HDV Black Frames hardware dependent?

PeterWright wrote on 6/13/2007, 11:07 PM

Laurence and several others have posted about this problem.

I have experienced this several times. Here it's not on downrezzed DV but on native m2t files captured either straight from Z1 Camera Tape or from my DR60 HD recorder attached to camera.

I have always been able to workaround by creating a looped region from just before to just after the black frames, and rendering to new track, and the "missing" frames reappear.

BUT - I have just made a startling discovery - the TWO BLACK FRAMES syndrome seems to be somehow hardware dependent, and the problem only occurs in the Vegas timeline, not in Windows Media Player.

I have a clip which on my main editing PC has two black frames consistently at a specific time code.
I copied it on to a memory stick and transferred it to two other PCs.

Here are my test results. YES means Black Frames appear. NO means frames play normally:

1] Main PC (Core 2 Duo E6700):

Vegas Timeline played from Hard Drive – YES
Vegas Timeline played from Thumb Stick – YES
Windows Media Player played from Hard Drive - NO
Windows Media Player played from Thumb Stick - NO

2] Second Desktop (AMD Dual Processor 2000)

Vegas Timeline played from Hard Drive – NO
Vegas Timeline played from Thumb Stick – NO
Windows Media Player played from Hard Drive – Would not play m2t (?)
Windows Media Player played from Thumb Stick – Would not play m2t (?)

3] Vaio Laptop (Core 2 Duo T7400)

Vegas Timeline played from Hard Drive – NO
Vegas Timeline played from Thumb Stick – YES
Windows Media Player played from Hard Drive - NO
Windows Media Player played from Thumb Stick - NO

So, summarising:

Only One out of three PCs showed the black frames when playing from Hard Drive in Vegas Timeline
Apart from the laptop, symptoms were the same from Hard Drive and Thumb Stick
The black frames did not appear in WMPlayer from either thumb stick or hard drive.

Hopefully someone can make sense of this.

Comments

Serena wrote on 6/13/2007, 11:29 PM

Peter, that the problem might be hardware related was the reason for my contribution to the previous thread http://www.sonycreativesoftware.com/forums/ShowMessage.asp?Forum=4&MessageID=5294742 Black Frame bug...this needs to be fixed now[/link]

As I said then, I hope the fates don't strike me with black frames but this isn't a problem I've experienced (yet). Clearly some people get them all the time, but because those threads don't get a lot of contributions I thought it possible that a lot of users are "black frame" free.

farss wrote on 6/14/2007, 1:09 AM

It would seem to be speed related or thread related, possible a thread syncronisation problem perhaps.

One other interesting test would be to put a bottom layer of red on the timeline and see if the black frame become red frames.

I've always suspected that these problems might have something to do with how Vegas converts time to frames and rounding errors.

Bob.

PeterWright wrote on 6/14/2007, 2:08 AM

> "One other interesting test would be to put a bottom layer of red on the timeline and see if the black frame become red frames."

Interesting idea Bob, but I just tried it and the frames remain black.

... and to test consistency I again rendered to New Track and there are the original frames as large as life and just as mysterious....

farss wrote on 6/14/2007, 3:20 AM

OK, say you move the clip x frames along the T/L, do the black frames stay in the same place in the clip or the same place on the T/L or do they just disappear?

PeterWright wrote on 6/14/2007, 3:56 AM

It stays in exactly the same place in the clip, Bob - I've applied Time Code Media FX to check this out.

... but, as I've reported before, after rendering to New Track and getting the missing frames back, they then reappear not only in the New Track, but also in the original m2t. file.
(After you posed the question - I had to close down Vegas, reboot the PC then reopen Vegas to get the problem back!)

farss wrote on 6/14/2007, 5:46 AM

Wow, this is a wierd one.
So one might conclude that one factor is what's in the frame(s) that Vegas has a problem decoding. You encode it to a new file and then Vegas appears to be able to decode these frames OK. But then you restart the PC and Vegas cannot decode them again.

I'm kind of running out of ideas but after you render the new track which appears OK does the original clip still have the problem or does it too come good?

Bob.

PeterWright wrote on 6/14/2007, 6:02 AM

The New Track retains the missing frames permanently, Bob, and although at the time of rendering to new track, the missing frames immediately also reappear in the original clip - after closing/rebooting, they go back to black in the original, but stay in the New Track.

Yes, it is very hard to pin this down .......

farss wrote on 6/14/2007, 6:37 AM

Ok, this is sounding good!

Latest Bob Crazy Theory:
It is a RAM thing. When you render the new track Vegas reads from RAM, get's it wrong as it encodes the new track but flushes RAM in the process.
What's different about the three PCs you tested it on, the amount of RAM I'd guess. Even reading the same file from a different device might cause the OS to allocate different amounts of RAM. Changing or zeroing the Preview RAM in Vegas might have an impact. But you might need to change the value and then restart Vegas to see an effect.

Bob.

Serena wrote on 6/14/2007, 10:08 PM

The other day I noted something that might be related to "black frames" and when CS2 has finished installing I'll go and repeat the steps. Are the black frames only at the beginning and end of clips? The above descriptions open the possibility that they occur mid-clip.

john-beale wrote on 6/14/2007, 11:15 PM

When I've seen the black frames, they've always been well into a clip, say 20 minutes in or more. If it were at the very beginning or end, it would be much less of a problem.

PeterWright wrote on 6/14/2007, 11:15 PM

No Serena, for me they've always been mid-clip.

I've just reopened a Support thread from March 07 where I asked them to download a rogue clip, specifying the exact timecode where the black frames were, to see if they could replicate the problem.

Serena wrote on 6/15/2007, 12:15 AM

Ah well, I've never seen that.
What I noted the other day was quite puzzling and initially caused me some angst. Suddenly I found I had 1 frame dissolves instead of straight cuts. The clips were not overlapped and when I separated the cut the clips on each side had dimmed frames on each side of the cut. Checking the fade offset it showed 00:00:00:00, so the fade didn't exist unless it was in the original clip. But these were cuts, not complete camera takes. Closing up the cut (making certain there was no overlap) and I had a 1 frame dissolve (even rolling through a frame at a time with the Shuttle Pro).
Just now, repeating the process, I found that some cuts showed this but most I checked did not.
What I found the other day was that this happened only when previewing on the external monitor in "best/full". Usually I preview in "preview/half" which I find quite adequate (once I've checked the clips) but I had been doing some colour grading and forgot that I'd done that in best/full. Once I reset to preview/half the problem went away. In my check today I found the problem occurs only in "best/full". Any other setting and no problem. The dissolves did not appear in an HD render. Could there sometimes be a small hiccup in Vegas driving the graphics card and collecting clips from the hard-drive? Even though the video is stationary?

So my thought was that some people might be experiencing "fades" to black rather than the 50% that happened on my system. However if they're happening in the middle of clips the two phenomena may not be related.

rmack350 wrote on 6/15/2007, 9:53 AM

Although I'm not using any sort of HDV media, I'm still curious.

Peter, when you render to a new track, what codec are you rendering with?
Are you saying that the render on the new track doesn't have the black frames?
You've got the MediaFX timecode turned on. Do the black frames appear at consistent timecode points in the clips?
Are all the people having this problem in PAL land?

My understanding is that Vegas caches frames to RAM as it plays. I wonder if Vegas is somehow caching "nothing" to RAM at very specific spots. The fact that Vegas makes black frames so consistently on a clip is interesting.

<time passes...>It's not surprising that WMP doesn't display the same black frames, since it doesn't cache frames into RAM like Vegas does. It's interesting that the AMD system doesn't have the same problem. All sorts of factors could come into play, I suppose, like different memory controllers or some sort of difference in the way the systems read storage media. But we're still looking at black frames at specific spots, which either says to me that there's something specific about the media clips or there's a Vegas error that only occurs at certain points, maybe over certain types of frames in an hdv file.

I wonder if changing Vegas settings would cause the black frames to move within the clip?

Rob

Rob

PeterWright wrote on 6/15/2007, 6:46 PM

Thanks for your thoughts, Rob.

I'll respond to each point, then add some other observations.

When I render to new track, I use the Vegas HDV 1080-50i template, the same as the captured footage. The newly rendered clip has no black frames and remains that way, whilst the original clip also loses the black frames temporarily, but they reappear in the original clip after closing and reopening the project.
Yes, the black frames are always at the exact same spot within the clip.
Not sure whether all sufferers are in PAL land - Laurence?

I re-opened my thread to Sony Support, and they've just replied that I might be suffering from a corrupt installation of the program. They suggest that I uninstall ALL Sony and Sonic Foundry software, then follow some instructions in REGEDIT and MSCONFIG before reinstalling everything.
I would try this if I thought it would change things, but I'm a little loathe to go through all that - my problem is with specific clips, not the software generally. Also, I have seen the same black frames on my laptop, and following an off-forum email, John Meyer downloaded the clip and also saw the black frames .... and several others have experienced this same thing - they surely can't all have corrupt installations?

Another point is that if I recapture the same footage a second time, there are no black frames.

It is certainly strange that not all PCs show the black frames - if anyone has the time and inclination, the clip (101Mb) is at:

http://members.iinet.net.au/~ariad/BlackFrames

and the two black frames are at 00:01:12.14 and 15

4eyes wrote on 6/15/2007, 9:46 PM

I'm using VMS 7 Platinum and Vegas trial, I've come across black frames. I split before the black frames and after then delete the gap. Then render to a new .m2t file and delete the original with the black frames or convert to cineformhd before any editing.

I contributed these black frames to some corruption in the mpeg (.m2t) file.
Turned out being my tape(s), I now only use the Sony DV Premiums or Sony HDV tapes, preference is with the HDV tapes, they have been much more reliable.

farss wrote on 6/16/2007, 12:07 AM

Fixed it, changed Dynamic RAM Preview to 0 Bytes and I cannot get the black frames back, even after restarting Vegas 7.0

Can't seem to ge them in Vegas 6 either, even with 128MB of Dynamic RAM.

Bob.

PeterWright wrote on 6/16/2007, 1:16 AM

Thanks Bob - a most interesting discovery.

I've done some more tests following your findings, and although it may muddy the waters, there is some inconsistency going on here, suggesting that there is something Dynamic involved - maybe the amount of RAM being used for other tasks.

On my Core 2 Duo desktop, Reducing Dynamic Ram from 1024 to Zero = no black frames.

Then I tried reducing to 800. Result = ONE black frame

I then reduced Ram in increments of 100, and One Black frame remained until I got down to 100, then there were NO black frames.

I then went to my AMD Dual CPU, where Vegas Dynamic Ram was set to 800.

Yesterday, I saw NO black frames on this machine.

Today, after changing Dynamic Ram to Zero,

The clip played from HD displayed ONE black frame
The clip played from Memory Stick showed No black frames.

Changing Dynamic Ram back to 800 produced exactly the same results:

The clip played from HD displayed ONE black frame
The clip played from Memory Stick showed No black frames.

Grrrr!

riredale wrote on 6/16/2007, 8:14 AM

I don't think that's it.

I haven't run any very recent tests, but for the past year I ran my AMD x2 system with 0 for RAM Preview, and had the occasional black frame pair pop up. Recently, I discovered that Vegas7 would only use one core for rendering unless the RAM Preview was set to some non-zero number, so now it's at "1." Still get Black Frames.

BTW this is a 59.94 setup, not PAL.

Hmmm... Maybe it's a dual-core thing? I wonder what would happen if I work with only a single core? Does anyone have the Black Frame bug on a single-core system?

Stuart Robinson wrote on 6/16/2007, 9:16 AM

Hope this isn't the kiss of death, but I use PAL HDV on a quad core machine (two AMD Opteron 280 processors) and have not seen any black frames. But if this is RAM related, I should also point out that I'm on Windows x64.

Peter, have you tried capturing to Cineform, using NEO? There's a 15-day trial and while it's somewhat expensive and creates larger files, it'd be interesting to see if they are black-frame free. Personally, I never edit my final projects from M2T files, although I do play a lot of them back as rough cuts via the timeline.

jeff-beardall wrote on 6/16/2007, 1:09 PM

yes...the ram preview change is the key for me...change it and the frames disappear. I've mentioned this in past threads...I wonder if all the 'black-frame' folks are using 2 gigs or less of ram...any 4 gig users that have the problem out there?
vegas 6 had SD black frames, Vegas 7 has HDV black frames...no SD ones as far as I know.

farss wrote on 6/16/2007, 3:39 PM

Just to confirm, I loaded Peter's clip onto an old single core non HT P4 and got the same two black frames, setting RAM to 0 and they were gone.
With V6 regardless of RAM, no black frames. Of course with V6 the HDV playback was painfully slow.

Interesting other thing, they never showed up in the thumbnails.

Bob.

Stuart Robinson wrote on 6/16/2007, 6:48 PM

For what it's worth, I don't see any black frames in that clip.

A bit OT, but a note to Peter, large portions of your website aren't compatible with Firefox, it'd be worth checking that out when you've finished trouble-shooting this issue. It's just one thing after another. ;-)

PeterWright wrote on 6/16/2007, 9:29 PM

Thanks Stuart

I must admit I can't even view the site properly with my own main browser (Opera) - I created it a few years ago with Mediator, which I mainly use for interactive CD Roms. Although it can include features I've not seen elsewhere, such as mouse over (no click) for enlarged image, it apparently produces lots of "redundant" html code.

The website is more of an indulgence than a serious business portal, but one of these days I'll build a new one with a different program, maybe SwishMax, which I've had for ages without using it ...

Serena wrote on 6/17/2007, 12:04 AM

>>>Recently, I discovered that Vegas7 would only use one core for rendering unless the RAM Preview was set to some non-zero number, so now it's at "1."<<<

My system is an AMD 64 2x 4800+ so I just checked this. Both processors employed equally with RAM preview set to zero. I think we're turning up problems that are related to system specifics and how Vegas employs the system. A great problem for software developers is ensuring that their software is truly independent of the hardware it runs on, which is practically impossible with so many different chips and mother boards, and RAM. Obviously that is one advantage for Steve Jobs guys.