MPEG-2 I-frame as a workaround? (black frames issue)

phonelover wrote on 6/24/2003, 8:32 AM

There have been a lot of discussion in the past concerning the "black frames" issues when rendering an MPEG-2 source file.
I was told by MainConcept that their MPEG encoder perfectly works. I tried to use a framserver between Vegas and TMPGEnc and I still get black frames, so I tend to believe them. I was also told that SonicFoundry created the MPEG-2 PlugIn version 1.2, and I think that maybe THIS should be the point. Is a new enhanced/improved plugin version out to come?

SonicFoundry help desk tells me to use MPEG-2 I-frames only in the projects, because this way I will have no black frames. Did any of you try this? And with which results?
I captured a 30 seconds video, both in MPEG-2 IBP and I-only frames, and then applied 20 cross-fade effects to each file and then rendered them into PAL SVCD.
The rendered "IBP file" presented black frames after 18 seconds, the "I-frame-only" one no black frames at all. Can anyone of you confirm this issue?
I don't want to create a 3h30m project and then find out I still have black frames, that's why I am asking...

Thank you for your feedback!
John.

Comments

TheHappyFriar wrote on 6/24/2003, 8:45 AM

I've been working with Mpeg I-Frames in Vegas at work for a few months now. Besides working a little slower because it must decompress, it works fine. The reason is (which is also the reason why Vegas sometimes has a hard time working with WMV, DivX, and a few others) is that timestamps must be on ALL frames, and normaly mpeg only does it on i frames (WMV is every X frames). Mpeg with IPB defaults to timestamps on only I frames, so when a P or B frames is displayed, it shows black.

I hope this helps.

phonelover wrote on 6/24/2003, 9:00 AM

Great news! And thanks also for the technical description.