitch to 15 microns at the loss of recording time to improve tape interchange and increase the robustness and reliability of insert editing.
Panasonic's DVCPRO increases track pitch and width to 18 microns, and uses a metal particle tape for better durability.
DVCPRO also adds a longitudinal analog audio cue track and a control track to improve editing performance and user-friendliness in linear editing operations. Newer DV camcorders offer an LP mode to increase recording times, but the 6. Digital8 tapes themselves use the same timecode as DV. It appears to be the 8mm division's way of keeping its customer base from defecting to DV. By leveraging the massive investments of 15 years in 8mm analog camcorders and transports, the unit cost of Digital8 gear is kept very low, roughly half of what a comparable DV camcorder would cost, and its ability to play back legacy analog tapes is worthwhile for those with large libraries of 8mm.
Hitachi also produced Digital8 camcorders although these seem to be hard to come by thanks to James M. DeLuca for bringing these "stealth" camcorders to my attention.
All Digital8 camcorders can record from the analog inputs at least outside the EU , and all are equipped with i. Link ports for digital dubbing and NLE connections. On a scale of 1 to 10, where 1 is just barely video and 10 is as good as it gets, I would arrogantly rate assorted formats as follows:. My feeling was that while D-2 and D-3 are excellent first-generation formats for composite analog playback and NTSC broadcast, the compositing of color with luma which includes a color bandwidth limitation even more severe than DV or BetaSP employ makes clean multigeneration and multi-layer image compositing problematic at best even such simple things as adding titles.
However, I was severely upbraided by several folks with extensive digital composite experience, who all rated D-2 and D-3 between DV and DigiBeta. If you've got a high-end all-digital postproduction chain, the quality in these formats holds up over multiple generations extremely well, much better than any analog format, be it component or composite.
While this is certainly true, if you don't have that all-digital pathway, I'm doubtful about how they would fare Again, folks who live in high-end digital suites all day suggested this, and I have to agree.
But after you sit in front of analog component or digital monitoring using BVM or Panasonic broadcast-grade monitors, your attitudes start to adjust upwards, and you start to discern differences between the merely very good stuff and the truly excellent stuff a bit more readily! Please note that I'm rating the formats here, not any particular implementation. Don't confuse the images produced by a bit of equipment with the underlying capability of its recording medium.
Sony rates BetaSP's luma frequency response to 4. Oxide playback i. Chroma resolution on BetaSP is essentially the same as on DV, so were BetaSP a digital format, its sampling might be characterized as for comparison purposes. Of course, BetaSP is not sampled on a fixed spatial grid, so such numerical comparisions should always be taken with a grain of salt. I am hoping to get permission to repost that article on my site, as it's no longer available on DV's website nor in the Internet Archive.
The most noticeable spatial artifact is mosquito noise around any sharp, contrasty edges. These are compression-induced errors usually seen around sharp-edged fine text, dense clusters of leaves, and the like; they show up as pixel noise within 8 pixels of the fine detail or edge causing them. The best place to look for them is in fine text superimposed on a non-black background. White on blue seems to show it off best. The magnitude of these errors and their location tends to be such that if you monitor the tape using a composite video connection, the artifacts will often be masked by dot-crawl and other composite artifacts.
A spatial quilting artifact can sometimes appear at the boundaries between 8x8 pixel blocks, most noticeable on shallow diagonals or on slightly-defocused backgrounds, typically when there is some motion in the scene to make the fixed "grid pattern" a bit more obvious. Some DV codecs seem to be much more prone to this than others, and with a few the quilting really starts to appear only after a few generations of rendering.
Motion blocking occurs when the two fields in a frame or portions of the two fields are too different for the DVC codec to compress them together.
Motion blocking is best observed in a lockdown shot of a static scene through which objects are moving: in the immediate vicinity of the moving object say, a car driving through the scene , some loss of detail may be seen. This loss of detail travels with the object, always bounded by DCT block boundaries. However, motion blur in the scene usually masks most of this artifact, making this sort of blocking almost impossible to see in most circumstances.
Finally, banding or striping of the image occurs when one head of the two on the scanner is clogged or otherwise unable to recover data. The image will show 10 horizontal bands 12 in PAL countries , with every other band showing a "live" picture and the alternate bands showing a freeze frame of a previous image or of no image at all or, at least in the case of the JVC GR-DV1u, a black-and-white checkerboard, which the frame buffers appear to be initialized with.
Most often this is due to a head clog, and cleaning the heads using a standard manufacturer's head cleaning tape is all that's required. It can also be caused by tape damage, or by a defective tape. If head cleaning and changing the tape used don't solve it, you may have a dead head or head preamp; service will be required. This sort of banding dropout occurs fairly often; about once per DV tape in my experience.
Usually it isn't even noticeable -- a single frame of banding due to a momentarily clogged head won't be visible unless there's motion in the scene to show off the frozen stripes. Have a look through your old tapes frame by frame on a slow day, of course!
DVCAM, with its 15 micron track width, or DVCPRO with its 18 micron track, are sufficiently on the safe side of the bleeding edge so that this sort of droput is much less likely to occur.
One visible dropout per hour-long tape, on average, is not something to get flustered about. The tape data rate is doubled to 50 Mbps video and the compression work is split between the two codecs.
The result is a image compressed about 3. It's visually lossless and utterly gorgeous. Think of Digital Betacam, albeit at 8 bits instead of 10, at a bargain price.
Only JVC is supporting this format, which has resulted in a less-than-headlong rush by the video community to embrace it. Watch it, though; it's hot.
If you're doing high-end EFP on a budget, this is the format to use. DVCPRO50 kit is also a lot more portable and lightweight than D-9, so it's the format of choice if you're doing high-end EFP with a somewhat bigger budget and you want to keep your camera operators from wearing out as quickly!
Both firms gang four DV codecs together to get the Mbps datastream, while preserving the same equipment form factor and operational methodologies used in the current 50 Mbps products. Thus the line DV formats have slightly lower luma resolution than HDCAM but slightly better chroma resolution see the next section for a discussion of sampling.
I have not found a second source for this information, so I can't confirm it. It should be noted that both Panasonic and JVC are well-placed to serve the growing DTV market whatever image format a broadcaster selects.
The first number refers to the The The other two numbers refer to the sampling rates of the color difference signals R-Y and B-Y or, more properly in the digital domain, Cr and Cb. Thus you have color samples in each of Cr and Cb per scanline. The Cr and Cb samples are considered to be co-sited with every fourth luma sample. Yes, this sounds horrible -- but it's still enough for a color bandwidth extending to around 1. Fortunately not! Chroma is sampled times per line, but only on every other line of each field.
The theory here is that by evenly subsampling chroma in both H and V dimensions, you get a better image than the seemingly unbalanced , where the vertical color resolution appears to be four times the horizontal color resolution. Alas, it ain't so: while works well with PAL and SECAM color encoding and broadcasting, interlace already diminishes vertical resolution, and the heavy filtering needed to properly process images causes noticeable losses; as a result, multigeneration work in is much more subject to visible degradation than multigeneration work in But wait, there's more!
Practically speaking, this is a headache for developers of codecs, encoders, and DVEs, but for DV purposes it's not especially exciting, since only European DV is Sometimes there is a reason for the higher prices that the poor Europeans are saddled with when it comes time to purchase gear Part of the standard JVC sales pitch for D-9 is the superiority of which is true , and the utter doom and degradation that awaits you should you try to do anything -- including chroma-key -- with a format which is, shall we say, a wee bit exaggerated.
But that doesn't mean that you can't do very satisfactory work in Just be sure you take the hype with a grain of salt. True, the chroma performance of formats is superior to formats, especially in multigeneration analog dubbing. But by the same token, is as superior to as is to or Where DV can get into trouble is that the coarse resolution of the chroma signal only samples per scanline in leads to a very regular, "steppy" key signal, most noticeable on near-vertical edges or vertical edges where motion is present, especially if the codec's decompression simply replicates the chroma sample across the intervening pixels instead of low-pass filtering or interpolating between samples.
The Matrox RTX. Using these tools I can make very clean and acceptable keys, certainly for hard-edged keying. You may also find that layering different key signals gives you excellent results. I've used a heavily-choked chroma key to cut my main matte, but then add one or two luma, extract, or difference keys to define the edge detail that the chroma key can't get.
Each luma key may only work for a small part of the image; it may lose the greenscreen background but also lose the interior of a similarly-bright face. However, it usually is able to get edge detail, because the edges of a person fall off in shadow or are picked out brightly by the rimlight, and the chroma key holds the interior matte that the luma key won't provide. I simply kick myself for not trying it out sooner!
John Jackman has some good examples of DV keying on his post-production pages at greatdv. Of more concern is that DV artifacts, especially mosquito noise, may become annoyingly prominent when upconverted. However, the jury is still out on this; I've performed upconversions without excessive artifacts, but a lot depends on the subject material. Again, reducing edge enhancement helps. Also, HD material is The way many DV cameras produce by throwing away vertical resolution is enough to send shudders up my spine for SDTV work; for HD, it'll be a complete disaster.
Perhaps I should add a section on shooting for HD upconversion; there are lots of issues No decompression or recompression occurs. If a digitally-perfect copy is a 10, and a point-the-camera-at-the-screen-and-pray transfer is a 1, here's how DV picture quality holds up over different transfer methods:.
Since a transfer is a direct data dump, this is understandable; if a cross-format transfer were to be possible it would require that one deck or the other "translate" the signal to or from the DVCPRO data format to the Blue Book format.
Remember, DVCPRO was designed first and foremost as an ENG format; robustness of the signal was paramount, and interconnection of gear in the ENG world is done via analog or via SDI is too limited an interface for the broadcast world, where the ability to switch and route video over thousand-meter runs is both necessary and taken for granted; has a length limit of 4.
This economy measure is simply one of allowing the audio clock to "hunt" a bit around the desired frequency; the phase-locked loop or other slaving method used to keep the audio sampling in sync with the video sampling can have a bit more slop in its lock-up, with the audio sampling sometimes running a bit slower, sometimes a bit faster, but always staying in sync over the long run.
It's the difference between walking a dog on a short leather leash, always forcing the dog to stay right by your side locked audio , and using a long, elastic leash or one of those "retractable clothesline" leashes that allows the dog to run ahead a bit or lag behind unlocked audio.
0コメント