Progressive vs. Interlaced

[LNielsen76]

I have a P4 2.4Ghz processor on a mainboard with 533FSB and 512MB DDR Mem. I am capturing via firewire and ADVC-100. I have a 120GB 7200rpm Hard Drive.

What I've found in my captures?

Though the quality is much better capturing interlaced, the audio/video are always out of sync. Though the original may maintain sync when using PowerVCR II, it is never in sync when using MC Mpeg Encoder. However, demuxing/cutting/muxing always leaves the end product out-of-sync even when using the original PowerVCR II rendered mpeg. I notice that during capture the video stalls or hangs up and so does the audio.

Though the quality is poorer capturing progressive, the audio/video are always in sync. Demuxing/cutting/muxing produce no ill side effects to the end product. I notice no video stalls or hang ups in the audio or video during capture.

End thought: Seems that capturing interlaced requires more system resources and higher end hardware to capture correctly. I guess this explains why MC Mpeg Encoder uses so much of a systems resources when transferring A/V data. MC Mpeg Encoder is no doubt designed for interlaced transfer of data. I have tried the PowerVCR II registry hacks but I have the same problems with A/V sync regardless fewer system resources are used.

No problems when capturing progressive with my configuration. Nothing but problems when capturing interlaced with my configuration.

Please Advise.

[bugster]

Capture to DV avi (that is what the canopus outputs) and encode to mpeg afterwards.

More control, better quality, less problems (and yes, DV is interlaced, bottom field first IIRC)

[LNielsen76]

Doesn't MC Mpeg Encoder capture to AVI and then convert to MPEG? If this is the case, then capturing to AVI will not correct the problem. Right? I tried Intervideo WinDVR 3 and it does the same: Captures to AVI and then converts to Mpeg. The only difference between WinDVR and MC Mpeg Encoder is that WinDVR converts to progressive Mpeg and Mpeg Encoder to interlaced Mpeg.

Here I have the same problem: No problems with the WinDVR conversion of AVI to progressive Mpeg and nothing but problems with the Mpeg Encoder conversion of AVI to interlaced Mpeg. Am I wrong here? Does WinDVR capture to progressive or interlaced AVI and then convert to progressive Mpeg?

Thanks.

[bugster]

What you appear to be doing is encoding to mpeg 'on the fly'. What I am suggesting is that you capture the DV avi as it is deleivered by the Canopus and encode to mpeg later. This way the encoder does not have to operate in real time and you can use higher quality settings. Encoding DV avi to mpeg should not cause audio sync problems when done properly.

However, demuxing/cutting/muxing always leaves the end product out-of-sync even when using the original PowerVCR II rendered mpeg.

Mpeg was never intended to be a format for editing. DV avi is. So if you capture to DV avi, edit to your hearts content and encode to mpeg as the last stage, your sync problems will go almost certainly go away.

[LNielsen76]

I greatly appreciate your help. I am a novice at this and don't much understand how the transfers work, but am learning and do use the guides as much as possible in order to reduce my participation in the forums. Thanks for your willingness to help.

I guess I had just hoped to get around the fact that the ADVC-100 should only be used for AVI Interlaced captures and not MPEG captures. I will have to take the long route but I am sure the quality pay off will be worth it.

One last thing: What program would you suggest for capture to Uncompressed AVI/Uncompressed PCM? I do have Adobe Premiere if you think this is the best way to go.

[bugster]

If Premiere works for you then there is nothing to stop you using it. Other (free) choices are DVIO (no preview) or WinDV. Many reccomend scenalyzer, though I have never tried it.

[upshot]

All of the progs mentioned above are fine... I've been liking IUvcr the best lately... Gives you good control, different formats, and the ability to do timed caps...

The jury is still out on a real time mpeg cap via firewire...