ATI MMC (7.6) - Should Deinterlace option be checked or not?

[marsmayhem]

My setup is as follows:
- WinXP Pro with 768MB
- 7200 RPM 40GB (x2)
- MMC 7.6
- RADEON 64MB DDR VIVO + latest drivers

I can achieve MPEG2 720x480 @ 8Mbps, 0 frames dropped, everything in synch.

The profile I use has IFrames Only, Visual Masking OFF, and Deinterlace CHECKED. I'm encoding to multiple target formats (X/VCD, X/SVCD) to play around with different results.

Would I get a smoother picture if I unchecked Deinterlace, or is it okay to let the ATI card combine the fields for me? I can't see a problem with the picture, VCD comes out pretty okayish.

Anyone played with this?

[Anonymous65]

When making a VCD it doesn't matter but for making a SVCD or DVD, you should turn OFF the deinterlacer. It will give you a sharper image when playing back on a TV set, but will show some interlace artifacts when playing on a PC monitor. However, the NTSC TV standard calls for interlaced video.

[Sulik]

Actually, you should NEVER turn off deinterlacing with MMC 7.x, since it only creates progressive sequences (If you do you'll end up with a non-deinterlaced progressive sequence with bad interlacing artifacts).

Unless of course you're capturing < 240NTSC/288PAL lines.

Hopefully they will fix that in the next version of MMC, but until then, keep deinterlaced checked.

In general, there are pros & cons about interlaced captures:
- Pros: better when viewed on an interlaced display (TV/VCR) -> playback is always interlaced.
- Cons: interlaced captures require typically 10-20% more bitrate in order to achieve the same quality than the same deinterlaced sequence (the deinterlacer acts somewhat as a noise reduction filter).

It's a trade-off between deinterlacing artifacts (blur effect on text) vs MPEG compression artifacts (blocky video) due to the extra bits needed for encoding interlaced.

[energy80s]

Actually, you should NEVER turn off deinterlacing with MMC 7.x, since it only creates progressive sequences (If you do you'll end up with a non-deinterlaced progressive sequence with bad interlacing artifacts).

Yes, this is true. When I installed MMC 7.6 I mistakenly switched off the deinterlacing on capture, and although the file (when converted with TMPG) did play OK on my PC it wouldn't play right on my DVD player, with the picture shaking all over the place!

[Nelson37]

I disagree. I find using Deinterlace OFF and Visual Masking ON, hi-bitrate MPG2, I-frame only 720x480 looks best for me (AFTER re-encoding), APEX 500 DVD playback on 27" TV. However, I use IVTC on almost everything I capture (Digital Cable Movies). When IVTC is not applicable, I usually Deinterlace in processing rather than on capture.

[energy80s]

I assume you are talking about NTSC here. I am talking about PAL. That doesn't need any of this frame rate reduction to 23fps. Source @ 25fps, final disc @ 25fps.