HDV Scene Split Bug Fixed in 7.0e ?

johnmeyer wrote on 5/7/2007, 7:25 PM
In this post:

Issues with scene detection in Vegas 7.0 HDV

the HDV scene detection capture bug is described: If you enable scene detection on HDV, you will get a few frames at the end of one scene that are actually from the next scene. What's worse, a few frames disappear completely at the scene boundaries.

This was documented in several other posts.

I just did a quick cut of a baseball game, and didn't catch this until I'd done the entire render. Four hours down the drain.

I do not really want to install 7.0e, since it apparently forces my system to accept more additional code (C++) and also doesn't have anything I need. However, if it fixes this bug, I'd go ahead and upgrade.

Does anyone know the answer?

Thanks!

Comments

John_Cline wrote on 5/7/2007, 7:38 PM
"it apparently forces my system to accept more additional code (C++)"

Just curious... why is this a problem?
Laurence wrote on 5/7/2007, 8:20 PM
What you're seeing is Vegas chopping the clips to the nearest iFrame which sometimes is a frame or two into the previous scene. You might like HDVSplit since this chops exactly at the timecode changes (and generates new iFrames and GOP sequence at the boundries).
johnmeyer wrote on 5/7/2007, 8:54 PM
Just curious... why is this a problem?

Bloat.

Why would I care about bloat? Stuff happens. Some seemingly innocuous programs can really screw things up. Let me tell you about the HP multifunction driver or the Norton antivirus background programs. Or the card reader DLL installed for the older HP "Photosmart" printers (hpha1mon.dll) that rendered Firewire capture useless.

As I said at the end of another post yesterday:

"Less is more."

(Mies Van der Rohe, of course).

P.S. If anyone knows the answer to the original question (i.e., is it fixed in 7.0e?), I'd sure like to know.



PeterWright wrote on 5/7/2007, 9:22 PM
I've just done some HDV capture in 7.0e and this "feature" is still there - I hesitate to call it a bug, because, as Laurence says, it could just be some thing to do with locating the nearest i frame. My "solution" is to never stop the camera during important footage.
John_Cline wrote on 5/7/2007, 11:08 PM
"Some seemingly innocuous programs can really screw things up. Let me tell you about the HP multifunction driver or the Norton antivirus background programs. Or the card reader DLL installed for the older HP "Photosmart" printers (hpha1mon.dll) that rendered Firewire capture useless.

There is nothing "innocous" about HP drivers or Norton programs. Personally, I think you'd be safe installing 7.0e, our friends at Sony write far superior code compared to HP and Norton.
riredale wrote on 5/8/2007, 8:34 AM
Like it or not, I've forced myself into never using the very beginning or very end of an HDV clip--I always now make sure I chop off at least a couple of frames. That way I'd assured of getting the real "meat" of the clip. Just like trimming away the excess fat on a cut of beef.
Laurence wrote on 5/8/2007, 9:08 AM
If you capture with ConnectHD or Neo as Cineform you can use the clips all the way to the end. If you capture with Vegas or HDV Split as mt2, you need to leave a couple of frames at the beginnings of the clips because of GOP sequence issues around the cut points.
johnmeyer wrote on 5/8/2007, 9:12 AM
Like it or not, I've forced myself into never using the very beginning or very end of an HDV clip--I always now make sure I chop off at least a couple of frames. That way I'd assured of getting the real "meat" of the clip. Just like trimming away the excess fat on a cut of beef.

Well, I don't like it (although don't think I am disagreeing or getting mad at you -- I'm not). MY beef is that this is not the way the feature should work. If you put a scene detect feature into a product, then it should detect scenes, exactly, and reliably. There is no "almost" permitted. I mean, this is video editing: Since when is it even remotely "OK" to be "within a few frame" of frame accurate?

I realize that this is a bug, and not something done by design, so all I am trying to say is that we shouldn't excuse it as OK, or something we are willing to live with. I realize that some of you don't use scene detect, and I understand that. Your workflow doesn't require it. However, mine does, and having always had it with DV, I plan for it when I shoot. This cut on the baseball footage took only about ten minutes for a full game because I had start/stopped the camera after each pitch (yes, if I did 162 games a year, I'd probably wear out my camera). As a result, I was able, just by looking at the length of each scene, to delete the pitches where nothing happened, and do so in just a few seconds. I was left with just the plays where things happened and would have been able to deliver a game film with just a few minutes work if it hadn't been for this bug.

Fortunately, I found a script that was written back when this bug was first discovered that trims the head/tail of the clips, and that was good enough for this project.

Laurence wrote on 5/8/2007, 9:20 AM
It's not so much a bug as it is a limitation of trying to work with a highly compressed format that was designed for delivery rather than editing. This kind of thing is exactly why products like the Cineform line exist. Capture with ConnectHD or Neo and you can go back to your old workflow.
Christian de Godzinsky wrote on 5/8/2007, 10:18 AM
Hi,

I would say that this definitely is a BUG - that is a LIMITATION - of how you must arrange your workflow.

Computer "science" is a precise art. There is other software (Cineform etc.) that can do it - Vegas should be able to do it as well - it is after all a professional piece of software. Or is it?

A feature like this (as advertized) should work as expected. You cannot expect anything less than having the same precision of splitting video as during DV-capture. Yes - I know that DV is just a series of independently compresseg frames, HDV is GOP. The problem of handling various GOP sequences is handled correcly during editing, it should not be that difficult to solve when detecting scenes...

BTW: I had the impression that HDV-cam's stop the scene recording at the last frame of an GOP sequence. Or in other words, the first frame of a new take is the first master frame for a new GOP sequence. Or how would the cam otherwice be able to assemble the video content on the DV-tape??? Rolling back the tape and reading frames to be able to exactly start the recording with new material from another take - in the middle of an GOP sequence? Hardly... So why is the splitting so difficult for Vegas???

I reported this bug to Vegas support when testing 7.0a. Yes - it is still there in 7.0e. They confirmed that this is a bug that they are able to repeat, and it will be fixed in a future release. That future release has not yet surfaced. Is there going to be a 7.0f before 8.0 ???

I have some special material that I have to split manually since the scene detection does not work as it should. A very tedious work in my special case. Have you notice - you also loose the audio at the end of every clip - during a couple of frames??? The audio problem is the one that pisses me most.

I am disappointed that this did not get fixed in 7.0e. I had high hopes too....

I hope Vegas support follow the conversations here, or is it so that this is purely a users forum???

Best regards,

Christian

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johnmeyer wrote on 5/8/2007, 10:22 AM
Christian,

Thanks for answering my question, and great post. I agree with every syllable of everything you said.
PeterWright wrote on 5/8/2007, 6:23 PM
Ok John and Christian - there is something here to be improved, and I must say I didn't realise there were instances where the first and last frames of a take were used.
I don't think I've ever NOT trimmed each end down to the exact frame I needed, whether HDV, DV, SVHS or 16mm film.