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-   -   720p24 ingest / conversion via streamclip (http://www.dvinfo.net/forum/jvc-gy-hd-series-camera-systems/93755-720p24-ingest-conversion-via-streamclip.html)

Thomas Weilguny May 10th, 2007 07:30 PM

720p24 ingest / conversion via streamclip
 
Iīm not sure whether this is the right place to ask but Iīve been having weird problems converting the m2t files captured from the camera (hd110e).

On some shots, especially pans or shots with lots of movement there have been frame drops - not in the original m2t material but in the outputted files (both in apple intermediate and HDV). Whenever it happens I only get an effective frame rate of 12, with every other frame being a duplicate of the previous.

has anyone encountered this problem or know what might be the cause?

Steve Benner May 10th, 2007 09:01 PM

do you have the frame rate of 23.976 set in the "Frame Rate" window of MPEG Streamclip? That insures proper pulldown.

Matthew Rogers May 10th, 2007 10:18 PM

Quote:

Originally Posted by Thomas Weilguny (Post 676934)
Iīm not sure whether this is the right place to ask but Iīve been having weird problems converting the m2t files captured from the camera (hd110e).

On some shots, especially pans or shots with lots of movement there have been frame drops - not in the original m2t material but in the outputted files (both in apple intermediate and HDV). Whenever it happens I only get an effective frame rate of 12, with every other frame being a duplicate of the previous.

has anyone encountered this problem or know what might be the cause?

I have been getting that also. I am also sure that I have the frame rate set to 23.976, so I don't know what's happening. If I go back and re-export the section of the clip, everything is fine. I'm guessing it's some bug in streamclip.

Matthew

David Knaggs May 11th, 2007 02:07 AM

Quote:

Originally Posted by Matthew Rogers (Post 677031)
I have been getting that also. I am also sure that I have the frame rate set to 23.976, so I don't know what's happening. If I go back and re-export the section of the clip, everything is fine. I'm guessing it's some bug in streamclip.

Matthew

Yes, I've also had problems with 720p24 conversions with MPEG Streamclip even when setting the frame rate to 23.976. I would tend to get repeat frames towards the end of longer clips. Although Tim and others swear by the 24p conversions done by Streamclip, I have a policy to only use it on 25p conversions, where it works brilliantly and is 100% rock-solid.

For 720p24 conversions I have a policy to only use HDVxDV. It gives 100% accurate frame conversions, but has the drawback of audio drift on longer clips. So I've had to become something of an expert at re-synching dialogue to match the actors' mouths. But at least you can still get out a product that way. Footage with repeat frames, of course, is totally useless. Also, you should know that HDVxDV gives the conversions at exactly 24p (not 23.98).

The only perfect and easy workflow I've found (and now use exclusively with all new 720p24 footage) is native HDV 720p24 capture through FCP. I just make sure that I allow at least 10 sec pre-roll and that "FireWire NDF" is set as part of my capturing preferences. I've even worked out a method where I only lose about 2 seconds from the start of each clip (instead of 5-7 seconds).

There's a recent post by Tim where he isolate the factors causing variations in capturing success with this camera and FCP. Things such as: the tape you use, how clean your heads are (and whether you've changed the brand of tapes that you use), processor type (G4, G5 or Intel) and speed, amount of RAM, plus the available space in the drives that you are capturing to.

I think that if you jockey these factors around, you can increase your FCP capturing efficiency with 720p24 footage. For example, I've had 100% success with capturing my last two 720p24 tapes. I just made sure that I had over 100GB of available space on the external drive that I was capturing to. (I've read that a drive slows down as it fills up with data.)

Thomas Weilguny May 14th, 2007 05:23 AM

thanks for the info. so far with changing the framerate the amount of duplicate frames has lessened, but it still occurs occasionally in a pretty much random fashion (apart from all sequences being motion-intensive).

unfortunately for the current project capturing via fcp is not an option because most of the segments donīt include enough pre-roll...

when capturing a whole tape Iīve managed to reduce the amount of pre-roll final cut automatically deducts to about a second, but itīs still a bit too close for comfort.
I know this is a long shot, but is there any way to disable this completely? (I donīt see it as a necessary feature because itīs intended to allow the tape drive to spin up - which is pretty redundant when not capturing single clips)


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