Playback Quality is Poor encoding at 352x576 but OK with 288

[bigc]

Hi,

Basically what I’m trying to do is transfer camcorder (Vid 8) and VHS tapes to a digital format (CD-R) that I can play on my standalone (Sony Davs500).

Using the advice from this site I have captured at 352x576 in VirtualDub using Picvideo MJPEG compression (setting 18). I have since been experimenting with different encoding settings to find the best quality that will allow up to 50mins per 80min CD-R. When I encode at 352x288 (I'm PAL BTW), all seems ok with the output displayed on my TV with a typical VCD type crapness to it. So to better this I have tried using the CVD format 352x576, the problem is the output looks terrible on my TV, very blocky and worse than VCD. I have tried various bit rates, 2 pass VBR, CBR 1900-2500...but it makes no difference. I had a feeling the problem may be to do with the interlacing, as when I view the captured output on my PC monitor the interlace lines seem very bad. If I first use a de-interlace filter on the captured output before I encode to CVD then things look better, but they don’t improve THAT much. I was wondering if I am going wrong somewhere, surely it is possible for me to encode using CVD and expect a decent output isn’t it? Or should I just forget it and wait until I can afford a DVD burner?

Any help will be very much appreciated.


Craig

[wulf109]

I think your problem is your source file,you say you can see interlace lines when you view the original capture. Re-encodeing can only make that worse. Your seeing worse results in 352x576 because the higher vertical resolution is exagerating the interlacing. you need to capture to better source file. Try capturing to an mpeg file. I was capturing Laserdisks with the Huff avi codec and the results were pretty good,you might try the huff avi codec.

[SatStorm]

Your source is probably the most difficult source for low bitrate formats like CVD.
The only way to succed quality, is go 1/2 D1 DVD.

That means to encode to 352 X 576/480 with an average bitrate about 3500kb/s and burn to DVD-/+R disc

[DJRumpy]

I agree with wulf109, capture using Huffman codecs if possible to maximize quality.

Any cam is going to strain the limits of VCD, SVCD, or CVD due to the shakey vision thing going on. It will eat up bitrate like candy, giving you excessive macroblocks.

Someone correct me if I'm wrong, but aren't all CAM's interlaced? If so, consider running it through a deinterlacer before encoding to see if it improves your result. I don't own a cam, so I'm definately not speaking from experience. Someone should be able to give you pointers on converting CAM sources.

It's strange that your VCD format looks better than CVD though. CVD has more than double the bitrate capacity of VCD, when only the horizontal resolution has doubled, giving you more bitrate for your buck. What are you using to encode your MPEG?

[fingernailX]

One reason you have better results with a lower resolution capture is that typically one of the two fields in a frame is 'thrown away' when capturing at 288 (240 ntsc). That is one way to fix your interlacing problem but you also don't get 50% of the video information that way. You might try capturing in reverse field order (swap fields in vdub capture settings) as some capture cards get it wrong. see http://nickyguides.digital-digest.com/interlace.htm

[DJRumpy]

That would depend on the capture device. Ich..what a messy way to do a capture.

[bigc]

Thanks for the replies so far.

I think we have hit the nail on the head here...I tried again with the CVD format (2-pass VBR, standard bitrate settings, Picvideo MJPEC codec) but this time de-interlacing first using the smart de-interlace plug-in in Vdub. Things were much better (but still not great); leading me to believe the problem was down to the source file interlacing.

I agree with wulf109, capture using Huffman codecs if possible to maximize quality. .

Indeed I tried the HUF codec also but this just eats too much disk space for not that much difference (at this level)....but without doubt it produced the best results.

Any cam is going to strain the limits of VCD, SVCD, or CVD due to the shakey vision thing going on. It will eat up bitrate like candy, giving you excessive macroblocks.

...but I think this comment really says it all and my source material just isn't good enough to expect decent compression at low bitrates, so it looks like I may just have to wait for the DVD burners to drop in price a bit more!!!

As an aside, as well as using the HUF and MJPEG codecs when capturing I also tried using the DIVX 5.x codec. This seems to produce really good results and v. small files. Is there anything I should be aware of using this codec because there seems to be little difference (using my source) between them?


Thanks again,

Craig

[SatStorm]

DIVX for capturing?
Erghhh... No
It is not a good option.

[Nelson37]

Having done a lot of these, let me emphasize what will give you the most dramatically enhanced encodes of your family videos.

USE A TRIPOD WHEN SHOOTING. This eliminates most of the shaking in the source, which sucks up bitrate.

Also, consider using higher bitrates and resolutions. Yes, this takes you non-standard, but many players will handle it, your PC always will, and you could re-write to DVD in the future, as long as you use a DVD compatible resolution (not SVCD).

I use a Blend De-interlace and 720x480, bitrate 3000, also some without de-interlace and SVCD standard, VCD just isn't good enough for my family videos.

Did I mention USE A TRIPOD?

[ItsMe]

bigc, you might want to try reversing the field order.