MPEG2 Problems

StevieB66 wrote on 12/19/2003, 8:27 AM

I use the Compro Videomate Gold+ TV PCI Card to capture analog video off of different sources (TV/Hi8 Camcorder/VCR). The PVR software that comes with the card can only capture in MPEG1 or MPEG2. I captured a 2 minute clip off of the TV. It plays just fine in the PVR software and the Microsoft Media Player.

I want to trim the clip in MS. I import it into the media pool and drag it into the timeline. This is where MS has a problem. It goes through the process of building peaks which completes. When I play the clip from the timeline, the audio loses sync and extra frames appear. I get the same thing in the output file when I render using any template. MS should be able to handle MPEG2 files, but I am suspecting the different frame types (I,B,P) are causing "heartburn".

I have tried changing the properties from progressive->upper field and progressive->lower field without any luck. I know it is not good practice to edit MPEG files, but MS should be able to handle the file without problems. I do have the ability capture to AVI (YUY with Huffyuv compression) using VirtualDub but at only 320X240 since it uses the WDM drivers. The PVR software allows a lot more options, as far as frame size. I would like to be able to use that.

Comments

StevieB66 wrote on 12/19/2003, 11:15 AM

I found the answer to my own question. It can found in the knowledgebase under Answer ID 491:

"MPEG video playback performance in an editing application can suffer because it is difficult to seek to individual frames within MPEG streams. This is because not all of the frames in an MPEG stream can be individually accessed. When you are editing on the timeline, all of the previewed frames require a 'seeking' operation, and performance can slow dramatically when this is required of source material.

We do not recommend using MPEG-1 or MPEG-2 video files as source material for editing in VideoFactory or Vegas Video. MPEG video is designed to be accessed linearly from beginning to end, or in other words 'played'. Ideally, MPEG files are created at the end of an editing session as the final, destination format. Any subsequent editing to the project should be done using the original source material.

MPEG1 and MPEG2 video files can be used in the VideoFactory or Vegas Video projects, but playback rate, seeking, and recompression artifacts may be less than satisfactory. MPEG is best used as a final output rather than as a source file format."