I am sorry I don't live up to the story you made up about me.
A username is just a username. Why such an interest to matters unrelated to the topic? I am not asking you why your avatar has straws up their nose.
I don't remember I claimed they are the same. But thanks anyway.
And your point is? The very first link that opens up for a "what is Long GOP format" says: "(long Group Of Pictures compression) The interframe coding of digital video in which a full video frame (the "keyframe") is followed by a number of delta frames ("difference frames") until the next keyframe is reached." It does not specify a particular number of delta frames. If you want to standardize this term, maybe you can join one of those video coding standards groups. I am sure they can make use of such an, um, imaginative brain like yours.
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@DB83,
Mpeg2 in general can have long, short, or no (single) GOP lengths. DVD-specific (like those numbers you quoted) is much more constrained. But so were most general mpeg2 systems back in the day. Remember, GOP length support is directly proportional to the size of the available buffer, and early systems had minimal buffer sizes. Only with mpeg4 and beyond did gop lengths really grow beyond the 100 frame mark.
@sm-p,
DV == Digital8. The only difference is the tape characteristics.
@ConsumerDV,
With a name like that, you are kind of putting yourself out there like you would know a bit about DV. Yet, I have also noticed you still need more training in that area to live up to the moniker. Just sayin'.
Also, that document you reference is flawed, both in facts and in how it is presented to the end user. Both jpeg, mpeg, mjpeg, and dv all derive from dct-based compression methods. Jpeg being the earliest is the least efficient. Mjpeg was never a true standard, just a variety of jpeg images strung together with some additional efficiency regarding motion. One big difference between mjpeg and dv has to do with the coefficient tables, which IIRC is fixed for dv but variable for mjpeg. That amounts to slight differences in size and quality for similarly encoded material, but with mjpeg the size will vary somewhat depending on the material while the dv will not.
Regardless, for identical bitrates of 25Mbps, they are nearly identical quality-wise. Dv is preferred in pro workflows, only because the strict standard leaves less room to make mistakes in settings.
And mpeg2 has a few additional features that are not available to dv or mjpeg, most important of which is longer, and variable gop lengths and vbr, but also of multiple options for scan pattern, and for differently weighted coefficient tables.
Yet, if you compare apples to apples, for I-frame-only 25Mbps cbr mpeg2 encodes, it only has a slight lead over the others.
Scott -
Don't look too deep into it, it is just a username that matches my YouTube channel. "DV" can mean a zillion different things, not necessarily a particular video standard that some fifty companies agreed upon almost thirty years ago. At least it does not start with "Lord".
I linked two different documents. Both are flawed?
Comparing what you said to what I quoted, "Variations on M-JPEG algorithm are used in desktop SD video editing systems, consumer digital video camcorders (25 Mbps), and professional SD video camcorders such as the Sony Digital Betacam (90 Mbps) and Panasonic DVCPro 50 (50 Mbps), and others," I don't see a lot of difference. You tell the history and some technical aspects, while they provide what an end user needs, which is how do they compare in real-life usage.
Again, comparing to my quote, "DV coding can be thought of as something half-way between Motion JPEG and MPEG. ... At equal bitrates, DV is somewhat better than MJPEG (which is very similar), and is comparable to intraframe MPEG-2. Note that many MPEG-2 encoders for acquisition applications do not use intraframe compression," I don't see major difference. You say that MPEG-2 intra is slightly better than DV, they say that DV is comparable to MPEG-2 intra. I know about variable GOP and VBR, but the original argument stemmed from you informing me that MPEG-2 can be used in intra mode. So it "only has a slight lead" over DV, good to know. Will anyone use MPEG-2 intra in real practice is another question.
Not that I have an axe to grind, these are not my articles but calling them "flawed" may be a bit too harsh. I appreciate all the info you share, though, thanks! -
@ConsumerDV
Now I am sure I read in one of your posts that you had knowledge about DV. But if you have edited them - and I can not be arsed right now to check - then there is no way to even proove that.
True that a username is just that. We all choose one that means something to us. FYI info mine has nothing to do with Daimler Benz but is a take on my own first and last initials plus the legacy DOS format of 8 chars before and 3 after. And I have also used it elsewhere.
And as for the pic then do look it up. Or read my other posts in these pages if you still do not appreciate it.
Now this is, or it was until the kinda stream-downloaders took over, a video forum. DV has a particular meaning and is NOT an abbreviation of whatever you want it to be. Even Digital Video.
But do you 'betray' yourself ? There is only member on here that has 'Lord' in his username (of course his pic kinda explains it as does Scott's with his 'worship' - not without reason - of Groucho Marx). So why throw such a comment on here ?. Call me anything - suspicious, paranoid blah, blah. -
@DB83, you got me, a forum name is not just a handle, sometimes we want it to reflect something. I don't know what the reference to 8.3 filename pattern should allude to. Maybe it is nostalgia for simpler text-mode single-task times?
I learned some new info (that there are intra MPEG-2 implementations), but this does not help with figuring out actual recording format on an 8mm tape OTOH, the topic starter seem to have left this thread long ago. -
The major difference is this:
NTSC DV butchers colors, and uses a reduced bandwidth from the era of Pentium III computers (Pentium II min specs). It's damned old, outdated tech. The 4:1:1 just obliterates color detail, blocks up colors, and shifts tints.
PAL DV is more akin to DVD-Video spec MPEG.
MPEG-2 is far better than DV. It can increase (or decrease) resolution, GOP, bitrate, etc. DV is fixed.Want my help? Ask here! (not via PM!)
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I guess Panasonic did not get the memo, deciding on keeping with 4:1:1 for PAL DVCPRO. 4:1:1 works well for VHS or Hi8 because it samples color from every line. VHS and Hi8 have only about 40 color samples per line, while 4:1:1 DV has 180, more than enough for the job.
EDIT: Changed 160 to 180 before anyone pointed to itLast edited by ConsumerDV; 3rd Apr 2022 at 21:04.
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In my opinion the idea of NTSC DV chroma is worse than PAL DV chroma is moot, NTSC chroma is 180x480 (out of 720x480 luma) and PAL chroma is 360x288 (out of 720x576 luma).
In other words;
- NTSC DV samples the chroma horizontally at 1/4 the resolution (180 pixels of chroma), PAL samples the chroma horizontally at 1/2 the horizontal resolution, (360 pixels of chroma).
- NTSC DV samples the chroma vertically of every scan line including odd and even lines (480 lines of chroma), PAL samples chroma of odd and even lines with the same chroma value slashing the vertical chroma resolution in half (288 lines of chroma).
If I have a choice to reduce chroma resolution I would reduce it horizontally where it is very low and keep it vertically where it's rich. -
You think you're being clever, but you're not. The conversation here is Digital8, essentially MiniDV aka DV25. So your random smartass comment about DVCPRO doesn't apply. And 4:1:1 sucks regardless of format.
Furthermore, you speak theory, not practical application. In theory, yep, all the bandwidth you could want. But in practice, it never happened. Butchered colors, cooked colors, color artifacts, shifted tints. The reason? It was never intended as a conversion format. It was barely adequate as a shooting format. So analog-to-DV is butchered, shot DV is just slightly lacking with dull colors. All of it has artifacts, both chroma and blocks.
In terms of the Digital8 tapes at home, it is what it is, a product of its time.
In terms of Hi8/Video8, don't be a lazy shmuck, convert it using something better (aka lossless 4:2:2) than 1990s tech (DV).Last edited by lordsmurf; 7th Apr 2022 at 09:02. Reason: Typo
Want my help? Ask here! (not via PM!)
FAQs: Best Blank Discs • Best TBCs • Best VCRs for capture • Restore VHS -
Of course I am being clever, I can read. Thank you for confirming that you know that Digital8 is the same as DV25. DVCPRO is 4:1:1 across PAL and NTSC just like NTSC DV, which you happen to dislike.
"Sucks" is a relative term. It is good enough it can even be keyed.
It was so barely adequate that it created a whole new industry of digital shooters and DV rebels who started making real movies, while VHS became famous mostly for shooting porn and low-budget horror flicks.
I don't remember having such a harrowing experience with DV including using it for conversion from analog, but thanks for pointing out to the artefacts to look for, I shall double check.
I did come across a JVC DV camcorder that exhibited blocky structure, but my Canon and Panasonic have none of that. I would follow your advice if I were in PAL land, after all 4:2:0 skips every other line. But for NTSC there is little if anything to be gained by [sh]mucking with lossless through SVideo.Last edited by ConsumerDV; 5th Apr 2022 at 22:41.
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I have to agree with Lordsmurf in the area of capturing AVI 4:2:2 lossless vs lossy DV from my personal experience of my wedding video tapes and other family members' tapes, I digitized them using the best DV device I could get my hands on at the time, the Edirol VMC-1. Fast forward few years later I started to learn about capturing AVI 4:2:2 and happened to be at digitalfaq.com (although I do disagree occasionally with LS), to my surprise the quality difference was huge when I did some tests, So re-captured them all and made h.264 files for the family and they confirmed the quality of lossy mp4 files was better than DV files, notably the vividness of colors. I still don't think there is a difference between NTSC DV and PAL DV in terms of chroma, I think both butcher it.
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Serendipity ! I am thinking of recapturing all my videos (PAL and NTSC) as I only had a DV device at the time... I want to do this as well: Capture Lossless etc. but with what device?
I am based in the EU but have both NTSC and PAL analog sources... not Digital 8 though... -
Long GOP is just an old term usually associated with MPEG2/H.264 Camera recording settings, that generally means it has a GOP larger than 1. In the camera settings it will usually be listed as generic Long-GOP. I doubt the higher end H.264 cameras go above 30-60 frame GOP even though H.264 supports hundreds of frames.
JPEG (MJPEG) - DV - "MPEG2 I-frame Only" all heavily rely on 8x8 DCT for the bulk of their compression. -
Do I understand it correctly, that you fed SVideo or composite signal into an external box, VMC-1, which output DV? In this case, since you are using an external box, it does not hurt to try different converters. Maybe your box simply had a crappy implementation of DV.
But if you have a Video8 or Hi8 cassette, then the easiest and least error-prone approach is to play it in a Digital8 camcorder and let it convert into DV. You will get a well-known codec with broad support, decent video quality and correct metadata. Also, many Digital8 camcorders have built-in line TBC. I did not see any serious macroblocking or butchered chroma when I used this method. Neither do I see noticeable artefacts in VWestlife's conversion. Compared to the "professional" service he roasted, his version looks amazing. Can it look better? Possibly. But I think it looks good enough to not bother with picking up breadcrumbs. -
Those were VHS-C and full size VHS tapes, even for V8 and Hi8 the VMC-1 is better than any DV route I've tested so far, Except Lossless, hands down.
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Originally Posted by ConsumerDV
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It looks like that he uses a Digital8 camcorder as a playback and conversion device from Video8 and Hi8 to DV. I believe he also uses it for other analog sources in passthrough mode.
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This is an interesting thread. I can see reasoning against DV for compressing noisy analog recording. Yet, I wonder how much vitriol against DV is caused by the Canopus ADVC-100, which seems to be a rather crappy A/D converter, and how much is attributed to in-Digital8-camera conversions for Video8 and Hi8 videos.
In the first video that pippas posted in that thread, I can see "pumping" or flickering in large blocks, not shimmering of individual pixels. I can see similar effect in this video, for example. These guys used ADVC-100 as well. I don't see this effect in VWestlife's video. I need to check my Hi8 to DV conversions. -
Why wouldn't I be happy? just because some guy chooses his own way to capture that means I have to be mad? I capture people's precious memories for money and I have the gear that makes the smile in their faces (literally), So use whatever you can afford or think is good enough for you buddy I can care less how you capture as long as it makes you happy, when members reach out to me for help I offer it through posts or PM's for free but I don't dictate how they proceed after.
Here is the full discussion by the way in that thread and I go by latreche34 there. -
Why wouldn't I be happy? just because some guy chooses his own way to capture that means I have to be mad?
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Thanks! Tons of info, especially in the second thread, which then veers in a different direction. I will read them more closely later and will pixel-peep on the samples and will return back, but after a quick glance it seems that the main issue with in-camera conversion to DV is slightly elevated white level. There is no mention of excessive macroblocking or "butchered colors". This is much better info than empty proclamations that DV "was barely adequate as a shooting format."
I checked out your SVHS conversions on YouTube - they look VERY nice! Well, 50 Hz TV has 20% more lines than NTSC. Still, very nice, detailed clean samples. -
after a quick glance it seems that the main issue with in-camera conversion to DV is slightly elevated white level. There is no mention of excessive macroblocking or "butchered colors
The main problem was not the colors, but the DV compression, not very bad on standard viewing, but annoying for AviSynth restoration filters.
I checked out your SVHS conversions on YouTube - they look VERY nice! Well, 50 Hz TV has 20% more lines than NTSC. Still, very nice, detailed clean samples. -
I see, thanks! (This forum would benefit from a "like" feature for posts). It is the nature of low bit depth low chroma formats, they are not very suitable for editing. It is a common practice among videographers to convert to a visually lossless intermediate codec for editing and effects. I agree, if one wants to do extensive work on captured video, then going directly to a better codec makes sense.
Your videos are public, but you don't seem to welcome comments on them I guess you limit the discussion to a very tight circle of crazy passionate people -
Also, DV may be "workable" for greenscreen, but it is considered only barely acceptable, as both the macroblock compression artifacts and the color subsampling wreak havoc with edges, even with well lit, spill supressed environments. I think DV's workability only stemmed from the fact that it was seen as way ahead of greenscreening VHS, and other composite/color-under consumer material (which it is).
When pros can afford it, they'll always go for better than DV to greenscreen.
Scott -
Your videos are public, but you don't seem to welcome comments on them
Edit: I had many comments waiting for my approval to be published. I did not know that . I apologize, and will answer to all of them!Last edited by lollo; 7th Apr 2022 at 15:27.
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The problem with DV route for analog sources is not just its low quality, the size of its files makes it not a shareable format so what one ends up doing is convert it to a modern codec like h.264, now it just became a useless middle man or a step that should've never existed, the wise choice is to offcourse capture at the highest quality and encode to a more manageable format saving an extra unnecessary and destructive step.
I've recommended DV route in special circumstances where someone is frustrated with USB 2 devices, drivers and Microsoft OS's and they don't seem to have the adequate knowledge to navigate through those hurdles. -
Nevertheless, it is "workable". And it has been successfully used in many productions.
When pros can afford it, they go for the best But I reject the notion that DV "was barely adequate as a shooting format." Actually, it is VHS / SVHS / Video8 / Hi8 were barely adequate as shooting formats. And they would practically disintegrate after being edited on a VCR, while DV can be edited losslessly*
* with straight cuts only. -
Nonsense.
DV was "in" because of TINA (there is no alternative). Therefore DV was "best" (and only). But that was 25 years ago, the 1990s.
I can't believe it's now the 2020s, and people still try to defend DV quality. It was already a has-been format by the early/mid 2000s. We've all moved on. Perhaps you should as well.
VHS was a flawed format, but DV was just as flawed. And sadly, in some ways (color/chroma), flawed worse.Want my help? Ask here! (not via PM!)
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