Sony dvcpro codec

What does a connection do for me? Locked vs unlocked audio - What's the difference between locked and unlocked audio? Will unlocked audio hurt me? How do I deal with it? How do I intermix locked and unlocked audio? Does unlocked audio explain why my audio loses sync in Adobe Premiere?

Which DV devices support Closed Captioning? What about DTV Captioning? Are all digital formats like DV in this regard? How's it handled for broadcast? How do I handle lack of setup on my NLE's analog outputs?

Can I fix it by adding setup on capture? How do I define my pedestal level in my show? Is the "7. Didn't find what you wanted here? Try the other pages listed below DV FAQ - etc. DV Pix DV sampling, artifacts, tape dropout, generation loss, codecs. DV is an international standard created by a consortium of 10 companies for a consumer digital video format. Ltd, Hitachi, Ltd. Since then others have joined up; there are now over 60 companies in the DV consortium.

Not a lot! The basic video encoding algorithm is the same between all three formats. But the video data recorded in all three formats is essentially identical, though there may be minor differences in the actual codec implementations. A summary of differences and similarities is tabled in Technical Details.

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: D-5 bit uncompressed digital 10 D-1 8-bit uncompressed digital 9. DV artifacts [ Pix: Artifacts ] come in three flavors: mosquito noise, quilting, and motion blocking. Other picture defects [ Pix: Defects ] encountered are dropouts and banding a sign of tape damage or head clogging.

Unlike D-9, second-sourcing is available from Philips, Hitachi, and Ikegami. As PAL DV was intended as a consumer format for off-air recording or camcorder acquisition, multigeneration losses in were considered a less important factor than the optimization of first-generation performance. Yes indeed. As previously mentioned, BetaSP could be considered a format in terms of component bandwidth, and BetaSP is used for chroma-key applications all the time.

IEEE is a standard communications protocol for high-speed, short-distance data transfer. Check out the Trade Association , white papers on Adaptec's website, and DVCentral's links for pointers to additional sites for detailed information.

Sony calls their implementation of "i. They appear to have been developed together. The data stored on DV tape appear to reflect the packet structure sent across a link to a frightening degree of exactness. You can do cuts-only linear editing over , with no generation loss. You can stick a board into your computer PC or Mac , and transfer DV to and from your hard disk. If your system can support 3. Some time ago I edited a friend's wedding, going from Hi8 camera originals to a DV edit master.

The minute ceremony was covered by two cameras; we sync-rolled the VTRs and mixed the show in real time as if it were live. At the end, we weren't sure we liked it. So we dubbed it off via to another DV cassette, inserted a fresh DV cassette, and had another bash at the edit. This time, we liked it. We put the tape into the VX and set up the DHR VTR as the recorder, using the built-in editor to drop the second attempt in frame-accurately atop the first across the wire.

No generation loss. And we still had the first edit on the backup tape, should we have changed our minds. A dub is a digital copy. It's identical to the original. That's really nice. These changes were made by Panasonic's engineers to improve the robustness and reliability of the DVCPRO system when compared to DV, but they do mean that certain data header bits do not conform to Blue Book standards. Locked vs unlocked audio What's the difference between locked and unlocked audio?

Locked audio is "audio done right": the audio sample clock the digital time reference used in the sampling process is precisely locked to the video sample clock such that there is exactly the same number of audio samples recorded per "audio frame" of video not all TV formats and sound sample rates have a neat integer relationship between audio samples and frames, so an "audio frame" is my term [similar to a "color frame"] for the number of video frames it takes for audio and video to match up in the same phase relationship.

Since DV was designed as a consumer format, unlocked audio was allowed as a cost-saving measure. Unlocked audio: real life: "The difference between theory and real life is that in theory, there is no difference between theory and real life, but in real life, there is a difference.

Some manufacturers appear to take the word "unlocked" literally; a completely separate clock seems to be used for the digitization of audio, with no direct linkage or locking to the video clock.

The result is an audio timebase stability that's excellent since no "hunting" around a target frequency is present , but the possibility arises of a long-term drift between audio and video, when processed independent of each other. Analog is always safe to use for dubbing or editing.

As discussed above, DV audio data are converted to analog in real time as the data come off the tape, and audio slippage simply doesn't occur regardless of the accuracy of the sampling clock.

It's best not to intermix any variations of digital audio on the same tape. Some non-linear editors are very uppity about audio changes; if you start digitizing a 48 kHz clip and the audio changes to 32 kHz, you'll get silence for the entire 32 kHz section or vice versa; once the capture card and software start grabbing data at a certain rate, they're too busy to try to change rates in mid-stream.

Furthermore, the meta-data stored with the clip can only remember one audio format per clip. And if you try to digitally feed such mixed-mode tapes' audio into further digital processing, major glitches can be expected. Well, yes and no. Adobe Premiere 4. Premiere 4. This particular problem is variously attributed to the difference between 30 Hz and the It's part of the spec. Not all decks or DV-to-analog converter boxes handle CC properly note: even decks and camcorders that don't properly support CC data will properly transfer it over FireWire.

I haven't checked the low end ones. None of any of the other FireWire to analog boxes that are currently on the market [as of October ] do CC correctly including the Promax. Jeff says that Digital8 camcorders from Sony process CC properly, and that's what he recommends for folks looking for a cheap DV-to-analog or analog-to-DV converter that processes CC data correctly.

San Antonio College in Walnut, CA: We have braved our way through many layers of support at Sony, most of their support people told us that it should work, but when we challenged them to duplicate our efforts, they finally admitted that the 85 does not do captions.

They also said that there should be a menu setting, but when they got into the machine, they couldn't find it either. Apparently CC got squeezed out of this special-purpose deck, which earns its keep performing 4x realtime SDTI transfers. To date there are no DV codecs to my knowledge that handle ATSC captioning other than embedded compatible line 21 captions.

This "pedestal" or "setup" is what's being discussed. How's this handled in analog broadcast? Those guys use a deck that properly adds setup to analog outputs and strips it from analog inputs. Sure it is. If I haven't lost you yet, you'll have twigged to the fact that digital, as long as it's digital , ain't got no setup nohow, nowhere, no way.

Whether it's FAST. Most do, or can be configured for it see below for the details using DigiSuite. What's wrong? The unsetup analog means that no setup is being added on the analog outputs. It's possible that the system was installed with "NTSC Japan " selected, in which case no setup will be added no matter what, or that the 7. I'll discuss the DigiSuite DTV in detail, because I'm familiar with it, but the same general concepts apply to other NLEs as well, so you might want to keep reading and look for similar configuration options in your system of choice.

Can I deal with the problem by adding setup at the capture stage so that the analog output would be correct? Is a digital signal with setup applied wrong? It's wrongwrongwrongwrongwrong! Did I mention it was wrong? My pedestal needs defining. Define it by recording bars at the head of your tapes that encode the proper black level.

That way when the operator at the dupe house or the station puts your show up on the scopes she'll see whatever level the blacks are at and tweak her proc amps appropriately.

It doesn't hurt to label the cassette with a setup-level warning, too. Don't use it! It does not add setup to the analog outputs; it modifies the digital data coming from the camera head by boosting the black level, resulting in washed-out blacks, reduced precision, and nonstandard tapes as described above. As a result the analog video played back from the camcorder or viewed live has its blacks at 7.

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Detailed listing of this site's DV contents, and links to other sites. DV Technical Details. HDV records to tape.

HDV compresses to and records at 25 Mbps. Both are long-GOP, meaning their compression stretches out over several frames rather than each frame's compression being contained within the individual frame itself. This has ramifications for editing, and generally means more rendering time. Both can record at i and p, though it is unlikely that all camcorders will be able to switch between the two.

Nothing earth-shattering about the comparison between the two formats, so far. One key to the camcorder format is that it is designed for "red laser" 8cm DVDs, which are relatively cheap.

Though it has nothing to do with the encoding, the MPEG-2 transport stream was chosen because modern digital TVs and set-top boxes already work with it. Among the comments were references to the fragility of DV-size tape as a recording media, and the problems with drop-out in an I-frame of the long-GOP encoding. On the negative side, posters pointed out the one hour recording time of an HDV tape versus the approximately minute recording time of the 8 cm red laser DVDs, and questioned the battery life of an AVCHD camcorder with its more computationally intensive encoding scheme.

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