Buffer Overrun whilst Capturing

[Kamran Sekha]

Hello Everyone,

I am new to this forum, and am thrilled to be here in the company of so many experts.

I have a 15-day trial version of CineForm Prospect HD (version 3.0.5) which I am seriously considering buying due to many favourable comments about CineForm but I am having problems.

Your help will be greatly appreciated.

I have so far captured footage from three different one hour DV tapes but each time the CineForm capture log window shows the following message:

“Buffer overrun whilst writing captured data to disk. Please try defragmenting your hard disk”.

I also get another problem, which I think (am not 100% sure) is related to this buffer overrun issue. Before starting to capturing, I chose the CineForm HD link option to capture data simultaneously as AVI and m2t files.

Whilst capturing for the first time, the capture process stopped a few times (maybe 3 or 4 times) for a second but then immediately continued. The second and third captures were slightly better because the capture process stopped only once or twice for a second.

When viewing the completed AVI and m2t files, I noticed that the duration of the AVI files was slightly shorter (by 3-5 seconds) than the duration of the m2t files.

I also noticed that the m2t files showed the points were the footage froze, whereas the AVI files did not show the footage freezing but instead skipped that footage completely. Maybe this explains why the AVI files are shorter in duration.

From reading on the Internet, I gather that my capture suffered from dropped frames.


Now here are my questions:

1. Am I right in assuming that the freezing during capture resulted in dropped frames?

2. Is the Buffer overrun message the reason for the freezing and / or the dropped frames or vice-versa?

3. How can I avoid this Buffer overrun problem? I have done defragmenting but it has not worked. Whilst capturing, I made sure that I had no applications running, so that the CPU and Memory are not overloaded.

4. I set my capture settings in CineForm Prospect HD to Film Scan 2. Could such a high setting be the cause for this Buffer overrun problem?


I have the following equipment:

• Sony HDV camcorder – HDR-HC1 (NTSC) which records in 1080i

• Belkin firewire cable (a good quality cable)

• An Apple I-Mac with Bootcamp that I use for the Windows partition under which I am doing my movie work. The computer has 2GB of RAM and a 2GHz Intel Core 2 Duo processor.

• An internal hard drive of 250GB (with 150GB for the Windows partition) and four external hard drives ranging between 320GB and 500GB in capacity.


Thank you in advance for your help.

Kamran

[David Newman]

There is a lot of info here that probably should be set to support, however I think I can guess what is happening. Boot Camp tends to give the Window XP a FAT32 partition, no one should every use this for video work. You need a dedication hardware drive or partition formatted with NTFS, the Windows normal default (you can add this by USB for your iMac if needed.) The problem with the old FAT32 filesystem it limits file to 4GB, and the M2T capture buffer need to support an HDV tape length which is 13GB.

Prospect HD only converts valid M2T data, so pauses and other glitch are removed from the final output.

Note: Filmscan2 = overkill is our eyes. It is higher quality than what you get with an Sony HDCAM-SR deck, no point in using that for HDV material. Use High or Filmscan 1.

[Kamran Sekha]

David,

It's great to be able to get in touch with you.

Thank you for your extremely quick reply.

I have no other computer besides the i-Mac, so I have no other option but to use the Windows partition on it.

I have actually captured the footage on my external hard drive which has a NTFS partition, so the 4GB size limit is not an issue. Is this good enough? If not, then what should I do?

Thanks,

Kamran

[David Newman]

The external drive should do fine, you are limited a little by USB2 or Firewire bandwidths but this is generally not a problem -- certainly much better than using a FAT32 system drive.