Blackmagic capture, no dropped frames?

[dpalomaki]

Two possible additional symptoms of drops are audio and video losing sync, and/or gaps in the audio waveform.

The main rub with BMD analog signal capture gear has long been that it expects a good, stable, legal video signal. Also, the Intensity Pro 4K is NOT suitable for component analog video capture, a known problem that BMD has decided not to fix; I suspect little market demand for it to justify the cost. On the other hand the original IP was OK, but fussier about the signal. (I have not use the card you have.)

These days I mainly used the BMD cards for HDMI and SDI capture.

The bottom line is you will have to judge for yourself whether or not what you can do now meets your needs, or if changes in workflow/gear are in order.

[latreche34]

Same here, I just use BM for SDI digital streaming to HDD where the data is already serialized and packed just like ripping a DVD to HDD or transferring DV to HDD, Media Express doesn't know where the frames are within the data pocket to drop them.

Since the OP is capturing analog into Media Express, to find out if it is dropping frames is to set it to stop capture if dropped frames are detected and try to disconnect the analog input to the capture card and see what happens, alternatively playback a video around the end of the tape where it reaches the static area, Though if the card is built in TBC it may fight the signal drop.

[durian]

I had it on and a tape i was capturing had a 2 frame drop outs on the tape that repeated at the same place at 7 mins in 17 mins in. it definitely catches dropped frames and seems pretty sensitive to it.

[lordsmurf]

Quote:

Originally Posted by latreche34

Though if the card is built in TBC

No such TBC exists in any capture card made to date. At most, you have some TBC(ish) type function within the closed loop SDI appliances, with varying degrees of strength.

[latreche34]

Quote:

Originally Posted by durian

I had it on and a tape i was capturing had a 2 frame drop outs on the tape that repeated at the same place at 7 mins in 17 mins in. it definitely catches dropped frames and seems pretty sensitive to it.

That's what I thought, Does it stop capture though? It will be a handy feature for capturing full tapes so when the tape reaches the end, the app stops the capture. Please do try it and let us know, I can't use this feature because I'm not capturing analog into Media Express.

[durian]

It stops capture. I would love to see two things in media express a simple counter or better a log file that shows the drops and when they occurred but leaves the capture running.second a way to sync the camera or deck to stop when the recording stops.

[lordsmurf]

Software that doesn't show drops is inexcusably bad, not suggested whatsoever. That's been the case for decades now. When a company like BM doesn't add it, then it really shows you what a crappy afterthought feature analog/SD capturing was. It's an HD cards that "also does" SD, and quite badly. It's a very non-standard piece of gear. It's now been a few years, but if VirtualDub worked at all, it'd also drop silently in it. So zero reporting, and it may not even log in the hardware. Even the $2 Easycap shows dropped frames! Pathetic, really.

I had high hopes for the BM, some 10+ years ago, when it was not yet released, showcased at NAB.

[latreche34]

Quote:

Originally Posted by durian

It stops capture. I would love to see two things in media express a simple counter or better a log file that shows the drops and when they occurred but leaves the capture running.second a way to sync the camera or deck to stop when the recording stops.

Camera control is a wishful thinking, This is not BM fault, Analog camcorders and VCR's cannot be controlled externally by software since they don't have any digital interface like DV camcorders and decks do.

If you want to see the statistics of dropped frames just capture with vdub.

[durian]

i know its wishfull thinking. lordsmurf what part of vdub is not working ? what is the card doing "quite poorly" .after capturing over 90 tapes ,10 terrabytes of files.i am not having problems with dropped frames, the card has not one time stopped capturing during rewinds changing sources etc. it reports dropped files perfectly in vdub and stops capturing in media express if you have it set to do it . i wish media express had reports of frames dropped too but that is the software not the card. with no TBC 0-2 dropped frames per 120 minute tape seems very reasonable

[lordsmurf]

Re-read what I wrote. BM cards will drop frames without reporting. It's in the hardware. So a VirtualDub counter showing 0 frames dropped is still not accurate. Frames drop, without being reported. This has been known for about a decade now. And BM has never fixed it. In fact, all BM really did in that time was silently drop their marketing for the card being good for VHS/etc.

You can still get drops reported from VirtualDub, but it's after the capture card. For example, system I/O underrun causing drops, such as capturing to the OS drive.

Media Express is a proprietary software for the card. Not too different from ATI MMC. During the AGP/PCI/USB AIW era, MMC had an accurate drop counter. It was removed in PCIe, so unusable. But at least the PCIe AIW still accurately reported to VirtualDub. No so with BM cards.

[durian]

Thanks Lordsmurf i have not looked at every bit of footage but i will use the footage as the final call as to if the card is doing a good job. so far what i have looked at has been ok.i am on my last tape when i get a bit of time i will retry the tape i know had 2 dropouts when i was capturing last night. i know the exact times and places it happens ill see if it goes through vdub with or without reporting it and report back.im doing the last tape in vdub now and having the decklink output to my atamos which is much more sensitive to dropped frames . for what its worth i shot a bunch of bodyboarding videos back in the 90s and my partner and i released 3 tapes to market and i contributed to a bunch more so i am archiving all the old surf footage . i need the actual shots to be as high quality as possible for archive and possibly will remaster and release some of the tapes...just wrapped up the end of my last tape as i was typing and noticed the telltale popping hit 6 times right at the end of the tape i know that media express would have stopped recording if i had it set to stop on drop frames but vdub reported it as 6 frames inserted and none dropped so i can confirm what your telling me as far as vdub and reporting . now on to fun projects like video glitch art and weird vhs finds at thrift stores for youtube my partner still has 120 hi 8 tapes to go through but thank god im done

[dpalomaki]

Quote:

...Analog camcorders and VCR's cannot be controlled externally by software since they don't have any digital interface like DV camcorders and decks do...

To amplify a bit this is true for much consumer stuff and for much capture software. However, many Video8/Hi8 camcorders and Video8/Hi8 VCRs supported Sony's LANC protocol that did allow control of the camcorder/VCR by software provided the PC had the proper interface. The bad news was only a few PC software products supported it for linear editing purposes. LANC is a serial data protocol that provides device control as well as time code (if present). LANC is still found on Sony and Canon MiniDV, HDV, and HD camcorders and is used by tripod handle camcorder controllers.

Also a lot of industrial/professional analog gear supported control via RS422 protocols provided the computer had the appropriate software running.

Panasonic (Edit jack) and JVC (compulink jack) had similar edit control interfaces on gear such as the AG-19xx and HR-Sxxxx but I am not aware of corresponding PC software, only firmware is dedicated edit control devices.

[durian]

the decklink actually has a connection for the rs422 .i think the betacam deck also has it. getting all to work together and stop the deck on a frame drop is probably not something that anyone will program. i run decklink out to the atamos shogun to check for clipping or crushing . i was told to make sure i check use video levels in resolve settings or the blacks will crush. and i try to monitor out to a 4k 65 inch tv while im capturing from the atamos which is nice to have.. i am on the lookout for it after you warned me

[latreche34]

I was not aware that the decklink has a connection for the RS422, otherwise I would have worded my last post differently, I know pro tape decks do have such a feature to communicate with SDI cards for pure digital streaming, Didn't know an analog capture card has it, I guess you got everything you wanted so far.